Going through labor in the right posture can make it shorter, less intense and less prone to complication, according to many midwives, who say that when mothers use the posture known as "hands and knees," it helps the baby shift into a position that eases delivery.
However, a new review of studies finds that although hand-and-knees posture can help ease back pain, most labor outcomes are not affected.
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 in South Africa
The updated review included three studies, comprising 2,794 mothers. One study focused on using this position during labor 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 fetal position, fetal position during labor and at delivery, duration of labor, 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 labor, engaging in the posture for 10-minute intervals in the final weeks of pregnancy had no benefit on the outcome of labor and did not significantly seem to help shift the position of the fetus.
In the study that focused on labor, 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 labor 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 labor 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 labor, the angle of delivery can slightly extend the diameter of the head when it is crowning.
“Labors 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 centimeter diameter of the fetal head, which is why the cervix has to dilate to 10 centimeters. A posterior position has an 11.5 centimeters presenting diameter,” Stone-Godena said. “Two centimeters in a small space is a lot.”
When a woman adopts the hands-and-knees posture during labor — 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.