The position, though it sounds awkward, "might relieve back pain by several mechanisms," said review co-author G. Justus Hofmeyr. "It might simply be a more comfortable position for some women; it might shift the pressure of the pregnant uterus from the mother's back; or, it may assist the baby to turn from the posterior position, which is thought to be associated with more back pain."
Hofmeyr is a professor with the Effective Care Research Unit at the University of Witwatersrand.
The updated review included three studies, comprising 2,794 mothers. One study focused on using this position during labour and the other two measured outcomes using the position twice a day for 10 minutes after the 37th week of pregnancy.
Reviewers measured study outcomes in terms of the change in foetal position, foetal position during labour and at delivery, duration of labour, pain scores, amount of analgesia used, method of delivery, perinatal outcomes and maternal satisfaction.
While the position seemed to provide relief from backache and possibly helped babies shift during labour, engaging in the posture for 10-minute intervals in the final weeks of pregnancy had no benefit on the outcome of labour and did not significantly seem to help shift the position of the foetus.
In the study that focused on labour, the women who tried the hands-and-knees posture for 30-minute intervals experienced a significant reduction in persistent back pain.
The study focusing on labour did not confirm with any certainty that the position is effective in changing the baby's position.
"There were more babies in the hands-and-knees group that changed position than in the control group, but the difference was not significantly different," Hofmeyr said. "While there was not yet enough evidence to recommend the posture as a method for correcting the baby's position, it may certainly be recommended for women who find that it is more comfortable, particularly for relieving back pain."
The review appears in the current issue of The Cochrane Library , a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.
The ideal position for a baby during labour and delivery is headfirst, with the back of its head facing the spine (anterior). When the back of the baby's head faces the mother's side (transverse) or spine (posterior) during labour, the angle of delivery can slightly extend the diameter of the head when it is crowning.
"Labours are statistically longer and the incidence of Caesareans is more than twice as high for women whose infants are posterior or transverse versus women whose infants are in the anterior position," said Teri Stone-Godena, certified nurse-midwife and faculty practice director in that specialty at the Yale School of Nursing.
"An anterior position generally presents with a 9.5 centimetre diameter of the foetal head, which is why the cervix has to dilate to 10 centimetres. A posterior position has an 11.5 centimetres presenting diameter," Stone-Godena said. "Two centimetres in a small space is a lot."
When a woman adopts the hands-and-knees posture during labour - face downward, with her body weight supported by their extended arms and bent knees - midwives have said it is easier for the baby to shift into a more advantageous position.
During pregnancy, midwives might recommend exercises involving the hands-and-knees position to help strengthen both the muscles that support pregnancy weight and those that women might need to rely on during labour.
"We know the hands-and-knees position helps relieve backache for those pregnant and not pregnant," Stone-Godena said. She said that using the position allows the spaces between bones of the spine to expand, so there is less chance of pinching or applying pressure to the nerves that extend from the spine. During pregnancy, the position can shift the baby's head off the mother's spine, giving temporary relief.
Some midwives recommend the posture during pregnancy as a way to turn a baby that presents in breech (feet first) position. Researchers wondered if adopting the posture as an exercise during late pregnancy might also help a baby shift into facing the right way. However, the review findings did not support that hypothesis.
For many midwives, no further research is required.
"In midwifery we have a saying, 'Listen to women,'" said Stone-Godena. "Basically that means if you take your cues from the woman you will enhance her comfort, sense of control and well being. And unless there is evidence to demonstrate the woman wants to do something unsafe, she knows what she needs. Our job as a midwife is to help her identify it. That sometimes translates into us saying, 'many women have found that this helps'-and then we suggest the hands-and-knees position."
The Cochrane Collaboration is an international non-profit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions.
Visit http://www.cochrane.org for more information.
Source: http://www.news-medical.net/
