Can Pregnancy Stall an Eating Disorder?

As a neuroscientist, one of the most fascinating topics I have encountered is the complex relationship between pregnancy and eating disorders (EDs). As someone with a 15-year-long history of anorexia, I am intimately familiar with the worries that many women with a current or past history of EDs have as they consider or become pregnant (see, for example, this opinion piece). Will they be able to carry the pregnancy through? Will the fetus develop normally? Will their child also develop an eating disorder?

But perhaps the most interesting and overlooked question is: how will the mother feel about her body during the pregnancy? It’s natural to assume that the physical changes induced by a pregnancy will be difficult to tackle for someone with a present or past ED. Yet, in my interviews, another pattern emerged: these women independently reported a ‘spontaneous’ improvement in their ED behaviors during pregnancy. Interestingly, scientific research supports this relationship, with both prospective and retrospective studies reporting that pregnancy is associated with an improvement in the symptoms of EDs (1, 2, 3, 4, 5. But see 6).

It’s important to note that women with EDs have an increased likelihood of developing postpartum depression and, unfortunately, their ED symptoms often start to re-emerge during the first six to 12 months after delivery (1, 7). This means that for women with active EDs, the pregnancy and early postpartum period are associated with a brief but significant reduction in their symptoms.

Why is that?

Spontaneous improvement is a unconscious process likely mediated by changes in the brain and body

It’s easy to assume that sheer willpower and love for their unborn child is what carries these positive changes, but that’s not how EDs work. If you could recover by choice, most EDs would be very short-lived, yet they remain some of the most persistent and debilitating mental illnesses (8). Could a transcendent love for your child unlock new behaviors within you? Perhaps, but why then do the majority of these women relapse to their serious ED behaviors during the first year postpartum? (1, 7). It’s possible that this relapse occurs as a consequence of their newborn no longer depending on their physical support (breastfeeding and pregnancy). In other words, the women may no longer feel like the ED would “hurt” their child. While that makes sense, it forces us to return to the assumption that having an eating disorder is to some extent a choice. Is that the full story?

In my interviews, I learned that this spontaneous improvement occurred at a nonconscious level, happening naturally without effort or intention.

“I abstained [from purging and restricting] during the entire pregnancy. It was strange, none of the [ED] thoughts were there. Then, six months after having my baby, I started struggling again.” —Jessica Grenzy, 41, Florida

The lack of full awareness and reflection indicates that the women were not ‘choosing’ to improve, just as they did not choose to be ill. Likewise, the recurrence of ED symptoms during the first year postpartum suggests that something intrinsic to pregnancy itself provides a temporary protective effect against EDs. It’s plausible to think that these women experienced temporary changes in their brain and body that relieved their urges to continue their ED behaviors. Understanding the underlying mechanisms of this process could transform ED treatments, but is also a scientific feat to be reckoned with.

During pregnancy and the first year postpartum, the body and brain undergo substantial and dramatic changes in hormone and neurotransmitter levels. While it’s impossible to review all of these changes here, I will focus on a few key candidates that show the most evidence and promise.

Estrogen may stall eating disorder symptoms during pregnancy

Starting from conception, estrogen, along with progesterone, gradually increases until peaking at the time of birth. Estrogen is an intriguing hormone, as research has shown it can protect against certain mental illnesses, including schizophrenia and depression (9, 10). A series of studies have also found that symptoms of depression and bipolar disorder worsen during natural hormone cycles when estrogen decreases (11). It is important to note that while estrogen does not prevent mental illness, higher levels seem to provide a protective effect (11).

It’s well-established that EDs directly impact hormone levels, and studies have found that women with anorexia and bulimia have lower levels of estrogen, with higher symptom severity associated with lower estrogen (12). A few studies have identified a correlation between an improvement in ED symptoms and pregnancy-induced increases in estrogen (13, 14). These results suggest that estrogen may indeed be the key to why some women experience a unconscious improvement in their ED symptoms during pregnancy. However, estrogen levels drop rapidly shortly after giving birth, so why does it take up to a year before women start experiencing ED symptoms again?

Eating Disorders Essential Reads

Psychological Maintenance Processes of Binge-Eating Disorder

When an Eating Disorder Isn't Just About Body Image

The possible roles of oxytocin and serotonin in improving eating disorder symptoms during the first year postpartum

“I abstained [from purging and restricting] during the entire pregnancy. It was strange, none of the [ED] thoughts were there. Then, 6 months after having my baby, I started struggling again” Jessica Grenzy, 41, Florida

Source: Jonathan Borba/Pexels

To understand this, we may need to look at other hormones and neurotransmitters. Oxytocin, known as the ‘love hormone’ for its role in bonding, rises during labor and breastfeeding. Some studies suggest it might reduce anorexia symptoms (15), but the variability in oxytocin release patterns during pregnancy complicates its impact on EDs postpartum (16).

Serotonin is another important factor that increases 1000-fold during pregnancy and the postpartum period (17). Low serotonin levels are linked to depression, and reduced serotonin activity is common in postpartum depression. While serotonin’s role in anorexia is unclear—some studies show reduced levels in anorexia (18), while others find increased activity (19, 20)—reduced serotonin is often seen in bulimia and binge-eating disorder (20, 21). The temporarily elevated serotonin during the postpartum year might help maintain and prolong the improvement in the women’s ED symptoms.

In summary, estrogen might influence ED symptom improvement during pregnancy, but postpartum maintenance is less clear. Oxytocin and serotonin likely play important roles.

Eating disorders are contextual and require community support

EDs are not a choice; they are influenced by genetic factors, environmental conditions, and personal experiences. As we explore how ED symptoms might 'spontaneously' improve during pregnancy, it's essential to prioritize support through community and evidence-based methods. Additionally, we must consider any other concurrent illnesses women may face. There may also be important differences in how pregnancy affects women with active EDs compared to those with a history of EDs. Much research remains to better understand the complex relationship between EDs and pregnancy.