Comparison between Foley Catheter plus Oxytocin and Oxytocin Only For Induction of Labour after Membrane Rupture

Abstract

Premature Rupture of Membranes (PROM) at term is defined as rupture of membrane at least 1 hour before the onset of uterine contractions at a gestational age of 37 weeks or more, it complicates 8% of all pregnancies [1]. It is associated with a risk of chorioamnionitis, which increases with duration of PROM, latency beyond 24 hours increases the incidence of chorioamnionitis and neonatal sepsis [2,3]. Spontaneous labour occurs in 60%–67% of these patients within 24 hours [2,4]. If no labour occurs, labour induction must be the best management for women with PROM at term. Labour induction is usually performed when the risks of continuing a pregnancy are more than the benefits of delivery as in PROM. Cervical ripening is an important factor for a successful induction. Unripe cervix with a lower Bishop score is associated with an increased risk of induction failure, while a favorable cervix significantly predicts a timely delivery [5]. Different methods are used for labour induction but none of the available methods of induction of labour is free of associated medical risks; therefore, labour should only be induced when there is a risk of the continuation of pregnancy. The agents used for induction should simulate spontaneous labour without causing excessive uterine activity. The most common methods of labour induction involve Pharmacological methods which include many agents, such as Prostaglandins (PGs (E2 orE1), progesterone receptor antagonists (mifepristone), oxytocin, and Nitric Oxide (NO) donors, but the most commonly used are PG and oxytocin) [6], and mechanical methods as Intracervical Foley catheter which is the most common mechanical method that was first described by Embrey and Mollison in 1967, where a Foley is inserted into the cervical canal and inflated just past the internal os with mild traction outward dilating the cervix directly, as well as indirectly stimulating (PGs) and oxytocin secretion [7-11]. The American College of Obstetricians and Gynecologists (2009) recommended using oxytocin for induction of labour in case of PROM at term, even if the cervix is unfavorable [12]. Several studies have evaluated the combination of oxytocin and mechanical devices, as oxytocin alone has not been shown to affect the risk of chorioamnionitis [13-15]. Induction of labour by mechanical device is accepted in cases with intact membrane, although mechanical treatment does not show any advantage over vaginal PGs regarding rates of chorioamnionitis, endometritis and neonatal infection [16]. In PROM, a concern with mechanical cervical ripening is increased risk of intraamniotic infection and other infection morbidity, which is not increased when membranes are intact [13]. Although the Foley catheter has been established as safe and effective in women with intact membranes, its efficacy has not been established in women with PROM. Chorioamnionitis was defined as temperature 38°C or greater with at least two of the following: uterine tenderness, maternal tachycardia, fetal tachycardia, foul odor of the amniotic fluid, or maternal leukocytosis (greater than 15,000 cells/mL3) [17].