Hormonal Changes After Pregnancy

Woman holding newborn baby as he holds a lock of her hair in his fist
January 18th, 2019 0 Comments

Hunter Bennett

The human body is a pretty amazing thing. The fact that it actually has the physical capacity to grow and carry an entire human baby for up to 10 months is incredible. Pregnancy does take a toll on the body – mostly in the form of physical changes, and obviously with a whole lot of discomfort. Less discussed are the hormonal changes that occur during pregnancy, and hormonal changes after pregnancy.

What happens to my hormones during pregnancy?

As most of you are aware, your hormone levels will be all over the place throughout the length of your pregnancy. While this may at times seem chaotic, it is a chaos of the most organized kind (Kumar, 2012).

These hormonal changes are necessary for supporting the growth and development of your unborn child, while also ensuring that your health is maintained as well.

Some of the largest hormonal changes throughout pregnancy are:

  • A huge increase in progesterone levels
  • Increases in estrogen levels, which peaks during the third trimesterPregnant woman hiking
  • Rises in the production and secretion of your two thyroid hormones, T3 and T4
  • Steady increases in cortisol secretion, which peaks around 40 weeks
  • Massive spike on oxytocin levels at the time of birth

These steady changes are almost entirely responsible for stimulating physical changes. Hormones are required to grow, develop, and support your unborn baby, while also preparing you for the rigors associated with childbirth.

It truly is amazing.

Related Article: Moms & Sleep- What to Expect

What happens to my hormones during birth (how does this affect the baby)?

So, we know what happens to our key hormones during pregnancy, but what about during the initiation of labor?

The onset of labor is a very complex thing (Buckley, 2015).

It is believed that the timing of labor ultimately comes down to a combination of the baby’s physical growth and maturation, in conjunction with the mother’s readiness for birth – hence the reason that it so challenging to predict.

But what we do know is what happens to our hormones during this process, and why.

You see, at the initiation of labor, the hormonal system is perfectly organized for a safe birth and an optimal postpartum period. As such, these hormonal changes facilitate the initiation of breastfeeding, and the development of the mother-child maternal attachment.

These key hormonal changes include:

  • A spike in estrogen levels (which helps activate the uterus for labor)
  • An increase in oxytocin (improving cervix function, while promoting powerful contractions and facilitating breastfeeding)
  • Cortisol spikes rapidly (to prepare the child for labor)

Unlike the observed changes discussed above, these hormonal changes only occur for a brief time period, essentially preparing both the mother and child for the rigors of birth and the immediate days after.

What happens to my hormones after giving birth?

Once birth has been completed, things start getting a little interesting. You see, you no longer have the need to provide certain hormones for the growth and development of your child. For the most part, they are already developed!

However, there are some rather severe hormonal changes that occur after childbirth that can be a bit of a shock to the system.

These include:

  • Increased prolactin production and secretion
  • Reduction in cortisol levels
  • Heightened oxytocin levels
  • A sharp decline in T3 and T4 levels
  • Progesterone production and secretion reduces
  • Estrogen production and secretion falls rapidly

Now, these changes are completely normal.

Some of them, such as the increases in prolactin and oxytocin, are essential for breast milk production and developing that maternal correction.

However some of the declines we see simply represent a normal ‘dip’ that occurs after childbirth.

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How long does it take for hormonal changes after pregnancy to subside?

Now this question itself can have a somewhat unsatisfying answer because ultimately, it depends.

In the perfect scenario, most women will start to see most of their hormone levels returning to normal around 6-8 weeks postpartum.

However, there are some caveats to this (Hendrick, 1998).

Those women who are breastfeeding will see a sustained increase in prolactin levels until they lose the capacity to continue doing so. Additionally, around 10% of pregnant women will see some sort of thyroid dysfunction after pregnancy. This can take around 6 months to correct itself after giving birth.

How do hormones affect breastfeeding?

So, taking this into consideration, you might be wondering how those hormones affect breastfeeding – and it ultimately comes down to interactions between progesterone, estrogen, and prolactin (Ostrom, 1990).

As I have already discussed in detail, throughout the pregnancy period we see a gradual increase in the level of these three hormones – however, at birth, both progesterone and estrogen levels drop, while prolactin stays elevated.

Interestingly, while prolactin is responsible for promoting the development of breast milk, its effect on causing breast milk secretion is actually blocked by estrogen and progesterone.

As a result, the sharp decline in these two hormones we see after birth is essential to allow the production of breast milk throughout the postnatal period.

Do hormones impact postpartum depression?

Postpartum depression is arguably one of the most important public health concerns that we can endeavor to address.

As a disease, postpartum depression has been suggested to impact up to 20% of new mothers, in which it can have severely negative outcomes for both mother and baby (Schiller, 2015).

Unfortunately, for the most part, the root cause of postpartum depression remains unclear.

However, there is some suggestion that the changes in hormone levels observed after pregnancy may be one of the many culprits (Meltzer-Brody, 2011).

Both estrogen and progesterone have been shown to exhibit neuroregulatory effects on the human brain, in which they essentially help maintain normal mood and cognitive function.

Subsequently, their sharp decline has been suggested to play a role in facilitating the potential onset of postnatal depression.

Now, with all this in mind, it is important to note that these changes in hormone levels do not mean that you will get postnatal depression – but rather, that you are going to be more susceptible to its development than you would be under normal circumstances.

Do hormones affect weight loss after giving birth?

As an exercise professional by trade, I tend to get a lot of questions around weight loss specifically.

Especially in those individuals who have just entered their postnatal period.

Within this, a large number of people are very interested in the role that their hormones can play in inhibiting weight loss.

I believe this comes down to the fact that around 20% of women retain a large portion of the weight they gained during pregnancy. The vast majority of these women find it extremely difficult to get that weight off (Østbye, 2012).

Now, there is a reason to believe that this may partly due to the influence of cortisol.

Cortisol Levels After Pregnancy

Cortisol is often considered the stress hormone because it is released during times of duress.

While this is a fairly normal reaction, if its increased cortisol becomes chronic, it can wreak havoc with the body. In this scenario, it drives up inflammation and reduces energy metabolism. This makes it easier to gain weight, and harder to lose it (Straub, 2016).

Although we see a significant drop in cortisol immediately after pregnancy, it should return to normal within 6-8 weeks.

If a new mother doesn’t deal with stress well, it shoots through the roof. Then inflammation becomes chronic, energy levels decline readily, and weight loss becomes near impossible.

This fact is thought to be a key reason as to why some new mothers seem to struggle to lose weight after pregnancy. It could ultimately be that they cannot handle the stress of being a new mother all that well.

The other hormone that plays a role in healthy weight management is prolactin (Stuebe, 2009).

Prolactin Levels After Pregnancy

Prolactin not only ensures the development of breastmilk but also helps metabolize fats for energy, returning the body’s metabolic rate to pre-pregnancy levels. It can also lower stress and help mitigate the negative effects of heightened cortisol levels.

However, prolactin levels only remain elevated if you continue breastfeeding.

In fact, those new mothers who continue breastfeeding for at least 3 months after giving birth tend to see a heightened rate of weight loss than those who do not (Jarlenski, 2014).

And it can all be because of prolactin.

Related Article: Exercise in the Postpartum Period: The Practical Applications

Tips on balancing hormones after giving birth

There a few simple things that you can do after giving birth to help return your hormone levels to normal as quickly as possible. In doing so, these can help you lose weight, and even reduce your risk of developing depression after your baby is born.

Get In Some Exercisewoman running on a road in red tights

Exercise can be extremely helpful during the postnatal period.

Regular moderate-intensity exercise has been shown to increase levels of prolactin.  Exercise also reduces stress and positively influencing cortisol levels (Hammer, 2000; Osman, 2014).

Sort Out Your Sleep

Poor sleep quality has been shown to cause a significant increase in cortisol. It is also linked to reductions in the levels of progesterone and estrogen (Song, 2015; Ruchała, 2017).

This ultimately means that getting your child sleeping through the night as quickly as possible is integral to getting your hormone levels back to normal!

Manage Your Stress

Last but not least, I want to touch on stress management.

Becoming a new mother will place you under a whole lot of new stress. Finding little ways to help you better manage that stress throughout the day can make a world of difference.

One of the most simple and effective methods of de-stressing comes through meditation.

Finding even ten minutes of your day to squeeze in some meditation can have a huge impact on your mental state. Meditation can aid in reducing stress and improving your hormone levels in the process (MacLean, 1997).

Take Home Message

As beautiful as it is, pregnancy places a huge toll on the human body, in which it can mess with your hormone levels as a result.

Hormonal changes during pregnancy are necessary to ensure both your health and the health of your baby. After pregnancy, they may actually have a negative impact on your health. Getting them back to normal as quickly as possible is always in your best interest!


Kumar, Pratap, and Navneet Magon. “Hormones in pregnancy.” Nigerian medical journal: journal of the Nigeria Medical Association 53.4 (2012): 179.

Buckley, Sarah J. “Executive summary of hormonal physiology of childbearing: evidence and implications for women, babies, and maternity care.” The Journal of perinatal education 24.3 (2015): 145.

Hendrick, Victoria, Lori L. Altshuler, and Rita Suri. “Hormonal changes in the postpartum and implications for postpartum depression.” Psychosomatics 39.2 (1998): 93-101.

Ostrom, K. M. “A review of the hormone prolactin during lactation.” Progress in food & nutrition science 14.1 (1990): 1-43.

Schiller, Crystal Edler, Samantha Meltzer-Brody, and David R. Rubinow. “The role of reproductive hormones in postpartum depression.” CNS spectrums 20.1 (2015): 48-59.

Meltzer-Brody, Samantha. “New insights into perinatal depression: pathogenesis and treatment during pregnancy and postpartum.” Dialogues in clinical neuroscience 13.1 (2011): 89.

Østbye, Truls, et al. “Predictors of postpartum weight change among overweight and obese women: results from the Active Mothers Postpartum study.” Journal of women’s health 21.2 (2012): 215-222.

Straub, Heather, et al. “Evidence for a complex relationship among weight retention, Cortisol and breastfeeding in postpartum women.” Maternal and child health journal 20.7 (2016): 1375-1383.

Stuebe, Alison M., and Janet W. Rich-Edwards. “The reset hypothesis: lactation and maternal metabolism.” American journal of perinatology 26.1 (2009): 81.

Jarlenski, Marian P., et al. “Effects of breastfeeding on postpartum weight loss among US women.” Preventive medicine 69 (2014): 146-150.

Hammer, Roger L., Jan Perkins, and Richard Parr. “Exercise during the childbearing year.” The Journal of perinatal education 9.1 (2000): 1.

Osman, Hibah, et al. “Interventions to reduce postpartum stress in first-time mothers: a randomized-controlled trial.” BMC Women’s health 14.1 (2014): 125.

Song, Hong-tao, et al. “Effects of sleep deprivation on serum cortisol level and mental health in servicemen.” International Journal of Psychophysiology 96.3 (2015): 169-175.

Ruchała, Marek, et al. “Obstructive sleep apnea and hormones–a novel insight.” Archives of medical science: AMS 13.4 (2017): 875.

MacLean, Christopher RK, et al. “Effects of the transcendental meditation program on adaptive mechanisms: changes in hormone levels and responses to stress after 4 months of practice.” Psychoneuroendocrinology 22.4 (1997): 277-295.

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