Duration of the second-stage labor
Eight trials involving 1809 women were included in this outcome, 1723
women contributed data. The result of meta-analysis indicated that women
in lubricant group had a shorter duration of the second-stage labor when
compared with those in standard care group (MD -13.72 minutes, 95%CI
-22.68, -4.77; I2=98%; very low certainty due to
serious risk of bias, serious inconsistency and serious imprecision)
(Table 1, Figure S26).
Subgroup analyses showed that there was significant subgroup effect
between lubricant type subgroups (Pinteraction=0.02) (Figure S27), and not between overall
risk of bias subgroups (P interaction=0.37)
(Figure S28). Subgroup analysis according to lubricant type indicated
that obstetric gel (MD -16.9 minutes, 95%CI -27.03 to -6.78) had a
shorter duration of the second-stage labor than liquid wax (MD -8.38
minutes, 95%CI -11.11 to -5.65). The heterogeneity of high risk of bias
groups was reduced after subgroup analysis (I2=65%),
while significant heterogeneity remained within low high risk of bias
groups (I2=99%). This heterogeneity might partially
result from studies of low high risk of bias (Figure S28).
The result analyzed based on parity indicated that nulliparous women in
lubricant group had a shorter duration of the second-stage labor when
compared with those in standard care group (MD -14.46 minutes, 95%CI
-24.58, -4.34; I2=98%) (Figure S29). There was
insufficient data to perform subgroup analysis for this outcome for
multiparous women.