Kielland's rotational forceps delivery: A comparison of maternal and neonatal outcomes with rotational ventouse or second stage caesarean section deliveries

Objectives: The objective of our study was to derive accurate estimates of risks of maternal and neonatal complications associated with Kielland's rotational forceps delivery (KRFD) compared to rotational ventouse delivery (RVD) or 2nd stage caesarean section (CS).

Methods: This was a retrospective cohort study undertaken at a large tertiary maternity and neonatal unit in the United Kingdom between January 2010 and June 2018. Pregnancies with fetal demise, major fetal defects, those lost to follow-up, those delivering by elective or emergency CS in the first stage of labour and non-rotational instrumental deliveries were excluded. The study population included singleton pregnancies delivering by Kielland's forceps, rotational ventouse, 2nd stage CS or spontaneous unassisted cephalic vaginal delivery; the latter forming the control group. The maternal outcomes examined included post-partum haemorrhage (PPH) and obstetric anal sphincter injury (OASIS). The neonatal outcomes included admission to neonatal intensive care unit (NICU), 5-minute Apgar scores <7, hypoxic ischaemic encephalopathy (HIE), jaundice, shoulder dystocia and birth trauma. Absolute risks with 95 % confidence intervals (CI) were calculated in the study groups. Univariate and multivariate logistic regression analysis was carried out to estimate crude and adjusted odds ratio (OR) with 95 % CI.

Results: The study population of 23,786 pregnancies included: 491 (2.1 %) requiring KRFD, 344 (1.4 %) requiring RVD, 840 (3.5 %) that had a 2nd stage CS and 22,111 (93.0 %) spontaneous cephalic vaginal deliveries. With regard to maternal adverse outcomes, in pregnancies that had a KRFD compared to RVD, there was no significant difference in the incidence of OASIS (p = 0.599) or PPH (p = 0.982). In contrast, the risk of PPH was significantly higher in those delivering by a 2nd stage CS compared to KRFD (27.5 % vs. 12.4 %; p < 0.0001). With regard to neonatal adverse outcomes, in those delivering by KRFD compared to RVD and 2nd stage CS, there was no significant difference in the incidence of admission to NICU (p = 0.912; p = 0.746, respectively), 5-minute Apgar score<7 (p = 0.335; p = 0.150, respectively), jaundice (p = 0.810; p = 0.332, respectively), mild shoulder dystocia (p = 0.077), severe shoulder dystocia (p = 0.603) or birth trauma (p = 0.265; p = 0.323, respectively). The risk of maternal composite adverse outcome was highest after 2nd stage CS (OR 7.68; 95 %CI: 6.52-9.04) and lowest after KRFD (OR 3.82; 95 %CI: 2.98-4.91). The risk of composite neonatal adverse outcome was higher in those delivering by RVD (OR 2.87; 95 %CI: 2.10-3.91), compared to KRFD (OR 2.23; 95 %CI: 1.67-2.97) or 2nd stage CS (OR 2.02; 95 %CI: 1.60-2.54).

Conclusion: Our study demonstrates that KRFD is a safer management option when compared to RVD or 2nd stage CS for the management of persistent fetal malposition in labour.