Obstetric Characteristics and Outcomes of Teenage Pregnancies

Abstract

Objective: To quantify the age-related risks of adverse pregnancy outcomes in primigravid women aged less than 20 years.
Methods: We conducted a retrospective cohort study based on the data in the Obstetrics Clinical Information System of our hospital for the period 2006 to 2008. Pregnancy outcomes of primigravid women were compared in age-groups of less than 20 years (n = 394) and 20 to <35 years (n = 6838).
Results: There was a lower rate of gestational diabetes mellitus with an odds ratio (OR) of 0.1, and 95% confidence interval (CI) of 0.01-0.4 in the teenage group. Apart from a lower mean gestational age at delivery, they had a higher rate of preterm labour at less than 37 weeks (OR = 2.0; 95% CI, 1.3-2.9) with a significantly higher rate of extremely preterm labour between 24 and 28 weeks (2.5; 0.7-8.4). The teenage group had a lower incidence of induction of labour (OR = 0.7; 95% CI, 0.5-0.8) but a higher rate of augmented labour (1.7; 1.4-2.1). They were more likely to achieve spontaneous vaginal delivery (OR = 3.9; 95% CI, 2.9-5.1), with a significantly lower risk of instrumental delivery (0.4; 0.2-0.5) and elective (0.1; 0.03-0.6) and emergency Caesarean section (0.3; 0.2-0.5). Babies of the teenage group had a lower mean birth weight, with more low-birth-weight babies (OR = 1.7; 95% CI, 1.2-2.4) and less  macrosomic babies (0.2; 0.05-0.8). Despite more of their babies having low Apgar scores at 5 minutes (OR = 2.6; 95% CI, 0.9-7.4), the neonatal outcome was good.
Conclusion: Teenage pregnancies carry a higher risk of preterm delivery. Nevertheless, they had a higher chance of spontaneous vaginal delivery and good neonatal outcomes.