Both high and low gestational weight gain, compared with the recommended weight gain, are associated with increased risks of adverse perinatal outcomes, according to a systematic review and meta-analysis.
Researchers reviewed 302 studies that categorized women by their prepregnancy body mass index and followed them for gestational weight gain, as well as maternal and neonatal outcomes. They included in their meta-analysis 23 cohort studies involving 1,309,136 pregnancies in 10 countries. Only studies assessing singleton pregnancies in women aged 18 years and older were included.
Gestational weight gain was below 2009 Institute of Medicine guidelines in 23% of these pregnancies, within recommended guidelines in 30%, and above recommended guidelines in 47%, said Rebecca F. Goldstein, MBBS, of Monash University, Victoria, Australia, and her associates.
Compared with the recommended gestational weight gain, low weight gain was associated with a 5% higher risk of a small-for-gestational-age (SGA) neonate and a 5% higher risk of preterm birth. However, low weight gain reduced the risks of a large-for-gestational-age (LGA) neonate and macrosomia.
Compared with the recommended gestational weight gain, high weight gain was associated with a 4% higher risk of cesarean delivery, a 4% higher risk of a LGA neonate, and a 6% higher risk of macrosomia. However, high weight gain reduced the risk of an SGA neonate by 3% and that of preterm birth by 2%, the researchers reported ( JAMA. 2017;317:2207-25 ).
These increases and decreases in risks remained consistent regardless of the mother’s prepregnancy BMI, they noted.
The effect of either high or low gestational weight gain on the risk of gestational diabetes could not be determined because of inconsistencies across the 23 cohort studies concerning definitions and treatments.
The Australian Department of Education and Training and the Australian National Health and Medical Research Council supported the study. Dr. Goldstein reported having no relevant financial disclosures; one of her associates reported serving on the Women’s Health Global Advisory Board for Pfizer.