Some studies have demonstrated a
time-dependent fall in fetal pH during the second stage25-27
but this has been challenged28. An extensive review of
25,069 births found that the duration of the second stage
was not significantly associated with the risk of a low
Apgar score or admission to a special care baby unit29.
Different studies have investigated outcomes of different
pushing methods. Substantial evidence supports the use
of spontaneous maternal pushing for both maternal and
fetal benefit and a few studies have specifically compared