Midwives and mothers who have learned about, and used, Optimal Foetal Positioning techniques are convinced that it works. There is a wealth of anecdotal
evidence in favour of it. However, there have not been many trials or studies on the subject so far, because they would be extremely difficult to organise. Practising techniques to turn a posterior baby can take a lot of commitment on the part of the mother, which could not be assumed in a randomised trial. There would also be ethical problems with a trial - would mothers in the control group be told not to adopt upright or forward-leaning postures? Or would they simply not be told that taking care with their posture could lead to an easier labour?
Stremler et al study on hands-and-knees in OP labours
The most recent research on using hands-and-knees position in labour, where the baby is known to be OP, has supported OFP theory. Stremler and colleagues
confirmed that babies were OP by ultrasound, then asked the women concerned to spend at least 30 minutes out of an hour on hands-and-knees while labouring. The baby's position was checked after an hour. Twice as many babies had turned OA at the end of that hour in the hands-and-knees group, as in the control group. However, because of the small numbers involved this did not reach statistical significance. I think most of us would be prepared to take a chance on that! What did reach statistical significance, however, was the women's experience of back pain; the hands-and-knees group experienced significant reductions in persistent back pain than the control group.
BMJ article on hands-and-knees in late pregnancy
A study published in the British Medical Journal January 2004 found that just going on hands-and-knees in late pregnancy (but not labour) was not enough to stop you having a posterior baby at birth. This is probably because many babies (approx two thirds) who are OP in labour, have only turned OP during labour. Therefore it's not what you do before labour which is important, so much as what you do during labour. The reference is:
Azar Kariminia, Marie E Chamberlain, John Keogh, and Agnes Shea
Randomised controlled trial of effect of hands and knees posturing on incidence of occiput posterior position at birth
BMJ, Jan 2004; 10.1136/bmj.37942.594456.44
The Kariminia et al study (above) did not really look at OFP techniques in the way a committed woman might practise them - women in the study were asked to go on hands and knees and do pelvic rocks for just 10 minutes, twice a day. It did not look at whether babies were posterior or anterior at the start of labour - only at their position at the end of labour. It did not look at the position or movements of the mothers in labour, and the study didn't include any advice to women on labour positioning. Finally, it did not note whether the babies who were OP at the end of labour, had started labour OP, or had started labour OA and had turned OP during labour. So what it tells us is that a token, brief attempt at OFP techniques from 37 weeks onwards, is not on its own going to do very much for the average woman. I don't think many OFP supporters would disagree with that! It's a great shame that the study did not look at the positions the babies were in at the start of labour, or the positions of the mothers during labour. I imagine that the briefness of the OFP exercises was probably because the motivation came from the researchers, not the mothers; if they'd asked women to commit to a more comprehensive exercise and positioning package, fewer women would have complied.
There is an interesting letter
from three UK midwives criticising the study, on the BMJ website. They say:
"The use of hands and knees posturing, otherwise referred to as the 'all fours posture', is widely used by midwives. It is surprising that Kariminia et al (2004) refer to it as an intervention based on personal belief (1). The use of the all fours posture has long been supported by the laws of physics and physiology (2). The law of gravity states that all objects are drawn towards the earth, and that the acceleration of movement is dependent on the mass and the availability of space. If this is applied to the fetus where the mother has adopted the all fours posture the heaviest poles of the fetus (the trunk and the occiput) would be drawn towards the earth, and into an anterior position. Such movement would be hindered only in two cases;  if the mass (the fetus) was not heavy enough to exert a force of acceleration or  if there was no available space into which the mass (fetus) could move. It appears that such principles were not considered by the authors for the intervention used in their study. Firstly, by implementing the intervention at 37 weeks, the availability of space was restricted. Midwifery practice advocates such intervention at 34-35 weeks when more space is available. Secondly the intervention was not implemented when the fetus was in an active state, which would have encouraged further movement of an already moving object. Another very important principle that was neglected related to the specific nature of the associated rocking with the all-fours posture. If 'rocking' equates to swaying of the pelvis from side to side this would exert only a frictional force which, solely, would not be of great benefit. If, however, posturing included movement of the maternal trunk backwards and forwards whilst on all fours this would both increase the available space at the pelvic inlet and along with gravitational and buoyancy forces will encourage frictional movement (3). As the mother moves her trunk forward, her spine is encouraged to move away whilst the maternal symphasis drops down, thus increasing the available space in the pelvic inlet and allowing the fetus more room to rotate to an anterior position.
If the study intervention did not consider any of these vital principles, it is hardly surprising that the result of the trial was negative. At best what the authors can claim is that their particular form of maternal posturing was both ineffective at decreasing the incidence of occiput-posterior position at birth and painful to the study participants. It cannot by any means be concluded that appropriate hands and knees exercise should be discontinued as a way of changing fetal position. No doubt further research is required, but it would be a mistake to use this study alone as a rationale for dismissing maternal posturing as a potentially effective means of changing fetal position. "
Aishah Bibi, Registered Midwife
Bernadette Earley, Registered Midwife
Sara Webb, Registered Midwife
Birmingham Women's Healthcare NHS Trust
(1) Kariminia et al (2004) Randomised controlled trial of effect of hands and knees posturing on incidence of occiput posterior position at birth. British Medical Journal 2004(328) pp.490-493
(2) Barnum C G (1915) The effect of gravitation on the presentation and position of the fetus. Journal of the American Medical Association. 64 pp.498-502 (3) Sears F W & Zemansky M W (1960) College Physics (3rd Edition) Addison-Wesley Publishing Company, Reading, Mass.
There has been one other small study  which looked at the short-term effects of mothers adopting a hands-and-knees position, compared to sitting, when their baby was in a lateral or posterior position. Mothers were asked to go on hands and knees, or to sit, for a short period of time, and the position of the baby was noted ten minutes afterwards. The study found that babies were far less likely to remain posterior after mothers had been on hands and knees.
This could be very useful for women whose babies are in the posterior position when they go into labour. However, since the babies' positions were only assessed for ten minutes after one session on hands and knees, this study doesn't tell us very much about the longer-term effects of alterations in the mother's posture. You can read the abstract in the Cochrane Pregnancy and Childbirth Database
Some good evidence for the effectiveness of the theory comes from its author's own practice. When Jean Sutton was appointed Principal Nurse Midwife at a maternity unit in New Zealand, she emphasised antenatal education on foetal positioning. The transfer rate from maternity unit to hospital fell from 30% to 5 % and the forceps delivery rate fell from 3-4 per month
, to 2-4 per year
, over a period of several years .
Perhaps the most valuable aspect of OFP theory is that it gives you a set of tools to use if you find your baby has turned OP during labour. Remember that many babies are OA at the start of labour, but may turn OP as the labour progresses - thought to be more likely if the mother is lying back or sitting back, and if she has an epidural. If you can move, you can
do something about it.