Pregnancy Hormones: The Role of Hormones in Childbirth
Hormones are chemicals released by your brain to control or regulate the activity of different systems in your body.
Hormones play a major role in the entire labour process from start to finish and throughout your entire pregnancy. These hormones help your uterus grow as your baby does. It also creates milk ducts in your breasts, changes the growth cycle of your hair and nails, allows your muscles and ligaments to relax and stretch to help birth your baby. It even helps your body cycle through to be able to get pregnant in the first place.
In many cases, your body is capable of starting labor, giving birth, and feeding your baby without intervention! Your hormones are also instrumental in the bonding and affection you feel when you hold that baby in your arms. The automatic flow of all of these hormones drives these processes and creates the changes you see throughout your pregnancy.
How do your hormones affect your labour and birth?
There are 4 main pregnancy hormones we are going to cover: Oxytocin, Adrenaline, Endorphins, and Prolactin. These birth hormones help you and your baby in many ways, including:
- Preparing your body to give birth
- Creating your labour contractions (intensity and consistency)
- Preparing your baby for labour and life outside your body
- Preparing your breasts to make milk and getting your baby ready to breastfeed
- Promoting your natural instincts for bonding and caring for your baby
By learning what these pregnancy hormones can do, you can understand what will happen during labor and birth. You can also learn how to make decisions about your care to support the optimal function of your hormones.
Oxytocin is called the “love hormone” because it is involved with lovemaking and fertility. It also helps contractions during labour, and the release of milk in breastfeeding. It makes you feel good, safe, and affectionate.
Your body will produce more and more Oxytocin gradually through pregnancy and have a huge increase during labor – especially at the end when you have a surge of it before beginning to push (said to be part of the overwhelming feeling of transition). Oxytocin creates powerful contractions in your uterus that help to thin and open the cervix (efface and dilate) and move the baby down the birth canal. It helps you release and push out the placenta, limits bleeding at the site of the placenta, and help your uterus stay contracted after birth as it shrinks to pre-baby size. During labor and birth, the pressure of the baby against your cervix signals the release of oxytocin and creates contractions.
Oxytocin levels are directly impacted by the hormone cortisol (the stress hormone which causes the fight or flight response). The more cortisol present, the lower your oxytocin levels may be.
Low levels of oxytocin during labour and birth can cause:
- Contractions to stop or slow, and make labour longer.
- Result in hemorrhage or excessive bleeding after birth.
You can promote oxytocin release during labour by:
- Staying calm, comfortable, and confident – being prepared for birth is essential to this.
- Avoiding disturbances or anything that breaks your trust or concentration (too many people, loud noises, panic, bright and busy places)
- Staying upright and using gravity to your advantage in labour and pushing.
- Stimulating your nipples (ie: pumping as a labour augmentation) and breast/chestfeeding after birth.
Endorphins are naturally occurring opiates (acting similarly to morphine and heroin on your pain receptors). When you face stress or pain, your body produces calming and pain-relieving hormones called endorphins. For people who don’t use pain medication during labour, the level of endorphins rises dramatically throughout the labour and birth process.
High endorphin levels during labour and birth can put you into what I call “Labour-Land.” It’s where your brain dissociates from what is happening and helps you cope with the contractions. Some people feel like this is an impossible state to get into, but it is greatly impacted by your ability to remain calm and in the present moment.
When a baby is born, high endorphin levels make you feel very alert. You won’t feel much (if any pain) from your delivery, and endorphins create some of the immediate bonding hormones. Interventions such as mental-altering medications (medications, epidurals, C-Sections) can impact the level of endorphins present in your body. Most studies on this have found a significant drop in endorphins when an epidural was present. A drop in endorphin levels around the 3-day mark after birth is partially to blame for the “postpartum blues” that many women experience after birth. The Baby Blues differs from postpartum depression as it only lasts 2 weeks and is due to the massive shift of hormones.
Low levels of endorphins can cause problems in labour and birth by:
- Making labour more painful and difficult to tolerate.
- Adding interventions to the process, which further escalates the lack of endorphins.
You can help your body make more endorphins by:
- Doing the mindset work ahead of time. That way, you’ll be calm, cool, and collected.
- Avoiding any distracting or unwanted interactions
- Delaying or avoiding epidural or opioids for pain relief (though certainly a good option when you feel you need it – I am not here to judge how you go through your birth process).
Adrenaline (properly called Epinephrine) is the “fight or flight” hormone that you produce to help ensure survival – it is produced when you are scared, anxious, hungry, or cold. If you feel (consciously or subconsciously) threatened during labor your body will produce more adrenaline which can slow labour or stop it altogether in the earlier stages. Our ancestors used this disruption to get to safety if there was a threat while they gave birth.
In the later stages of labour, a rise in adrenaline will also increase your prostaglandin (cervical ripening hormone) and cortisol levels to help you have the burst of energy you need to push out your baby in a vaginal birth.
Too much adrenaline can impact your labour by:
- Causing distress to the baby before birth (seen in the fetal heart rate)
- Causing contractions to stop, slow, or have an erratic pattern, and making labour longer
- It can increase the feelings of panic and pain
- Increasing interventions (pain management) due to the other listed above.
Controlling your adrenaline response can happen by:
- Staying calm, comfortable and relaxed – achieved with education and a sense of understanding of the normal progress of labour.
- Preparing and gathering information
- Having trust and confidence in your body and your innate ability to give birth.
- Having trust and confidence in your care providers and birthplace.
- Creating an environment where you feel relaxed and safe.
- Being with people who can provide comfort measures, good information, positive words, and other forms of support (your partner, doula, midwife, nurse, or doctor)
- Avoiding intrusive, painful, disruptive procedures if and whenever possible
Known as the “mothering” hormone, Prolactin production during and after labour helps the body prepare for breastfeeding (milk production, Montgomery gland development, and possibly areolar colour change). It also progresses labour and helps the newborn adjust to life outside the womb.
Prolactin’s main function is for breast milk production. High levels of prolactin, combined with the early introduction of breastfeeding, can increase caretaking behaviors and help reduce the likelihood of postpartum mood disorders.
Low levels of prolactin are rare and usually only occur in people with a pituitary issue. It can cause:
- A tougher transition for the baby after birth
- Slower or difficult growth for baby
- More difficulty adjusting to motherhood
- Breastmilk supply issues
- Immune system issues in the mother
You can help the body’s production of prolactin by:
- Waiting for labor to start on its own when safe to do so.
- Minimizing stress during labor and after birth.
- Encouraging skin to skin and keeping baby close after birth.
- Breastfeeding early and frequently (this would include pumping and hand expression too)
Maximizing the Role of Birth Hormones
As you have likely guessed, most of our typical hospital birthing rooms are not ideally designed for supporting these labour hormones. Lots of noise, people, unfamiliar people, and medical interventions can interfere with your body’s natural processes. But, good news! If you learn your options ahead of time and let people know what you would like to see happen in your birth you can control a lot of these things! Simple requests- like dimming the lights, minimizing people in and out of the room, and having some coping techniques learned before entering labour- can help calm your stress response and make you relaxed.
Of course, I’m not saying that having a beautiful and smooth birth is impossible if you are feeling stressed or have interventions like pain medications! I have worked with hundreds of birthing parents and that is absolutely not the case. This article is just to have the information and to help you make decisions that are best for you and what you want and need to feel safe, cared for, and supported – all essential for your birth experience!
Home births or Out-of-hospital birth settings with Midwives (like a Birthing Center) and one-on-one continuous labor support, like a Doula, are other options for your birth that can help you to feel more comfortable through the process depending on what you feel is best for you.
In the end, the most important thing is that you and your health care providers understand how to work with these hormone’s processes and support you through your Birth Preferences.
For more information on pregnancy hormones that affect your labour and postpartum, check out the Empowered Birth Prenatal Course. Education is one of the most effective ways to reduce fear and help you to understand your options surrounding birth!