Individual correction of birth weight for parental stature with special reference to small-for-date and large-for-date infants

Identification of newborns with Fetal Growth Restriction (FGR) in weight and/or length based on constitutional growth potential

This study was carried out to build statistical models for defining FGR (Fetal Growth Restriction) in weight and/or length after taking growth potential of an infant into account. From a cohort of pregnant women having given birth to 47,733 infants in 141 French maternity units, two statistical models gave individualized limits of birth weight and birth length (based on the 5th centile) below which, after adjustment for its individual growth potential, a newborn must be considered as FGR in weight and/or in length. A sample of 906 infants had measures taken of cord blood growth factors (IGF1, IGFBP3). The FGR(W) definition (weight<5th centile for growth potential) permitted the identification of infants who presented rates of maternal hypertension (13.6%) and of Apgar score at 5 min<6 (2.9%) higher than in the classical group SGA(W) (weight<5th centile for sex and gestational age) (9.6% and 2.2% respectively). By combining FGR(W) and SGA(W), a subgroup of infants, not currently recognized as SGA, presented very high rates of maternal hypertension (19.9%) and of low Apgar score (3.9%). Conversely a subgroup of infants, currently recognized as SGA(W), had rates as low as in the normal infants group, and had to be considered as "constitutionally small" (that is to say 24% of the SGA(W)). Combining FGR(W) and FGR(L) (length<5th centile of growth potential), 7.6% of infants appeared growth-restricted, and 1.8% appeared constitutionally small in weight and/or in length. The FGR(W)-FGR(L) infants showed the lowest mean values of IGF1 (126.2+/-3.2) and IGFBP3 (0.86+/-0.03). These new definitions of FGR(W) and FGR(L) could help to better identify infants at birth requiring neonatal care, and monitoring of growth catch-up and neurodevelopmental outcome.

Secular trend in the rate of small-for-gestational-age infants: Haguenau Study 1971-1985

Between 1971 and 1985, at the Haguenau Maternity Hospital, a 20% decrease was observed in the rate of small-for-gestational-age infants (birthweight less than 10th centile using figures from all the study births) among 20,101 births between 28 and 42 weeks. This decrease could not be explained by simultaneous changes in socio-demographic and anthropometric characteristics of the pregnant women, nor a recruitment bias. The earliness of prenatal care at the Maternity Hospital may have played a role in the downward trend. Further research is needed to confirm the influence of prenatal care on the rate of small-for-gestational-age babies.

Increased hair cadmium in newborns of women occupationally exposed to heavy metals

Newborn and maternal hair samples were obtained from subjects occupationally exposed to heavy metals and from matched controls. The geometric means of levels of cadmium and lead in hair from exposed mothers and of cadmium in hair from transplacentally exposed newborns were twice as high as levels present in samples from controls. There was a positive correlation between levels of cadmium in maternal and newborn's hair, but no such correlation for lead. Despite statistically significant evidence of increased exposure to cadmium, no adverse health effects were documented in the small group of exposed newborns included in this study. Problems associated with exogenous contamination of hair by heavy metals and potential advantages of hair sampling for measuring fetal exposures to heavy metals are discussed.