Cervical inflammation and preterm delivery in pregnant women with a history of preterm delivery.

BACKGROUND

A previous preterm delivery is a risk factor for preterm delivery in a subsequent pregnancy. We tested the hypothesis that evidence of inflammation on a Papanicolaou smear obtained during pregnancy is a risk factor for preterm delivery for women with a history of preterm delivery.

METHODS

We studied women who had two singleton deliveries at a university hospital during an 8-year period. Women eligible for our study were those whose first delivery was preterm (< 37 weeks of gestation) and for whom a Papanicolaou smear was obtained during the second pregnancy. These smears were examined for evidence of inflammation by a cytopathologist. Information about the second pregnancy was obtained by chart review.

RESULTS

The cytopathologist reviewed Papanicolaou smears from 92 study pregnancies and found evidence of cervical inflammation on 34 smears (37 percent). Preterm delivery ended 24 (26.1 percent) of the second pregnancies. The incidence of preterm delivery in women with inflammation on Papanicolaou smear was 41.2 percent compared with an incidence of 17.2 percent in women without inflammation (relative risk of 2.40 with a 95 percent confidence interval of 1.19 to 4.83). This association remained significant after controlling for potential confounding variables. A stratified analysis found that the association of cervical inflammation with preterm delivery was limited to women who had systemic exposure to an antibiotic during pregnancy.

CONCLUSION

Among pregnant women with a history of preterm delivery, evidence of inflammation on Papanicolaou smear was associated with an increased risk of preterm delivery. If replicated in other studies, this finding might have implications for the management of pregnancies in women with a history of preterm delivery.