In First Pregnancy, The Presence Of Intra-Amniotic Debris Increases Risk For Early Preterm Birth

Main Category: Pregnancy / Obstetrics
Article Date: 13 Feb 2013 - 0:00 PST


In a study to be presented on February 14 between 8 a.m. and 10 a.m. PST, at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting ™, in San Francisco, California, researchers will report findings suggesting an increased risk of early (less than 35 weeks) preterm birth when intra-amniotic debris is present in nulliparous women with a short cervix. The babies born to women with debris had worse outcomes than those born to women without debris, likely due to the earlier delivery.

The multicenter study, presented by Dr. George Saade for the Eunice Kennedy Shriver National Institute of Child Health and Human Development in Bethesda, Md., looked at intra-amniotic debris in 657 nulliparous women (women who have never given viable birth) with slightly short cervix, examined as part of a treatment trial. The study did not look at women with normal cervical length.

The medical community has long been aware of the risk of preterm birth associated with shortened cervix, but not much is known about debris in amniotic fluid during pregnancy, including what the debris is and how it influences preterm birth.

"Some think it could be proteins, or cells floating around, or infections, or inflammation," said Dr. Saade. "We aren't sure, but from the research: when it is present, the risk for preterm birth is higher."

The women, as part of the treatment for the shortened cervix, had transvaginal ultrasounds, by sonographers certified in cervical length measurements, as well as identification of intra-amniotic debris and cervical funneling.

Dr. Saade says more information about the debris is still needed.

"What is it? Why does it cause preterm birth? And how can it be treated? These are our next steps," stated Saade.

Abstract 6: Cervical funneling or intra-amniotic debris and preterm birth in nulliparous women with short cervix

OBJECTIVE: To evaluate whether the presence of cervical funneling or intra-amniotic debris is associated with higher rates of preterm birth (PTB) in asymptomatic nulliparous women with a short cervical length (CL).

STUDY DESIGN: Secondary analysis of a multicenter trial of women between 16 and 22 weeks with a singleton gestation and a CL < 30 mm on transvaginal ultrasound randomized to either 17 hydroxyprogesterone caproate (17-OHPc) or placebo. Sonographers were centrally certified in CL measurement, as well as identification of intra-amniotic debris and cervical funneling (with measurement of the funnel if present). Univariable and multivariable analyses were performed.

RESULTS: Of the 657 randomized patients, 157 (24%) had funneling, 78 (12%) had debris, and 45 (7%) had both on the screening ultrasound. Women with either of these findings were older (22.7 vs. 22.0 mean years, p = 0.03), had a higher pre-pregnancy body mass index (27.6 vs. 25.0 kg/m2, p < 0.001) and a lower CL (19.5 vs. 25.6 mm, p < 0.001) than those without these findings. PTB < 37 wks was higher for women with a funnel (2.2 OR, 95% CI 1.5-3.3) or debris (1.7 OR, 95% CI 1.0-2.9). Results were similar for progressively earlier preterm delivery (Table). The associations persisted when controlling for 17- OHPc administration, but not after adjusting for CL, except in the case of debris and delivery prior to 35, 34, or 32 weeks. Preterm birth was also associated with the length of the funnel, but was no longer significant after controlling for CL.

CONCLUSION: The presence of cervical funneling is not independently associated with preterm birth in nulliparous women with a short cervix. However, the presence of intra-amniotic debris increases the risk of early preterm birth (< 35 wk) independently of the cervical length.

• Additional
• References
• Citations