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Objectives: Many women report declines in cognitive function during pregnancy, but attempts to empirically evaluate such changes have yielded inconsistent results. We aimed to determine whether pregnancy is associated with objective declines in cognitive functioning, and to assess the progression of any declines during pregnancy. Study design: We undertook a meta-analysis, applying a random effects model, of 20 studies that have reported quantitative relationships between pregnancy and changes in cognition. Data sources: Full text articles indexed by Cumulative Index to Nursing and Allied Health Literature (CINAHL) Complete, MEDLINE Complete, and PsychINFO. Data synthesis: The 20 studies assessed included 709 pregnant women and 521 non-pregnant women. Overall cognitive functioning was poorer in pregnant women than in non-pregnant women (standardised mean difference [SMD], 0.52 [95% CI, 0.07-0.97]; P = 0.025). Analysis of cross-sectional studies found that general cognitive functioning (SMD, 1.28 [95% CI 0.26-2.30]; P = 0.014), memory (SMD, 1.47 [95% CI, 0.27-2.68]; P = 0.017), and executive functioning (SMD, 0.46 [95% CI, 0.03-0.89]; P = 0.036) were significantly reduced during the third trimester of pregnancy (compared with control women), but not during the first two trimesters. Longitudinal studies found declines between the first and second trimesters in general cognitive functioning (SMD, 0.29 [95% CI, 0.08-0.50]; P = 0.006) and memory (SMD, 0.33 [95% CI, 0.12-0.54]; P = 0.002), but not between the second and third trimesters. Conclusions: General cognitive functioning, memory, and executive functioning were significantly poorer in pregnant than in control women, particularly during the third trimester. The differences primarily develop during the first trimester, and are consistent with recent findings of long term reductions in brain grey matter volume during pregnancy. The impact of these effects on the quality of life and everyday functioning of pregnant women requires further investigation.
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Cognitive impairment during pregnancy:
a meta-analysis
Sasha J Davies, Jarrad AG Lum, Helen Skouteris, Linda K Byrne, Melissa J Hayden
Baby brainrefers to a subjective decline in cognition
reported by up to 81% of women who have been
pregnant.
1,2
Memory problems, reading difculties,
confusion, disorientation, poor concentration, increased absent-
mindedness, and reduced motor coordination have been noted,
1,3-5
as has a general slowing of cognition; forgetfulness is the most
frequently cited change.
1
Similar decits in broader cognitive
processes have also been reported, including in executive functions
and attention.
1-3
The impact of these decits on everyday life can be signicant. In
case study interviews, currently and recently pregnant women
have described a variety of real world consequences of baby
brain, including impaired conversational uency at work and
home, greater reliance on note-taking for organising work and
domestic commitments, frequent forgetting of appointments, dif-
culties with reading comprehension, and even the inability to
return to work because of severe memory problems.
1
Objective conrmation of these perceived cognitive decits during
pregnancy has, however, been equivocal, despite an accumulating
body of empirical research. While evidence of adverse cognitive
effects during pregnancy has been reported,
2,6-12
other
investigations have found little or no change.
3,13-15
This inconsis-
tency was also evident in the most recent meta-analysis of reports
on the impact of pregnancy on memory (2007),
16
which found
evidence for decits in some, but not all, components of memory.
No recent meta-analysis of ndings regarding pregnancy and
memory dysfunction has been published, nor has this relationship
been explored in cognitive domains apart from memory. Our pri-
mary aim was therefore to examine whether pregnancy is associ-
ated with differences in memory performance (compared with
non-pregnant women or with their own earlier performance), or
with differences in overall cognitive function, executive function,
and attention. Our second aim was to identify the specic gesta-
tional stages at which any differences emerge.
Methods
Study design
We undertook a meta-analysis of studies that have reported
quantitative relationships between pregnancy and changes in
cognition.
Eligibility criteria
Published studies were eligible for inclusion in our analysis if they
included:
a sample of healthy adult pregnant women and a control
group of healthy adult non-pregnant women;
at least one standardised objective measure of cognitive
function (eg, Wechsler Adult Intelligence Scale [WAIS]
subtasks); and
data appropriate for meta-analysis (eg, means with standard
deviations [SDs]).
Studies that included adolescent women (under 18 years of age) or
women with high risk pregnancies, or which exclusively employed
customised, naturalistic, or self-reported cognitive measures were
excluded. There were no restrictions with regard to gestational
trimester, parity, socio-economic status, or ethnic background. All
included studies were published in peer review journal, without
restriction on publication date.
Information sources and study selection
We searched three databases Cumulative Index to Nursing
and Allied Health Literature (CINAHL) Complete, MEDLINE
Complete, and PsychINFO for a panel of terms and their
Abstract
Objectives: Many women report declines in cognitive function
during pregnancy, but attempts to empirically evaluate such
changes have yielded inconsistent results. We aimed to
determine whether pregnancy is associated with objective
declines in cognitive functioning, and to assess the progression
of any declines during pregnancy.
Study design: We undertook a meta-analysis, applying a
random effects model, of 20 studies that have reported
quantitative relationships between pregnancy and changes in
cognition.
Data sources: Full text articles indexed by Cumulative Index to
Nursing and Allied Health Literature (CINAHL) Complete,
MEDLINE Complete, and PsychINFO.
Data synthesis: The 20 studies assessed included 709 pregnant
women and 521 non-pregnant women. Overall cognitive
functioning was poorer in pregnant women than in non-pregnant
women (standardised mean difference [SMD], 0.52 [95% CI,
0.07e0.97]; P¼0.025). Analysis of cross-sectional studies
found that general cognitive functioning (SMD, 1.28 [95% CI
0.26e2.30]; P¼0.014), memory (SMD, 1.47 [95% CI, 0.27e2.68];
P¼0.017), and executive functioning (SMD, 0.46
[95% CI, 0.03e0.89]; P¼0.036) were signicantly reduced
during the third trimester of pregnancy (compared with control
women), but not during the rst two trimesters. Longitudinal
studies found declines between the rst and second
trimesters in general cognitive functioning (SMD, 0.29 [95% CI,
0.08e0.50]; P¼0.006) and memory (SMD, 0.33 [95% CI,
0.12e0.54]; P¼0.002), but not between the second and
third trimesters.
Conclusions: General cognitive functioning, memory, and
executive functioning were signicantly poorer in pregnant than
in control women, particularly during the third trimester. The
differences primarily develop during the rst trimester, and are
consistent with recent ndings of long term reductions in brain
grey matter volume during pregnancy. The impact of these
effects on the quality of life and everyday functioning of
pregnant women requires further investigation.
Deakin University, Melbourne, VIC. m.hayden@deakin.edu.au jdoi: 10.5694/mja17.00131
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combinations, including pregnan*,cogniti*, and reward
seek*(full list in the online Appendix). The date of the nal search
was 11 November 2016. Two authors (SD, MH) screened the
abstracts of articles for eligibility, and disagreements (< 5%) were
resolved by discussion. Article reference lists were screened for
additional relevant records.
Study quality and characteristics
The methodological quality of the studies included in the
meta-analysis was assessed with a modied version of the
NewcastleeOttawa Scale for cohort studies.
17
SD and MH inde-
pendently assessed the quality of all included articles; no studies
were excluded by the quality assessment.
Data extraction and effect size calculations
From each article we extracted data on author, publication year,
sample size, study design, gestational trimester, age, parity, and
measure scores (mean, SD). The effect size in our analysis was the
standardised mean difference (SMD); that is, the difference
between the pregnant and control women groups for a given
outcome variable, expressed in standard deviation units. Effect
sizes were computed for general cognitive functioning, and for the
three primary cognitive domains: memory, attention, and execu-
tive functioning. For cross-sectional data, positive SMD values
indicated that the performance of the control group was superior to
that of the pregnant women group; for longitudinal studies, posi-
tive values indicated that the cognitive performance of pregnant
women was superior at the later of two compared assessments.
Summary data from statistical tests were extracted to calculate the
SMD and its variance. For 18 studies, these values were calculated
from the reported means and SDs.
2,7,10,12,14,15,18-29
We contacted
the authors of eight studies for which these data were not reported,
but which were otherwise eligible for inclusion. The authors of two
provided the additional data, and the studies were included in our
analysis.
30,31
Of the remaining six studies, the authors responded in
two cases that they no longer had access to the data;
3,11
we received
no response regarding the other four studies.
6,8,32,33
A random effects model weighted individual studies to compute
an average effect size for all studies. The model assumed that dif-
ferences between study-level effect sizes reected the contribution
of within-study error and of sampling and systematic inuences
(true heterogeneity).
34
Systematic inuences may arise from study-
level differences in participant characteristics (eg, age, gestational
stage, parity), the aspects of cognitive functioning assessed, and
differences in methodological quality. The I
2
statistic was calcu-
lated; it quanties the heterogeneity between individual studies as
a percentage (25% ¼low, 50% ¼moderate, 75% ¼high levels of
systematic heterogeneity).
35
To assess potential bias in the report-
ing of effects, a fail-safe N (ie, the number of additional studies with
an effect size of zero that would need to be found to render the
overall effect size for the studies included in the meta-analysis non-
signicant) was also calculated.
For cross-sectional studies of subgroups of pregnant women
(trimester 1 [T1], T2, T3), the subgroups were collapsed to a single
pregnant women group for initial analyses comparing the perfor-
mance of pregnant and non-pregnant women by computing a
weighted average mean and SD for the cognitive task scores. Each
subgroup was then separately compared with the non-pregnant
control women.
In longitudinal studies of cognitive performance across pregnancy
included in our meta-analysis, correlations between effect sizes
were not reported. We therefore estimated effect size correlations
at r¼0.5 for each study; each trimester was separately compared
with each of the other two trimesters.
Results
Study selection
After removing duplicates, the initial search identied 3805
records, of which 3734 were excluded as irrelevant after screening
their titles and abstracts. The full texts of the remaining 71 records
were assessed for suitability, and 26 articles were deemed relevant;
of these, sufcient data were available for twenty (see paragraph 2
of Data extractionfor details) to include them in our meta-
analysis (Box 1). The 20 studies included a total of 709 pregnant
women and 521 non-pregnant women.
Study characteristics and quality assessment
The sample size, participant characteristics, study design, and the
cognitive tasks assessed in each study and the methodological
quality of each study are summarised in the online Appendix.In17
of 20 studies, the pregnant women and control groups were
matched by age and education or IQ level. Eight studies included
a follow-up assessment, with four allowing an inter-assessment
interval of longer than 12 weeks. The fail-safe N indicated that
210 additional studies with non-signicant effect sizes would be
required for the difference in overall cognitive performance
1 Preferred Reporting Items for Systematic Reviews and
Meta-Analyses (PRISMA) outline of the selection of
articles for inclusion in our meta-analysis
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between pregnant and control women to be statistically non-
signicant (ie, P> 0.05).
General cognitive functioning
We dened general cognitive functioning broadly as encompass-
ing a range of processes, including memory, attention, executive
functioning, processing speed, and verbal and visuospatial abili-
ties (online Appendix, table 1).
Effect sizes and weighted averages for all 20 studies comparing the
general cognitive performance of pregnant and non-pregnant
women were calculated. Overall cognitive functioning was
poorer in pregnant women than in non-pregnant women (SMD,
0.52 [95% CI, 0.07e0.97]; P¼0.025; I
2
¼91%).
Additional between-groups analyses were conducted to identify
the specic gestational stage at which cognitive performance
changes in pregnant women. There was no signicant differences
in cognitive functioning between pregnant women during T1 and
controls (four studies: SMD, 0.84 [95% CI, e0.47 to 2.15]; P¼0.21;
I
2
¼94%), nor between pregnant women during T2 and controls
(three studies: SMD, 1.25 [95% CI, e0.83 to 3.34]; P¼0.24;
I
2
¼96%) (data not shown). Cognitive functioning in women
during T3 was signicantly poorer than that of control women
(six studies: SMD, 1.28 [95% CI, 0.26e2.30]; P¼0.014; I
2
¼93%)
(Box 2).
Four longitudinal studies reported effect sizes for changes in
overall cognitive performance between T1 and T2; the difference
was signicant, with no heterogeneity (SMD, 0.29 [95% CI,
0.08e0.50]; P¼0.006; I
2
¼0%) (Box 3). In contrast, differences
between T2 and T3 (six studies: SMD, 0.11 [95% CI, e0.18 to 0.39];
P¼0.46; I
2
¼64%) and between T1 and T3 (ve studies: SMD,
e0.13 [95% CI, e0.65 to 0.39]; ; P¼0.63; I
2
¼88%), were non-
signicant (data not shown).
Memory
We dened memory as encompassing a range of subdomains,
including working memory and retrieval from long term memory
via recognition and recall. The 19 studies that assessed memory
applied a range of measures, including several WAIS tasks (eg,
digit span backwards and forwards) as well as a broad selection of
other recall and recognition tasks (eg, facial recognition sets, the
Rivermead behavioural memory task, visualeverbal learning
tasks). Overall memory performance was signicantly lower in
2 General cognitive functioning: comparison of pregnant women in their third trimester with non-pregnant control women
(studies reporting between-group comparisons)
CI ¼condence interval; SMD ¼standardised mean difference. u
3 General cognitive functioning: comparison of pregnant women in their rst and second trimesters (studies reporting
within-group comparisons)
CI ¼condence interval; SMD ¼standardised mean difference. u
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pregnant than in non-pregnant women (SMD, 0.48 [95% CI,
0.04e0.92]; P¼0.033; I
2
¼91%).
Cross-sectional studies comparing the memory performance of
pregnant women at each gestational trimester with control women
found signicantly lower values for pregnant women during T3
(ve studies: SMD, 1.47 [95% CI, 0.27e2.68]; P¼0.017; I
2
¼94%)
(Box 4), but not during T1 (four studies: SMD, 0.84 [95% CI, e0.47 to
2.15]; P¼0.21; I
2
¼94%) or T2 (three studies: SMD, 1.17 [95% CI,
e1.04 to 3.38]; P¼0.30; I
2
¼97%) (data not shown). There was a
high degree of heterogeneity between studies for each comparison.
Longitudinal studies comparing memory performance at different
stages of pregnancy found a signicant reduction in performance
between T1 and T2, with negligible heterogeneity between studies
(four studies; SMD, 0.33 [95% CI, 0.12e0.54]; P¼0.002; I
2
¼0%)
(Box 5), but not between T1 and T3 (ve studies: SMD, e0.20
[95% CI, e0.73 to 0.34]; P¼0.48; I
2
¼0%) or between T2 and T3 (six
studies: SMD, 0.12 [95% CI, e0.17 to 0.42]; P¼0.41; I
2
¼0%) (data
not shown).
Executive functioning and attention
Executive functions, mediated by the frontal cortex, include
attention, planning, shifting between ideas (exibility), generating
new responses (uency), problem-solving, and abstraction, as well
as the ability to inhibit inappropriate responses. The nine studies
that assessed executive functions applied a range of measures,
including the Cambridge Neuropsychological Test Automated
Battery intra-/extra-dimensional shift task, the concept shifting
test, and the paced auditory serial addition test. Attention refers to
both the initial orientation of attention and sustained attention
towards a given stimulus, and is included as a subset of executive
functioning processes. Tasks utilised by the eight studies to assess
attention included the test of everyday attention, the letter
cancellation task, and the Stroop task.
Effect sizes were calculated for cross-sectional studies that
compared executive functioning (nine studies) or attention (eight
studies) in pregnant and control women. The averaged effect sizes
for these studies were small and non-signicant (executive func-
tioning: SMD, e0.12 [95% CI, e0.52 to 0.28]; P¼0.54; attention:
SMD, e0.22 [95% CI, e0.70 to 0.26]; P¼0.37).
Two cross-sectional studies compared attention and executive
functioning during T3 with those of controls;
10,14
while the effect
size for executive functioning was signicant (SMD, 0.46 [95% CI,
0.03e0.89]; P¼0.036; I
2
¼0%) (Box 6), that for attention was not
(SMD, 0.37 [95% CI, e0.06 to 0.80]; P¼0.09). One study compared
attention and executive functioning during T2 with those of con-
trols,
14
but found no signicant differences (executive functioning:
4 Memory functioning: comparison of pregnant women in their third trimester with non-pregnant control women
(studies reporting between-group comparisons)
CI ¼condence interval; SMD ¼standardised mean difference. u
5 Memory functioning: comparison of pregnant women in their rst and second trimesters (studies reporting within-group
comparisons)
CI ¼condence interval; SMD ¼standardised mean difference. u
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SMD, 0.32; P¼0.26; attention: SMD, 0.30; P¼0.30). No studies
compared attention or executive functioning of women during T1
with those of control women.
Longitudinal studies comparing attention and executive func-
tioning in pregnant women at different stages of pregnancy found
no signicant differences. One study reported non-signicant
effect sizes for differences in executive functioning and attention
changes between T1 and T2 (executive functioning: SMD, 0.11;
P¼0.61; attention: SMD, 0.21; P¼0.31).
12
Two studies provided
data that permitted us to calculate the effect size for changes in
attention between T2 and T3;
12,14
neither was signicant (executive
functioning: SMD, 0.07; P¼0.68; attention: SMD, 0.10; P¼0.53).
One study provided data that permitted us to calculate the effect
sizes for changes in attention between T1 and T3;
12
each was small
and non-signicant (executive functioning SMD, 0.02; P¼0.94;
attention: SMD, 0.03; P¼0.89).
Discussion
Many, but not all, women report increased forgetfulness and
reduced cognitive functioning during pregnancy. We applied a
meta-analytic quantitative approach to investigating the associa-
tion between pregnancy and changes in cognitive functioning, and
reached two major conclusions. First, the general cognitive func-
tioning, memory, and executive functioning performance of
pregnant women is signicantly lower than in non-pregnant
women, both overall and particularly during the third trimester.
Secondly, the memory performance of pregnant women appears to
decline between the rst and second trimesters.
These ndings are consistent with those of the 2007 meta-analysis
by Henry and Rendell.
16
But our meta-analysis also identied
further impairments of general cognitive and executive func-
tioning in pregnant women, and that there are also differences
between trimesters. Specically, memory performance declined
during the early stages of pregnancy, but the decline either slowed
or stopped from mid-pregnancy. Moreover, the magnitude of the
changes in overall cognition and memory during the third
trimester of pregnancy is not only statistically, but also clinically
signicant.
Given the small to moderate effect sizes of the differences and the
limited number of longitudinal studies available, our ndings need
to be interpreted with caution, particularly as the declines were
statistically signicant, but performance remained within the
normal ranges of general cognitive functioning and memory. These
small reductions in performance across their pregnancy will be
noticeable to the pregnant women themselves and perhaps by
those close to them, manifesting mainly as minor memory lapses
(eg, forgetting or failing to book medical appointments), but more
signicant consequences (eg, reduced job performance or impaired
ability to navigate complex tasks) are less likely. However, the
available literature is highly heterogeneous; further research is
required to elucidate more clearly the impact of these changes on
the everyday life of pregnant women.
Our meta-analysis has two important strengths. First, by adopting
a quantitative meta-analytic approach it was possible to estimate
the inuence of articial variance by examining systematic vari-
ables in the presence of highly heterogeneous results. A medium to
high degree of heterogeneity between studies was found, with a
mean I
2
for studies with signicant effect sizes of 61.5%. In
response, we employed meta-regression to examine whether
participant characteristics inuenced each comparison (data not
reported here). While participant age was found to be a non-
signicant source of articial variance, other potential sources of
systematic inuence (eg, parity, education, pre-partum IQ, socio-
economic status, study task selection) could not be explored
because the necessary data were not available. Nevertheless, the
fail-safe N indicated that 210 additional studies with zero effect
sizes would be required to abrogate the signicance of the overall
difference, indicating that the ndings of our meta-analysis are
robust despite the degree of study heterogeneity.
Second, both the total sample size and the effect sizes were larger
than in previous meta-analyses. We included nine studies pub-
lished since the 2007 review by Henry and Rendell,
16
encompass-
ing an additional 312 pregnant and 162 non-pregnant women
(76% and 45% increases respectively). This resulted in a substantial
increase in the magnitude of the effect sizes for changes in memory
performance. Most of the individual studies included in our meta-
analysis had relatively small sample sizes compared with the
cumulative total, and would not have adequate power to detect
effect sizes of the magnitude we found. However, comparisons of
performance in the domains of attention or executive functioning
were limited to a cumulative total sample of 105 pregnant women
and 82 non-pregnant controls across a maximum of two studies per
comparison, so that effect sizes were small. Consequently, con-
dent conclusions can be drawn only with respect to the effect of
pregnancy on memory. Further research may establish whether
subtler impairments in other cognitive domains might be detectable.
Our review provides novel insights into the impact of pregnancy
on cognitive functioning, particularly memory and executive
functioning. While Henry and Rendell
16
concluded that processes
requiring active memory processing (eg, working memory and
6 Executive functioning: comparison of pregnant women in their third trimester with non-pregnant control women (studies
reporting between-group comparisons)
CI ¼condence interval; SMD ¼standardised mean difference. u
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recall) appeared to be selectively impaired in pregnant women,
analyses we have undertaken (not reported here) indicate that
memory performance was signicantly affected even when
working memory was isolated from other facets of memory. This
suggests that pregnancy may be associated with declines across
broader memory functions, not just working memory. This
conclusion is further supported by the results of a recently pub-
lished longitudinal neural imaging study which found that preg-
nancy was signicantly associated with reduced grey matter
volume in brain regions involved in social cognition.
36
While our meta-analysis builds on past research by identifying the
gestational trimester during which cognitive decits may develop,
it remains unclear whether these impairments are exacerbated by
increasing parity, or whether memory and executive functioning
return to pre-partum performance levels after giving birth.
Uncertainty about the precise mechanisms underlying these de-
cits also persists, and about whether these diminutions of function
are equivalent to those observed in neurological or psychiatric
conditions associated with poorer performance in memory
domains requiring active processing.
In summary, our meta-analysis identied that performance related
to memory and executive functioning was signicantly poorer in
pregnant than in control women, particularly during the third
trimester. It is recommended that future research adopt a longi-
tudinal design to clarify the progression of these cognitive
differences during pregnancy, and to establish their impact on the
day-to-day cognitive functioning of pregnant women.
Competing interests: No relevant disclosures. n
ª2018 AMPCo Pty Ltd. Produced with Elsevier B.V. All rights reserved.
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Meta-analysis
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... memory (Davies et al., 2018) and mood during their pregnancy (Ross et al., 2004). However, the quantitative and correlational nature of these enquiries may mean that the nuances of mood and memory changes are not fully captured. ...
... In doing so, this will ensure that (1) there are no memory and mood changes that women experience in pregnancy that are 'missed' or not captured by quantitative investigations, (2) women's self-reported experiences are centred within prenatal research (Staneva et al., 2015), (3) the findings of quantitative investigations are either contested or corroborated by women's first-hand accounts. Qualitative enquiries are also necessary given the inconsistencies in much of the existing literature (see, Davies et al., 2018). In order to investigate women's first-hand accounts of memory and mood changes in their pregnancy, in this study, women's anecdotal responses to free-text responses about their memory and mood changes in pregnancy were investigated. ...
... Some participants in this typology also spoke specifically about tiredness and lack of sleep as a driver of feeling foggy in pregnancy; for example: 'I was VERY tired, and found myself forgetting things which would normally be very simple to me/ finding simple tasks difficult'. Overall, this typology represents the chronic sense of memory 'fog' that participants experience in pregnancy, which relates to factors, such as organisation, tiredness, and information processing (as per Davies et al., 2018). ...
Article
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Objective: This qualitative study aimed to explore how pregnant women and new mothers self-report changes to their mood and memory during pregnancy. Background: Researchers have investigated the various changes that women report throughout their pregnancy. Despite this evidence base, there is a notable lack of studies that take a qualitative approach to understanding how pregnant women and women in the postpartum period experience memory and mood changes through their pregnancy. Method: The present study involved a qualitative content analysis of women's first-hand accounts. Of the 423 participants who responded, 118 participants provided textual responses to questions about their memory and 288 participants provided textual responses to questions about their mood. Data were collected online via a free-text survey and analysed using both deductive inductive open coding. Results: A qualitative content analysis generated four overall categories: two typologies of self-reported memory changes in pregnancy ('short-term memory lapses' and 'chronic memory fog') and two typologies of self-reported mood changes ('mood instability and constant change' and 'low mood and parenting anxiety'). Conclusion: These typologies represent unique profiles of the memory and mood changes that women experience during pregnancy and serve to accompany and expand the quantitative literature, which documents the changes women experience during pregnancy.
... A plethora of cognitive psychologists have attempted to understand the extent to which 'baby brain' has a 'real' effect on cognitive measures, and whether the cognitive changes that women experience occur due to biological reasons (e.g., hormones, physiological changes, and differences in sleep patterns; Duarte-Guterman et al., 2019). Experimental cognitive studies have suggested that pregnancy is associated with poorer concentration, worse memory recall and motor coordination problems (Casey, et al., 1999;Davies et al., 2018;Henry & Rendell, 2007). However, while some studies report large differences in memory ability (Brindle et al., 1991;Henry & Sherwin, 2012), others report null effects between pregnant women and controls (Orchard et al., 2021;Schneider, 1989). ...
... Despite some reviews boldly claiming that 'baby brain' is a real or genuine phenomenon (e.g., Davies et al., 2018;Henry & Rendell, 2007), many studies find no evidence for an effect. For example, in a seminal study of pregnant women's cognitive abilities, Brindle et al. (1991) tested pregnant women's performance on memory-based cognitive tasks in comparison with non-pregnant women. ...
... Similarly, the Personality and Total Health (PATH) Through Life Project (Christensen et al., 2010) assessed cognitive functioning longitudinally over 8 years, and found no evidence of cognitive deficits during pregnancy. Therefore, there are clear inconsistencies in this literature, and some scholars have begun to highlight the unclear or inconclusive findings that plague the 'baby brain' literature (Davies et al., 2018;Hurt, 2011). ...
Article
Full-text available
The colloquial concept of ‘baby brain’ suggests that throughout pregnancy and into the immediate postpartum period, women have reduced cognitive abilities and are more distracted, forgetful, and incompetent. To date, a plethora of cognitive and neuropsychological research testing the cognitive functioning of pregnant women relative to other groups has yielded inconsistent and unclear findings. However, there is a notable lack of literature that adopts a social psychological perspective, critically assessing the contribution of social context to the ‘baby brain’ phenomenon. In this paper, we review the current ‘baby brain’ literature and outline two potential social perspectives that provide insights into this research area: stereotype threat theory and objectification theory. We argue that inconsistencies in the ‘baby brain’ cognitive literature may be impacted by under‐explored social phenomena, which may result from activation of stereotypes or objectifying cues throughout pregnancy and into early new motherhood. We end with suggestions for future social and personality psychological research directions in the area of ‘baby brain’.
... Com relação a défi cits de memória durante a gestação, a meta-análise de Henry e Rendell 16 demonstrou que alguns componentes da memória são afetados, mas não todos. Já os artigos que fi zeram parte da meta-análise de Davies et al. 17 evidenciaram que, no período gestacional, a função cognitiva geral, a função executiva e a memória são afetadas negativamente, principalmente no terceiro trimestre. ...
... Entretanto, assim como as alterações na marcha simples parecem ocorrer principalmente no terceiro trimestre gestacional, sugere-se que as alterações cognitivas em gestantes também estão diretamente relacionadas ao fi nal da gestação. Davies et al. 17 demonstraram que a função cognitiva geral, a função executiva e a memória das gestantes foram signifi cativamente inferiores às não-gestantes, principalmente na comparação com as gestantes do terceiro trimestre. Hampson et al. 44 avaliaram a memória de trabalho de gestantes e também verifi caram mais alterações em gestantes do terceiro trimestre quando comparadas às gestantes do segundo trimestre; enquanto na comparação com mulheres não-gestantes, as gestantes do terceiro trimestre também demonstraram leves declínios nas capacidades cognitivas de memória de trabalho e atenção 45 . ...
Article
Full-text available
Verificar se atividades de dupla tarefa interferem nos parâmetros cinemáticos da marcha de gestantes. Materiais e métodos: 24 mulheres divididas em grupo gestante e não-gestante fizeram parte da amostra. Primeiramente, foram realizadas as tarefas simples: tarefa simples (TS) da marcha, tarefa aritmética de subtração, de fluência verbal e de leitura no telefone celular. Após, as duplas tarefas (DTs) foram realizadas, nas quais a marcha foi executada ao mesmo tempo de cada uma das tarefas cognitivas. Variáveis de marcha analisadas foram velocidade, cadência, comprimento da passada, largura do passo e tempo da passada. Para as interações entre as tarefas e entre os grupos, foi utilizado ANOVA mista, seguido do pós-hoc de Tukey, e o nível de significância adotado foi p < 0,05. Resultados: Nas comparações entre as tarefas, ambos os grupos não demonstraram alterações estatisticamente significativas da marcha quando comparadas as DTs com a TS da marcha. Também não foram encontradas diferenças significativas da marcha na comparação entre os grupos.
... Over 50% of women report memory problems or other cognitive deficits during pregnancy (Janes et al., 1999;Davies et al., 2018). This has led to the colloquial phrase ''pregnancy brain'' or ''baby brain'' (Brown and Schaffir, 2019). ...
Article
Full-text available
As the population of older adults grows, so will the prevalence of aging-related conditions, including memory impairments and sleep disturbances, both of which are more common among women. Compared to older men, older women are up to twice as likely to experience sleep disturbances and are at a higher risk of cognitive decline and Alzheimer’s disease and related dementias (ADRD). These sex differences may be attributed in part to fluctuations in levels of female sex hormones (i.e., estrogen and progesterone) that occur across the adult female lifespan. Though women tend to experience the most significant sleep and memory problems during the peri-menopausal period, changes in memory and sleep have also been observed across the menstrual cycle and during pregnancy. Here, we review current knowledge on the interrelationships among female sex hormones, sleep, and memory across the female lifespan, propose possible mediating and moderating mechanisms linking these variables and describe implications for ADRD risk in later life.
... Talking about adolescents, we tend to attach heavy weight to their hormones and changing hormonal levels as an explanation for their challenging social behaviors, and indeed there is some empirical basis for this widespread idea [1,2]. The same is true when pregnant women and new mothers complain about their failing memories, the so-called 'baby brain': hormonal changes are supposed to have affected their brains [3,4]. But what happens to men when they become fathers? ...
Article
How do hormonal levels in men change from pregnancy to after the birth of their firstborn child, and what is the role of oxytocin, alone or in interplay with other hormones, in explaining variance in their parenting quality? We explored in 73 first-time fathers the development of five hormones that have been suggested to play a role in parenting: oxytocin (OT), vasopressin (AVP), testosterone (T), oestradiol (E2) and cortisol (Cort). In an extended group of fathers ( N = 152) we examined associations with fathers’ behaviour with their 2-month-old infants. OT and E2 showed stability from the prenatal to the postnatal assessments, whereas AVP and T decreased significantly, and Cort decreased marginally. OT on its own or in interplay with other hormones was not related to paternal sensitivity. Using an exploratory approach, the interaction between T and E2 emerged as relevant for fathers’ sensitive parenting. Among fathers with high E2, high T was associated with lower sensitivity. Although we did not find evidence for the importance of OT as stand-alone hormone or in interplay with other hormones in this important phase in men's lives, the interaction between T and E2 in explaining variation in paternal behaviour is a promising hypothesis for further research. This article is part of the theme issue ‘Interplays between oxytocin and other neuromodulators in shaping complex social behaviours’.
... Pregnancy is an important period during a woman's life that can bring about dynamic changes in cognition. Previous studies have shown that pregnancy can induce cognitive reorganization [1,2]. Most cognitive changes in pregnant women are physiological. ...
Article
Full-text available
Background: Pregnancy induces cognitive reorganization which can lead to mental disorders. The aim of this study is to determine differences in cognitive scores, short-chain fatty acids (SCFAs) and related metabolites between pregnant and non-pregnant participants. Methods: This cross-sectional study included 67 full-term pregnant women and 31 non-pregnant women. We compared scores of mental state and cognitive assessment tests, as well as serum concentrations of SCFAs, hormones, inflammatory factors, and neurotransmitters between these groups. Results: Scores for information processing speed, immediate visual memory, motor response speed and accuracy, execution ability and verbal use ability in the pregnant group were lower than those in the non-pregnant group (p < 0.05 for all tests). Total serum SCFAs in the pregnant group were significantly lower than those in the non-pregnant group (P = 0.031). Among them, acetate and propionate were significantly decreased (P = 0.013 and 0.037, respectively) whereas butyrate was significantly increased (P = 0.035). Serum peptide YY, glucagon-like peptide-1, γ-aminobutyric acid, and dopamine showed no differences between the two groups. However, cortisol, adrenocorticotropic hormone, and acetylcholine were significantly increased in the pregnant group as compared with the non-pregnant group (P = 0.039, 0.016, and 0.012, respectively). Tumor necrosis factor-α was increased and interleukin-10 significantly decreased in the pregnant group (P = 0.045 and 0.019, respectively). Conclusion: According to our study findings, cognitive reorganization in the third trimester of pregnancy showed that both the passive storage capacity of working memory and the executive function of online information processing were decreased to varying degrees. At the same time, the changes in total SCFAs, the proportions of SCFAs and related metabolites were also detected. These changes in the internal environment may be increasing the risk of perinatal mental illness.
... The effects of pregnancy on cognitive demands are suggested by several studies (Pearson et al. 2009;Stickel et al. 2019). A meta-analysis by Davies et al. (2018) reports, for instance, that the overall cognitive function (memory, executive function and attention) is poorer in pregnant women compared with their nonpregnant counterparts, especially during the third trimester. On the level of brain morphology, our results along with those of animal studies suggest that pregnancy triggers (at least transitorily) a reduction of hippocampal volume (Galea et al. 2000;Barrière et al. 2021). ...
Article
Full-text available
There is growing evidence that pregnancy may have a significant impact on the maternal brain, causing changes in its structure. To investigate the patterns of these changes, we compared nulliparous women (n = 40) with a group of primiparous women (n = 40) and multiparous mothers (n = 37) within 1-4 days postpartum, using voxel-based and surface-based morphometry (SBM). Compared with the nulliparous women, the young mothers showed decreases in gray matter volume in the bilateral hippocampus/amygdala, the orbitofrontal/subgenual prefrontal area, the right superior temporal gyrus and insula, and the cerebellum. These pregnancy-related changes in brain structure did not predict the quality of mother-infant attachment at either 3 or 12 weeks postpartum nor were they more pronounced among the multiparous women. SBM analyses showed significant cortical thinning especially in the frontal and parietal cortices, with the parietal cortical thinning likely potentiated by multiple pregnancies. We conclude that, compared with the brain of nulliparous women, the maternal brain shows widespread morphological changes shortly after childbirth. Also, the experience of pregnancy alone may not be the underlying cause of the adaptations for mothering. As regards the exact biological function of the changes in brain morphology, longitudinal research will be needed to draw any definitive conclusions.
Article
Objectives: The relationship between fertility history and human health has long fascinated scholars; however, whether there is a link between number of children and cognitive function in older adults remains unclear. We investigated the associations between parity and the timing of first and last births with the cognitive function of older adults over 65. Methods: The mini-mental state examination (MMSE) was selected as a tool to measure cognitive function. We analyzed data on 5847 older adults in rural and urban communities in China from the 2018 Chinese Longitudinal Healthy Longevity Survey using ordinary least squares. To further explore the transmission mechanism, we also conducted a mediating effect analysis. Results: We found a negative association between number of children and cognitive function in older adults. Compared with older adults with four children, the MMSE scores of older adults with more than five children decreased significantly, and the score of older adults with zero to three children increased. Further, a late age at first birth (≥35) and a late age at last birth (≥35) were negatively associated with cognitive function. We also found that the associations between parity and cognition might be partly explained by variations in health. Conclusion: Our analyses provided evidence from China to support the link between fertility history and cognitive function that has been observed in previous international studies: We suggest that high parity (≥5) is negatively associated with cognitive function.
Article
Objectives Clusters of low fitness and high obesity in childhood are associated with poorer health outcomes in later life, however their relationship with cognition is unknown. Identifying such profiles may inform strategies to reduce risk of cognitive decline. This study examined whether specific profiles of childhood fitness and obesity were associated with midlife cognition. Design Prospective study. Methods In 1985, participants aged 7–15 years from the Australian Childhood Determinants of Adult Health study were assessed for fitness (cardiorespiratory, muscular power, muscular endurance) and anthropometry (waist-to-hip ratio). Participants were followed up between 2017 and 2019 (aged 39–50). Composites of psychomotor speed-attention, learning-working memory and global cognition were assessed using CogState computerised battery. Latent profile analysis was used to derive mutually exclusive profiles based on fitness and anthropometry. Linear regression analyses examined associations between childhood profile membership and midlife cognition adjusting for age, sex and education level. Results 1244 participants were included [age: 44.4 ± 2.6 (mean ± SD) years, 53% female]. Compared to those with the highest levels of fitness and lowest waist-to-hip ratio, three different profiles characterised by combinations of poorer cardiorespiratory fitness, muscular endurance and power were associated with lower midlife psychomotor-attention [up to −1.09 (−1.92, −0.26) SD], and lower global cognition [up to −0.71 (−1.41, −0.01) SD]. No associations were detected with learning-working memory. Conclusions Strategies that improve low fitness and decrease obesity levels in childhood could contribute to improvements in cognitive performance in midlife.
Article
Pregnancy involves radical hormone surges and biological adaptations. However, the effects of pregnancy on the human brain are virtually unknown. Here we show, using a prospective ('pre'-'post' pregnancy) study involving first-time mothers and fathers and nulliparous control groups, that pregnancy renders substantial changes in brain structure, primarily reductions in gray matter (GM) volume in regions subserving social cognition. The changes were selective for the mothers and highly consistent, correctly classifying all women as having undergone pregnancy or not in-between sessions. Interestingly, the volume reductions showed a substantial overlap with brain regions responding to the women's babies postpartum. Furthermore, the GM volume changes of pregnancy predicted measures of postpartum maternal attachment, suggestive of an adaptive process serving the transition into motherhood. Another follow-up session showed that the GM reductions endured for at least 2 years post-pregnancy. Our data provide the first evidence that pregnancy confers long-lasting changes in a woman's brain.
Article
There are 2 families of statistical procedures in meta-analysis: fixed- and random-effects procedures. They were developed for somewhat different inference goals: making inferences about the effect parameters in the studies that have been observed versus making inferences about the distribution of effect parameters in a population of studies from a random sample of studies. The authors evaluate the performance of confidence intervals and hypothesis tests when each type of statistical procedure is used for each type of inference and confirm that each procedure is best for making the kind of inference for which it was designed. Conditionally random-effects procedures (a hybrid type) are shown to have properties in between those of fixed- and random-effects procedures.
Article
Current literature on cognitive functioning in pregnancy and postpartum is mixed, with most research showing deficits in memory and attention during pregnancy or no difference between pregnant participants and controls with little emphasis on the postpartum period. In the current study, we used a longitudinal controlled design and 42 primarily not depressed participants to compare pregnant women in the third trimester and approximately three months postpartum with matched controls over the same time period on neuropsychological domains including memory, attention, learning, visuospatial, and executive functioning. We also evaluated the role of mood and quality of life as potential moderators of cognitive functioning in pregnancy/postpartum. Results indicated no differences between controls and pregnant/postpartum women on neuropsychological measures at any time points. Self-reported memory difficulties, however, were higher in the pregnant/postpartum women. Pregnant and postpartum women had worse self-reported mood and quality of life than controls. Mood and quality of life slightly moderated specific measures of attention and verbal fluency; however, neither mood nor quality of life moderated overall neuropsychological functioning in either group. Number of previous pregnancies had no effect on the study findings. Results suggest differences in subjective memory complaints, but no differences in objective neuropsychological test results between controls and pregnant/postpartum women who are primarily not diagnosed with depression.
Article
The present study was aimed at identifying potential behavioral and neural correlates of cognitive and emotional processing during pregnancy using scalp-recorded Event-Related Potentials (ERPs). We used a 4-stimulus visual oddball task, combining emotional and non-emotional stimuli. Responses to target and non-target stimuli were compared across groups of 17 pregnant women on their third trimester and 19 non-pregnant women. Participants also completed a non-emotional test of sustained attention and response inhibition; the Online Continuous Performance Test (OCPT). Pregnant women had poorer performance than controls on most indices of the OCPT and the oddball task. ERP results indicated that pregnancy significantly interacted with the type of target stimuli. Results of the P3 component have demonstrated a comparative reduction in P3 amplitude in pregnant women in response to the target emotional faces but not in response to the target shapes. Moreover, among pregnant women, P3 amplitude was greater for the target shapes than for the target faces, while in non-pregnant women P3 amplitude was greater for the target faces than for the target shapes. Results of the N170 component showed that N170 to faces, but not to shapes, was more pronounced in pregnant women compared with non-pregnant women. The current results provide indication of modulation of cognitive-affective function during pregnancy. ERP alterations may suggest changes in the recruitment of neural resources to process emotional stimuli and alterations in attention allocation and evaluation of emotional stimuli among pregnant women.
Article
This study investigated episodic and procedural memory retention in early and late pregnancy and whether memory retention was related to sleep disruption. Twenty-six women in the third trimester of pregnancy, 20 women in the first trimester of pregnancy, and 24 non-pregnant controls were administered a battery of verbal and visual episodic memory tasks and two procedural memory tasks before undergoing an overnight sleep study. Memory retention was assessed the following morning. Results indicated that as compared with controls, both pregnant groups had reduced retention in verbal episodic memory but were unimpaired on visual and procedural memory tasks. The pregnant women also demonstrated significant disruption of sleep patterns. Reduced verbal memory retention during pregnancy was not attributable to any measure of sleep; however, small correlations between some indices of sleep and memory do not allow full dismissal of the sleep-dependent memory consolidation hypothesis.
Article
This study investigated women's subjective complaints of problems with memory during pregnancy and their objective performance on a variety of tests of attention and memory. Objective testing revealed no differences between pregnant women (n = 52) and controls (n = 35) on tests of attention (dot probe), intentional and incidental recall, and direct and indirect memory (stem completion). On the baseline stem condition, pregnant women completed more (neutral) stems with pregnancy words than did controls. In an incidental recognition task, third trimester pregnant women recognized more pregnancy than neutral or anxious words. Women and their informants reported memory to have deteriorated during pregnancy. Given the power of the study, these findings suggest that pregnant women (1) may perform better than controls when the material is pregnancy-related and (2) may ‘falsely’ perceive their memory to have deteriorated during pregnancy.
Article
There are 2 families of statistical procedures in meta-analysis: fixed- and random-effects procedures. They were developed for somewhat different inference goals: making inferences about the effect parameters in the studies that have been observed versus making inferences about the distribution of effect parameters in a population of studies from a random sample of studies. The authors evaluate the performance of confidence intervals and hypothesis tests when each type of statistical procedure is used for each type of inference and confirm that each procedure is best for making the kind of inference for which it was designed. Conditionally random-effects procedures (a hybrid type) are shown to have properties in between those of fixed- and random-effects procedures. (PsycINFO Database Record (c) 2012 APA, all rights reserved)