Objective: This study aimed to determine the incidence of teenage pregnancy and compare obstetric and neonatal complications of teenage mothers with adult mothers.
Material and Method: This is a retrospective study conducted at the Department of Obstetrics and Gynecology, Chonburi Hospital, Thailand. The study group consisted of primigravida women aged 13-20 years who gave birth at Chonburi Hospital from 1 January 2000 to 31 December 2005. The control group consisted of primigravida women aged 20-25 years who gave birth during the same period. Demographic, obstetric, and neonatal complications information were collected and compared between the study and control groups.
Results: The study group consisted of 2,490 women and the control group consisted of 3,909 women. The study found that incidence of teenage pregnancy at Chonburi Hospital was 90 cases per 1,000 mothers. The study group had a lower gestational age at delivery than the control group and a higher preterm delivery rate (20.1% vs 13.9%, p < 0.001). The study group had more inadequate antenatal care than control group (25.9% vs 13.4%, p < 0.001). Vaginal delivery was the major route of delivery in study group. Anemia was a significant difference between the study and control groups (17.1% vs 11.1%, p < 0.001). Low birth weight infant rate in study group was higher than control group significantly.
Conclusion: The incidence of teenage pregnancy was found to be 9%. Teenage mothers had lower levels of education and higher levels of inadequate antenatal care. Preterm labour and anemia were the obstetric complications in the teenage pregnancy. Low birth weight was the only neonatal complication in teenage pregnancy in the study.

Keywords: Teenage pregnancy, Preterm labor, Low birth weight