Bipolar... and Pregnant

Bipolar disorder and pregnancy need more study but pregnancy appears to help the disorder

/ Author:  / Reviewed by: Robert Carlson, M.D

They say pregnancy can give women crazy mood swings as her hormones are in flux. So what if a woman already has bipolar disorder and becomes pregnant?

Apparently, much of the medical community just doesn't know. A review of the research reveals that there are not many studies that have helped researchers understand bipolar disorder during pregnancy.

"Discuss bipolar treatment with your OBGYN and psychiatrist."

Bipolar disorder used to be called manic depressive disorder because it involves alternating episodes of depression and either mania or "hypomania." Hypomania is not as intense as full blown mania, but it is a sustained level of higher-than-normal mood or activity.

There are four different types of bipolar disorder, mainly bipolar I, bipolar II, cyclothymia and "bipolar disorder not otherwise specified" (BP-NOS). Bipolar I tends to be the most severe, with manic or mixed episodes lasting at least a week and depressive episodes that last at least two weeks. Bipolar II is a milder form that shifts between depressive episodes and hypomanic episodes without full blown mania.

Cyclothymia is the mildest form, with episodes of hypomania that shift back and forth with mild depression for at least two years. Bipolar NOS means a person has symptoms of bipolar but not enough symptoms or the types of symptoms that allow them to be classified into one of the other three types.

Evidence has shown that having any type of bipolar disorder that is untreated can have adverse effects not only for a woman but also for her developing baby if she is pregnant. Some effects noted in research include premature birth, low birth weight or behavioral problems.

Overall, however, little is known about the relationship between bipolar disorder and pregnancy. Anecdotal evidence has led some to believe that pregnancy can have a positive effect on the disorder, just as it does in some other conditions, like multiple sclerosis and rheumatoid arthritis.

In an attempt to better understand what studies have found about bipolar disorder and pregnancy, two researchers reviewed the evidence available. Verinder Sharma, MBBS, and Carley J. Pope, BA, both of the Mood Disorder Program at Regional Mental Health Care in London, Ontario, Canada, conducted a search of the MEDLINE PsycINFO and EMBASE databases of medical articles dealing with mental health.

They pulled 70 articles that included the keywords "pregnancy, bipolar disorder, manic depressive disorder, suicide, hospitalization, pharmacotherapy and psychotherapy." They found that, in general, being pregnant appears to have a positive effect on women with bipolar disorder, but the research was so sparse and contradictory that it was difficult for them to draw many conclusions.

How Many Pregnant Women Have Bipolar?

Surprisingly, they found only four studies that dealt with the prevalence of bipolar disorder during pregnancy. Together, these seemed to indicate that all forms of bipolar disorder are rare among pregnant women.

One Italian study of 1,066 women found that 0.3 percent had bipolar I, 1.1 percent had bipolar II and 0.6 percent had bipolar NOS — but that was throughout their lifetime. During actual pregnancy, none met the criteria for bipolar I, 0.3 percent met the criteria for bipolar II and 0.2 percent met it for bipolar NOS. All of the women with bipolar II in this study had gone into remission while pregnant.

Another Swedish study of 1,795 women found similar results: just one woman had bipolar disorder. Further, it appears to be only during pregnancy that the prevalence of the disorder is low. In another study in the United Kingdom, only 1.4 percent of 446 women had symptoms of hypomania at 12 weeks of pregnancy, but this number jumped to 11.7 percent after they gave birth.

The authors also found that bipolar pregnant women also tended to have fewer and shorter episodes. Overall, pregnant women were less likely to have any mood disorder than women who were not pregnant. The authors did not find any studies discussing a first diagnosis of bipolar disorder during pregnancy, but of what they could find, it appeared that pregnancy and bipolar disorder don't appear to mix much.

In fact, one study that looked at 2,252 pregnancies among 1,162 women found the rate of bipolar symptoms dropped to nearly half when the women were pregnant. There were 338 women with bipolar II who had 641 pregnancies and 283 women with bipolar I who had 479 pregnancies. During pregnancy, 22.7 percent of these women had bipolar episodes while 51.5 percent had episodes after delivery, most of which were depressive.

The Challenge of Medication

One of the biggest difficulties presented by the research relates to the challenges of tracking women's medication during pregnancy and the possibility that women were misdiagnosed.

There are a variety of medications that are used to treat bipolar disorder, usually called mood stabilizers. One of the most common, especially for bipolar I, is lithium. Others are anticonvulsants, or anti-seizure medications, that can be used to balance out a bipolar person's moods.

However, both lithium and anticonvulsants can have negative side effects on unborn babies if they are used while a woman is pregnant. Lithium raises the risk of a rare heart defect called Ebstein's anomaly, and anticonvulsants have been linked to underdeveloped spinal cords that don't fully close, which can cause spina bifida.

Therefore, many women with bipolar disorder stop taking their mood stabilizers while they are pregnant. In the studies covered in this review, some bipolar women remained on their medication during pregnancy while others stopped taking it. This made it difficult to determine what actual effects bipolar had on pregnancy and vice versa.

A few of the more recent studies indicated that women who discontinue their mood stabilizers are more likely to then experience more episodes. In one, 85.5 percent of the women who stopped taking their medications had a recurrence of episodes compared to only 37 percent of those who continued taking their mood stabilizers. The risk of a recurrence was greater in women who discontinued their medication cold turkey instead of gradually weaning themselves off it.

Another study found that all the women who went off their mood stabilizers had a recurrence. Among those who stayed on the mood stabilizer called lamotrigine, only 30 percent had a mood episode.

Recurrence was found to be especially true among women diagnosed with bipolar II disorder and those who had an unplanned pregnancy, had been diagnosed earlier, had more recurrences per year, had been recently ill, had used antidepressants or had used anticonvulsants instead of lithium.

Yet there is not good evidence on the best way to treat bipolar in pregnant women.

"Remarkably little is known about the comparative efficacy of different medications to treat bipolar disorder during pregnancy," the authors wrote. "The risk of [birth defects] associated with use of psychotropic drugs during the first trimester should be carefully weighed against the risks to the mother and the fetus of an untreated bipolar disorder."

Another possible complication in assessing the research is that women may not be taking the right medication for their condition. Bipolar disorder is often misdiagnosed as depression, but antidepressants can worsen bipolar disorder.

Outcomes During Pregnancy Versus After Birth

One reason that research is "urgently needed" on the interaction of bipolar disorder and pregnancy, according to the reviewers, is that the findings in these studies vary considerably from what is known about bipolar disorder during the postpartum period.

After having a baby, research had already shown that bipolar women are at a much higher risk for postpartum depression. They are also at an elevated risk for extreme circumstances or behavior. They are at a higher risk for needing psychiatric hospitalization, and they are at a higher risk for attempting suicide or even causing harm to their baby.

Yet there are no known studies related to a woman's risk of suicide if she is bipolar and pregnant. Similarly, there are no known studies looking at bipolar disorder during pregnancy and hospitalization rates.

"There is no period in a woman's life when the risk of relapse of bipolar disorder is as high as in the postpartum period," Dr. Sharma said. "This is in sharp contrast to pregnancy, when women may experience an improvement in their symptoms. If we fail to understand the effect of pregnancy on bipolar disorder, we will fail to understand bipolar disorder."

So that cautious conclusion from the study is that being pregnant appears to be a good thing for women with bipolar disorder. But that "good thing" might be affected by whether she chooses to stay on her medication or not, which can also have implications for her baby.

"The possible protective effect of pregnancy could have been offset by the destabilizing effect of antidepressant use or by the abrupt withdrawal of mood stabilizers during pregnancy," they wrote. One possibility patients can discuss with their OBGYN and psychiatrist if they are concerned about side effects of mood stabilizers on their baby is to wean gradually off a medication while attempting to get pregnant or at the start of a pregnancy. Then, both doctors can monitor the woman to see if she has any episodes and decide from there whether to continue the medication.

Ultimately, any decision a woman makes regarding her treatment for bipolar disorder and her pregnancy should be discussed with both her mental health professional and her prenatal caregiver.

This review of studies on bipolar disorder and pregnancy was published August 21 in The Journal of Clinical Psychiatry. The research was funded by the Ontario Mental Health Foundation. Dr. Sharma has received grant funds, served on scientific advisory boards or done speaking engagements for the pharmaceutical companies AstraZeneca, Bristol-Myers Squibb, Cephalon, Eli Lilly, Janssen, Lundbeck, Pfizer and Servier. He has also received support from the Ontario Mental Health Foundation and the Stanley Foundation. Co-author Carley J. Pope indicated no conflicts of interest.

Review Date: 
August 27, 2012