Preterm Birth, Low Birthweight, and Small for Gestational Age Among Women with Preeclampsia: Does Maternal Age Matter?

Objectives: To better understand the effects of maternal age on birth outcomes among preeclampsia (PE) patients, we examined the rates of preterm birth, low birthweight, and small for gestational age (SGA) among different age groups and explored whether maternal age was associated with those adverse outcomes.

Study Design: This is a multicenter retrospective study. Data from 1128 PE patients, including 580 with early onset PE and 548 with late onset PE, were analyzed.

Main Outcome Measures: Maternal age was categorized into three groups: <25, 25-34, and ≥35 years. The outcome variables were preterm birth (<37 weeks; subgroups: <28 weeks, 28-33 weeks, and 34-36 weeks), low birthweight (<2500 g; subgroups: <1500 g and <1000 g), and SGA. Logistic regression was used to analyze the associations between maternal age groups and outcomes.

Results: In early onset PE, compared with maternal age 25-34 years, maternal age ≥35 years was associated with elevated risk for preterm delivery before 28 weeks, and maternal age <25 years was associated with elevated risk for low birthweight and SGA. When the analysis was restricted to women who underwent cesarean section, elevated risks for preterm birth and/or low birthweight were observed for women younger than 25 years in both early and late onset PE.

Conclusions: Among women with PE, maternal age <25 years could add risk to preterm birth and/or low birthweight. For women with early onset PE, maternal age ≥35 years is a risk factor for preterm delivery before 28 weeks.