Stress and lack of social support as risk factors for small-for-gestational-age birth

Aim: To determine the contributions of social support and perceived stress to the risk of small-for-gestational-age birth. Methods: The investigation was a case-control study of mothers of infants born at 37 or more completed weeks of gestation. Cases weighed less than the sex-specific 10th percentile for gestational age at birth (small for gestational age (SGA), n = 836), and controls (appropriate for gestational age (AGA), n = 870) comprised a random selection of heavier babies. Results: In univariate analyses measures of informal social support, but not perceived stress or formal social support, were associated with SGA birth. It was found that Asian mothers are less likely to receive support from families and friends. After adjustment for ethnicity, informal social support was not associated with SGA. Conclusions: Support appears to reduce the risk of SGA births, but after adjustment for ethnicity this is no longer the case. Stress during pregnancy was not associated with SGA birth.