Who remains undelivered more than seven days after a single course of prenatal corticosteroids and gives birth at less than 34 weeks?

Abstract

Minimal information exists as to how women who give birth more than seven days after initial corticosteroid treatment, who may benefit from repeat prenatal corticosteroids, differ from women who give birth within seven days, at < 34 weeks gestation. Objectives: To examine the differences, if any, between women who received a single course of prenatal corticosteroids and remained undelivered more than seven days later and women who gave birth within seven days of treatment, at < 34 weeks gestation. Design: Retrospective cohort. Setting: Women's and Children's Hospital, Adelaide. Population: Women who gave birth at < 34 weeks gestation from 1 January 1994 to 31 December 1996. Methods: Data were extracted from medical records and retrieved from the hospital's database. Main potential predictors collected: Prenatal corticosteroid exposure, reason for risk of preterm birth, maternal demographics and previous and current obstetric history. Results: Of the 506 women, 122 (24%) remained undelivered more than seven days following prenatal corticosteroid therapy. Initial corticosteroid treatment was given on average 1.6 weeks earlier to women who remained undelivered more than seven days after treatment. Women who were given prenatal corticosteroids for placenta praevia (RR 6.03, 95% CI 2.67-13.61, p < 0.01) or cervical incompetence (RR 3.40, 95% CI 1.06-10.95, p = 0.04) were more likely to give birth more than seven days after corticosteroid treatment. Conclusions: Women who give birth very preterm, who remain undelivered more than seven days after prenatal corticosteroids, differ in the reasons for and timing of their first course from women who give birth within seven days.