Factors influencing maternal perception of uterine contractions

Objectives The purpose of this study was to assess factors associated with perception of uterine contractions. Study design A database of ambulatory uterine activity monitoring was examined. All patients having singleton pregnancies evaluated between March 1997 and March 2002 were eligible for analysis. Data were divided into 4 groups by maternal prepregnancy body mass index (BMI): lean (<20 kg/m2), normal (≥20 to <25 kg/m2), overweight (≥25 to <30 kg/m2), and obese (≥30 kg/m2). The percentage of contractions perceived during observation was compared between groups. Variables interrogated included maternal weight and parity. Statistical analysis included t test, analysis of variance (ANOVA), and linear regression. Results Data from 7808 patients (556,382 hr) were analyzed. A significant reduction in perception of contractions occurred with increasing BMI between each classification, P<.001. A significant reduction in perception of contractions was also noted between nulliparous and multiparous patients at each weight classification, P<.001. Conclusion Obese, nulliparous patients have the greatest difficulty perceiving contractions. Such data may help explain unattended birth or late presentation for care in this group.