Effect of maternal weight gain on infant birth weight

Abstract

Objective: To ascertain whether increased weight gain during pregnancy resulted in higher birth weight infants.

Methods: A database was constructed from valid data of a sample of 159 healthy women between 19 to 37 years of age. The inclusion criteria were: maternal age of 19–37 years, term gestations (37–42 weeks), a baseline weight obtained at 0–15 weeks gestation, and a final weight obtained within 2 weeks of delivery. Weight gain was calculated by subtracting baseline weight from the final weight. A documented height enabled calculation of BMI. A negative screen for gestational diabetes was required.

Results: Women with lower first trimester BMI (<25) had infants of lower birth weight than women of higher BMI (>25). Women with lower gain (<35 lbs) delivered smaller infants than women with higher gain (>35 lbs). Women of higher BMI and higher gain delivered the largest infants (F = 5.37; p = 0.0015). Underweight women (BMI <19) gained less weight than women of normal weight (BMI 19–25), who gained the most weight. Obese women (BMI > 29) gained the least weight (F = 6.26; p = 0.0005).

Conclusion: The results confirmed that excessive maternal weight gain in pregnancy (> 35 lbs), does result in higher birth weight infants.