Most of what passes for natural childbirth “knowledge” is entirely made up. Why? Because in large part, natural childbirth advocacy is just reflexive defiance of obstetric practice without any scientific evidence to support it.
The latest natural childbirth claim to bite the dust is the insistence that upright positions improve the chances of vaginal birth.
[pullquote align=”right” cite=”” link=”” color=”” class=”” size=””]The authors set out to show that upright position improves the chance of vaginal birth, but instead found the opposite.[/pullquote]
According to Lamaze Health Birth Practice #5:
Avoid giving birth on your back and follow your body’s urges to push.
There was never any evidence to support the claim that giving birth on your back impeded vaginal delivery and now there is evidence of the opposite.
The new paper is Upright versus lying down position in second stage of labour in nulliparous women with low dose epidural: BUMPES randomised controlled trial. The authors set out to show that upright position improves the chances of vaginal birth, but instead found the opposite.
Evidence shows that lying down in the second stage of labour results in more spontaneous vaginal births in nulliparous women with epidural analgesia, with no apparent disadvantages in relation to short or longer term outcomes for mother or baby.
Surprise!
It shouldn’t have been a surprise because there had never been a study that showed that upright position was superior:
A Cochrane review of position in the second stage of labour in women without epidural showed a reduction in instrumental vaginal delivery in the upright group, although the quality of the included trials was reported to be generally poor… A Cochrane review of position in the second stage of labour for women with epidural analgesia was published in 2017 … This review included trials that compared upright with recumbent positions and suggested no effect. The risk ratio of operative birth (caesarean section or instrumental vaginal delivery) reported in the five included trials, comprising 879 women in total, was 0.97 (95% confidence interval 0.76 to 1.25)…
This is the largest study of its type ever undertaken:
Between 4 October 2010 and 31 January 2014, 3236 women were randomised and 3093 (95.6%) included in the primary analysis (1556 in the upright group and 1537 in the lying down group). Significantly fewer spontaneous vaginal births occurred in women in the upright group: 35.2% (548/1556) compared with 41.1% (632/1537) in the lying down group (adjusted risk ratio 0.86, 95% confidence interval 0.78 to 0.94). This represents a 5.9% absolute increase in the chance of spontaneous vaginal birth in the lying down group (number needed to treat 17, 95% confidence interval 11 to 40). No evidence of differences was found for most of the secondary maternal, neonatal, or longer term outcomes including instrumental vaginal delivery (adjusted risk ratio 1.08, 99% confidence interval 0.99 to 1.18), obstetric anal sphincter injury (1.27, 0.88 to 1.84), infant Apgar score
Although the authors report that there was no difference in most secondary outcomes, they also note:
Of infants born to mothers in the upright group one was a stillbirth, one experienced birth trauma, one had cardiorespiratory collapse one hour post birth, and one had suspected Erb’s palsy.
Moreover:
The duration of the active second stage of labour showed a statistically significant difference at the 1% level, with a shorter duration of labour in the lying down group (median difference of 7 minutes, 99% confidence interval 0 to 13). Other secondary maternal outcomes, such as instrumental vaginal delivery, caesarean section and perineal trauma, were suggestive of an increased risk associated with the upright position, but these differences were not statistically significant at the 1% level. For example, the incidence of episiotomy increased in the upright group (58.8%, 914/1556) compared with the lying down group (54.6%, 838/1537) (although not statistically significant at the 1% level). There seemed to be a higher incidence of obstetric anal sphincter injury in the upright group (6.7%, 104/1556) compared with the lying down group (5.3%, 81/1537), but again this difference was not statistically significant at the 1% level.
The authors conclude:
This study provides evidence that adopting a lying down position in the second stage of labour results in more spontaneous vaginal births in nulliparous women with epidural analgesia, with no apparent disadvantages for short or longer term outcomes for mother or baby. The intervention seems to be easy to adopt and is cost free. This evidence will allow pregnant women, in consultation with their healthcare providers, to make informed choices about their position in the second stage of labour.
Kudos to the authors for being willing to acknowledge that their hypothesis was disproven. My personal view is that the authors made a bit too much of their data. The actual differences between the upright group and the lying down group were so small as to be trivial. It seems to me that a more accurate conclusion is that position in labor makes no difference to the likelihood of spontaneous birth, so women should be encouraged to adopt the position that they prefer.
We don’t know if the results of the study are generalizable to multiparous women or to women who don’t have epidurals, but as I pointed out above, there’s never been any evidence that position makes any difference for those groups either.
The bottom line is that another piece of natural childbirth “wisdom” has been shown to be false. That’s not surprising since there was never any data to support it in the first place. Natural childbirth advocates simply made it up as part of their reflexive demonization of modern obstetrical practice.
