Neonatal complications

After any instrumental vaginal delivery, the baby may suffer hypoxia, have lower Apgar scores and require appropriate resuscitation. Facial or scalp abrasions or bruising are common. A cephalhaematoma may develop because of friction between the fetal head and pelvis or forceps blade, as well as from the suction of the ventouse cup. There may be an increase in jaundice due to reabsorption of haemoglobin associated with this bruising (Dennen & Hayashi 2005). Facial palsy, which is usually temporary, may occur owing to the compression of the facial nerve which runs anteriorly to the ear, by the forceps blade. Intracranial trauma and haemorrhage is higher amongst infants delivered by vacuum extraction, forceps or caesarean section (Towner et al 1999). In more rare circumstances, tentorial tears and rupture of the great vein of Galen may occur, leading to bleeding and compression of the brainstem. Skull fractures are usually linear but occasionally a depressed fracture can result in a subarachnoid haemorrhage. Kielland’s forceps can cause unexplained convulsions. Retinal haemorrhages are more common in vacuum extraction deliveries (Vacca 1996). The most serious complication to occur is that of subgaleal haemorrhage.

Maternal complications

The most common injuries to the genital tract are cervical, vaginal and perineal tears, haematomas and rectal lacerations (see Ch. 40). Bladder or urethral injury may occur, causing urinary retention and even the formation of a fistula. Perineal pain due to bruising, oedema, trauma and episiotomy can impair sexual function and infant feeding. Pelvic floor disorders and long-term pelvic floor morbidity are strongly associated with instrumental delivery (Bahl et al 2005). There is an increased risk of haemorrhage (Walsh 2000). A rare complication is that the cervix and lower segment of the uterus may be damaged.

The psychological effects of instrumental delivery may include fear and anxiety in relation to subsequent pregnancy, and feelings of failure, inadequacy and disappointment. Both forceps and ventouse-assisted deliveries were found to be predictive factors of acute trauma symptoms and post-traumatic stress disorder as a result of women’s birth experiences (Creedy et al 2000). Jolly et al (1999) concluded that caesarean section and vaginal instrumental birth are associated with voluntary and involuntary infertility as many mothers may be left with fearful feelings about future childbirth: 13% more of women who had a caesarean section and 6% more of those who had instrumental births had not had a second child compared with those following normal birth.

Policies

Blanket policies to treat prolonged labour and ‘failure to progress’ should be examined as there is much literature available to explore long-held beliefs of the definition of the duration and progress of labour. Even in 1973, when medicalization was really taking control of childbirth, Studd (1973) questioned the arbitrary application of time limits on labour considering the confusion over the diagnosis of the onset of active labour. Yet this confusion remains and time limits for stages of labour remain in place.

Position for labour and delivery

An upright position, preferably mobile, assists the woman to feel in control, can reduce her distress and help her to adopt comfortable positions more easily. During a review of trials for The Cochrane Library, Gupta & Nikoderm (2001) highlighted that adopting upright positions in labour appeared to reduce the number of assisted deliveries and fewer abnormal fetal heart rate patterns were noted (see Chs 36 and 37).

Diet, fasting and nutrition

Fasting women throughout a normal labour can add to exhaustion, as labour is a time of great energy demand and it is estimated that a labouring woman may require 800–1100 kcal/hour (Ludka & Roberts 1993). Whilst women adapt to a small rise of ketones in labour, blood pH can be reduced in starving women and result in ketoacidosis. Even as far back as the 1960s, Mark (1961) discovered that uterine activity was influenced by environmental pH and that myometrial cells spontaneously contract with increased alkalinity, preferably between 7.8 and 7.1. Ketones that build up may also cross the placenta, and if there is an accumulation in the fetus, this can affect fetal wellbeing and fetal activity (Swift 1991).

Supportive presence during labour

A Cochrane review highlights that the presence of an appropriate support person throughout labour is associated with a decreased incidence of epidural anaesthesia, dystocia and instrumental deliveries (Hodnett 2001).

Amniotomy and Syntocinon

Amniotomy can increase the requirement for instrumental delivery and caesarean section (Johnson et al 1997). It is recognized that amniotomy causes fetal heart abnormalities owing to cord and head compression, which then increases the risk of interventions. It can inhibit the rotation of some malpositions – for example, occipitoposterior positions – which may predispose to delay. There is an increase in pain during contractions, which may, in turn, increase the demand for epidural analgesia. Syntocinon reduces the oxygen supply to the baby’s brain. The fetus may then display signs of fetal distress, increasing the need to dramatically shorten the labour (O’Regan 1998).

Pain relief

Epidurals are associated with a substantially increased use of assisted vaginal delivery (Mander 1994). Epidurals increase the length of the first and second stages, often affecting the efficacy of contractions, increasing the need for Syntocinon (Page 2000).

Procedure

Prior to the delivery, the mother is helped into the lithotomy position. The midwife must ensure that the woman is covered with a sheet as much as possible and for as long as possible, to protect her dignity. Both legs are flexed simultaneously and gently onto the abdomen, and the feet moved to the outer sides of the supports and placed in the leg rests or stirrups together to avoid sacroiliac strain. To prevent obstruction of venous return and possible thrombosis by pressure, care is taken to ensure that the legs are fully abducted. Once the mother is correctly positioned, the foot part of the bed is lowered and the mother’s buttocks lifted to the edge of the bed. The operator can now proceed.

Ventouse vs forceps

Debate exists over the preferred instrument for vaginal delivery once it is believed to be necessary. There are two methods for instrumental delivery: forceps and vacuum (ventouse) extraction. A Cochrane systematic review of nine randomized controlled studies involving 2849 primiparous and multiparous women compared vacuum extractions with forceps. Ventouse appears to be significantly more likely to fail at achieving a vaginal delivery, but is less likely to produce maternal trauma and less likely to be associated with severe perineal pain. However, it does produce increased rates of cephalhaematoma, retinal haemorrhages and low Apgar scores at 5 minutes. There appeared no difference in long-term outcome between the two instruments (Johanson & Menon 2000).