The causes of postpartum depression are not completely clear, but a likely culprit is due to sudden changes in the levels of hormones after pregnancy. A woman’s hormonal changes are associated with depression throughout life, with the risk of depression increasing during puberty and perimenopause.

Hormone fluctuations prior to menstruation also cause depression symptoms in some women, so itÕs reasonable to assume that in some women with postpartum depression, hormones after pregnancy are to blame for the condition.

Postpartum Depression Hormones

A woman’s ovaries produce hormones that play important roles in both the menstrual cycle and pregnancy. Ovaries release eggs from follicles. Once the egg is released, the ruptured follicle produces estrogen and progesterone, which prepare the uterus for pregnancy.

If conception occurs, levels of estrogen and progesterone continue to rise during pregnancy. By the third trimester, estrogen levels are about 50 times non-pregnancy levels. Progesterone increases to 10 times the level seen before pregnancy.

After childbirth, levels of progesterone and estrogen plummet to normal levels within 24 hours. Researchers believe that this rapid reduction in hormones after pregnancy causes the “baby blues” in the first few days after pregnancy. The baby blues are a period of anxiety, mood changes and mild depression often seen in new mothers. In women who are susceptible to depression, hormone changes after pregnancy could trigger postpartum depression.

Thyroid Hormones After Pregnancy

Estrogen and progesterone levels are not the only hormonal fluctuations after pregnancy. Thyroid hormones also drop after childbirth, which appears to increase a woman’s risk of thyroid problems.

According to an article published in the Academy of Psychosomatic Medicine, the normal rate of thyroid dysfunction in the general population averages 3 to 4 percent. For 6 months after childbirth, the rate of thyroid problems in women rises to 7 percent.

Changes to thyroid hormones after pregnancy may cause hypothyroidism, which can cause depression symptoms. Possible symptoms of hypothyroidism include:

  • Cold intolerance
  • Lethargy
  • Weight gain.

Women who present with signs of postpartum depression and possible hypothyroidism will likely be checked for thyroid dysfunction. The presence of thyroid dysfunction changes the treatment options for postpartum depression.

Postpartum Depression, Hormones and Other Risk Factors

Hormonal changes after pregnancy are complex. All new mothers experience significant hormone changes after pregnancy, but relatively few develop postpartum depression. This may indicate that women who suffer from postpartum depression are more susceptible to hormonal changes than others, or that hormonal changes are only causes of postpartum depression when combined with additional depression risk factors.


British Medical Journal Group Staff. (2010). Postnatal depression: Hormone changes after childbirth. Retrieved May 11, 2010, from the Guardian website:

Childbirth Connection Staff. (2007). Hormones driving labor and birth. Retrieved May 11, 2010, from the Childbirth Connection website:

Dresner, N. (n.d.). After giving birth, how do hormone levels change? Retrieved May 11, 2010, from the EmpowHer website:

Hendrick, V.; Altshuler, L.; Suri, R. (1998). Hormonal changes in the postpartum and implications for postpartum depression. Retrieved May 11, 2010, from the Psychiatry Online website:

U.S. Department of Health and Human Services Staff. (2009). Depression during and after pregnancy. Retrieved May 11, 2010, from the WomenÕs Health website:

 Posted on : June 26, 2014