Facts verified by Dr Raewyn Teirney and Dr Scott Dunlop.
About 11% of births in Australia are assisted deliveries (also referred to as instrumental or operative vaginal deliveries) which require an obstetrician or midwife to use instruments and methods that help a baby to be born.
Indications for assisted/instrumental delivery
1) A delay in the second stage of labour when the baby is failing to move steadily through the birth canal due to an unusual presentation, when the head is not an ideal position (such as being occiput posterior position or transverse position) and assistance is needed to help reposition it for birth.
2) A baby showing signs of distress during the active, transition or final stages of labour, such as passing meconium, or having a slowed heart rate.
3) When the mother has an underlying medical condition that could make it dangerous to push for a prolonged period (eg: diabetes, high blood pressure, respiratory or cardiovascular diseases) or if there are other complications such as heavy bleeding or if the baby is premature.
4) If the woman in labour is too exhausted to continue to push and/or her contractions are tailing off.
5) If the mother has been given an epidural and has a diminished sensation of pressure which can reduce the urge to push during contractions or lead to tearing when the mother pushes before being properly dilated.
The first form of assisted delivery is with inducing labour for overdue babies or where the health of the mother or the baby is of a concern and the baby needs to be born sooner rather than later, or when the placenta is functioning less efficiently in delivering oxygen and nutrients to the baby. This is done by prostaglandin gels being inserted to soften the cervix for dilation.
Alternatively when contractions have slowed down or stopped completely, administering oxytocin via a drip or artificially rupturing the membranes is another form of intervention that is used to progress labour.
The possibility of needing an assisted delivery can be reduced by staying upright as much as possible during labour (see birth positions during labour article), or by either avoiding an epidural or having an epidural early in labour so that women have better muscular control to push during the second stage of labour.
However sometimes an assisted delivery is unavoidable regardless of the measures taken to prevent them and in these cases, your midwife or obstetrician should explain why you need an assisted delivery and whether forceps or ventouse is more suitable for your situation. You may be asked to put your legs in stirrups for the procedure to take place.
Choosing between ventouse and forceps delivery
Each method has a different profile of reasons and complications. Delivery of the baby is more likely to be achieved with forceps than vacuum and will occur over a shorter time interval. However forceps is associated with a higher rate of complications for the mother such as vaginal/perineal tears, incontinence and the requirement for pain relief.
However most doctors will prefer to use ventouse before using forceps, because ventouse can be manoeuvred more easily (and an episiotomy is not always required although some women do still need one). A vacuum extractor cup made of plastic (or sometimes metal) with a handle, is placed securely around a certain area on the baby’s head which the doctor then pulls on while pumping the vacuum during a contraction. This usually helps the baby move forward through the birth canal (without slipping back slightly after each contraction which happens regularly during the first stage of a natural labour) and stay in position so that the baby can begin crowning after reaching the vaginal opening. But if after three attempts there is no movement, or alternatively if the suction cap is not attaching properly, then the doctor may decide to use forceps, as there can be detrimental consequences for the baby if repeated vacuum pulls are applied.
Forceps are curved metal prongs that are designed to fit around the baby’s head, similar to a ventouse, except they offer more dexterity. However an episiotomy can be required for forceps to be used, which is when a cut is made between the vagina and the perineum so the forceps can be inserted and manipulated with greater ease. Forceps usually require a regional anaesthetic or a local anaesthetic called a pudendal block (rarely a general anaesthetic) to be given at the birth and stitches given after the birth, with a higher chance of sustaining injury to the pelvic floor muscles and perineum. Women who have stitches will have a longer recovery time and will experience discomfort when using the toilet and may have to wait longer to resume having intercourse but medication can be prescribed to help with the pain. Forceps can only be used when a woman is fully dilated to ten centimetres and the baby is not located too far up the birth canal.
Should neither ventouse nor forceps be successful in helping the baby to be born, a Caesarean delivery is the next step. Where doctors can determine ahead of time that an assisted delivery is likely to be necessary, many doctors will opt for a planned Caesarean rather than waiting until the day of the birth to have an assisted delivery or perform an emergency Caesarean.
When a baby is born by ventouse, their scalp could possibly have a cone-like appearance for a few days or weeks afterwards, and sometimes blood blisters will also appear due to the abrasion caused by the ventouse to the skin in the area. Similarly, babies that are born with the use of forceps will usually have facial bruising for a short time but these things will soon return to normal.
Women who have assisted deliveries can suffer from birth trauma and fear of birth for subsequent pregnancies. Birth trauma is a form of post-traumatic stress disorder that has been linked to assisted ventouse or forceps deliveries where women find them to be an extremely negative experience for various reasons (which can include anything from inadequate pain relief, medical complications or overall unsatisfactory medical care) which causes them medium- to long-term emotional distress. For more information see the birth trauma article.
Birth trauma is also associated with post-natal depression and previous traumatic incidents such as abuse, making it more likely that if one incident has initially taken place, that either one of or both of the other conditions will develop later on. However there is nothing to say that women who have assisted deliveries will not be able to have natural births without intervention in the future.
Water births are sometimes chosen for later pregnancies by women who have previously had assisted deliveries, as recommended by some medical professionals who believe water births lower the chance of a ventouse, forceps or caesarean delivery. This could be worth considering for some women who are recovering from birth trauma but who wish to have more children.
Dr Raewyn Teirney is gynaecologist, obstetrician and fertility specialist and a visiting medical officer at the Royal Hospital for Women in Sydney and also consults from her private rooms at Maroubra and Kogarah.
Dr Scott Dunlop is a consultant paediatrician at Sydney Paediatrics, Woollahra.