Sarah Thompson
L.Ac., CFMP, Doula
@functionalmaternity
Summary
Many of you may be familiar with hyaluronic acid. If you are it is most likely through skin care products and less through labour physiology. Yet, hyaluronic acid is one of the key chemicals in cervical ripening and may be the key to better labour outcomes.
Hyaluronic acid is naturally produced in the body through the breakdown of carbohydrates. It’s found in cartilage, and soft tissues, and makes up a large part of the body’s synovial fluid. It has a high affinity for water molecules and is a hydrator and softener of skin and cartilage.
Hyaluronic Acid and Cervical Ripening
During pregnancy, the concentration of hyaluronic acid in the cervix is relatively low, but at the onset of labour, there is a rapid and significant increase. [1] Earlier in pregnancy high amounts of cortisol from the growing and maturing baby begin to remodel the cervix. The collagen fibres of the cervix knot themselves together early in pregnancy, and as cortisol levels increase, they slowly unwind themselves making a more parallel fibre structure. In addition to the structural changes, increasing estrogen levels from the placenta stimulates prostaglandin production which gives these fibres flexibility. With its high affinity for water molecules, hyaluronic acid suspends these molecules between the newly remodelled collagen fibres of the cervix. It also produces collagenase, which breaks down the collagen fibres. As the bonds break, there are bigger gaps for the hyaluronic acid-bound water molecules to penetrate and accumulate, adding to cervical effacement.
Without enough hyaluronic acid, the cervix cannot soften or efface. This could lead to slower labour progression, or “failed” inductions. Some studies have investigated the use of hyaluronidase as a method of induction, with limited success, mostly due to the method of delivery via cervical injections. An article published in March 2024 in the American Journal of Obstetrics and Gynecology reviewing updated research on various induction methods noted the limitations on studies currently available on the use of hyaluronidase for labour induction, yet the potential for its use. [2] Several studies have shown a positive response to hyaluronidase injections in the cervix and the promotion of cervical ripening. A small study done in 2005 compared the use of hyaluronidase injections to the Foley catheter for cervical ripening. Both methods were found to be effective without adverse reactions. [3] A 2006 Cochrane review on hyaluronidase for cervical ripening and induction of labour concluded that compared to placebo, cervical injections of hyaluronidase resulted in fewer cesareans, less need for Pitocin, and increased cervical favorability after 24 hours. There were no side effects found for the mother or baby. [4]
At this time additional research has been stalled due to the biggest concern being the method of delivery via cervical injection. What these studies do is highlight the importance of natural hyaluronic acid production for healthy labour outcomes.
Nutritional Components to Hyaluronic Acid Production
Hyaluronic acid production is a positive feedback mechanism. PGFsα is necessary for hyaluronic acid synthesis, and hyaluronic acid stimulates the production of PGF2α. PGF2α is one of the primary prostaglandins produced in response to increasing estrogen levels in pregnancy.
Disaccharides make up the primary structure of hyaluronic acid, and hyaluronic acid can be 2500 disaccharides long. That’s a lot of carbohydrates! The synthesis of hyaluronic acid is dependent on minerals. Specifically, magnesium and manganese. Manganese deficiency has been associated with lower levels of hyaluronic acid in cartilage and collagen.
Supporting healthy levels of hyaluronic acid during pregnancy begins early in the third trimester by supporting healthy placental production of estrogen and prostaglandins needed for production. As well as foods rich in starches, magnesium and manganese needed for proper synthesis. Outside of natural production, consuming hyaluronic acid directly in the diet is also beneficial. Bone broth made with connective tissues, or eating bone in skin on chicken provides the hyaluronic acid found in these tissues.
Links to other resources
Websites
WebsitesBooks
BooksReal Food for Pregnancy by Lily Nichols
Film Audio, Apps and Podcasts
Film Audio, Apps and PodcastsBaby Buddy app, created by the Best Beginnings Charity
References
- El Maradny E, Kanayama N, Kobayashi H, et al. The role of hyaluronic acid as a mediator and regulator of cervical ripening. Hum Reprod. 1997;12(5):1080-1088. doi:10.1093/humrep/12.5.1080
- Sanchez-Ramos L, Levine LD, Sciscione AC, et al. Methods for the induction of labour: efficacy and safety. Am J Obstet Gynecol. 2024;230(3S):S669-S695. doi:10.1016/j.ajog.2023.02.009
- Surita FG, Cecatti JG, Parpinelli MA, Krupa F, Pinto E Silva JL. Hyaluronidase versus Foley catheter for cervical ripening in high-risk term and post-term pregnancies. Int J Gynaecol Obstet. 2005;88(3):258-264. doi:10.1016/j.ijgo.2004.12.006
- Kavanagh J, Kelly AJ, Thomas J. Hyaluronidase for cervical ripening and induction of labour. Cochrane Database Syst Rev. 2006;2006(2):CD003097. Published 2006 Apr 19. doi:10.1002/14651858.CD003097.pub2
