For a baby to be born, the mother's cervix needs to change from being closed to being open to about 10 centimetres (‘dilated’). Vaginal examinations provide information on how widely dilated the cervix is, how much it has thinned and the position of the presenting part of the baby in the mother's pelvis. This is part of assessing the woman's progress in labour, although knowing the dilation of the woman's cervix is a poor predictor of when she will give birth. Patterns and speed of labour can vary substantially between different women, and in the same woman in different labours. Very slow labours can be associated with difficulties for both the mother and baby. Abnormally slow labours (dystocia) can sometimes lead to neurological problems in the baby and long-term urinary and fecal incontinence in the mother, especially in low-income countries. Vaginal examinations aim to reassure the woman (and staff) that the woman is labouring normally, and to provide early warning if this is not the case. In low-income countries, it can take some time to get to help, and vaginal examinations may enable appropriate transfer from community settings to hospital care. If labours that are slow, but not abnormal, are mis-diagnosed as being abnormal, this can lead to unnecessary interventions such as drugs to try to speed labour on or caesarean section or forceps for giving birth. There are also concerns about introducing infection to the uterus and to the baby, especially in low-income countries where disposable gloves, or reusable gloves and disinfectants, are not readily available. In addition, some women find the process of vaginal examinations uncomfortable or distressing, and so it is important that there is good evidence for its use. We looked for studies to see how effective routine vaginal examinations in labour are at reducing problems for mothers and babies.
We found two studies, undertaken in the 1990s in high-income countries, but their quality was unclear. One study, involving 307 women, compared routine vaginal and rectal examinations in labour. Here, fewer women reported that vaginal examinations were very uncomfortable compared with rectal examinations. The other study, involving 150 women, compared two-hourly and four-hourly vaginal examinations, but no difference in outcomes was seen.
We identified no convincing evidence to support, or reject, the use of routine vaginal examinations in labour, yet this is common practice throughout the world. More research is needed to find out if vaginal examinations are a useful measure of both normal and abnormal labour progress. If vaginal examination is not a good measure of progress, there is an urgent need to identify and evaluate an alternative measure to ensure the best outcome for mothers and babies.
On the basis of women's preferences, vaginal examination seems to be preferred to rectal examination. For all other outcomes, we found no evidence to support or reject the use of routine vaginal examinations in labour to improve outcomes for women and babies. The two studies included in the review were both small, and carried out in high-income countries in the 1990s. It is surprising that there is such a widespread use of this intervention without good evidence of effectiveness, particularly considering the sensitivity of the procedure for the women receiving it, and the potential for adverse consequences in some settings.
The effectiveness of the use and timing of routine vaginal examinations in labour, and other ways of assessing progress in labour, including maternal behavioural cues, should be the focus of new research as a matter of urgency. Women's views of ways of assessing labour progress should be given high priority in any future research in this area.
Vaginal examinations have become a routine intervention in labour as a means of assessing labour progress. Used at regular intervals, either alone or as a component of the partogram (a pre-printed form providing a pictorial overview of the progress of labour), the aim is to assess if labour is progressing physiologically, and to provide an early warning of slow progress. Abnormally slow progress can be a sign of labour dystocia, which is associated with maternal and fetal morbidity and mortality, particularly in low-income countries where appropriate interventions cannot easily be accessed. However, over-diagnosis of dystocia can lead to iatrogenic morbidity from unnecessary intervention (e.g. operative vaginal birth or caesarean section). It is, therefore, important to establish whether or not the routine use of vaginal examinations is an effective intervention, both as a diagnostic tool for true labour dystocia, and as an accurate measure of physiological labour progress.
To compare the effectiveness, acceptability and consequences of digital vaginal examination(s) (alone or within the context of the partogram) with other strategies, or different timings, to assess progress during labour at term.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2013) and reference lists of identified studies.
We included randomised controlled trials (RCTs) of vaginal examinations (including digital assessment of the consistency of the cervix, and the degree of dilation and position of the opening of the uterus (cervical os); and position and station of the fetal presenting part, with or without abdominal palpation) compared with other ways of assessing progress of labour. We also included studies assessing different timings of vaginal examinations. We excluded quasi-RCTs and cross-over trials. We also excluded trials with a primary focus on assessing progress of labour using the partogram (of which vaginal examinations is one component) as this is covered by another Cochrane review. However, studies where vaginal examinations were used within the context of the partogram were included if the studies were randomised according to the vaginal examination component.
Three review authors assessed the studies for inclusion in the review. Two authors undertook independent data extraction and assessed the risk of bias of each included study. A third review author also checked data extraction and risk of bias. Data entry was checked.
We found two studies that met our inclusion criteria but they were of unclear quality. One study, involving 307 women, compared vaginal examinations with rectal examinations, and the other study, involving 150 women, compared two-hourly with four-hourly vaginal examinations. Both studies were of unclear quality in terms of risk of selection bias, and the study comparing the timing of the vaginal examinations excluded 27% (two hourly) to 28% (four hourly) of women after randomisation because they no longer met the inclusion criteria.
When comparing routine vaginal examinations with routine rectal examinations to assess the progress of labour, we identified no difference in neonatal infections requiring antibiotics (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.01 to 8.07, one study, 307 infants). There were no data on the other primary outcomes of length of labour, maternal infections requiring antibiotics and women's overall views of labour. The study did show that significantly fewer women reported that vaginal examination was very uncomfortable compared with rectal examinations (RR 0.42, 95% CI 0.25 to 0.70, one study, 303 women). We identified no difference in the secondary outcomes of augmentation, caesarean section, spontaneous vaginal birth, operative vaginal birth, perinatal mortality and admission to neonatal intensive care.
Comparing two-hourly vaginal examinations with four-hourly vaginal examinations in labour, we found no difference in length of labour (mean difference in minutes (MD) -6.00, 95% CI -88.70 to 76.70, one study, 109 women). There were no data on the other primary outcomes of maternal or neonatal infections requiring antibiotics, and women's overall views of labour. We identified no difference in the secondary outcomes of augmentation, epidural for pain relief, caesarean section, spontaneous vaginal birth and operative vaginal birth.