Maternal nutrition and spontaneous preterm birth

Area of Science:

• Obstetrics and Gynecology
• Perinatal Epidemiology
• Maternal-Fetal Medicine

Background:

• Previous studies on maternal undernutrition and preterm birth risk had methodological limitations.
• These limitations included using total weight gain instead of net rate and including induced preterm births.

Purpose of the Study:

• To investigate the roles of prepregnancy body mass index, net rate of maternal weight gain, height, and other factors in spontaneous preterm birth.
• To overcome methodological shortcomings of prior research on preterm delivery determinants.

Main Methods:

• Analysis of a cohort of 13,102 women with early ultrasound-confirmed gestational age.
• Investigation of spontaneous preterm birth using multiple logistic regression.
• Examination of prepregnancy BMI, net weight gain rate, height, and sociodemographic factors.

Main Results:

• Total weight gain was associated with spontaneous preterm birth, but net rate of gain was not.
• Significant determinants of preterm birth (<37 weeks) included short maternal stature, low education, smoking, diabetes, UTIs, hypertension, and prior adverse pregnancy outcomes.
• These factors, particularly low maternal education, remained significant for more severe preterm birth (<34 and <32 weeks).

Conclusions:

• Prepregnancy weight-for-height and gestational weight gain are not primary determinants of spontaneous preterm birth.
• Methodological errors in prior studies may have mistaken shortened gestation for its cause.
• Biologic and social factors are crucial for understanding and intervening in preterm birth.