The relationship of neonatal serum vitamin B12 status with birth weight.

Earlier studies have shown a relationship between maternal vitamin B12 status and birth weight. This study extends those findings directly in terms of neonatal vitamin B12 status and birth weight. One hundred and twelve women were followed from the first trimester of pregnancy and maternal blood was obtained in all three trimesters along with cord blood at birth of their neonates. The maternal and cord serum vitamin B12 concentrations were examined in relation to birth weight. There was a significant correlation between vitamin B12 concentration in maternal antenatal serum during each of the trimesters of pregnancy and cord serum (all P< 0.01). Neonates that were born with lower birth weights (categories of <2500 g and 2500-2999g) had significantly lower mean cord serum vitamin B12 concentrations when compared to those who were > or = 3000g (P = 0.02 and P = 0.05 respectively). A similar, however, non significant trend was observed for antenatal vitamin B12 concentrations at first and third trimesters. Cord serum vitamin B12 concentrations were significantly correlated with birth weight, up to 40 weeks of pregnancy (r=0.28, P=0.01) but not beyond that (> or =40 weeks gestation). Vitamin B12 status in the mother was related to neonatal vitamin B12 status as measured by cord serum vitamin B12 concentration. In addition, low neonatal vitamin B12 concentrations were adversely associated with low birth weights.

Anthropometry and body composition of south Indian babies at birth.

OBJECTIVES: To assess the consequences on body composition of increasing birth weight in Indian babies in relation to reported values in Western babies, and to assess the relationship between maternal and neonatal anthropometry and body composition. DESIGN: Prospective observational study. SETTING: Bangalore City, India. SUBJECTS: A total of 712 women were recruited at 12.5+/-3.1 weeks of gestation (mean+/-standard deviation, SD) and followed up until delivery; 14.5% were lost to follow-up. Maternal body weight, height, mid upper-arm circumference and skinfold thicknesses were measured at recruitment. Weight and body composition of the baby (skinfold thicknesses, mid upper-arm circumference, derived arm fat index and arm muscle index; AFI and AMI, respectively) were measured at birth in hospital. RESULTS: The mean+/-SD birth weight of all newborns was 2.80+/-0.44 kg. Birth weight was significantly related to the triceps and subscapular skinfold thickness of the baby. In a small number of babies with large birth weight for gestational age, there was a relatively higher normalised AFI relative to AMI than for babies with lower or appropriate birth weight for gestational age. Maternal height and fat-free mass were significantly associated with the baby's length at birth. CONCLUSIONS: Skinfold thicknesses in Indian babies were similar to those reported in a Western population with comparable birth weights, and the relationship of AFI to birth weight appeared to be steeper in Indian babies. Thus, measures to increase birth weight in Indian babies should take into account possible adverse consequences on body composition. There were no significant relationships between maternal anthropometry and body composition at birth on multivariate analysis, except for sum of the baby's skinfold thicknesses and maternal fat-free mass (P<0.02).