[External anthropometric measurement and pelvimetry among nulliparous women in Lubumbashi: risk factors and predictive score of mechanical dystocia].

INTRODUCTION: Maternal and perinatal morbi-mortality is higher in most of sub-Saharan Africa compared to the rest of the world. All women at risk for mechanical dystocia should be screened before labor and referred to a better equipped Hospital for childbirth. This would reduce morbi-mortality. This study aims to develop a predictive score of mechanical dystocia during childbirth among nulliparous Congolese women.

METHODS: We conducted a cross-sectional study of nulliparous women with single pregnancy in 7 Maternity Units in the city of Lubumbashi (DRC). Women' size, weight, and external pelvimetry results were collected and analyzed. Univariate and multivariate analyses were performed. Discrimination score was assessed using the ROC curve.

RESULTS: We included in the study 535 nulliparous women, of whom 126 (23.55%) had given birth by cesarean section due to mechanical dystocia. After logistic modelling, three criteria emerged as predictive factors for mechanical dystocia: maternal height <150 cm (adjusted OR=2.96 [1,49-5,87]), bi-ischiatic diameter <8 cm (adjusted OR =15.96 [3,46-73,56]), and Trillat's pre-pubic diameter <11 cm (adjusted OR =2.34 [1,36-4,01]). The area under the ROC curve of the score was 0.6549 with a sensitivity of 23.81%, a specificity of 97.80% and a positive predictive value of 76.92%.

CONCLUSION: It has been observed that 10th percentile of the three maternal anthropometric measures was predictive of mechanical dystocia. When they were used together, these three values allowed for the development of lowest-cost screening score for use in low income settings.