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Pregnancy is a period that places great physiological stress on both the mother and the fetus. When pregnancy is compounded by endocrine disorders such as hypothyroidism, the potential for maternal and fetal adverse outcomes can be immense. While a lot of attention has been focused on the adverse fetal outcomes consequent to hypothyroidism, attention is also being gradually directed towards the adverse maternal outcomes of this disorder. Role of antibody positivity in influencing outcomes in a euthyroid woman, also needs further clarification. Prompt diagnosis and treatment of hypothyroidism in pregnancy is very essential. Subclinical hypothyroidism also needs to be detected and treated to prevent adverse outcomes, especially maternal. Since women with hypothyroidism during pregnancy, especially of the autoimmune variety might have a flare up of the disorder post-partum, or might continue to require thyroxine replacement post-partum, adequate follow-up is mandatory. While targeted case finding is generally practised, recent evidence seems to indicate that universal screening might be a better option. In conclusion, routine screening, early confirmation of diagnosis and prompt treatment. Allied with regular post-partum follow up, is required to ensure favourable maternal and fetal outcomes.
Hypothyroidism in Pregnancy
Marilyn Sutandar, MD, Facundo Garcia-Bournissen, MD, Gideon Koren, MD
The Motherisk Program, Division of Clinical Pharmacology and Toxicology, Hospital for Sick Children, University of Toronto, Toronto ON
J Obstet Gynaecol Can 2007;29(4):354–356
Hypothyroidism is a relatively common illness in preg-
nancy. Between 2.2% and 2.5% of women have been
found to have serum thyroid stimulating hormone (TSH)
levels of 6 mU/L or greater at 15 to 18 weeks’ gestation.1,2
Maternal hypothyroidism may place the mother at an
increased risk of adverse obstetrical outcomes. Untreated
hypothyroidism is associated with increased risk for
preeclampsia, low birth weight, placental abruption, miscar-
riage, and perinatal mortality.3,4 Recently, Idris et al. found
that in addition to an increased risk of low birth weight,
hypothyroidism (as defined by increased serum TSH) early
and late in pregnancy may also increase the rate of Caesar-
ean section (CS).5Raised maternal serum TSH in the
second trimester is also associated with an increased rate of
fetal death after 16 weeks’ gestation.2Recent studies have
found that although women treated for hypothyroidism
may have higher rates of preeclampsia6and CS7than
euthyroid women, they are not at any higher risk for adverse
outcomes such as fetal anomalies, fetal demise, or preterm
birth. In a study of 419 hypothyroid women, Tan et al.
observed that women who are treated with levothyroxine
(L-T4) in pregnancy were not at increased risk of maternal
or neonatal morbidity.8
In addition to adverse obstetrical outcomes, maternal
hypothyroidism is associated with adverse neonatal
outcomes. As the fetus does not begin to produce its own
thyroid hormones until approximately 12 weeks’ gestation,
it is solely dependent on maternal thyroxine (T4) during
early gestation.9,10 After 12 weeks, thyroid hormone in the
fetus continues to be partly supplied by the mother.11
Neuropsychological deficits in the offspring from as early
as 3 weeks to 9 years of age have been observed. Recently,
Kooistra et al. studied 108 neonates born to mothers with
serum free thyroxine (fT4) levels below the 10th percentile
at 12 weeks’ gestation. Compared with control subjects,
these infants had decreased neonatal behavioural
assessment scores at three weeks of age.12 Pop et al. studied
220 healthy infants and found that having maternal serum
fT4 levels below the 10th percentile at 12 weeks’ gestation
was a significant risk for impaired psychomotor develop-
ment at 10 months of age.13 A similar result was observed
by Kasatkina et al.14 The finding of a low maternal serum
fT4 level at five to nine weeks’ gestation correlated signifi-
cantly with a lower coefficient of mental development
(which is thought to represent neuropsychological develop-
ment) at 6, 9, and 12 months of age.14 In a study of 63 cases
with matched controls, mothers with low serum fT4 at
12 weeks’ gestation who continued to have low levels at
weeks 24 and 32 were at risk of having a child with delays in
mental and motor development at one and two years of age.
This neurodevelopmental delay was even more profound
when the mothers had a continuing decrease in serum fT4
as pregnancy progressed.15 Children born to women who
were not treated for thyroid deficiency during pregnancy (as
defined by increased serum TSH) had average IQ scores at
Key Words: Pregnancy, thyroid disease, hypothyroidism, therapy
seven to nine years of age that were 7 points lower than
those of controls.16
Fortunately, treatment of maternal hypothyroidism
decreases the risk of neurodevelopmental deficits in the off-
spring. The stage of development during which the lack of
T4 in the fetus is most detrimental for neurodevelopment is
thought to be the first trimester.17 However, Pop et al.
showed that maternal treatment at a later stage in pregnancy
is also beneficial for neonatal outcome. In this study, the
offspring of women who had an ongoing increase in mater-
nal serum fT4 from 12 to 32 weeks’ gestation showed
neurodevelopment at one and two years of age that was not
significantly different from that of controls.15 Other investi-
gators have noted similar benefits with treatment of
maternal hypothyroidism. The offspring of mothers who
had correction of serum fT4 by week nine of gestation using
L-T4 had the same level of neurodevelopment at one year
of age as control subjects.14 Interestingly, Haddow et al.
observed that even when pregnant women were insuffi-
ciently treated for hypothyroidism (based on serum TSH
measurements), the IQ scores of their offspring were not
significantly different from those of controls.16
Given the increased risk for adverse obstetrical and neona-
tal outcomes in untreated patients, it is prudent to treat all
pregnant women who have hypothyroidism. Levothyroxine
is the treatment drug of choice. As LT-4 is a synthetic drug,
the hormonal content is standardized and more reliable.4It
is considered safe to use in pregnancy and has not been
shown to have teratogenic potential.18,19 Clinicians should
also bear in mind that some medications, including iodine,
lithium, carbamazepine, phenytoin, rifampin, amiodarone,
aluminum hydroxide, cholestyramine, sucralfate, gluco-
corticoids, and propanolol have the potential to interfere
with L-T4 requirements. Mechanisms involved include
inhibition of thyroid hormone synthesis or release, inhibi-
tion of T4 conversion to T3, increase of thyroxine clear-
ance, interference with binding of T4 or T3 to transport
proteins, and interference with intestinal absorption of
L-T4.4,20 As many pregnant women take vitamin
supplementation, it is also important to note that ferrous
sulfate21 and calcium carbonate22 can each reduce the
absorption of L-T4 if taken concurrently.
It is evident that treatment of maternal hypothyroidism dur-
ing pregnancy greatly improves both obstetrical6–8 and
neonatal14–16 outcomes. In fact, treating maternal hypo-
thyroidism is beneficial to the offspring, even if treatment is
insufficient.16 Nonetheless, women should be made
euthyroid as quickly as possible after the diagnosis of
hypothyroidism, and all attempts should be made to
maintain thyroid balance. The dose of L-T4 usually needs to
be increased as pregnancy progresses.5,23–25 This increase
can be as great as 47% of the pre-pregnancy dosage.24 Some
authors have even suggested that women who are taking
L-T4 prior to conception should increase the dosage (by
30–60%) once pregnancy is confirmed.5,20,23,24 Because of
this increased requirement of L-T4, thyroid status should be
monitored frequently throughout pregnancy.
There is no consensus about whether it is better to monitor
the serum level of fT4 or TSH in maternal hypothyroidism,
as it is not clear which of these better represents the T4 sup-
ply to the fetus.26 Several investigators have suggested that
TSH levels should be monitored to assess the adequacy of
thyroid hormone replacement during pregnancy4,24,27;
Montoro et al. have even suggested the time intervals at
which TSH should be measured (at 6–8 weeks, at 16–20
weeks, and at 28–32 weeks).4However, others have argued
that serum fT4 levels should be monitored, because these
more closely reflect the hormone available to cross the
Currently there are also no clear reference ranges for serum
levels of fT4 and TSH in pregnancy.26 This deficiency is
complicated by the fact that human chorionic gonadotropin
(hCG) is a weak thyroid stimulator and thus will cause
maternal serum TSH levels to decline.29 Additionally, iodine
insufficiency may cause a decrease in serum fT4 levels with-
out a measurable change in TSH.10 In a review, Soldin has
presented some trimester-specific reference ranges for
serum levels of both TSH and fT4.20 However, more
research in larger populations is required to confirm these
reference ranges as valid.24 Several placebo-controlled ran-
domized trials are currently in progress to evaluate the fetal
effects of L-T4 in pregnant women who have an increased
level of serum TSH without clinical signs of
hypothyroidism. At present, it is left to the clinician to
decide the ideal serum levels of fT4 and TSH during preg-
nancy. That being said, the correction of an isolated low
level of fT4 (without elevation of TSH) has more potential
for benefit than harm, given the adverse obstetrical and
neonatal outcomes of maternal hypothyroidism.26
Treatment of maternal hypothyroidism is essential, because
adverse outcomes for both mother and baby are greatly
reduced, if not eliminated, when patients are treated. Even
when treatment is initiated later in pregnancy or is insuffi-
cient to restore a euthyroid state, the babies of treated
mothers will show more normal neurodevelopment than
the babies of non-treated mothers. Clinicians must follow
Hypothyroidism in Pregnancy
hypothyroid women closely during pregnancy and increase
the dose of L-T4 as required.
Neurodevelopmental follow-up of the babies of hypothy-
roid mothers is also recommended in order to identify
cognitive deficiencies as early as possible and provide
appropriate management.
The preparation of this manuscript was supported by a
grant from the Canadian Institute for Health Research.
Facundo Garcia-Bournissen has received funding from the
Clinician Scientist Training Program, which is funded, fully
or in part, by the Ontario Student Opportunity Trust
Fund–Hospital for Sick Children Foundation Student
Scholarship Program.
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... Gestational hypothyroidism (GH), as a common endocrine disorder in pregnant women, exerts a wide range of adverse maternal and fetal outcomes, including postpartum hemorrhage, miscarriage, low birthweight, preterm birth, respiratory distress, and risk for infectious morbidity of the offspring [1][2][3][4][5][6]. While a lot of attention has been focused on the routine screening, early confirmation of diagnosis and prompt treatment, the pathogenesis of GH remains largely undetermined. ...
... Seven metabolic pathways were significantly associated with anti-thyroid antibodies positivity (FDR-adjusted p < 0.05, Fig. 4b, Table S5), including phenylalanine, tyrosine and tryptophan biosynthesis, D-Glutamine and D-glutamate metabolism, phenylalanine Table S1. c S-Plot constructed from the OPLS-DA model shown in Fig. 1b, showing the covariance p [1] against the correlation coefficient p(corr) [1] of the 1H-NMR features with altered abundances in the Anti-TPO antibodies positivity group. The solid cycles were colored according to the values of spearman rank correlation coefficient as shown in the color bar. ...
... Seven metabolic pathways were significantly associated with anti-thyroid antibodies positivity (FDR-adjusted p < 0.05, Fig. 4b, Table S5), including phenylalanine, tyrosine and tryptophan biosynthesis, D-Glutamine and D-glutamate metabolism, phenylalanine Table S1. c S-Plot constructed from the OPLS-DA model shown in Fig. 1b, showing the covariance p [1] against the correlation coefficient p(corr) [1] of the 1H-NMR features with altered abundances in the Anti-TPO antibodies positivity group. The solid cycles were colored according to the values of spearman rank correlation coefficient as shown in the color bar. ...
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Background Thyroid disease is one of the common endocrine disorders affecting the pregnant women, in which thyroid autoimmunity can alter the progress and the outcome of pregnancy. Women with euthyroid status but anti-thyroid peroxidase (anti-TPO) antibodies positivity before pregnancy are prone to subclinical gestational hypothyroidism. However, the connections between anti-TPO antibodies positivity and gestational hypothyroidism remain largely unknown. The aim of the present study is to investigate the differences of fetal metabolic profile at birth according to maternal anti-TPO status. Methods We performed 1H-NMR metabolomics on cord blood of a nested case control cohort of 22 pregnant women with matched thyroid hormone levels and demographic data, including 11 women with euthyroid status but anti-thyroid antibodies positivity (into the anti-TPO antibodies positivity group) and 11 matched women as controls with euthyroid status and negative anti-thyroid antibodies (into the control group). Results Distinct metabolic profiles were observed between the anti-TPO antibody positivity group and the nested control group, from which a total of 10 metabolites with between-group altered abundances were structurally identified. Five out of the 10 metabolites were up-regulated in the anti-TPO antibodies positivity group, including D-Glucose, L-Glutamine, 3-Hydroxybutyric acid, Myo-Inositol, Creatinine. The other 5 metabolites were down-regulated in the anti-TPO antibodies positivity group, including L-Leucine, L-Lysine, L-Glutamic acid, L-Tyrosine, and L-Phenylalanine. All the 10 metabolites have been previously reported to be correlated with hypothyroidism. Metabolite set enrichment analysis and pathway analysis suggested that amino acid metabolism pathways (especially the phenylalanine metabolism) were associated with anti-TPO antibodies positivity. Conclusion The results of this study suggested that fetal metabolic disorder is correlated with anti-TPO antibodies positivity, representing by abundance alteration of hypothyroidism associated metabolites and the related disturbance of amino acid metabolism pathways.
... Alterations of thyroid function, such as hypothyroidism and hypothyroxinemia, are common in pregnant women [198,205]. Hypothyroidism is a condition that is characterized by a low concentration of THs [206]. Hypothyroidism is one of the most common maternal thyroid dysfunctions during pregnancy [205]. ...
... Hypothyroidism is a condition that is characterized by a low concentration of THs [206]. Hypothyroidism is one of the most common maternal thyroid dysfunctions during pregnancy [205]. The prevalence of gestational hypothyroidism is estimated to be 0.3-1.9% for overt hypothyroidism and 1.5-5% for subclinical hypothyroidism [207]. ...
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Citation: González-Madrid, E.; Rangel-Ramírez, M.A.; Mendoza-León, M.J.; Álvarez-Mardones, O.; González, P.A.; Kalergis, A.M.; Opazo, M.C.; Riedel, C.A. Risk Factors from Pregnancy to Adulthood in Multiple Sclerosis Outcome. Int. J. Mol. Sci. 2022, 23, 7080. ijms23137080 Academic Editors: Violetta Opoka-Winiarska, Ewelina
... A total of 774 women were diagnosed with thyroid dysfunction of various etiologies. Of the pregnant population, 448 (4.4%) were diagnosed with SCH, which is within the prevalence range of 3-8% [18] and 2-5% [19] but less than what was obtained in a study by Siobhan et al. (15-28%) [20] and Jianxia et al. (13.6%) [21]. There were 259 (2.6%) hypothyroid women, which appears to be higher than the typical pregnancy prevalence value of 0.3-0.5% [17] and also higher than the prevalence rate of 1.0% [22]. ...
... Various authors have suggested that the time of diagnosis and management of thyroid dysfunction could be a contributing factor to the pregnancy outcome as some believe that early diagnosis and management improves the outcome of pregnancy for both the mother and the baby [19]. We analyzed the relationship between thyroid dysfunction in all the four groups with pregnancy outcomes, and no significant differences were observed in the rates of thyroid dysfunction and pregnancy outcomes between all the groups. ...
Full-text available
Background Thyroid hormones play a significant role in placenta formation. Hence, it can determine the outcome of pregnancy in both the mother and the fetus. Failure to manage thyroid dysfunction will result in complications and undesirable pregnancy outcomes. Due to lack of consensus management approach towards this condition, complications associated with thyroid dysfunction have been on the increase. In this study, we examined the outcomes of the management of pregnant women who were screened and diagnosed with thyroid dysfunction in Second Affiliated Hospital of Chongqing Medical University.Methods This was a retrospective cohort study of 774 pregnant women diagnosed with thyroid dysfunction in the Second Affiliated Hospital of Chongqing Medical University from 2016 to 2018. Data were extracted from the hospital’s patient records. Only 724 patients that met the inclusion criteria were included in the study. The participants were divided into four groups according to the time they were diagnosed and managed. Multiple logistic regression and binary logistic regression statistical analyses were conducted using SPSS, and the potential confounders, such as maternal age, parity, and gravida, were adjusted.ResultsWe found a significant association between maternal age and abortion among pregnant women diagnosed with subclinical hypothyroidism (P = 0.018 [OR 1.459, 95% CI 1.067–1.997]) and a significant difference in pregnant women who developed intrauterine growth restriction after being diagnosed with hypothyroidism in the second trimester (P = 0.048 [OR: 0.152, 95% CI 0.024–0.981]). A significant difference in gravida (P = 0.032 [OR 1.368, 95% CI 1.028–1.821]) and normal delivery mode (P = 0.010 [OR 2.521, 95% CI 1.246–5.100]) was also observed.Conclusion Of all the common complications found among pregnant women with thyroid dysfunction which were analyzed in this study, abortion/miscarriage among pregnant women with subclinical hypothyroidism and intrauterine growth restriction among women with hypothyroidism who were diagnosed in the second trimester were significant. Multigravid women are at a higher risk of complications among pregnant women with thyroid dysfunction. More attention needs to be paid to the management of subclinical hypothyroidism during pregnancy to curb the rate of abortion/miscarriage, as well as hypothyroidism in the second trimester to minimize intrauterine growth restriction. Policies to intensify antenatal care among multigravida women diagnosed of thyroid dysfunction are needed.
... Iodine is an element that plays a critical role in developing a set of organs and functions in the body and these include the thyroid and neurological functions. The absence of iodine in the body in concentrations that meet the requirements of a deficiency has extremely adverse effects on fetus development, where it could increase the risk of both maternal and fetus hypothyroidism (Sahay and Nagesh, 2012). ...
Background: Despite the imperative role of sufficient vitamin intake during pregnancy, not all women are capable of following a balanced diet during these times. As an attempt to resolve the issue of micronutrient deficiencies, many women resort to the use of multivitamins; ones often made for pregnant women. Aim: The review aims to compare the Daily Recommended Dietary Allowance of each vitamin, micronutrient, and macronutrient with the doses available in a sample of products found in the Turkish markets, whether imported or manufactured in Turkey. Methods: The Daily Recommended Dietary Allowance doses were collected from the CDC, WHO, and IOM databases. The doses present in each product were gathered using the database offered by the Turkish pharmacist association "Tebrp" as well as RxMediaPharma. Elevit® and decavit® were selected as they've been approved by the Turkish Ministry of Health, while the other products were randomly chosen using a computer program. Results: Several formulations available in Turkey display higher or lower daily contents of vitamins and minerals than is normally ideal for pregnant women as specified by the Recommended Dietary Allowance (RDA). Formulations that exceed the recommended RDA while remaining underneath the tolerable Upper Intake Level (UL) range for specific vitamins includes Pregnacare®, Decavit®, and Elevit®. Conclusion: All of these variances in multivitamin content must be considered by physicians and clinical pharmacists when selecting the appropriate multivitamin for pregnant women, taking into account all of the hazards and benefits that vitamin supplements may bring to fetus health and development.
... There is a lot of evidence that untreated overt hypothyroidism has negative impacts on maternal and fetal health. The therapy of subclinical hypothyroidism during pregnancy, on the other hand, has insufficient evidence(Singh S, & Sandhu S, 2021).The most effective treatment for maternal hypothyroidism is the use of levothyroxine(Sahay, R. K., & Nagesh, V. S., 2012). Exogenous replacement doses of levothyroxine during breastfeeding have been shown to have no harmful effects in newborns, according to limited research. ...
Full-text available
Preface and Acknowledgements This is the first text book that is prepared as a joint work between four Arab countries including Egypt, Jordan, Lebanon and Syria (in alphabetical order) which seeks to present and integrate relevant information related to the field of infant and young child feeding. It is prepared for individuals who wish to specialize in the field of lactation management for promoting, supporting and protecting breastfeeding and continued support of infant feeding in the first five years of life. It is intended for use by countries in different regions of the world with a focus of developing countries and countries where breastfeeding is mandatory for saving lives and achieving the Sustainable Development Goals. This book was prepared in three phases, the first phase was done between the main authors, in the second phase a team from Egypt and a team from Lebanon reviewed and edited the chapters, in the third phase the book was again reviewed and finalized by the main authors. It is divided into 22 chapters that cover the academic, clinical, nutritional and critical management procedures necessary for nutritionists, physicians, health providers to support mothers at different levels of care and in different chronological periods of child development from conception to five years of age and is centered around the needs of both the mother, the baby and the family and community at large for promoting, supporting and protecting breastfeeding. It is tailored to the needs of specialists globally, but especially for those from the developing countries. This book would not have been made possible without the bulk of authentic and growing literature updates and research work, from all over the world, that was accessed online. We are sincerely grateful to the Nutrition Unit in the Eastern Mediterranean Region (EMRO) for its support in the editing and finalization RI�the book to reach its current state. We sincerely appreciate the team in Lebanon led by Dr. Maha Hoteit and included: Lactation Specialist Rim El Hajj Sleiman; Ms. Carla Ibrahim, Holy Spirit University of Kaslik (USEK); Ms. Hala Mohsen, Lebanese University, and Ms. Nour Yazbeck, Lebanese University, who dedicated much time and effort in this work. We are also grateful to the team who assisted Dr. Azza Abul-Fadl from Egypt who included Professor Salah Ali Ismail Ali, Sohag University; Dr. Ahmed Alsaed Younes, Head of EPA and ESBMF; the team from Benha Univeristy including Professor AlRawhaa Abuamer and Dr. Ranya Abdelatty from Benha Faculty of Medicine, and the team from Alexandria University; Professor Nadia Farghaly, Faculty of Medicine, Dr. Ahlam Mahmoud and Dr. Eman Kaluibi, Faculty of Nursing and the team from MCFC including Dr. Shorouk Haithamy and Dr. Samaah Zohair and Organizational psychologist Ms. Iman Sarhan from Newcastle University. This has been an intense and invigorating experience especially with the feedback received from Syria by Dr. Mahmoud Bozo who participated in the activity despite the difficult circumstances in Syria. We are grateful to Dr. Moataz Saleh, Nutrition Specialist and Dr. Naglaa Arafa, Nutrition officer from UNICEF, Cairo office for their technical support. Indeed this work would not have been made possible without the coordinating efforts of Dr Ms. Nashwa Nasr from WHO-EMRO. We received support from the administrators, designers and information technologists and many other experts who supported this work and to whom we are also very grateful. Last but not least we owe this work to the spiritual support of mothers struggling to breastfeed their babies who have inspired us throughout this work and we hope our efforts will reach out to them and to all those who are encouraging, guiding and supporting them in their exceptionally unique motherhood experience. We commend and applaud the many scientists, research workers and authors of books in this field and are grateful to those who delivered libraries to our homes by the internet. We sincerely hope that this material as a publication or an e-book will be a match of their work and meet the needs of a large spectrum of readers, learners and scientists who wish to expand their knowledge in this field. We look forward to expanding this work and making it available in different languages and welcome those who can assist us to accomplish this
... A study in a general population in China reported a prevalence of gestational clinical hypothyroidism of 0.5-0.6% and subclinical hypothyroidism of 2-3%. Subclinical hypothyroidism was observed to be the highest [28]. ...
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The hypertensive pregnant woman is at a higher risk of complications either before, during or after birth and the baby can be adversely affected leading to preterm birth, low birth weight, placental separation (abruption) and other complications. The aim of the study was to evaluate thyroid dysfunction among pregnant women with hypertension. The study participants were 150 hypertensive pregnant women, 25 non-hypertensive pregnant women and 25 non-hypertensive non-pregnant women. Exactly 5mL of blood was collected and used for the assay of triiodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH) using the enzyme-linked immunosorbent assay technique. Data were analyzed using appropriate statistical tools. The results showed a significantly higher (p < 0.05) age among hypertensive pregnant women when compared with non-hypertensive pregnant women and non-hypertensive non-pregnant women. The serum TSH was significantly higher (p < 0.035) among hypertensive pregnant women when compared with non-hypertensive pregnant women. The triiodothyronine (T3) of hypertensive pregnant women was observed to be significantly higher (p < 0.05) when compared with both non-hypertensive pregnant women and non-hypertensive non-pregnant women. Some 15/150 (10%) of hypertensive pregnant women had subclinical hypothyroidism, 13/150 (8.7%) had overt hypothyroidism, while 122/150 (81.3%) were euthyroid. Among those with thyroid dysfunction, five and four of the subjects had subclinical hypothyroidism and overt hypothyroidism during the second trimester, while ten and nine had subclinical hypothyroidism and overt hypothyroidism during the third trimester, respectively. Evaluation of hypertensive pregnant women for thyroid function may be routinely performed to enable early diagnosis and treatment.
... The increase in thyroid volume in pregnancy is compensatory due to hormone overproduction, but it is insignificant -about 10-15%. In areas with iodine deficiency, however, it can be important and is due to the functional effort of the thyroid to ensure the increased need for hormones 4 . ...
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There are international protocols for the management of hypothyroidism induced by autoimmune thyroid disease during pregnancy. In this descriptive study, we analyzed the implementation of international protocols regarding these pathologies, in local clinical practice. Analyzing the cases admitted to the Obstetrics and Gynecology department of Bucharest University Emergency Hospital on a period of 55 months, we identified the pregnancies with autoimmune hypothyroidism treated with Levothyroxine (LT4). We determined the prevalence of specific immunological markers for autoimmune hypothyroidism in pregnant women, we analyzed whether they are associated with distinct clinical phenotypes and ultrasound characteristics, and also, we evaluated the treatment of choice. Measurement of thyroglobulin antibodies, thyroid peroxidase antibodies, Thyroid-Stimulating Hormone, free fractions of Triiodothyronine and Thyroxine with substitute treatment instituted early (in the first 2 weeks postnatal) determine the normalization of cognitive development, especially in areas known for iodine deficiency, including Romania.
... 3rd trimester---0.3-4mIU/L Targeted screening includes women who either have a positive family history, goitre, type 1 dm, pre existing thyroid disorder, preterm delivery, antibody positivity, or prior therapeutic head or neck irradiation, and so on 10 . ...
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Thyroid diseases are common disorders affecting women of reproductive age group and hence constitute the commonest endocrine disorder in pregnancy also. According to ACOG, the prevalence of hypothyroidism in pregnancy is 2-5%. Women with hypothyroidism are at an increased risk for early pregnancy loss , low birth weight, placental abruption, low IQ babies etc. So early detection and treatment prevents such adverse outcomes. Aim And Objective: To study the fetomaternal outcome among pregnant women with hypothyroidism. Study Design: This is a retrospective study that includes pregnant women from the year june 2017 to may 2018, which consists of 103 patients with hypothyroid in the Results: The study consists of 103 patients with hypothyroidism out of 5034 deliveries (2.01%), in which 20 (19.4%) had overt hypothyroidism and 83(80.5%) had subclinical hypothyroidism out of total hypothyroid patients. Conclusion: The present study shows significant association between hypothyroidism and adverse fetomaternal outcomes. So routine maternal thyroid function testing, especially serum TSH should be done as soon as pregnancy is confirmed.
Background It is known that maternal thyroid dysfunction during early pregnancy can cause adverse pregnancy complications and birth outcomes. This study was designed to examine the association between ambient particulate matter with aerodynamic diameters ≤2.5 micrometers (PM2.5) and particulate matter with aerodynamic diameters ≤10 micrometers (PM10) exposure and maternal thyroid function during early pregnancy. Methods This study was based on data from a birth cohort study of 921 pregnant women in China. We estimated associations between ambient PM2.5 and PM10 exposure during the first trimester of pregnancy (estimated with land-use regression models) and maternal thyroid hormone concentrations (free thyroxine (FT4), free tri-iodothyronine (FT3), and thyroid-stimulating hormone (TSH)) collected between weeks 10 and 17 of gestation using linear regression models adjusting for potential confounders. Ambient PM2.5 and PM10 concentrations were modeled per interquartile range (IQR) increment and as tertiles based on the distribution of the exposure levels. Results An IQR increment (68μg/m³) in PM2.5 exposure was associated with a significant decrease in maternal FT4 levels (β = −0.60, 95% CI: −1.07, −0.12); and a significant decrease in FT4/FT3 ratio (β = −0.13, 95% CI: −0.25, −0.02). Further analyses showed that, relative to the lowest tertile, women in both the middle and highest tertiles of PM2.5 had significantly lower concentrations of maternal FT4 and FT4/FT3 ratio. No significant associations were found between PM2.5 and FT3 or TSH levels. PM10 exposure was not significantly associated with maternal thyroid function. Conclusions Our study suggested that higher ambient PM2.5, not PM10, exposed during the first trimester of pregnancy were associated with a significant decrease in maternal serum FT4 concentrations and FT4/FT3 ratio. Studies in populations with different exposure levels are needed to replicate our study results.
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Multiple sclerosis (MS) is an autoimmune disease characterized by a robust inflammatory response against myelin sheath antigens, which causes astrocyte and microglial activation and de-myelination of the central nervous system (CNS). Multiple genetic predispositions and environmental factors are known to influence the immune response in autoimmune diseases, such as MS, and in the experimental autoimmune encephalomyelitis (EAE) model. Although the predisposition to suffer from MS seems to be a multifactorial process, a highly sensitive period is pregnancy due to factors that alter the development and differentiation of the CNS and the immune system, which increases the offspring's susceptibility to develop MS. In this regard, there is evidence that thyroid hormone deficiency during gestation, such as hypothyroidism or hypothyroxinemia, may increase susceptibility to autoimmune diseases such as MS. In this review, we discuss the relevance of the gestational period for the development of MS in adulthood.
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The definition of what constitutes a normal TSH during pregnancy is in flux. Recent studies suggested that the first trimester upper limit of normal for TSH should be 2.5 mIU/liter. The objective of the study was to evaluate the pregnancy loss and preterm delivery rate in first-trimester thyroid peroxidase antibody-negative women with TSH values between 2.5 and 5.0 mIU/liter. The present study is a component of a recently published large-scale prospective trial that evaluated the impact of levothyroxine treatment on maternal and neonatal complications in thyroid peroxidase-positive women with TSH levels above 2.5 mIU/liter. The present study evaluated 4123 thyroid peroxidase antibody-negative women with TSH levels at or below 5.0 mIU/liter. Women were divided into two groups based on their initial TSH: group A, TSH level below 2.5 mIU/liter, excluding hyperthyroid women defined as an undetectable TSH with an elevated free T(4), and group B, TSH level between 2.5 and 5.0 mIU/liter. The study was conducted at two ambulatory clinics of community hospitals in southern Italy. A total of 4123 women were evaluated. There was no intervention. The incidence of pregnancy loss and preterm delivery in group A as compared with group B was measured. The rate of pregnancy loss was significantly higher in group B as compared with group A (6.1 vs. 3.6% respectively, P = 0.006). There was no difference in the rate of preterm delivery between the two groups. The increased incidence of pregnancy loss in pregnant women with TSH levels between 2.5 and 5.0 mIU/liter provides strong physiological evidence to support redefining the TSH upper limit of normal in the first trimester to 2.5 mIU/liter.
Hypothyroidism during pregnancy occurs in 1/1600-2000 deliveries, according to the most recent publications. The most common causes are chronic autoimmune thyroid disease, radiodine-131 treatment, or surgical removal. The diagnosis is difficult to make on clinical grounds alone, even in advanced cases, and a high index of suspicion is needed. Some women are at high risk of developing hypothyroidism, and they should be screened. These women may have had previous treatment for hyperthyroidism; high-dose neck irradiation, evidence of thyroid autoimmunity, amiodarone therapy, suspected hypopituitarism, and type I diabetics. The best laboratory test is the serum TSH, followed, if elevated, by a free T4 index and a TPO-ab titer. Thyroid antibodies have been associated with an increased (double) risk of miscarriage and postpartum thyroiditis. Frequent (22-44%) pregnancy-induced hypertension leading to preterm delivery, and prematurity is the main complication observed in those still hypothyroid near term. Proper therapy eliminates or reduces the risk. No congenital anomalies have been reported in the most recent studies, and the data available shows that both physical and mental development have been normal until children are 10 years old. However, one study reported lower IQs in children of euthyroid women with positive TPO-ab than in children of TPO-ab negative mothers. Levothyroxine is the treatment of choice. Euthyroidism must be reached and maintained in a timely fashion. Many women need more thyroxine during pregnancy, and surveillance of thyroid function is needed throughout gestation to make dose adjustments when needed. During the postpartum periods the thyroxine requirements decrease to preconception levels.
To determine whether simultaneous ingestion of ferrous sulfate and thyroxine reduces the efficacy of thyroid hormone in patients with primary hypothyroidism. Uncontrolled clinical trial. Outpatient research clinic of a tertiary care center. Fourteen patients with established primary hypothyroidism on stable thyroxine replacement. All patients were instructed to ingest simultaneously, a 300-mg ferrous sulfate tablet and their usual thyroxine dose every day for 12 weeks. After 12 weeks of ferrous sulfate ingestion with thyroxine, the mean level of serum thyrotropin (thyroid stimulating hormone, TSH) rose from 1.6 +/- 0.4 to 5.4 +/- 2.8 mU/L (P < 0.01), but the free thyroxine index did not change significantly. Subjective evaluation using a clinical score showed that nine patients had an increase in symptoms and signs of hypothyroidism; the mean score for the 14 patients changed from 0 to 1.3 +/- 0.4 (P = 0.011). When iron and thyroxine were mixed together in vitro, a poorly soluble purple complex appeared that indicated the binding of iron to thyroxine. Simultaneous ingestion of ferrous sulfate and thyroxine causes a variable reduction in thyroxine efficacy that is clinically significant in some patients. The interaction is probably caused by the binding of iron to thyroxine.
Thyroid antibody positivity during pregnancy has been associated with adverse outcomes including spontaneous miscarriage, recurrent miscarriage, and preterm delivery. The objective of the study was to determine whether thyroid antibody positivity in the first trimester of pregnancy in euthyroid women was associated with maternal and neonatal adverse outcomes. The present trial is a component of a prospective trial published in 2010 that evaluated screening for thyroid disease during pregnancy and the impact of levothyroxine therapy in women who were thyroid peroxidase positive with a TSH above 2.5 mIU/liter. The present study compared 14 maternal and neonatal adverse outcomes in 245 women who were euthyroid (TSH < 2.5 mIU/liter) and thyroid peroxidase positive in the first trimester to 3348 women who were euthyroid and thyroid peroxidase negative in the first trimester. The study was conducted in southern Italy at the ambulatory clinics of two community hospitals. The study consisted of 3593 women. There was no intervention. The main outcome measures were 14 maternal and neonatal complications. The main result was an increase in very preterm delivery (<34 wk gestation at delivery) [4.5 vs. 1.8%; χ(2)(df = 1) = 8.58; P = 0.003] and respiratory distress [3.3 vs. 1.2%; χ(2)(df = 1) = 7.80; P = 0.005] in women who were thyroid antibody positive. The present study provides further evidence of an association between thyroid antibody positivity and very preterm delivery in euthyroid women. The association with respiratory distress should be considered preliminary and awaits further study.