In utero exposure to endocrine disrupting chemicals, micro-RNA profiles, and fetal growth: a pilot study protocol.

Background: The developing fetus is particularly vulnerable to the effects of endocrine disrupting chemicals (EDCs). Molecular fingerprints of EDCs can be identified via microRNA (miRNA) expression profiles and may be etiologically implicated in the developmental origin of disease (DOHaD). Methods/design: This pilot study includes pregnant women at high risk (smoking at conception), and low risk (non-smoking at conception) for SGA birth (birthweight<10th percentile for gestational age). We have randomly selected 12 mothers (3 high-risk SGA birth, 3 low-risk SGA birth, 3 high-risk non-SGA birth, 3 low-risk non-SGA birth), with EDC measurements from gestational week 17. All offspring are female. We aim to test the stability of our samples (maternal serum, cord blood, placenta tissue), observe the differential expression of miRNA profiles over time (gestational weeks 17, 25, 33, 37, birth), and study the consistency between maternal EDC measures and miRNA expression profiles across our repeated measures. Expected impact of the study for Public Health: Results from this pilot study will inform the development of a larger cohort wide analysis, and will impact the current state of knowledge in the fields of public health, epigenetics, and the DOHaD.

Associations of Maternal Vitamin B12 Concentration in Pregnancy With the Risks of Preterm Birth and Low Birth Weight: A Systematic Review and Meta-Analysis of Individual Participant Data.

Vitamin B12 (hereafter referred to as B12) deficiency in pregnancy is prevalent and has been associated with both lower birth weight (birth weight <2,500 g) and preterm birth (length of gestation <37 weeks). Nevertheless, current evidence is contradictory. We performed a systematic review and a meta-analysis of individual participant data to evaluate the associations of maternal serum or plasma B12 concentrations in pregnancy with offspring birth weight and length of gestation. Twenty-two eligible studies were identified (11,993 observations). Eighteen studies were included in the meta-analysis (11,216 observations). No linear association was observed between maternal B12 levels in pregnancy and birth weight, but B12 deficiency (<148 pmol/L) was associated with a higher risk of low birth weight in newborns (adjusted risk ratio = 1.15, 95% confidence interval (CI): 1.01, 1.31). There was a linear association between maternal levels of B12 and preterm birth (per each 1-standard-deviation increase in B12, adjusted risk ratio = 0.89, 95% CI: 0.82, 0.97). Accordingly, B12 deficiency was associated with a higher risk of preterm birth (adjusted risk ratio = 1.21, 95% CI: 0.99, 1.49). This finding supports the need for randomized controlled trials of vitamin B12 supplementation in pregnancy.

Folic acid supplementation in early pregnancy and the risk of preeclampsia, small for gestational age offspring and preterm delivery.

OBJECTIVE: To assess whether folic acid intake during the first trimester of pregnancy is related to pregnancy outcomes preeclampsia, low birth weight or preterm birth. STUDY DESIGN: Prospective cohort study of 3647 women who were followed from the first trimester of pregnancy. Detailed information on quantity of folic acid intake before and during the first three months of pregnancy was recorded. Pregnancy outcome data were abstracted from obstetric records. RESULTS: Lean mothers who used folic acid supplementation the month before pregnancy had a 40% reduced risk of developing preeclampsia. The adjusted odds ratio (OR) with 95% confidence intervals (95%CI) for preeclampsia in lean mothers (BMI<25) who used folic acid supplements the month before pregnancy was 0.6 (95% CI 0.4-1.0). Obese mothers who used folic acid supplementation in the first trimester had an increased, but not statistically significant risk for preterm birth (adjusted OR 1.9 with 95% CI 0.9-4.0). There were no significant associations between folic acid supplementation and low birth weight. CONCLUSION: Our study supports a possible protective effect of folate intake in early pregnancy on preeclampsia in lean mothers. There was no support for any beneficial effect of folic acid use on preterm birth or low birth weight, and we found no evidence of any harmful effects of folate use for the outcomes included in our study.

Metformin's effect on first-year weight gain: a follow-up study.

BACKGROUND: The impact of metformin medication in pregnant women with polycystic ovary syndrome on weight gain during pregnancy and after delivery and the impact on growth of the offspring are essentially unexplored. METHODS: This is a follow-up study of a randomized controlled trial (The Metformin treatment in pregnant PCOS women study), conducted in 11 secondary care centers. Women with PCOS were randomized to metformin (2000 mg daily) or placebo from first trimester to delivery. Questionnaires were sent to 256 participants 1 year postpartum. Maternal weight development in pregnancy and the first year after delivery and offspring anthropometry at birth and weight 1 year postpartum were registered. RESULTS: Women randomized to metformin gained less weight during pregnancy compared with those in the placebo group. In the newborns, there was no difference between the 2 groups in weight or length. One year postpartum, women who used metformin in pregnancy lost less weight and their infants were heavier than those in the placebo group (10.2 ± 1.2 kg vs 9.7 ± 1.1 kg, P = .003). CONCLUSIONS: Women randomized to metformin were heavier in the first trimester, gained less weight in pregnancy, and lost less weight in the first year postpartum compared with women randomized to placebo. Children exposed to metformin weighed more at 1 year of age.

Being born small for gestational age reduces white matter integrity in adulthood: a prospective cohort study.

BACKGROUND: Being born small for gestational age (SGA) (birth weight <10th percentile) is connected to decreased white matter (WM) integrity in newborns and increased prevalence of psychiatric symptoms in adulthood. The aims of this study were to investigate whether being born SGA at term affects WM integrity in young adulthood and to explore possible relationships between fractional anisotropy (FA) and pre- and perinatal factors and cognitive and psychiatric outcomes in adulthood in SGA and controls. METHODS: Diffusion tensor imaging and tract-based spatial statistics were conducted to test for voxelwise differences in FA in SGAs (n = 46) and controls (n = 57) at 18-22 y. RESULTS: As compared with controls SGAs had reduced FA in ventral association tracts and internal/external capsules. In the SGAs, no relationship was found between FA and intrauterine head growth in the third trimester, although total intelligence quotient was negatively correlated to FA. In controls, a positive correlation was found between FA and brain growth in the third trimester and maternal smoking. No relationship was found between FA and psychiatric measures in SGAs or controls. CONCLUSION: These results demonstrate that being born SGA leads to reduced WM integrity in adulthood, and suggest that different factors modulate the development of WM in SGA and control groups.

Folic acid supplementation in early pregnancy and asthma in children aged 6 years.

OBJECTIVE: The objective of the study was to assess whether folic acid intake during the first trimester of pregnancy is related to asthma in the offspring by the age of 6 years. STUDY DESIGN: This was a prospective cohort study of 1499 women who were followed up from the first trimester of pregnancy. Their children were followed up until they were 6 years old. RESULTS: Fifty-one percent of the women used folic acid in the month before conception and 88% in the third month of pregnancy. The adjusted odds ratio for asthma per 100 µm increase in the average daily intake of folic acid was 0.98 (95% confidence interval, 0.93-1.04). For categories of daily folate intake, there was no evidence of associations with childhood asthma or evidence of any dose response relation for any time period (all P(trend) > .05). CONCLUSION: Our results do not support any association of folic acid supplementation in pregnancy and asthma risk in offspring by age 6 years.