Rates of and Factors Associated With Recurrence of Preterm Delivery

• Published in: Obstetrical & gynecological survey Vol. 55; no. 9; pp. 534 - 536
• Main Authors: Adams, Melissa M, Elam-Evans, Laurie D, Wilson, Hoyt G, Gilbertz, David A
• Format: Journal Article
• Language: English
• Published: Lippincott Williams & Wilkins, Inc 01-09-2000
• ISSN: 0029-7828; 1533-9866
• DOI: 10.1097/00006254-200009000-00003

Pregnant women who already have delivered preterm are likely to be in special need of guidance. This study used birth and fetal death certificates filed in Georgia in the years 1980–1995 to determine how often singleton preterm delivery recurs in a second pregnancy. The study population included 122,722 white women and 56,174 black women having first and second singleton deliveries between 20 and 44 weeks’ gestation. Gestational length was classified as 20 to 31, 32 to 36, and 37 weeks and later, and recurrence was defined as a repeated preterm delivery in the same subset.In white women, rates of all preterm deliveries, moderately preterm deliveries (32–36 weeks), very preterm deliveries (20–31 weeks), and low-birth-weight infants all were higher for first than for second pregnancies. The findings in black women were similar except that very preterm delivery and very-low-birth-weight infants were nearly as frequent for first and second pregnancies. For both black and white women, the rate of very preterm delivery increased over the years in first births but declined for second births. Crude recurrence rates for preterm delivery were higher for black than for white women. Among those whose first delivery was preterm, 26 percent of black women and 20 percent of whites had a second preterm delivery. In both instances the rate of preterm delivery in the second pregnancy increased as the length of the first pregnancy decreased. A second very preterm delivery was especially likely for black women younger than 18 at the time of their first very preterm delivery. Young age also was a risk factor for women who first delivered at 32 to 36 weeks’ gestation and whose first child was a moderately low-birth-weight infant. The proportion of second preterm deliveries increased as the gestational length of the second pregnancy decreased.It is not clear whether recurrent preterm delivery has the same cause as initial preterm deliveries, but many preterm deliveries in second pregnancies represent recurrences. The present findings suggest that recurrences constitute a substantial part of all preterm deliveries.JAMA 2000;283:1591–1596