During pregnancy, a lot of questions revolve around the “optimal” birthing position. In my practice, when I ask my clients what their expected outcomes from adopting an optimal birthing position include, many of them hope for decreased pain while giving birth, decreased severity of perineal trauma including avoidance of a need for an episiotomy, and faster postpartum recovery time. Many of these outcomes have been studied and researchers have compared birth postures to make recommendations for “ideal or optimal” birthing positions.
There is a lot of terminology used in this blog post related to birthing positions and reference to degrees of perineal tearing. Let’s start by defining these terms.
Birthing positions can be separated into two groups; upright and lying. Upright birthing positions include standing, squatting, kneeling, hands and knees, and using a birth seat.
Lying down birth positions include lying flat on the back with the head of the bed slightly elevated, lithotomy position, and lateral lying on one’s side.
The Australian Journal of General Practice, in 2018 reported that more than 85% of those who birth vaginally will undergo some degree of perineal tear. The higher the degree of tearing, the greater risk of adverse postpartum outcomes such as infection, postpartum perineal pain, pain with sex, incontinence (bladder and/or bowel), and long term prolapse risk. First degree tears are quite superficial and typically involve the vaginal mucosa or perineal skin. A second degree tear includes the area of the perineal muscles. Third degree tears extend beyond the perineal muscles into the anal sphincter complex. Fourth degree tears involve injury to the perineum extending into the anal sphincter complex and further into the anal epithelium.
Evidence and Recommendations in the First Stage of Labour
The first stage of labour is when the uterus starts to contract and relax. This helps to thin and open the cervix as the baby makes their way into the birth canal. Research has shown that the birthing parent’s ability to ambulate and change positions during this stage decreases pain intensity thereby reducing the need for an epidural. Pain intensity is also reduced with use of a water bath during this stage. Ambulation has been shown to shorten the duration of labor by approximately 3 hours and 57 minutes, reduces the likelihood of needing forceps or vacuum assistance, and reduces the chances of a cesarean delivery compared to those who labor in this stage lying down. However, the evidence to support upright postures versus lying down in those that have an epidural is much less conclusive. An expert review in 2020, encouraged upright and mobile positions for those without epidurals and recommended that those with an epidural should be supported to assume any position and move as often as desired. Further to this point, The Society of Obstetricians and Gynaecologists of Canada made a joint policy statement supporting freedom of movement throughout labour and spontaneous pushing in the birthing parent’s preferred position.
Evidence and Recommendations in the Second Stage of Labour
The second stage of labour starts when the cervix is fully dilated and ends with the birth of the baby. Researchers have encouraged the birthing parent to consider birthing in positions that avoid direct weight on the tailbone and sacrum as typically occurs in lying down birth positions. Birthing in upright postures, frees up the mobility of the pelvic bones and is believed to help promote a birth that is less likely to need intervention such as vacuum, episiotomies or forceps assistance. Flexible sacrum positions during the second stage of labour have also been shown to reduce the incidence of severe perineal trauma. Although side lying is considered a lying down birth position, it does allow for the mobility and expansion of the sacrum and therefore, is a potential option for those with epidurals who may have difficulty birthing in upright postures.
A Cochrane review conducted in 2017 found those birthing in upright positions without epidurals were less likely to need interventions such as forceps, vacuum and episiotomies, and less likely to have abnormal fetal heart rate patterns. However, there was evidence of an increased risk of a second- degree tear in upright positions (15% risk upright versus 12% lying down).
Despite the higher risk of spontaneous tearing in upright birthing positions, there is a tradeoff worth considering with respect to the lowered risk of episiotomy. Studies have found that episiotomies can actually increase the risk of third-degree and fourth-degree perineal tears in those who have had a previous birth. Some recommendations to help reduce the risk of second degree perineal tear when upright is to apply a warm compress to slow down the birth of the baby’s head as it emerges at the vaginal opening.
Despite all of the evidence supporting upright birthing positions, the question remains, why are the rates so low for this birthing position? A Canadian survey conducted in 2009 reported almost half (47.9%) of those who delivered vaginally reported lying flat on their back at the time of birth. Almost 98% of those reporting had given birth in a hospital or clinic setting.
It has been suggested that hospital setting health care practitioners promote lying down positions in the first stage of labour as this is more convenient for fetal heart rate monitoring and allows easier access for palpating the abdomen and vagina. When one is admitted to the hospital, the birthing parent is often directed to a bed and therefore, they may naturally lie down. It is a common misconception that for those who have epidurals, upright birthing positions are not possible.
I have directed my clients to this fabulous video that describes all the possible birthing positions available to those with an epidural:
A recent podcast I was listening to from The Evidence Based Birthing Podcast, recommended some excellent strategies to help promote and support the birthing parent in their position of choice for labour.
Some of these recommendations included more extensive training for medical students and nursing students on the various upright birthing positions that may be employed. That way they will have established the skills and variability needed to further support the birthing parent during labour. For those professionals who are already practicing, it is recommended that they advocate for a birthing environment that fosters and supports the birthing person to choose their birthing position. The wider integration of Doulas may also help further promote advocacy for the birthing person’s wishes to determine what position they would like to attempt to birth in.
– Leanna, MsC. PT Pelvic Health