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Obstetrics
Perinatal outcomes among women with bipolar disorder: a population-based cohort study

Presented at the 34th annual meeting of the Society for Maternal-Fetal Medicine, New Orleans, LA, Feb. 3-8, 2014.
https://doi.org/10.1016/j.ajog.2014.10.020Get rights and content

Objective

To evaluate the risk of adverse perinatal outcomes among pregnant women previously hospitalized for bipolar disorder.

Study Design

We completed a population-based cohort study of women with a singleton delivery in Ontario, Canada (2003 to 2011). Women previously hospitalized for bipolar disorder (n = 1859) or major depressive disorder (n = 3724) were each compared to women without a documented mental illness (n = 432,358). Main study outcomes were preterm birth, severe small for gestational age <3rd percentile birthweight, and severe large for gestational age >97th percentile birthweight. Secondary outcomes included stillbirth, congenital malformations, neonatal morbidity and readmission to hospital <28 days. Odds ratios (ORs) were adjusted for maternal age, parity, prepregnancy obesity, substance use, and diabetes mellitus or hypertension before or during pregnancy.

Results

Bipolar disorder (adjusted OR [AOR], 1.95; 95% confidence interval [CI], 1.68–2.26) and major depressive disorder (AOR, 1.91; 95% CI, 1.72–2.13) were each associated with preterm birth. Bipolar disorder was associated with severe large for gestational age (AOR, 1.31; 95% CI, 1.03–1.67). Major depressive disorder was associated with severe small for gestational age (AOR, 1.22; 95% CI, 1.05–1.42). Both mood disorder groups had significantly higher risk of congenital malformations, neonatal morbidity, and neonatal hospital readmission. Although study covariates explained some of the increased risk, we could not address all potential explanatory factors.

Conclusion

Women previously hospitalized for bipolar disorder are at increased risk of adverse perinatal outcomes compared with the general population. Their level of risk is comparable to women previously hospitalized for major depressive disorder. These risks must be considered in the management of pregnant women with a history of major mood disorders. Attention to potentially modifiable risk factors such as obesity, diabetes, and hypertension before and during pregnancy could reduce the risk for adverse perinatal outcomes.

Section snippets

Data sources

We used population-level health administrative data housed at the Institute for Clinical and Evaluative Sciences (ICES) in the Province of Ontario, Canada. ICES is an independent nonprofit research organization that has the capacity to link multiple provincial administrative health databases using unique identifiers for every Ontario resident with a provincial health card number. At ICES, patient-level records are linked anonymously via the Registered Persons Database (RPDB) that contains the

Results

Women with both bipolar disorder and major depressive disorder were more likely to be an adolescent than a woman without a history of mental illness, were more likely to be in the lowest income quintile, to have prepregnancy diabetes mellitus, and to have chronic hypertension (Table 1). Groups did not differ with regard to the timing or frequency of prenatal care. Twenty percent (n = 391) of women with bipolar disorder and 15% (n = 557) of women with depression had been hospitalized for mental

Comment

The newborns of women previously hospitalized for bipolar disorder were at up to 2 times higher risk for adverse perinatal outcomes, including prematurity and severe LGA birthweight. Other maternal characteristics could not fully explain this higher risk. Infants of women with major depressive disorder also had a similarly higher risk of adverse outcomes, but were more likely to be severely SGA rather than LGA.

Key strengths of this study include: (1) a large sample (n = 1859 women with bipolar

Acknowledgments

Alice Newman carried out the dataset creation and statistical analysis. Ms Newman is employed as an analyst at the Institute for Clinical Evaluative Sciences in Toronto, Ontario. Her time was funded through the operating grant that supported this study (Schizophrenia Society of Ontario). Ms Newman has consented to this acknowledgement.

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    The authors report no conflict of interest. All authors declare that no authors (nor their institutions) received payments for their efforts on this project. Within the last 3 years, S.N.V. received a one-time honorarium from MDH consulting for the development of continuing education materials related to perinatal mental health. The remaining authors report no financial disclosures.

    The operating costs of this project were funded by a peer-reviewed grant from the Schizophrenia Society of Ontario (Helen Pfohl Fund). In addition, this study was supported by the Institute for Clinical Evaluative Sciences (ICES), which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC).

    No endorsement by ICES or the Ontario MOHLTC is intended or should be inferred.

    Cite this article as: Mei-Dan E, Ray JG, Vigod SN. Perinatal outcomes among women with bipolar disorder: a population-based cohort study. Am J Obstet Gynecol 2015;212:367.e1-8.

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