Prenatal Imaging Features and Perinatal Outcomes of Foetal Volvulus–a Literature Review

OBJECTIVE:To conduct a review of the literature on foetal volvulus with emphasis on prenatal imaging, pregnancy characteristics and clinical outcomes.METHODS:A review of all published cases of foetal volvulus diagnosed prenatally and indexed in Medline, EBSCOhost, CINAHL, SOCIndex and Healthy Policy Reference Centre. Studies without antenatal sonographic signs of foetal volvulus and without a postpartum surgical diagnosis were excluded. Data were analysed for frequencies and distributions and tested for statistical significance.RESULTS:Eighty-eight cases of foetal volvulus were identified from 58 published case reports/series. The most common ultrasound findings were dilated bowel/stomach (77.3%), polyhydramnios (30.7%) and whirlpool/snail sign (28.4%). Median gestation at diagnosis was 31.9 weeks (IQR 27-34) and mean gestation at delivery was 34.5 weeks (SD 2.8). Underlying aetiology included intestinal malrotation (15.9%), cystic fibrosis (14.8% of all cases, 32.5% of tested cases) and abnormal mesenteric fixation (12.5%). Complications included intestinal atresia (36.4%) and foetal anaemia (9.1%). The overall perinatal mortality rate was 14.5%.CONCLUSION:Foetal volvulus is a rare condition with high rates of preterm birth and perinatal mortality. Intestinal malrotation and cystic fibrosis are common predisposing causes, although the majority are idiopathic. Bowel and/or gastric dilatation is by far the most common sonographic finding.