Maternal Height-to-Weight Ratios as Predictors of Emergency Cesarean Section Due to CPD in Chonburi Hospital
Kornkanok Wisalphat, MD¹, Thitikarn Lerthiranwong, MD¹
Affiliation : ¹ Department of Obstetrics and Gynecology, Chonburi Hospital, Chonburi, Thailand
Objective: To evaluate the association between maternal height-to-weight ratio and the occurrence of cesarean section due to cephalopelvic disproportion (CPD).
Material and Methods: A cross-sectional study was conducted on pregnant women later than 28 weeks gestation receiving antenatal care at Chonburi Hospital who met inclusion criteria. Informed consent was obtained. Baseline data were recorded, and participants were followed until delivery. Participants who met the exclusion criteria during follow-up were excluded. Enrollment continued until 97 women who delivered vaginally and 97 women who underwent cesarean section due to CPD were included for comparison.
Results: Based on data collected from 97 women who delivered vaginally and 97 women who underwent cesarean section due to CPD, the study showed that a maternal height-to-pre-pregnancy weight ratio cutoff at 2.89 or less was associated with an increased likelihood of cesarean delivery. This cutoff demonstrated an area under the curve (AUC) of 0.645, with a sensitivity of 67.0% and specificity of 58.8%. For the maternal height-to-weight at delivery ratio, a cutoff value of 2.25 or less was also associated with an increased likelihood of cesarean delivery, with an AUC of 0.67, sensitivity of 68.0%, and specificity of 58.8%. Both ratios demonstrated comparable, moderate discrimination to identify women who required cesarean delivery. Other predictive variables included the maternal height-to-gestational weight gain ratio, with a cutoff value of 3.79 or less indicating a higher likelihood of cesarean delivery with an AUC of 0.596, sensitivity of 71.7%, and specificity of 50.5%.
Conclusion: Maternal height-to-weight ratios can be used to predict the risk of emergency cesarean section due to CPD, using cutoff values of 2.89 or less for the height-to-pre-pregnancy weight ratio and 2.25 or less for the height-to-weight at delivery ratio. These cutoffs demonstrated moderate discriminatory ability, with better performance in predicting women requiring cesarean section than in identifying those who delivered vaginally. These ratios should be used in combination with other clinical factors to improve predictive accuracy.
Received 29 September 2025 | Revised 18 December 2025 | Accepted 23 December 2025
DOI: 10.35755/jmedassocthai.2026.2.03626
Keywords : Height/weight; Cephalopelvic disproportion; Cesarean section; Delivery route
