childbirth preparation: What the research says

Research Overview on Perineal Trauma, Prevention, and Birthing Positions

● Birthing individuals are not routinely informed regarding risks of perineal trauma and the sequelae, despite the physical and psychological impact these injuries can have. (Freeman et al., 2021)

● A survey of pregnant individuals reported that “it was important to them to know their PFD risk because it would: support informed choice, motivate them to undertake preventative activities; and allow preparation if PFD occurred.” (Bugge et al., 2020)

● “Perceived levels of control during childbirth are consistently predictive of satisfaction with childbirth, and have been proposed as the main variable related to childbirth satisfaction.” (Townsend, Brassel & Granyer 2020)

Overview on Perineal Trauma Risk (Dietz 2016)

● The pelvic floor muscles stretch 25 - 245% during birth (Svabik, Shek & Dietz, 2009)

● Forcep-assisted birth is a significant modifiable risk factor for both levator avulsion and anal sphincter injury.

● The strongest risk factors for pelvic floor dysfunction (UI, FI, POP) in clusters were vaginal birth, family history, and a perineal tear grade II or higher.

● Cesarean birth is less protective for UI than for POP and FI. However, at 6 and 12 years postpartum, any protective effect was lost.

● While Cesarean birth can be protective for some pelvic floor disorders, it should not be routinely recommended due to adverse effects on the birthing parent and infant. (King, 2021)

● Fecal incontinence prevalence is 5-25% after birth. Risk factors for severe perineal trauma during childbirth: an updated meta-analysis (Chin, 2014)

● Of 9000 primiparous at 1 year or more postpartum, 89% had uterine prolapse, 90% cystocele, 70% rectocele. Up to 65% had grade II or higher. (Durnea et al., 2014)

Levator Avulsions (DeLancey, 2016)

● Occur in 13-36% of vaginal births

● Found in 34-55% of individuals with pelvic organ prolapse, most often when 50% or more of muscle is affected

● Often involves pubovisceral portion (but not puborectalis)

● Major loss (where 50%+ of muscle is impacted) is associated with 40% reduction in pelvic floor muscle force

Perineal Trauma:

● Affects 53-79% of births, Obstetric Anal Sphincter Injury (OASIS) impacts 3-7% of individuals (Pergialiotis et al., 2020)

● A meta-analysis of 716, 031 births found the following: Instrumental delivery, midline episiotomy and a persistent occiput posterior position were associated with the higher risk of developing severe perineal lacerations. Mediolateral episiotomy did not increase, but was also not protective against perineal lacerations. (Pergialiotis et al., 2020)

Prevention:

● Dieb et al., 2020, provided education in digital perineal massage, pelvic floor muscle training, and education on prevention of pelvic floor disorders to 200 pregnant individuals at 36 weeks. Compared to the control group, these individuals had statistically significant decreases in perineal tears, episiotomy and postnatal pain. They also were more likely to have a grade I or II tear vs more significant tears in the control group, and required less need for analgesia during hospital stay.

● A systematic review and meta-analysis of 11 RCTs with 3467 individuals found that antenatal perineal massage significantly reduced incidence of episiotomies and perineal tears, particularly 3rd and 4th degree tears. They also had better wound healing and less perineal pain, reduced length of second stage of labor, reduced fecal incontinence, and improvement in Apgar scores at 1 and 5 min. (Abdelhakim et al., 2020)

● A systematic review and meta-analysis of 9 RCTs with 3374 individuals found that perineal massage performed during and between pushes during the second stage of labor led to a significantly lower risk of severe (grade III and IV) perineal tears. (Aquino et al., 2020)

● Neta et al. (2022) compared perineal trauma in 40 individuals provided with coached vocalization by physical therapists for second stage of labor to 171 controls. Those who were coached in vocalization had a statistically significant decrease in more severe trauma (greater than 2cm tears).

● Aasheim et al. (2017) reviewed eight trials involving 11,651 randomized women. There was a significant effect of warm compresses on reduction of third- and fourth-degree tears. There was also a significant effect towards favoring massage versus hands off to reduce third- and fourth-degree tears. Hands off (or poised) versus hand on showed no effect on third- and fourth-degree tears, but we observed a significant effect of hands off on reduced rate of episiotomy.

Position During Labor and Birth:

● ACOG recommends for most people giving birth “no one position needs to be mandated nor prescribed” (2017)

● A systematic review and meta-analysis of 8 RCTs found that flexible sacrum positions (kneeling, sidelying, birthing stool/squatting) led to shorter duration of the second stage of labor. They concluded that, “laboring women should be encouraged to choose her comfortable birth position.”(Berta et al., 2019)

● Gupta et al. (2017) in a Cochrane Review of 30 studies examining birthing position for individuals who had epidural anesthesia found benefits to upright postures including a small reduction in the duration of second stage of labor, reduction in episiotomy and reduction in assisted deliveries. However, they noted increased risk of blood loss and second degree tears.

● Hickey and Savage (2019) compared the use of a peanut ball to support changing position regularly for 341 individuals with epidural anesthesia during labor. They found that the use of a peanut ball led to a 50% reduction in C-section rates and reduced the first and second stage of labor.

● Evander et al. (2015) examined birth position and risk of OASIS in 113,000 birthing individuals. They found that “compared with sitting position, lateral position has a slightly protective effect in nulliparous women whilst an increased risk is noted among women in the lithotomy position, irrespective of parity. Squatting and birth seat position involve an increase in risk among parous women.”

● Simarro et al. (2017) found that the adoption of defined postural changes for a defined length of time (5-30 mins) during the passive phase of the second stage of labor is significantly associated with a shorter second stage of labor, less instrumental deliveries and cesarean sections and a better perineal outcome (significantly less episiotomies and no third-degree perineal tears in the experimental group).

References

Abdelhakim, A. M., Eldesouky, E., Elmagd, I. A., Mohammed, A., Farag, E. A., Mohammed, A. E., ... & Abdel-Latif, A. A. (2020). Antenatal perineal massage benefits in reducing perineal trauma and postpartum morbidities: a systematic review and meta-analysis of randomized controlled trials. International urogynecology journal, 31(9), 1735-1745.

Aasheim V, Nilsen ABV, Reinar LM, Lukasse M. (2017). Perineal techniques during the second stage of labour for reducing perineal trauma. Cochrane Database Syst Rev. 2017 Jun 13;6(6)

Berta, M., Lindgren, H., Christensson, K., Mekonnen, S., & Adefris, M. (2019). Effect of maternal birth positions on duration of second stage of labor: systematic review and meta-analysis. BMC pregnancy and childbirth, 19(1), 1-8.

Bugge, C., Strachan, H., Cheyne, H., Wilson, D., Pringle, S., & Hagen, S. (2020). Investigating pregnant women’s and heathcare professional’s views about knowing a woman’s individual risk of future pelvic floor dysfunction: A feasibility study for a randomised controlled trial. In Proceedings of UKCS meeting, https://ukcs. uk. Net.

Chin, K. (2014). Obstetrics and fecal incontinence. Clinics in colon and rectal surgery, 27(03), 110-112.

DeLancey, J. O. (2016). What’s new in the functional anatomy of pelvic organ prolapse?. Current opinion in obstetrics & gynecology, 28(5), 420.

Dieb, A. S., Shoab, A. Y., Nabil, H., Gabr, A., Abdallah, A. A., Shaban, M. M., & Attia, A. H. (2020). Perineal massage and training reduce perineal trauma in pregnant women older than 35 years: a randomized controlled trial. International urogynecology journal, 31(3), 613-619.

Dietz, H. P., Wilson, P. D., & Milsom, I. (2016). Maternal birth trauma: why should it matter to urogynaecologists?. Current Opinion in Obstetrics and Gynecology, 28(5), 441-448.

Durnea, C. M., Khashan, A. S., Kenny, L. C., Durnea, U. A., Smyth, M. M., & O’Reilly, B. A. (2014). Prevalence, etiology and risk factors of pelvic organ prolapse in premenopausal primiparous women. International urogynecology journal, 25(11), 1463-1470.

Elvander, C., Ahlberg, M., Thies-Lagergren, L., Cnattingius, S., & Stephansson, O. (2015). Birth position and obstetric anal sphincter injury: a population-based study of 113 000 spontaneous births. BMC pregnancy and childbirth, 15(1), 1-9.

Freeman, R. M., de Leeuw, J. W., & Wilson, P. D. (2021). Maternal birth trauma and its consequences: time to raise awareness. International Urogynecology Journal, 32(7), 1609-1610.

Gupta, J. K., Sood, A., Hofmeyr, G. J., & Vogel, J. P. (2017). Position in the second stage of labour for women without epidural anaesthesia. Cochrane database of systematic reviews, (5).

Hickey, L., & Savage, J. (2019). Effect of peanut ball and position changes in women laboring with an epidural. Nursing for women's health, 23(3), 245-252.

King, J. (2021). Are there adverse outcomes for child health and development following caesarean section delivery? Can we justify using elective caesarean section to prevent obstetric pelvic floor damage?. International Urogynecology Journal, 32(7), 1963-1969.

Neta, J. N., Amorim, M. M., Guendler, J., Delgado, A., Lemos, A., & Katz, L. (2022). Vocalization during the second stage of labor to prevent perineal trauma: A randomized controlled trial. European Journal of Obstetrics & Gynecology and Reproductive Biology.

Pergialiotis, V., Bellos, I., Fanaki, M., Vrachnis, N., & Doumouchtsis, S. K. (2020). Risk factors for severe perineal trauma during childbirth: an updated meta-analysis. European Journal of Obstetrics & Gynecology and Reproductive Biology, 247, 94-100.

Simarro et al (2017). A Prospective Randomized Trial of Postural Changes vs Passive Supine Lying during the Second Stage of Labor under Epidural Analgesia. Medical Sciences. Mar; 5(1): 5.

Svabik, K., Shek, K. L., & Dietz, H. P. (2009). How much does the levator hiatus have to stretch during childbirth?. BJOG: An International Journal of Obstetrics & Gynaecology, 116(12), 1657-1662.

Townsend, M. L., Brassel, A. K., Baafi, M., & Grenyer, B. F. (2020). Childbirth satisfaction and perceptions of control: postnatal psychological implications. British Journal of Midwifery, 28(4), 225-233.