Abstract

The objective of this study is to examine the correlation of maternal body surface area with cervical dilation in nulliparous women at term. Data from nulliparous women with a term pregnancy referred to Al-Zahra Maternity Hospital in Rasht were collected from November 2008 - May 2009. Inclusion criteria were: singleton pregnancy, nulliparity, estimated fetal weight of less than 4000 g, gestational age of 37 - 41 weeks, pre-pregnancy BMI of less than 30 kg/m², no history of medical disorders, no probable CPD, contractions of at least 3/10 min of more than 45 s duration, Bishop score of more than 10, vertex presentation, occiput anterior position and at least two dilation measurements on vaginal examinations by one person within one hour. Results showed that cervical dilation had a positive correlation with body surface area (r = 0.21, p < 0.012). It is concluded that maternal pre-pregnancy body surface area was independently affecting labor duration in the subjects studied.

Key words: Maternal pre pregnancy Body Surface Area, Active phase, Rate of cervical dilation, duration of labor, Body Mass Index, Rohrer Index.