Objective: To quantify the age related risk of adverse obstetric outcome in primigravid women less than 20 years of age.
Study design: The study sample was drawn from Cardiff Births Survey (a computerized maternity information database) comprising 66,271 pregnancies in the South Glamorgan region during 1990-1999. Pregnancy outcomes of primigravid women were compared in age groups less than 20 years (n=4126) and 20 to <35 years (n=17,615). SPSS version 11 was used for statistical analysis. Student's t-test was used for continuous variables, Chi square, Fishers exact test was used for categorical variables.
Results: There was a lower incidence of multiple pregnancies (OR=0.3(0.2-0.4)), spontaneous rupture of membranes >24h (OR=0.7(0.6-0.9)), and pregnancy-induced hypertension (OR=0.8(0.6-0.8)) amongst teenage primigravidae but a higher incidence of anaemia (OR=1.8(1.6-2.0)), and pyelonephritis (OR=1.5(1.1-2.0)). There was a lower incidence of induction of labour (OR=0.7(0.7-0.8)) and use of regional analgesia in the teenage group. Teenage women were more likely to have a spontaneous vaginal delivery (OR=2.1(2.0-2.3)) with a significantly lower incidence of instrumental delivery (OR=0.5(0.5-0.6)), and Caesarean section (OR=0.4(0.4-0.5)). Inspite of a higher incidence of preterm labour (corrected OR=1.4(1.1-1.7)) the perinatal outcome measures between the teenage group and the older group were not significantly different.
Conclusion: Teenage primigravidae are more likely to have a spontaneous vaginal delivery, without compromising the maternal or neonatal outcome.