For nulliparous cases presenting to the labor ward, maternal height & weight will be collected at the time of admission to calculate the BMI (body mass index) & further classified according to WHO (World Health Organization) categories. Putting into consideration the physiological increase in BMI related to pregnancy, the overweight participants whose BMI (25-29.9) will be combined with the normal range BMI (18.5-24.9) category. Labor characteristics of these participants will be then compared with those of the underweight (BMI less than 18.5) & obese (BMI 30 or higher) participants.Females are assigned in one of 3 groups based on their BMI; Underweight group (BMI <18.5kg/m2), Control group whose BMI within normal range (18.5-29.9 kg/m2),& Obese group (BMI more than or equal 30kg/m2).