Objective
Objectives of the supervision during the delivery stage are:
- establishing the start of delivery
- assessing the condition of the foetus
- ensuring that the passage of the foetus through the birth canal proceeds in the appropriate manner and within the time set for this
- detecting any complications that might occur during the delivery in good time and treating these appropriately.
Determining the start of the second stage
The delivery stage is the time that elapses between the moment of full dilation, associated with the woman’s urge to bear down, and the birth of the child. On average this period lasts longer in the case of a primigravida than for a multigravida. In general the risk of complications increases the longer the delivery stage takes. On average the delivery stage is shorter in a multipara because, if a vaginal birth has taken place before, she will have a birth canal which has already once accommodated the passing of a foetus during delivery. For multiparae with good contraction activity and a good pushing technique a maximum delivery stage lasting 30 minutes to one hour applies, and for primiparae under the same conditions a maximum delivery stage of 1 to 1.5 hours is usual. The times stated should preferably not be exceeded, which is why we refer to a time indication.
The obstetric internal examination during delivery is partly aimed at establishing whether sufficient progress is being made in the delivery process.
Monitoring of the foetal condition during delivery
The foetal heart sounds are auscultated to determine if the child is receiving sufficient oxygen during delivery and is therefore able to maintain a good physical condition. If the delivery does not progress quickly enough or if the child becomes distressed during delivery medical intervention may be necessary to artificially bring the delivery to an end. This is referred to as termination of the delivery. Examples of medical intervention include applying fundal pressure, episiotomy, vacuum extraction, forceps extraction or in the most extreme case, a caesarean section.
During delivery the terms ‘appearing’, ‘crowning’ and ‘emergence’ of the presenting part are used. Appearing refers to part of the scalp being visible in the vaginal orifice during pushing at the peak of a contraction. Once the contraction has passed, the scalp sinks back into the birth canal. When the scalp remains visible and no longer sinks back into the birth canal this is termed crowning. Then the birth of the head can soon be expected. When the scalp emerges, the widest part of the scalp passes the vulva and the head is born.
Pushing instructions
The traditional pushing advice is that at the start of the delivery (or pushing) stage the woman must push as hard and as long as possible during a contraction until the scalp appears. Nowadays, professionals are more inclined to let the woman determine this herself. Many women then spontaneously push less long and more frequently, but also more effectively, because this avoids reducing the oxygenation of the mother and child. Although the delivery takes longer with this approach, it poses less danger to the condition of the mother and child.
At the point when the scalp crowns or emerges, the woman should not continue pushing or should only push carefully, in order to prevent the head from being born too quickly which could result in the perineum being torn.