Bipolar disorder (BD) is a serious psychiatric illness that occurs in 0.5% to 1.5% of individuals in the United States (Kessler et al. 1994). For women, illness onset tends to occur during the reproductive years. For those affected, the disorder is a significant source of distress, disability, loss of life through suicide, and burden on relatives and other caregivers. It is also a chronic condition characterized by high rates of relapse, suicide, persistent subsyndromal morbidity and significant psychosocial dysfunction (Strakowski et al. 2000). Therefore, prevention and treatment of this illness is particularly important to women of reproductive age.
Typically, women with BD encounter significant obstacles from the professional community with respect to pregnancy; they are often counseled to avoid pregnancy or to terminate an established pregnancy to avoid either exposure to potentially harmful medications or the risk of the current illness (Cohen et al. 1994). To make this point, women with BD seeking prepregnancy consultation regarding management of their mood disorder during pregnancy were surveyed by a tertiary care hospital. Of the sample, 45% reported having been advised to avoid pregnancy altogether by a psychiatrist or another mental health professional (Viguera et al. 2002).
Physicians caring for women with BD who are either contemplating or experiencing pregnancy face a clinical challenge: to minimize risk to the fetus while limiting the morbidity in the mother and child offspring that might result from untreated psychiatric illness. Decisions about what constitutes reasonable risk during pregnancy require shared responsibility, but ultimately rest with the informed patient. Such informed choices, coupled with close psychiatric follow-up and coordinated care with an obstetrician, are the necessary components of a model to optimize the clinical care of patients with BD during pregnancy.
Risk and Course of Bipolar Disorder During Pregnancy
There is wide agreement that the early postpartum is a period of unusually high risk of illness recurrence in patients with BD and other psychiatric illness (Kendell et al. 1987; Lier et al. 1989). In contrast, risks associated with pregnancy remain less well characterized, and there is conflicting evidence as to whether pregnancy alters the risk of recurrence of major affective illness in women. Some clinical observations suggest that pregnancy may reduce the risk of acute psychiatric illness and specifically protect against recurrences of BD and other psychotic disorders (Sharma and Persad 1995).
In 2000, Groff and colleagues presented findings suggestive of an apparent protective effect of pregnancy on the course of BD. Although these findings were proposed to support the view that pregnancy may prevent recurrences of BD, the sample may not have been representative of broader groups of women with BD (Viguera et al. 2002). Moreover, other recent research and growing clinical experience, suggest that pregnancy probably does not consistently protect against recurrences of mania or major depression in women with BD; rather, it is often a time of substantial risk of relapse, particularly following discontinuation of ongoing mood-stabilizing maintenance treatment (Viguera et al. 2002, Blehar et al. 1998). Notably, in a large, well-characterized clinical sample of women with BD, Blehar and colleagues (1998) found that nearly one-half had experienced episodes of major affective illness during at least one pregnancy. More recently, Freeman and colleagues (2002) also found that approximately one-half of a sample of women with BD became symptomatic during pregnancy.
These studies suggest that any protective effects of pregnancy on the risk of recurrences of mania or depression in women with BD are limited. They also suggest that pregnancy is likely insufficient to protect most patients from the risk of recurrence that follows discontinuation of ongoing maintenance mood-stabilizing treatment. To some extent, risk may be predicted by past history of illness frequency or severity and, also by a history of prolonged wellness or proven ability to tolerate long periods without mood-stabilizing treatment. Clearly, more studies that control specifically for past illness, BD subtypes, and treatment status are required to clarify the course of BD during pregnancy.
Risk and Course of Bipolar Disorder During the Postpartum Period
In contrast to the course of BD during pregnancy, for which there are little data, the course of this disorder in the postpartum period has received far more study. For more than a century, this period has been recognized consistently as a time of vulnerability to relapse of mood disorders. Among women with BD, the recurrence rate in the postpartum period (i.e., 3 to 6 months after delivery) have ranged from 20% to 80% (Freeman et al. 2002, Blehar 1995, Viguera et al. 2000). Interestingly, these rates have tended, in more recent studies, to increase to well above 50% (with rates ranging from 67% to 82%). This may reflect more reliable diagnosis and greater interest in the potential problems (see Blehar 1995, Freeman et al. 2002, Viguera et al. 2000).
BD is also closely associated with postpartum psychosis. Several studies have demonstrated that women presenting with postpartum psychosis often go on to develop BD (Rhode and Maneros 2000). The reverse has also shown to be true: women with BD often go on to present with postpartum psychosis. Postpartum psychosis is a rare condition in the general population, with incidence estimated at 1 to 2 per 1000 (0.1% to 0.2%). However, for women with BD, the rate may be increased to 100 to 200 per 1000 (10% to 20%) (Platz and Kendell 1988, Stewart et al. 1991). Postpartum psychosis is characterized by a rapid onset of symptoms, often within the first 48 to 72 hours after delivery. Patients with postpartum psychosis may present with a delirium like condition that is often indistinguishable from manic psychosis. Postpartum psychosis is a psychiatric emergency associated with high rates of infanticide and suicide (D’Orban 1979). It requires hospitalization, aggressive treatment with a mood stabilizer, and neuroleptic agents or electroconvulsive therapy. Among women with a previous history of postpartum psychosis who have a subsequent pregnancy, risk of a recurrent episode of postpartum psychosis is estimated to be as high as 90% (Austin 1992, Stewart 1988. Stewart et al. 1991).
Several investigators have evaluated the extent to which treatment can minimize this high postpartum recurrence risk (Cohen et al. 1995, Stewart et al. 1991). Most of this research concerns the use of lithium prophylaxis. When lithium was given either several weeks prior to delivery or immediately postpartum, the risk of postpartum recurrence of BD was reduced on an average by three- to fivefold, compared with the risk in untreated women (Austin 1992, Cohen et al. 1995, Stewart 1988, Stewart et al. 1991). These reports concerning lithium leave open important questions about optimal dosages and treatment timing. Also, direct comparisons with the effectiveness of alternative treatments have not yet been reported. In view of the very limited research on this important problem, further systematic study of perinatal and postpartum prophylaxis with anticonvulsants, atypical antipsychotic drugs and nonpharmacologic interventions is urgently needed.
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Dr. Nicola Gray, MD