Membrane sweeping or stripping is thought to increase the probability of physiological onset of labour by encouraging the local release of prostaglandin. Evidence suggests that the process of undertaking this procedure, during which the examining fingers are introduced into the cervical os and detache the membranes from the decidua using a circular movement of the fingers, releases prostaglandins. This, in turn, increases the likelihood of spontaneous labour within 48 hours. However, it is an uncomfortable procedure that is associated with vaginal bleeding and irregular contractions.
Membrane sweeping is commonly offered to primparous women at 40 and 41 weeks gestation and multiparous women at 41 weeks.
Evidence in regard to membrane sweeping is inconclusive and women and midwives must take this into account in order to make a fully informed choice. There has been debate as to the frequency at which membrane sweeping should be repeated. Undertaking the procedure three times a week at 48-hour intervals has been found to be effective in encouraging spontaneous labour. For indications and contraindications for membrane sweep see Boxes 54.1 and 54.2.
When undertaking a membrane sweep it is important that the Bishop’s score is calculated (Table 54.1). The Bishop’s score considers five factors. These are: the position, consistency, effacement and dilatation of the cervix, along with the station of the presenting part. Although it is accepted that a score of 5 or more deems the cervix to be favourable or ‘ripe’, and thus the greater likelihood of the sweep being successful. It is possible to undertake a membrane sweep with lower Bishop’s scores as this may aid in the ripening of the cervix. If the cervix is closed or unfavourable and therefore the midwife is unable to undertake the membrane sweep, it is suggested that cervical massage is considered. This can be achieved by using the forefinger and middle finger to make gentle massaging circular movements on the cervix for about 15 seconds.
- Ensure that the mother has given fully informed consent.
- Gather equipment (Figure 54.1).
- Ensure that you have privacy and maintain her comfort and dignity throughout.
- Encourage the mother to have emptied her bladder prior to the procedure.
- Wash hands.
- Undertake a full antenatal examination including abdominal examination and auscultation of fetal heart with a pinnards stethoscope or hand-held sonicaid.
- Encourage the mother to adopt a semirecumbent position with her knees bent, ankles together and knees apart (Figure 54.2).
- Wash hands. Maintaining asepsis put on sterile gloves and undertake a vaginal examination to locate the cervix and determine the Bishop’s score.
- If cervix is closed then gently massage for 15 seconds.
- Do not proceed if you detect any abnormalities, i.e. vaginal infection, presence of the cord or the placenta in the cervical canal or close to the os, fetal malpresentation.
- Insert one or two fingers into the cervix and aim to gently dilate the os.
- Place examining fingers between the lower uterine segment and the membranes (Figure 54.3).
- Sweep your finger(s) in a 360-degree circular motion firmly but swiftly as this is uncomfortable for the woman. You must stop if the woman requests this.
- Remove examining fingers.
- Ensure the mother is clean, comfortable and not exposed following the procedure.
- Dispose of gloves correctly – wash hands.
- Auscultate fetal heart with Pinard stethoscope or hand-held sonicaid.
- Discuss findings with the mother and what to expect and when to contact the midwife/hospital, i.e. possible blood stained ‘show’, irregular contractions.
- Document all discussions, procedures, findings and advice given.
- Ensure documented plan of management is in place that mother is in agreement with.