Having read this chapter, the reader should be able to:
It has long been recognized that both malposition and malpresentation are associated with an increased risk of intervention during labour, including instrumental and operative delivery and increased morbidity for both the woman and the baby. Where it is possible to reduce the incidence of malposition and malpresentation before labour commences, the associated risks will also be reduced. This chapter considers the how the incidence of malposition and malpresentation can be reduced by encouraging the fetus into an optimal fetal position. It will consider the use of maternal positioning and alternative therapies. It does not discuss manual rotation of an occipitoposterior position during labour.
Malposition of the occiput: occipitoposterior position
A malposition is any position than is not occipitoanterior (OA) when the vertex is presenting.
The RCM (2012) suggest that between 15–32% of fetuses commence labour in an occipitoposterior (OP) or occipitolateral position, and it is more common in nulliparous women. Carseldine et al (2013) propose the rate of OP positions in the first stage of labour is 25%; many of these will rotate to an OA position during labour so that 5% of births are in a persistent OP position. Phipps et al (2014) suggest that about 70% of babies in an OP position in the early second stage will be born by caesarean section or instrumental delivery.
OP labour and deliveries have an increased risk of adverse effects for the mother and baby, including:
Sutton & Scott (1996) strongly advocate the use of different positions and postures from 34 weeks’ gestation to encourage the fetus to rotate to a lateral or anterior position and so facilitate engagement. They do advise women to discuss this with the health professional overseeing their pregnancy to ensure there are no contraindications to this.
The rationale for these positions is to provide the fetus with room to rotate within the uterus and adopt a position that is more comfortable and better for delivery. The fetus will be able to adopt a more flexed position if in a lateral or anterior position; as the head flexes, the engaging diameters will reduce and hence engagement is likely to occur earlier rather than later. Their advice centres on the regular use of upright and forward leaning postures, particularly during Braxton Hicks contractions, as this is believed to assist the fetus to manoeuvre into the optimum position.
Favourable positions to adopt
Positions that increase the likelihood of an OP position
The work by Sutton & Scott (1996) is not research-based; rather, their claims are supported by strong anecdotal evidence. This is an under-researched area and at present these positions do not appear to have any disadvantages for suitable women.
The use of an ‘all-fours’ position using knees and hands for support in conjunction with pelvic rocking has been used since the 1950s with little research as to its effectiveness. Hunter et al (2007) undertook a systematic review of the literature evaluating this intervention and concluded that while adopting this position for 10 minutes twice daily resulted in a positional change at the time, it had no effect on the fetal position at term. Even though there were no adverse effects, they do not recommend the hands–knees position as an intervention; however, they did find this position reduced the incidence of backache during labour. Kariminia et al’s (2004) small study compared this intervention (for 10 minutes twice daily) with a control group who had to undertake walking each day from 37 weeks. They concluded that although the hands–knees posture combined with pelvic rocking exercises is commonly used to encourage rotation from the posterior to the anterior position, their results did not support this practice and recommended that in the absence of any beneficial effects, the practice should be discontinued. However Simkin (2010) questions whether the intervention was too slight to fairly assess the potential value of pelvic rocking. Encouraging rotation of the occiput from a posterior to an anterior position remains an area for further research.
Malpresentation: breech presentation
The usual presentation in labour is vertex. A malpresentation refers to any presentation that is not vertex, e.g. breech, face, brow. Breech presentation occurs in approximately 3–4% of pregnancies at term; this figure is higher earlier in pregnancy. As Jackson et al (2013) suggest approximately one-third of breech presentations are not diagnosed until labour, midwives need to maintain their skills in undertaking a vaginal breech delivery through simulation.
Breech labour and delivery is associated with a number of complications: