Association between maternal hemoglobin concentration and educational attainment in mid-childhood in a high-resource obstetric setting: a prospective cohort study.

BACKGROUND: Although maternal hemoglobin levels during pregnancy are commonly associated with perinatal outcomes, their link to childhood neurodevelopment remains uncertain. OBJECTIVE: This study aimed to examine the associations between maternal hemoglobin in early and late pregnancy and the educational attainment of offspring mid-childhood in a high-resource obstetric setting. STUDY DESIGN: Pregnancy data from a prospective birth cohort (Pregnancy Outcome Prediction Study, Cambridge, United Kingdom, 2008-2012, N=3285) were linked to mid-childhood educational outcomes (Department for Education, United Kingdom). Regression models adjusted for maternal, child, and socioeconomic factors were used to determine associations between maternal hemoglobin, pregnancy complications, and offspring educational outcomes (aged 5-7 years). RESULTS: No association was observed between maternal hemoglobin at 12 weeks and the likelihood of either adverse pregnancy outcomes or children meeting expected educational standards between ages 5-7 years. Higher maternal hemoglobin at 28 weeks was associated with an increased risk of small-for-gestational-age infants (adjusted odds ratio, 1.26 [95% confidence interval, 1.11-1.59]; P=.002) and preterm birth (adjusted odds ratio, 1.38 [95% confidence interval, 1.11-1.81]; P=.005). There were no adverse birth outcomes associated with anemia. However, children of mothers who were anemic at 28 weeks had ∼40% increased risk of not attaining expected educational standards at age 5 (adjusted odds ratio, 1.42 [95% confidence interval, 1.03-1.95]; P=.03). There was no association between maternal anemia at 28 weeks and educational performance at ages 6-7. No associations were found between high maternal hemoglobin concentrations (top decile) or change in hemoglobin concentrations between 12 and 28 weeks and childhood educational attainment. CONCLUSION: Maternal anemia at 28 weeks of pregnancy is associated with reduced educational attainment at 5 years old but not at older ages (6-7 years old). A proactive approach to increasing maternal hemoglobin in high-resource settings is unlikely to impact long-term childhood educational attainment.

Maternal high body mass index, but not gestational diabetes, is associated with poorer educational attainment in mid-childhood.

BACKGROUND: Previous studies suggest that gestational diabetes mellitus is associated with poorer cognitive outcomes in children. However, confounding factors, especially maternal body mass index, have been poorly accounted for. OBJECTIVE: This study aimed to examine the independent associations between maternal body mass index, gestational diabetes mellitus status, and educational outcomes. STUDY DESIGN: Antenatal data from a prospective birth cohort (Pregnancy Outcome Prediction Study, 2008-2012, Cambridge, United Kingdom) were linked to mid-childhood educational outcomes (Department for Education, United Kingdom). A total of 3249 children born at term were stratified by maternal gestational diabetes mellitus status and body mass index at booking (<25 vs ≥25 kg/m2). Regression models adjusted for relevant maternal, child, and socioeconomic factors were used to determine associations with academic outcomes at ages of 5 to 7 years. RESULTS: No differences in educational attainment were found between children exposed to gestational diabetes mellitus and nonexposed children. Neither maternal glucose levels measured at 11 to 14 or 24 to 28 weeks, nor acceleration of the fetal abdominal circumference growth velocity were related to educational attainment at ages of 5 to 7 years. Children of mothers with booking body mass index ≥25 kg/m2 (vs <25 kg/m2) were ∼50% more likely to not meet expected educational standards regardless of gestational diabetes mellitus status (age 5: adjusted odds ratio, 1.44; 95% confidence interval, 1.19-1.74; P<.001; age 6: adjusted odds ratio, 1.61; 95% confidence interval, 1.28-2.02; P<.001). The association between maternal body mass index and offspring educational attainment is dose-dependent and robust to stratification by gestational diabetes mellitus status and adjustment for socioeconomic factors. CONCLUSION: Mid-childhood educational attainment is not associated with maternal glucose status. This may provide important reassurance for pregnant women and clinicians. However, maternal body mass index is associated with lower childhood educational attainment and may be modifiable with intervention before or during pregnancy.

Glucose and oxygen in the early intrauterine environment and their role in developmental abnormalities.

The early life environment can have profound impacts on the developing conceptus in terms of both growth and morphogenesis. These impacts can manifest in a variety of ways, including congenital fetal anomalies, placental dysfunction with subsequent effects on fetal growth, and adverse perinatal outcomes, or via effects on long-term health outcomes that may not be detected until later childhood or adulthood. Two key examples of environmental influences on early development are explored: maternal hyperglycaemia and gestational hypoxia. These are increasingly common pregnancy exposures worldwide, with potentially profound impacts on population health. We explore what is known regarding the mechanisms by which these environmental exposures can impact early intrauterine development and thus result in adverse outcomes in the immediate, short, and long term.

The direct measurement of embryogenic volume and nucleo-cytoplasmic ratio during mouse pre-implantation development.

After fertilization, the mammalian conceptus undergoes cleavage, a process of cell proliferation in the absence of interphase growth. It is not known when cleavage ends and gives way to fully replicative cell cycles with a stable nucleo-cytoplasmic ratio. We have used two-photon excitation and confocal microscopy to measure directly volumes and nucleo-cytoplasmic ratios of whole murine concepti and their individual constituent blastomeres during pre-implantation development up to the early uterine attachment stage (day 5). We show that the total cytoplasmic volume of the conceptus remains constant during pre-implantation development, and that the average nucleo-cytoplasmic ratio increases exponentially throughout the same period. Data from individual blastomeres show that both volume and nucleo-cytoplasmic ratio diverge in the inner and outer subpopulations evident from the 16-cell stage (fifth developmental cycle) onwards. Cells from emergent outer trophoblast populations are larger and have smaller nucleo-cytoplasmic ratios than those from emergent inner pluriblast populations. Moreover, the nucleo-cytoplasmic ratio of the trophoblast appears to be stabilizing, suggesting that for this subpopulation cleavage may end at the 16-32-cell transition. Putative hypoblast and epiblast cell subpopulations within the pluriblast were not distinguishable by volume or nucleo-cytoplasmic ratio. Embryonic stem cell volume was higher than that of either cell subpopulation of expanded blastocysts, and their nucleo-cytoplasmic ratio was similar to that of trophoblast cells.