UKOSS update

The proportion of caesarean sections performed in the second stage of labour is rising. Complications of second stage caesarean births are known to be greater for both mother and baby, which may in part be due to deep engagement of the baby’s head in the pelvis, so-called ‘impacted fetal head’. Many different disimpaction techniques have been described. The objective of this study was to use the UK Obstetric Surveillance System (UKOSS) to determine the incidence of, and complication rates from, impacted fetal head at full dilatation caesarean birth in the UK and record what techniques were used. 3,518 second stage caesarean births were reported from 152 of 194 UK obstetric units (82%) between 1st March and 31st August 2019. The surgeon used a disimpaction technique or reported ‘difficulty’ in 564 (16%) of these. The most common disimpaction techniques used were manual elevation of the head by an assistant through the vagina (n = 235) and a fetal ‘pillow’ (n = 176). Fifteen babies (3%) died or sustained severe injury. Four babies died (two directly attributable to the impacted fetal head). Thirty-four women (6%) required level 2 or level 3 critical care. This study shows that impacted fetal head is common and can result in significant maternal and neonatal complications. Although difficulty with delivery of the fetal head and the use of disimpaction techniques during second stage caesarean sections are common there is no consensus as to the best method to achieve delivery and in what order.