The present study aimed to address unanswered research questions regarding the maternal and neonatal impact of having a mood disorder in a sample of opioid dependent pregnant women. It is important to note that the outcomes examined in the present study were those of methadone-maintained pregnant women. Prior reports have indicated that psychiatric and substance use disorders, both separately and combined, are associated with poorer neonatal outcomes (e.g., 24). However, it is unclear what proportion of women in these studies was receiving treatment for either or both conditions. Of particular interest is whether pregnant drug dependent women diagnosed with a co-occurring mood disorder have worse delivery and neonatal outcomes. Because psychiatric symptoms often resolve with treatment stabilization (e.g., 25), it is unclear whether substance abuse treatment alone might improve both conditions sufficiently to ameliorate expected differences in neonatal outcomes. The present study addresses two primary questions, namely whether there are poorer maternal delivery and neonatal outcomes among women with a primary mood disorder compared to women without a current mood disorder.
Regarding the first question, the maternal delivery outcomes examined did not differ between women with and without a mood disorder. However, regarding the second question, infants of women with a mood disorder had longer NICU stays compared to infants of women without a diagnosis. In addition, a number of related neonatal birth outcomes, including EGA week at delivery, % of infants premature, and % of infants admitted to the NICU, were suggestive of poorer outcomes among infants of women with a mood disorder diagnosis.
Although the overall length of hospital stay for the neonates did not differ significantly between the two groups, infants of women with a mood disorder diagnosis spent more of their hospital stay in the NICU. The current cost of a 24-hour stay with routine observation in the NICU located in our hospital is $1417 compared to $330 for the same length of time in the newborn nursery. This difference in costs multiplied by the mean 2.5-day difference between groups in length of NICU stay works out to a $2717 increase in cost overall. This observation underscores the possible cost-effectiveness of assessing and treating co-occurring mood disorders in pregnant substance abusers.
There are several limitations of this study that should be noted. First, data were collected as part of a secondary observational study. A prospective trial designed to compare the delivery and neonatal outcomes of methadone-maintained patients with and without a current mood disorder could include more comprehensive measures and yield results supporting stronger conclusions. However, current results do support the conclusion that heroin-dependent pregnant patients with co-morbid mood disorders have neonates with increased complications resulting in longer, more costly hospital stays. The present data can inform the design of other direct comparisons between the most effective co-morbid psychiatric treatments for this patient population. Second, the sample sizes of the groups are modest and limit the power to detect differences. This limitation is tempered by the fact that differences in the expected direction were observed on a neonatal outcome measure. A larger sample size would allow for patients with current mood disorders to be further categorized as treated and untreated and may yield interesting information on the effect of treatment and no treatment on delivery and birth outcomes in this population. Third, while the present sample is similar to other samples of patients with substance use disorders (9
) the extent to which the outcomes observed in this sample generalize to the larger population of methadone maintained patients is unknown.
The present study provides initial data examining the relationship of mood disorders on delivery and neonatal outcomes in a group of pregnant women stabilized on methadone. Results suggest that poorer neonatal outcomes may persist among women diagnosed with a mood disorder and emphasize the need to assess and treat mood disorders among substance abusing pregnant women.