Found some good stats on sweeps here
www.midwifery.org.uk/index.php?option=com_content&view=article&id=230:sweeping-the-membranes-&catid=91:hidden-archives&Itemid=110
It includes the statistics that lead to the NICE recommendation that 1st time mums be offered sweep from 40 weeks, and snd/more time mums be offered sweep from 41 weeks. There is also some good midwife discussion about the subject if you follow the link.
the stats are here:
The following is from the NICE guidelines on IOL.
MEMBRANE SWEEPING
6.2.1 Performance 68
Sweeping the membranes in women at term reduced the delay between randomisation and spontaneous onset of labour, or between randomisation and birth, by a mean of three days.
Sweeping the membranes increased the likelihood of both:
o spontaneous labour within 48 hours (63.8% vs. 83.0%; RR 0.77; 95% CI 0.70-0.84; NNT 5)
o birth within one week (48.0% vs. 66.0%; RR 0.73; 95% CI 0.66-0.80; NNT 5).
Sweeping the membranes performed as a general policy from 38-40 weeks onwards decreased the frequency of prolonged pregnancy:
o over 42 weeks: 3.4% vs. 12.9%; RR 0.27; 95% CI 0.15-0.49; NNT 11
o over 41 weeks: 18.6% vs. 29.87%; RR 0.62; 95% CI 0.49-0.79; NNT 8.
Membrane sweeping reduced the frequency of using other methods to induce labour (formal induction of labour). The overall risk reduction in the available trials was 15%. This risk reduction of a formal induction of labour was 21.3% vs. 36.3% (RR 0.59; CI 0.50-0.70; NNT 7).
The risk of operative delivery is not changed by the intervention. There was no difference in other measures of effectiveness or adverse maternal outcomes.
Sweeping the membranes was not associated with an increase in maternal infection or fever rates (4.4% vs. 4.5%; RR 0.97; 95% CI 0.60-1.57).
Similarly, there was no increase in neonatal infection (1.4% vs. 1.3%; RR 0.92; 95% CI 0.30-2.82).
Induction of Labour 33
Evidence level
1a
No major maternal adverse effects were reported in the trials. A trial that systematically assessed minor adverse effects and women's discomfort during the procedure found that women in the sweeping group reported more discomfort during vaginal examination. Median pain scores were higher in women allocated to sweeping of membranes. Pain was assessed by
the Short Form of the McGill Pain Questionnaire,69 which included three scales:
o a visual analogue scale (0-10 cm)
o the present pain index (0-5)
o a set of 15 descriptors of pain scoring 0-3.
In addition, more women allocated to sweeping experienced vaginal bleeding and painful contractions not leading to the onset of labour during the 24 hours following the intervention. There was no difference in any fetal outcome between the membrane sweeping and the non-membrane sweeping groups. These results must be interpreted with caution due to the
presence of heterogeneity. The trials included in this review did not report in relevant clinical subgroups.
6.2.2 Summary
o Membrane sweeping is associated with a reduction in the length of time between treatment and spontaneous labour.
o Sweeping of the membranes reduces the incidence of prolonged pregnancy.
o Sweeping of the membranes reduces the need for the use of formal methods of induction of labour.
o Sweeping of the membranes is associated with an increase in maternal discomfort.