Maternal and neonatal morbidity in relation to the instrument used for mid-cavity rotational operative vaginal delivery: a prospective cohort study




To compare the maternal and neonatal morbidity associated with alternative instruments used to perform a mid-cavity rotational delivery.


A prospective cohort study.


Two university teaching hospitals in Scotland and England.


Three hundred and eighty-one nulliparous women who had a mid-cavity rotational operative vaginal delivery.


A data collection sheet was completed by the research team following delivery.

Main outcome measures

Postpartum haemorrhage, third- and fourth-degree perineal tears, low cord pH, neonatal trauma, and failed or sequential operative vaginal delivery.


One hundred and sixty-three women (42.8%) underwent manual rotation followed by non-rotational forceps delivery, 73 (19.1%) had a rotational vacuum delivery, and 145 (38.1%) delivered with the assistance of rotational (Kielland) forceps. The rates of postpartum haemorrhage were similar when comparing manual rotation with rotational vacuum (adjusted OR 1.42, 95% CI 0.66–3.98), and when comparing manual rotation with Kielland forceps (adjusted OR 1.22, 95% CI 0.71–2.88). The results were comparable for third- and fourth-degree perineal tears (adjusted OR 0.85, 95% CI 0.13–1.89; adjusted OR 0.94, 95% CI 0.39–1.82), low cord pH (adjusted OR 1.76, 95% CI 0.44–6.91; adjusted OR 1.12, 95% CI 0.44–2.83), neonatal trauma (adjusted OR 0.50, 95% CI 0.16–1.55; adjusted OR 3.25, 95% CI 0.65–16.17), and admission to the neonatal intensive care unit (adjusted OR 1.47, 95% CI 0.45–4.81; adjusted OR 1.04, 95% CI 0.49–2.19). The sequential use of instruments was less likely with manual rotation and forceps than with rotational vacuum delivery (0.6 versus 36.9%, OR 0.01, 95% CI 0.002–0.090).


Maternal and perinatal outcomes are comparable with Kielland forceps, vacuum extraction, and manual rotation, with few serious adverse outcomes. With appropriate training mid-cavity rotational delivery can be practiced safely, including the use of Kielland forceps.