Associations of Gestational Weight Gain with Perinatal Outcomes in Western Brazilian Amazon

To investigate the association between gestational weight gain (GWG) and perinatal outcomes in pregnant Amazonian women.

Data from 1305 mother-child pairs from the MINA-Brazil population-based birth cohort study were used. GWG was classified according to two methods, the Institute of Medicine (IOM) guidelines and INTERGROWTH-21st standards. Poisson and linear regression analyses were conducted to evaluate associations with perinatal outcomes.

Following IOM guidelines (n = 1305), the rates of insufficient and excessive GWG were found to be similar (32%). Excessive GWG was associated with higher new-born birthweight (BW) z-scores; increased risks of macrosomia, large for gestational age (LGA), and caesarean delivery; and lower risks of low birthweight (LBW) and being small for gestational age (SGA). Insufficient GWG was associated with lower new-born BW z-scores. Among women with normal pre-pregnancy body mass indices (BMIs, n = 658), inappropriate GWG was high following both methods (IOM: 41.2% insufficient, 24.8% excessive; INTERGROWTH-21st: 25.2% below - 1 z-score, 16.9% above 1 z-score). Both methods also indicated that new-borns of women with excessive GWG had higher BW z-scores and increased risk of macrosomia and LGA. Women with GWG below the INTERGROWTH-21st standards were more likely to deliver an infant SGA and with lower BW z-scores.

Inappropriate GWG remains a health concern irrespective of the method used to classify weight gain. GWG above the recommendations of both methods and below the INTERGROWTH-21st standard was associated with adverse perinatal outcomes. Therefore, INTERGROWTH-21st standards seem to be a better fit for healthy women in this population.