Psychosocial support for maternal stress during pregnancy: effect on birth weight

In a previous study we showed that moderate to severe stress during pregnancy was inversely related to infant birth weight. Using the same criteria for stress (according to the Social Readjustment Rating Scale of Holmes and Rahe), we studied 86 white mothers with singleton pregnancies and with no known medical or obstetric risk factors for reduced birth weight. After strict randomization, data were analyzed for 43 mothers who received psychosocial support between enrollment at +/- 20 weeks and delivery at +/- 38 weeks and for 43 control mothers who received standard care at the antenatal clinic. In the supported group seven infants weighed less than 3000 gm at birth versus 18 control infants (p = 0.008), and analysis revealed that this effect was more the result of improved intrauterine growth than of prolongation of pregnancy. These findings are of little clinical relevance as far as the neonate is concerned, but they do indicate that psychosocial support has a significant effect on birth weight. It is possible that previous studies that have looked only for an effect on low- or very-low-birth-weight rates might have missed this clinically measurable benefit of counseling.