Oxytocin: so much more than the hormone of love!

oxytocin molecule

Oxytocin & Pitocin, what’s the difference?

Oxytocin is perhaps the coolest hormone that I know of. Not only does it regulate social interactions and sexual behaviors and play a key role in maternal-infant bonding and breastfeeding, it is also so much more! Here’s a fun list of what oxytocin does in our bodies {1}:

  • stimulates uterine contractions during labor,
  • stimulates the letdown reflex during breastfeeding
  • helps the uterus shrink to minimize postpartum bleeding
  • is responsible for sexual arousal
  • promotes feelings of love, generosity, empathy, and trust
  • stimulates vasopressin receptors, making us THIRSTY (it’s not just the heavy breathing of sex and labor that make us so thirsty!)
  • interesting fact: the oxytocin receptor is thought to be involved in the etiology of autism

The blood/brain barrier

Pitocin, a synthetic form of oxytocin, is often used for labor induction and augmentation by stimulating contraction of the uterine muscles. However, here’s the thing: intravenous pitocin and natural oxytocin are not the same thing because they move through our bodies in very different ways! Oxytocin that has been released by the brain can circulate throughout the body; but, IV-injected pitocin cannot re-enter the brain very well, if at all. Of the small amount that may enter the brain, it is unclear whether it changes neuronal action significantly. Thus, the blood-brain barrier is a one way street for an oxytocin-sized molecule. The brain can be triggered to release more of its own oxytocin (especially by bringing on feelings of comfort, safety, and support… cue the doula!) but we can’t actually send oxytocin to the brain. {2} As a result:

  • the pituitary is not stimulated to release endorphins, which are natural pain-relievers; thus, why we hear of increased requests for anesthesia in inductions and labor augmentations (nevermind the encumbering wires, tubes, and monitors that restrict movement).
  • while IV pitocin can make the uterine muscle contract, it cannot provide the benefits of bonding and maternal behavior. As a matter of fact, when pitocin is injected into the bloodstream, the brain actually turns down production of its own oxytocin. A recent study has found that synthetic oxytocin increases the risk of postpartum depression and anxiety; however, it remains unclear whether those that receive IV pitocin in labor naturally make less oxytocin to begin with. {3}

Oxytocin receptors

Although your body produces oxytocin throughout your life and pregnancy, most labors don’t start until babies are term (37-42 weeks). Why, then, are we not just walking around with uterine contractions all the time? The answer lies in the oxytocin receptor sites; you do not have very many oxytocin receptor sites on your uterus in early pregnancy. In fact, one study has shown a 12-fold increase in receptor sites at 37-41 weeks compared to those at 13-17 weeks. {4} As your baby’s birthdate approaches, the number of oxytocin receptor sites increases dramatically.

Oxytocin protects you and your baby in birth!

OK, if I hadn’t yet convinced you how amazing oxytocin is, there’s still more!

There is some pretty solid evidence that oxytocin protects your baby’s brain in labor. {5} Oxytocin created in your brain travels through the body and crosses the placenta during labor to reach your baby’s brain; this calms the fetal brain during birth and makes it less vulnerable to damage from oxygen deprivation. {6} (Okay, maybe I should have put this as the first point in this blog post because HOW COOL IS THAT?)

Birth is a major oxytocin high!

Did you know that the highest concentration of oxytocin in the brain and body occurs in the 15 minutes surrounding the birth of a baby? In addition to the benefits to baby’s brain, this also facilitates the bonding of mother and child… a hormonal imprinting that will last a lifetime. {7}

Oxytocin is simple to make!

Oxytocin isn’t called the hormone of love for no reason! Here’s how to get your oxytocin flowing naturally:

  • Sexual arousal increases oxytocin release. Yes, that means sex, nipple stimulation and particularly orgasm, or a good make-out session.
  • Gentle touch/massage from your partner or doula.
  • Have a good cry… like the wiping snot away and tears rolling down your cheeks kind of cry. Do you ever get a feeling of relief or even euphoria after a big crying session? Oxytocin is one of the hormones that regulates emotional crying. If you are feeling stressed, give yourself an oxytocin boost and let it out!
  • Creating a safe, low-stress, sleepy environment could possibly promote oxytocin release, even if you can’t actually sleep. Oxytocin peaks naturally about 4-5 hours after falling asleep in order to keep cortisol (stress hormones) levels at bay to allow for a deeper sleep.
  • Choose your own adventure! Can you think of something that makes you feel warm and fuzzy, emotional or peaceful? It could be a sight, smell, taste, person or place. Make a list of those things and share them with your partner and/or doula.

{1} https://en.wikipedia.org/wiki/Oxytocin

{2} J Midwifery Womens Health. 2014 Jan; 59(1): 35–42.

{3} http://www.feinsteininstitute.org/2017/01/feinstein-institute-study-finds-medication-commonly-used-labor-associated-postpartum-depression/

{4} Am J Obstet Gynecol. 1984 Nov 15;150(6):734-41.

{5}  Prog Brain Res. 2008;170:243–257.

{6} Trends Endocrinol Metab. 2007 Aug;18(6):225-6

{7} http://scholarship.claremont.edu/cgi/viewcontent.cgi?article=1112&context=scripps_theses


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