The objective of this study is to compare pregnancy results which were used foley catheter or double-balloon catheter for cervical ripening among high-risk pregnant women.

This is a prospective observational study. The planned sample size was calculated as 109 patients per group with 80% power and 0.05 alpha error.

The inclusion criteria are age between 18 and 40, singleton pregnancy, vertex presentation, bishop score <6, using a foley catheter or cook balloon for cervical ripening and high-risk pregnancy (Oligohydramnios, polyhydramnios, intrauterine growth retardation, pregestational or gestational diabetes, hypertensive disorders).

The exclusion criteria are being younger than 18 or over 40, communication problems, bishop score >6, being at active labor, multifetal pregnancy, non-vertex presentation, scarred uterus (cesarean or myomectomy), fetal structural or chromosomal anomaly, non-reassuring fetal cardiotocography before cervical ripening, regional anesthesia during the first stage.

The primary outcomes are the rate of bishop score >6 after ripening, vaginal delivery rate and vaginal delivery within 24 hours of the initiation of ripening.

Inclusion Criteria:

• Age between 18 and 40
• Singleton pregnancy
• Vertex presentation
• Bishop score <6
• Using a Foley catheter or cook balloon for cervical ripening
• High-risk pregnancy (Oligohydramnios, polyhydramnios, intrauterine growth retardation, pregestational or gestational diabetes, hypertensive disorders)

Exclusion Criteria:

• Being younger than 18 or over 40
• Communication problems (foreign national)
• Bishop score >6
• Being at active labor
• Multifetal pregnancy
• Non-vertex presentation
• Scarred uterus (cesarean or myomectomy)
• Fetal structural or chromosomal anomaly
• Non-reassuring fetal cardiotocography before cervical ripening
• Regional anesthesia during the first stage

Pregnant women with unfavorable cervices and need to deliver for maternal or fetal health condition.