CLINICAL ARTICLE The consequences of previous uterine scar dehiscence and cesarean delivery on subsequent births ☆ Joel Baron ⁎, Adi Y. Weintraub, Tamar Eshkoli, Reli Hershkovitz, Eyal Sheiner Department of Obstetrics and Gynecology, Faculty of Health Sciences, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel abstract article info Article history: Received 20 July 2013 Received in revised form 15 February 2014 Accepted 17 April 2014 Keywords: Cesarean delivery Fetal complication Obstetric complication Risk factor Uterine rupture Uterine scar dehiscence Objective: To determine whether women with a previous uterine scar dehiscence are at increased risk of adverse perinatal outcomes in the following delivery. Methods: A retrospective cohort study was conducted of all subsequent singleton cesarean deliveries performed at the Soroka University Medical Center, Beer-Sheva, Israel, between January 1, 1988, and December 31, 2011. Clinical and demographic characteristics, maternal obstetric complications, and fetal complications were evaluated among women with or without a previous documented uterine scar dehiscence. Results: Of the 5635 pregnancies associated with at least two previous cesarean deliveries, 180 (3.2%) occurred among women with a previous uterine scar dehiscence. Women with this condition in a prior pregnancy were more likely than those without previous uterine scar dehiscence to experience subsequent preterm delivery (86 [47.8%] vs 1350 [24.7%]; P b 0.001), low birth weight (47 [26.1%] vs 861 [15.8%]; P b 0.001), and peripartum hysterectomy (5 [2.8%] vs 20 [0.4%]; P b 0.001). Nevertheless, previous uterine scar dehiscence did not increase the risk of uterine rupture, placenta accreta, or adverse perinatal out- comes, such as low Apgar scores at 5 minutes and perinatal mortality. Conclusion: Uterine scar dehiscence in a previous pregnancy is a potential risk factor for preterm delivery, low birth weight, and peripartum hysterectomy in the following pregnancy. © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved. 1. Introduction The number of cesarean deliveries performed has increased world- wide over time. For example, the rate recorded in the USA has risen from 5.0% in 1970 to 32.9% in 2009 [1]. Dehiscence of the uterine scar is a known complication of cesarean delivery. Various definitions of this condition are found in the literature for example: "a subperitoneal separation of the uterine scar, with the chorioamniotic membrane visible through the peritoneum" [2] and "the absence of the myometrium or the presence of an extremely thin myometrium diagnosed at the time of cesarean delivery" [3]. Uterine scar dehiscence is observed among 0.2%–4.3% of all pregnan- cies associated with a previous history of cesarean delivery [4–8] and can potentially lead to uterine rupture. The consequences of uterine rupture during a trial of vaginal delivery after cesarean delivery have been widely discussed in the literature and are associated with serious complications endangering both the mother and her offspring [9,10]. A study conducted by Landon et al. [9] reported a 0.38% perinatal morbidity rate following uterine rupture at term; furthermore, the intrapartum death rate was 0.03% and the rate of hypoxic–ischemic encephalopathy was 0.08%. Valentin et al. [11] found that uterine rupture was associated with a short interval between deliveries, a birth weight of 4000 g or over, induction of labor, oxytocin dose, and a thin lower uterine segment at 35–40 weeks of pregnancy; by contrast, a low risk of uterine rupture was noted among women with a previous vaginal delivery. In other studies, reported independent risk factors for uterine rupture included previous cesarean delivery, preterm delivery, malpresentation, parity, and dystocia during the first and second stages of labor [12–14]. Data regarding the consequences and complications of a previous uterine scar dehiscence on the following pregnancy are scarce. The aim of the present study was to investigate the maternal and perinatal outcomes in pregnancies associated with previous cesarean delivery and uterine scar dehiscence. 2. Materials and methods A retrospective cohort study was conducted that compared the pregnancy outcomes of women with and without a previous uterine scar dehiscence who underwent a subsequent singleton cesarean deliv- ery at the Soroka University Medical Center, Beer-Sheva, Israel, between International Journal of Gynecology and Obstetrics 126 (2014) 120–122 ☆ Abstract presented at the Society for Maternal-Fetal Medicine Annual Meeting, February 11–16, 2013, San Francisco, USA. ⁎ Corresponding author at: Department of Obstetrics and Gynecology, Soroka University Medical Center, POB 151, Beer Sheva 84101, Israel. Tel.: +972 8 6400423; fax: +972 8 6403854. E-mail address: baronj@bgu.ac.il (J. Baron). http://dx.doi.org/10.1016/j.ijgo.2014.02.022 0020-7292/© 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved. 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