Article

FASTER Research Consortium. Fetal growth in early pregnancy and risk of delivering low birth weight infant: prospective cohort study

Texas A&M University - Galveston, Galveston, Texas, United States
BMJ (online) (Impact Factor: 16.38). 05/2007; 334(7598):836. DOI: 10.1136/bmj.39129.637917.AE
Source: PubMed

ABSTRACT To determine if first trimester fetal growth is associated with birth weight, duration of pregnancy, and the risk of delivering a small for gestational age infant.
Prospective cohort study of 38 033 pregnancies between 1999 and 2003.
15 centres representing major regions of the United States.
976 women from the original cohort who conceived as the result of assisted reproductive technology, had a first trimester ultrasound measurement of fetal crown-rump length, and delivered live singleton infants without evidence of chromosomal or congenital abnormalities. First trimester growth was expressed as the difference between the observed and expected size of the fetus, expressed as equivalence to days of gestational age.
Birth weight, duration of pregnancy, and risk of delivering a small for gestational age infant.
For each one day increase in the observed size of the fetus, birth weight increased by 28.2 (95% confidence interval 14.6 to 41.2) g. The association was substantially attenuated by adjustment for duration of pregnancy (adjusted coefficient 17.1 (6.6 to 27.5) g). Further adjustments for maternal characteristics and complications of pregnancy did not have a significant effect. The risk of delivering a small for gestational age infant decreased with increasing size in the first trimester (odds ratio for a one day increase 0.87, 0.81 to 0.94). The association was not materially affected by adjustment for maternal characteristics or complications of pregnancy.
Variation in birth weight may be determined, at least in part, by fetal growth in the first 12 weeks after conception through effects on timing of delivery and fetal growth velocity.

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    • "Another study also reported that ultrasound exposure in utero could potentially cause hematopoiesis and reduced body weight in macaque (monkey) offspring [26]. Meanwhile, Bukowski et al. [27] and Smith et al. [28] reported that routine ultrasound measurement that shows small fetal size at early pregnancy is indicative of reduced birth weight. This indicated that fetus is at risk of poor growth. "
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    ABSTRACT: The aim of this in vivo experimental study is to determine the association between ultrasound exposure time and rabbit fetal weight. A total of 14 pregnant does were exposed to ultrasound heating for 30, 60, and 90 minutes of ultrasound exposure at their middle of each gestational stage, while another 4 pregnant does served as control. Total of 136 fetuses (1st stage, n=34 (25%); 2nd stage, n=28 (20.6%); 3rd stage, n=74 (54.4%)) were analyzed for fetal body weight. There were significant differences in fetal weight at all stages (p<0.05; 95% CI do not cross 0) of all groups at different length of exposure time. There were also negative correlation between groups with different exposure durations and fetal weight in the 1st and the 3rd stage (p<0.05; r = -0.40, p<0.05; r = -0.23 respectively). Exposure time was found poorly associated with fetal weight in the 1st and the 3rd stage (p<0.05; r2 = 0.15 and 0.04 respectively). This study suggests the heating effect of ultrasound exposure might act as a noxious agent that promotes intrauterine growth restriction in developing fetus that might consequently impacts the rabbit fetal weight. Therefore a considerably increase in awareness of negligible effects aroused from prenatal ultrasound exposure was concerned as it was widely applied to pregnant women.
    06/2014; 6(3):71-80. DOI:10.14257/ijbsbt.2014.6.3.09
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    • "Typically, however, maternal intervention trials have not begun in the first trimester or/and the periconceptional period despite observational evidence of a relationship between poor maternal nutrition at conception and LBW first reported a quarter of a century ago [5]. A series of observational and experimental studies suggest that intra-uterine growth retardation (IUGR), preterm birth (PTB) and stillbirths have their origins in part in early pregnancy [6-8]. When the fetus is smaller than expected in the first trimester, there is increased prevalence of PTB and IUGR [7,8]. "
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    ABSTRACT: Research directed to optimizing maternal nutrition commencing prior to conception remains very limited, despite suggestive evidence of its importance in addition to ensuring an optimal nutrition environment in the periconceptional period and throughout the first trimester of pregnancy.Methods/Study design: This is an individually randomized controlled trial of the impact on birth length (primary outcome) of the time at which a maternal nutrition intervention is commenced: Arm 1: >= 3 mo preconception vs. Arm 2: 12-14 wk gestation vs. Arm 3: none.192 (derived from 480) randomized mothers and living offspring in each arm in each of four research sites (Guatemala, India, Pakistan, Democratic Republic of the Congo). The intervention is a daily 20 g lipid-based (118 kcal) multi-micronutient (MMN) supplement. Women randomized to receive this intervention with body mass index (BMI) <20 or whose gestational weight gain is low will receive an additional 300 kcal/d as a balanced energy-protein supplement. Researchers will visit homes biweekly to deliver intervention and monitor compliance, pregnancy status and morbidity; ensure prenatal and delivery care; and promote breast feeding. The primary outcome is birth length. Secondary outcomes include: fetal length at 12 and 34 wk; incidence of low birth weight (LBW); neonatal/infant anthropometry 0-6 mo of age; infectious disease morbidity; maternal, fetal, newborn, and infant epigenetics; maternal and infant nutritional status; maternal and infant microbiome; gut inflammatory biomarkers and bioactive and nutritive compounds in breast milk. The primary analysis will compare birth Length-for-Age Z-score (LAZ) among trial arms (independently for each site, estimated effect size: 0.35). Additional statistical analyses will examine the secondary outcomes and a pooled analysis of data from all sites. Positive results of this trial will support a paradigm shift in attention to nutrition of all females of child-bearing age.Trial registration: ClinicalTrials.gov NCT 01883193.
    BMC Pregnancy and Childbirth 03/2014; 14(1):111. DOI:10.1186/1471-2393-14-111 · 2.15 Impact Factor
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    • "If fetal size (BPD) in early second trimester also differ according to maternal height, ultrasound dating may induce a biased estimate of EDD [31]. Femur length of the fetus at 18–19 gestational weeks has been reported to correlate with maternal height, [32]maternal height is a known determinant of offspring birth weight [5,33,34],and fetal size in early second trimester is positively associated with offspring birth weight [35,36]. Thus, it is not unlikely that ultrasound in 17–19 weeks of gestation may underestimate the true gestational age of a short woman and shift the EDD to a later date due to her smaller than average sized fetus, and vice versa for taller women. "
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    ABSTRACT: BACKGROUND: The objective of this study was to examine the association of maternal and paternal height with pregnancy length, and with the risk of pre- and post-term birth. In addition we aimed to study whether cardiovascular risk factors could explain possible associations. METHODS: Parents who participated in the Nord-Tr[latin small letter o with stroke]ndelag Health Study (HUNT 2; 1995--1997) were linked to offspring data from the Medical Birth Registry of Norway (1997--2005).The main analyses included 3497 women who had delivered 5010 children, and 2005 men who had fathered 2798 pregnancies. All births took place after parental participation in HUNT 2. Linear regression was used to estimate crude and adjusted differences in pregnancy length according to parental heights. Logistic regression was used to estimate crude and adjusted associations of parental heights with the risk of pre- and post-term births. RESULTS: We found a gradual increase in pregnancy length by increasing maternal height, and the association was essentially unchanged after adjustment for maternal cardiovascular risk factors, parental age, offspring sex, parity, and socioeconomic measures. When estimated date of delivery was based on ultrasound, the difference between mothers in the lower height quintile (<163 cm cm) and mothers in the upper height quintile (>= 173 cm) was 4.3 days, and when estimated date of delivery was based on last menstrual period (LMP) ,the difference was 2.8 days . Shorter women (< 163 cm) had lower risk of post-term births, and when estimated date of delivery was based on ultrasound they also had higher risk of pre-term births. Paternal height was not associated with pregnancy length, or with the risks of pre- and post-term births. CONCLUSIONS: Women with shorter stature had shorter pregnancy length and lower risk of post-term births than taller women, and when EDD was based on ultrasound, they also had higher risk of preterm births. The effect of maternal height was generally stronger when pregnancy length was based on second trimester ultrasound compared to last menstrual period. The association of maternal height with pregnancy length could not be explained by cardiovascular risk factors. Paternal height was not associated with pregnancy length or with the risk of pre- and post-term birth.
    BMC Pregnancy and Childbirth 02/2013; 13(1):33. DOI:10.1186/1471-2393-13-33 · 2.15 Impact Factor
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