(HealthDay) -- For healthy nulliparous women, the ability to predict spontaneous preterm birth (SPTB) using clinical characteristics is modest, according to a study published online July 16 in PLoS One.
Gustaaf Albert Dekker, M.D., Ph.D., from Lyell McEwin Hospital in Adelaide, Australia, and colleagues examined risk factors for SPTB among 3,184 healthy nulliparous women with a singleton pregnancy.
The researchers found that 4.9 percent of women had their pregnancy complicated by SPTB, including 3.0 percent with intact membranes (SPTB-IM) and 1.9 percent with prelabor rupture of the membranes (SPTB-PPROM). Shorter cervical length, abnormal uterine Doppler flow, use of marijuana before pregnancy, lack of overall feeling of well-bring, Caucasian ethnicity, maternal history of diabetes and/or preeclampsia, and family history of low birth weight babies were identified as independent risk factors for SPTB-IM. Independent risk factors for SPTB-PPROM included, but were not limited to, shorter cervical length, short stature, longer time to conceive, family history of recurrent gestational diabetes, hormonal fertility treatment, and mild hypertension. The risk of SPTB-PPROM was significantly increased for women with a low body mass index (less than 20 kg/m²; odds ratio, 2.64). After internal validation the area under the receiver operating characteristics curve was 0.69 for SPTB-IM and 0.79 for SPTB-PPROM.
"Given no reliable biomarkers have emerged as risk predictors of SPTB, the development of a clinically useful test will probably require SPTB phenotype-specific combinations of clinical risk factors and the discovery and evaluation of novel biomarkers," the authors write.