Association between external pelvimetry and vertex delivery complications in African women

Objective. To assess association between external pelvimetry and delivery c omplications in vertex presentation. Method's. Prospective cohort study of 1413 pregnant women antenatally measu red for height and external pelvimetry in four hospitals of the former Repu blic of Zaire. Outcome measures: Complications during delivery of single fe tus weighing 2000 g or more in vertex presentation. Cut-off values at risk for delivery complications were height and pelvic distances closest to the study population 10th percentile. Results. In univariate analysis, maternal height showed significant relativ e risk for predicting primary cesarean section for failure to progress: 2.0 (95% CI = 1.0-4.1; p = 0.050) and vacuum or forceps delivery: 15.7 (95% CI = 6.6-37.5; p < 0.001). Selected external pelvic distances showed signific ant relative risks for predicting the following complications: primary cesa rean section for failure to progress, elective repeat cesarean section, vac uum or forceps delivery and spontaneous intrapartum stillbirth. Among pelvi c predictors, transverse diagonal (TD) of Michaelis sacral rhomboid area wa s associated with all of these complications. Intertrochanteric (IT) diamet er was associated with three of them. The relative risks ranged from 2.3 (9 5% CI = 1.1-6.3; p = 0.030) to 9.6 (95% CI = 4.1-22,5; p < 0.001) for these strongest predictors. Conclusions. External pelvic distances help to predict vertex delivery comp lications in African women. The predicted complications are compatible with the cephalopelvic disproportion concept (CPD). After validation of current results in a separate cohort, measurements of IT and/or TD are recommended to improve antenatal screening of women at risk for CPD in limited resourc es settings.