The results of the retrospective observational study by Tempest et al. on the outcomes of operative cephalic births using either Kielland forceps or rotational ventouse compared with primary emergency caesarean section for malposition in the second stage of labour do not justify the Abstract.
It concludes that in cases of malposition, assisted vaginal birth by Kielland forceps, in experienced hands, is the most effective and safest method in preventing caesarean section. Although this stirs excitement at the possibility of a change in labour ward practice, further analysis reveals that although when compared with rotational ventouse, Kielland forceps reduced the odds of a woman needing a caesarean section (adjusted odds ratio [aOR] 8.20; 95% confidence interval [95% CI] 4.54–14.79), there was no statistical evidence of a reduced risk in maternal morbidity (namely massive obstetric haemorrhage: aOR 0.74; 95% CI 0.09–5.78) or in neonatal morbidity (neonatal admission to special baby care unit: aOR 1.20; 95% CI 0.65–2.22). Therefore the Abstract's conclusion that delivery with Kielland forceps was the safest method in preventing caesarean section cannot be correct.
More importantly, and highlighted as a potential weakness of the study, more emphasis should have been placed on the lack of statistical adjustment for station of vertex, the presence of caput or moulding, and uterine activity. These factors are fundamental in correct patient selection when deciding to attempt potentially difficult rotational instrumental deliveries or to proceed to a primary emergency caesarean section and they therefore impact greatly on the resulting outcome. How can the authors be confident that the women undergoing caesarean delivery were similar to those where a prospective decision was made instead to proceed to assisted vaginal delivery?
The need to balance maternal and neonatal morbidity through the reduction of unnecessary caesarean sections with the reality of reduced training hours and inexperience with complicated vaginal deliveries is foremost in the minds of all those involved with training and the delivery of obstetric care and remains a constant challenge. We are encouraged by studies that, at the very least, show no increase in neonatal morbidity and a reduction in emergency caesarean section rates with the correct use of rotational forceps but the lack of clear evidence as to a reduction in maternal morbidity continues to cast doubt over its place in current obstetric practice. The pertinent question remains as to how to increase competence with rotational forceps when those tasked with training have themselves minimal experience of it. Although the short-term and longer-term maternal risks with the use of rotational forceps compared with ventouse delivery or primary emergency caesarean section for malposition remain undefined, training and competence in the use of Kielland forceps is likely to remain inadequate. The real issue then becomes the current mode for recourse to emergency caesarean section without a previous attempt at instrumental delivery.
This study therefore does not show that rotational forceps are safer than other modes of delivery. Nor does it provide sufficient justification in respect of maternal morbidity with rotational forceps, without which a significant change in UK obstetric practice cannot occur.