The new study by researchers in the University of Maryland School of Public Health (UMD SPH) examined the relationship between gestational weight gain, mothers' body mass index (BMI) before and during pregnancy, and infant mortality rates.
The study was conducted by Dr. Regina Davis, associate executive director of the American Public Health Association, Dr. Sandra Hofferth, professor, and Dr. Edmond Shenassa, associate professor.
Davis said that their study showed that gaining too little weight during pregnancy is a risk factor for infant mortality for all but the heaviest women, asserting that gaining more weight than recommended was not a risk factor for infant mortality but may be related to subsequent maternal health problems.
Davis, Hofferth, and Shenassa analyzed data collected from 159,244 mothers who gave birth to live, single babies between 2004 and 2008 in order to determine whether there was a link between gestational weight gain (GWG), mothers' body mass index (BMI), and infant mortality.
Infant mortality risks in the study sample were 3.9 per cent among infants of mothers who gained an inadequate amount of weight during pregnancy, 1.2 per cent among infants of mothers who gained an adequate amount of weight, and .7 per cent among mothers who gained more than the recommended amount.
Mothers' pre-pregnancy BMI was also a key factor in infant survival. Mothers who were underweight before pregnancy and gained too little weight during pregnancy had six times the normal rate of infant mortality.
The study has been published in the American Journal of Public Health.