Comparing pregnancy in adolescents and adults: obstetric outcomes and prevalence of anemia

J Obstet Gynaecol Can. 2007 Jul;29(7):546-555. doi: 10.1016/S1701-2163(16)32506-3.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Anemia / epidemiology*
  • Female
  • Humans
  • Pregnancy
  • Pregnancy Complications, Hematologic / epidemiology*
  • Pregnancy Outcome
  • Pregnancy in Adolescence*
  • Retrospective Studies