Multiple births among adolescent women in Illinois

OBJECTIVE: To examine the occurrence of multiple births among adolescents using birth as the unit of analysis and to examine the association between maternal race/ethnicity and parity and the occurrence of multiple births among women less than 20 years of age. STUDY DESIGN: Computerized birth certificate files without personal identifiers were obtained from the Illinois Department of Public Health totaling 1,103,333 live births from 1989 to 1994. RESULTS: A total of 13.3% of births during this time were to mothers less than 20 years of age. The overall maternal multiple birth rate was 8.1/1,000 births. There were statistically significant differences in the numbers of pregnancies resulting in live, multiple births among black, Hispanic and white teenage mothers. There was a linear increase in maternal multiple birth rates among black P<.0001) and Hispanic (P<.0236) and white (P<.049) populations by age of the mother. The age- and parity-specific maternal multiple birth rate range from 4.4 per 1,000 pregnancies for Hispanic teenage mothers less than 18 years of age to 11.9 per 1,0000 pregnancies for black teenage mothers 19 years of age. At 0 and 1 parity, black women less than 20 years of age were at the highest risk for multiple births as compared to Hispanic and white mothers. CONCLUSION: This is the first study showing ethnic and racial differences in the rates of multiple births among teenage mothers. As in older women, increased age and a higher parity were associated with a higher probability of multiple birth among adolescents.