Maternal underweight and perinatal outcomes: a restrospective cohort study

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Public Health Nutrition

Background:

• Maternal underweight (Body Mass Index [BMI] < 18.5 kg/m2) has been associated with adverse perinatal outcomes.
• Existing research indicates potential links between maternal underweight and complications like spontaneous abortion and preterm birth.

Purpose of the Study:

• To investigate the influence of maternal underweight on labor onset, delivery route, birth weight, Apgar scores, and preterm birth rates.
• To quantify the risks associated with maternal underweight in a cohort of pregnant women.

Main Methods:

• Retrospective cohort study conducted between 2002-2011 at Hospital Universitario de Puerto Real.
• Comparison of underweight pregnant women (BMI < 18.5 kg/m2) with a control group of normal BMI pregnant women (18.5-24.9 kg/m2).
• Calculation of odds ratios (OR) for induction of labor, cesarean section, small for gestational age newborn, macrosomia, low Apgar score, and preterm birth.

Main Results:

• No significant differences were observed in labor induction, fetal macrosomia, low Apgar scores, or preterm delivery rates between groups.
• Maternal underweight was associated with a significantly decreased risk of cesarean section (adjusted OR 0.45).
• Maternal underweight showed a significantly increased risk of delivering a small for gestational age newborn (adjusted OR 1.74).

Conclusions:

• Maternal underweight at the beginning of pregnancy is associated with a reduced likelihood of undergoing a cesarean section.
• Pregnancy in underweight women carries an elevated risk of having newborns classified as small for gestational age (birth weight below the 10th percentile).