Objective: To characterize the obstetric outcome and prevalence of anemia in primiparous adolescents and compare them with those in older primiparas.
Methods: We conducted a retrospective chart review of 207 adolescents (<or19 years old) and 415 adults (>or20 years old) whose prenatal care was provided by a single obstetrician in Kingston, Ontario, and who had a live singleton birth at >or24 weeks gestation between 1996 and 2004.
Results: The mean age of the adolescents (T) was 17.5 years and of the adults (A) 27.3 years. More than 95% of the women were Caucasian. Mean gestational age at delivery was similar in the two groups (T 39.4 weeks, A 39.6 weeks, P = 0.25). Adolescents were more likely to have a preterm delivery (T 12.6%, A 7.5%, P = 0.038), although smoking rather than young maternal age was an independent risk factor for preterm delivery (odds ratio [OR] 3.2; 95% confidence intervals [CI] 1.47.5). A significantly lower proportion of adolescents delivered by Caesarean section (CS) (T 12.1%, A 27.7%, P < 0.001). Older maternal age, higher pre-pregnancy BMI, increased weight gain during pregnancy, and pre-delivery anemia were all independent risk factors for CS. Smoking was the most influential factor in predicting infant birth weight. Adolescents had significantly more low birth weight infants (< 2500 g) than adults (T 10.1% vs. A 4.3%, P = 0.008). Gestational age rather than young maternal age was the most significant risk factor for low birth weight (OR 3.3; 95% CI 1.95.7). After controlling for smoking status, adolescents were 2.5 times more likely than adults to be anemic at 26 to 35 weeks gestation and pre-delivery.
Conclusion: Our results suggest that primiparous adolescents have significantly different obstetric outcomes from primiparous adults. Smoking and anemia are significant risk factors for poor obstetric outcomes and are potentially modifiable.