An examination per vaginam is an intimate procedure that should be undertaken only when there is a clear clinical indication. Levin et al (2005) found that women experience an average of three VEs during labour; some women will have more than this. NICE (2007) advise that the midwife (and doctor) should be sure that it is absolutely necessary and that the findings will provide important information to the decision making process; they advise that for women in normal labour the frequency of the examination should be every 4 hours, although this may be considered as too frequent by some women and midwives who will undertake the examination only when clinically indicated.

Women can find this procedure very distressing and it is important that the procedure is discussed with the woman prior to undertaking the procedure. This discussion should include: the rationale for the procedure, what will happen, what is expected of the woman and confirmation that the procedure can be stopped at any point if requested by the woman. This discussion should be undertaken in a manner that allows the woman to ask questions and also to refuse the examination. During the examination itself, it is important to maintain both verbal and non-verbal communication with the woman, recognising when she is experiencing discomfort/pain and requires the procedure to end and providing her with information (Stewart 2005). Levin et al (2005) found that only 70% of women recalled having the subject of VE discussed with them before the procedure although 95% considered they were well informed of the findings. Only 40% felt they could refuse the examination and sadly 22.2% considered that their permission was not sought.

During labour, the midwife may undertake a VE to:

The midwife should not undertake a VE when there is:

Any abnormalities such as varicosities, oedema, warts or signs of infection should be noted, as should scarring, particularly if indicative of previous perineal or labial trauma or female genital mutilation; NICE (2007) warns that a VE may be very difficult in the presence of fibulated genital mutilation. The colour, consistency, amount and odour of any discharge or bleeding from the vagina should be recorded; amniotic fluid may be seen if the membranes have ruptured.

The cervix is assessed for position, consistency, effacement, dilatation and application to the presenting part. Prior to labour, the cervix is usually in a central or posterior position, firm, non-effaced with the os closed (unripe). In the latter weeks of pregnancy and early labour, the structure and position of the cervix alters as the cervix ripens, resulting in a cervix that feels less rigid and in an anterior position. A ripe cervix that feels soft and stretchy is associated with good dilatation of the os uteri, whereas a tight unyielding unripe cervix at term is more likely to be associated with prolonged labour. An unripe cervix requires three to four times more uterine effort than a ripe cervix (Burnhill et al 1962).

A cervix that is well applied to the presenting part is associated with good uterine activity (Blackburn 2007). The reverse may be true, that a poorly applied cervix is associated with less efficient uterine activity and slower progress. For example, when the fetus is in an occipitoposterior position, the head is not pushed directly onto the cervix; rather it is directed downwards and forwards against the back of the symphysis pubis, leading to a decrease in the effectiveness of uterine contractility, slower cervical dilatation and prolonged labour (Chamberlain 1993). The application of the cervix to the presenting part can be assessed by feeling between them.

Effacement usually precedes dilatation with the primigravida; these may appear to occur simultaneously with the multigravida. Effacement is assessed by the length of the cervix and the degree to which it protrudes into the vagina. A non-effaced cervix feels long and tubular, with the os closed or partly dilated. As effacement occurs, the cervix thins out and feels shorter, as the lower uterine segment takes it up (Fig. 30.1). A fully effaced cervix feels continuous with the lower uterine segment and does not protrude into the vagina.

Dilatation of the os uteri is measured in centimetres and is assessed by inserting one or both fingers through the external os and parting the fingers to assess the diameter. In early labour, when the cervix is less than 2 cm dilated, usually only one finger can be inserted. Towards the end of the first stage it may be easier to feel around the remaining rim of cervix to estimate dilatation; for example, a rim of 1 cm equates to a dilatation of 8 cm, as there is 2 cm of cervix remaining. When the cervix can no longer be felt, full dilatation has occurred, equal to 10 cm. This is the point at which the fetal head can pass through the cervix although for the preterm fetus, this may be less than 10 cm. If the presentation is breech, it is possible for the foot and leg to protrude through the cervix before it is fully dilated (footling breech). Dilatation of the os uteri should occur progressively throughout the first stage of labour and is one factor in determining progress (NICE 2007 suggest this to be 0.5 cm or more per hour).

The os uteri is usually closed in the primigravida until labour begins, but the os of the multigravida may allow one or two fingers through before labour, commonly referred to as a ‘multips os’.

Intact membranes may be felt as a shiny surface over the presenting part. This can be difficult to feel, particularly in early labour or if the forewaters are shallow and the membranes tightly pressed against the presenting part. If the membranes are difficult to feel, it may be mistaken for ruptured membranes. When the presenting part is poorly applied to the cervix, the membranes contain a greater amount of fluid and may bulge through the cervix. As the pressure increases in the forewaters during contractions, the membranes can become tense and may rupture spontaneously. This usually occurs earlier when the presenting part is ill-fitting or poorly applied; for example, with a malposition such as an occipitoposterior position, malpresentation such as face presentation or a high presenting part. If the membranes are felt intact but amniotic fluid is leaking, a hindwater rupture is the likely cause. Pulsation felt beneath the membranes may be indicative of cord presentation or vasa praevia.

In conjunction with information gained from the abdominal examination, the identification of landmarks on the presenting part help to confirm the presentation:

This is determined by assessing the distance between the presenting part and the ischial spines in centimetres (Fig. 30.2). The ischial spines are referred to as zero station, with the presenting part being above (− cm) or below (+ cm) this. The ischial spines may be difficult to palpate; this becomes a subjective measurement. It is important for the midwife to ensure it is the level of the presenting part being assessed and not caput succedaneum. Descent of the presenting part is one indicator of progress during labour and the assessment should correlate with the findings from the degree of engagement determined during the abdominal examination.

With a cephalic presentation, identification of sutures and fontanelles will confirm the position and attitude: