The purpose of this study is to evaluate the risk of cesarean delivery in pregnancies complicated with isolated oligohydramnios managed by induction of labor. This prospective case-control study was conducted in Hamıdıye Sisli Etfal Teaching and Research Hospital between January 2013 and June 2014. 159 women with isolated oligohydramnios and 165 women with postdate pregnancies who met the inclusion criteria underwent induction of labor with dinoprostone or oxytocin. The rate and the indications of C/S deliveries were compared between two groups.

The study was designed as a prospective study. The rates of cesarean section and maternal/fetal outcomes had been compared between pregnancies complicated with isolated oligohydramnios at term and postdate pregnancies. All patients with isolated oligohydramnios were term (37-40 weeks' gestation according to accurate last menstrual period and first trimester sonographic examination). Oligohydramnios was defined as an amniotic fluid index < 5 cm. The control group consisted of prolonged pregnancies in the absence of spontaneous labor and oligohydramnios. Prolonged pregnancy is diagnosed if 41 gestational weeks are completed according to accurate date of last menstrual period and first trimester ultrasound. All patients who accepted to join the study gave informed consent. All patients had a complete physical and obstetrical examination. Vital signs were recorded at regular intervals. The primary outcome measure was defined as cesarean section rates in pregnancies complicated with isolated oligohydramnios managed by induction of labor.

Inclusion Criteria:

• term isolated oligohydramnios
• postdate pregnancies
• vertex presentation
• singleton pregnancies
• primigravid and multigravid women

Exclusion Criteria:

• women with presence of any chronic disease
• maternal condition complicating the pregnancy

All patients with isolated oligohydramnios were term (37-40 weeks' gestation according to accurate last menstrual period and first trimester sonographic examination). Oligohydramnios was defined as an amniotic fluid index < 5 cm. The control group consisted of prolonged pregnancies in the absence of spontaneous labor and oligohydramnios. Prolonged pregnancy is diagnosed if 41 gestational weeks are completed according to accurate date of last menstrual period and first trimester ultrasound.