NEW ORLEANS – Intra-amniotic debris can portend a preterm birth, but doesn’t seem to be associated with any other adverse pregnancy outcomes, including small-for-gestational-age infants.
The debris – a mix of bacterial and inflammatory cells encased in an antibiotic-resistant biofilm – may actually trigger an early birth to help protect the fetus, Dr. George R. Saade said at the annual Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine.
Dr. George Saade
The debris is associated with placental senescence, "which leads to preterm birth before there can be further fetal compromise and growth restriction," said Dr. Saade, director of maternal-fetal medicine at the University of Texas Medical Branch, Galveston.
He presented a secondary analysis of a study that examined the effect of progesterone injections to prevent preterm birth in nulliparous women with a short cervix.
The study was halted in October 2012, after preliminary results showed no treatment benefit.
The main outcome for the study was a composite of fetal death, small-for-gestational-age infants, placental abruption, and gestational hypertension/preeclampsia. Of the 657 randomized to progesterone or placebo, 78 were found to have intra-amniotic debris on ultrasound.
These women were significantly older than were those without debris (23 vs. 22 years), had a significantly higher prepregnancy body mass index (28 kg/m2 vs. 25 kg/m2), and a significantly shorter cervical length on ultrasound (19 vs. 24 cm).
There were significantly more infants born at less than 37 weeks’ gestation in women with debris (35% vs. 23%). But there was no significant between-group difference in the composite outcome. When Dr. Saade looked at the individual outcome measures, he found only one significant difference. Despite the larger number of preterm births, there were no small-for-gestational-age infants born to mothers with the debris. However, 5% of those without debris did have small-for-dates babies.
Dr. Saade had no financial declarations.