Acta Obstet Gynecol Scand. 2008;87(2):247-9.
Induction of labour for post-term pregnancy and risk estimates for
intrauterine and perinatal death.
Heimstad R, Romundstad PR, Salvesen KA.
Department of Obstetrics and Gynecology, St. Olavs' Hospital, Trondheim
University Hospital, Norway. runa.heimstad@ntnu.no
Background:
Beyond term there is increased risk of intrauterine fetal
death (IUFD) and perinatal death, and we aimed to assess this risk
beyond 41 weeks and estimate numbers needed to treat to avoid 1 fetal or
neonatal death. DESIGN AND
Methods:
All singletons births beyond 41
weeks from 1999-2005 registered in the Norwegian Medical Birth Registry
were assessed concerning IUFD and perinatal death day by day, and
numbers needed to induce to avoid 1 death was estimated.
Results:
The
perinatal death rate increased with increasing gestational age. NNT for
perinatal death was 527 at day 287, and 195 at day 302 + (p-value=0.02).
Routine induction of labour at 41 weeks implicates >14,000 inductions
per year.
Conclusions:
NNT to avoid 1 fetal or neonatal death is high
(671-195), but decreases constantly with gestational age beyond 41
weeks.
