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/m(2)), normal ( 20 to <25 kg/m(2)), overweight ( greater than or equal to25 to <30 kg/m(2)), and obese (greater than or equal to30 kg/m(2)). 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. (C) 2004 Elsevier Inc. All rights reserved.