For more detailed information on the evidence, see the interventional procedure overview.
5.1 The review of evidence identified 1 non‑randomised comparative study. It compared women who had a balloon device inserted to disimpact an engaged fetal head before a caesarean section (n=50) against unmatched historical controls (n=124), that is, women who had a caesarean section during the second stage of labour. No other peer‑reviewed studies were identified. The non‑randomised comparative study described no safety outcomes directly related to the use of the balloon device. All outcomes were described in the study as efficacy outcomes.
5.2 In addition to safety outcomes reported in the literature, specialist advisers are asked about anecdotal adverse events (events which they have heard about) and about theoretical adverse events (events which they think might possibly occur, even if they have never done so). For this procedure, specialist advisers listed the following anecdotal adverse event: uterine rupture. They considered that the following were theoretical adverse events: infection and trauma to the mother's genital tract or fetal head during device insertion, or as a result of excessive pressure following device inflation.