Results Summary
What was the research about?
In the United States, 10 to 15 percent of pregnant women have depression. Two ways of treating depression are taking medicine or going to talk therapy.
In this study, the research team looked at whether pregnant women with depression had a higher risk of having babies born at least three weeks too early, with a low birth weight, or were smaller than expected, compared with pregnant women without depression. The team also looked at the risk of these health problems for babies when pregnant women
- Had therapy for depression
- Took medicine for depression
- Took medicine and also had therapy for depression
What were the results?
Pregnant women with untreated depression had a higher risk of having babies too early than those without depression.
Compared with pregnant women whose depression wasn’t treated, the risk of having a baby born too early was
- The same in pregnant women in therapy for depression
- Higher in pregnant women who took medicine for depression
- Higher in pregnant women who took medicine for depression and also had therapy
Having depression didn’t affect the risk of babies having a low birth weight or being smaller than expected at birth. Neither did any of the treatments for depression.
Who was in the study?
The study looked at health records for 91,084 women who gave birth at one California health system. Of these, 37 percent were white, 25 percent were Asian, 6 percent were African American, and 5 percent were another race or the race was unknown; 26 percent were Hispanic. Also, 13 percent of women were ages 18–24, 63 percent were ages 25–34, and 24 percent were over age 35.
The research team found that 21 percent of the women had depression or reported signs of depression. Of these women
- 7 percent were taking medicine
- 39 percent were in therapy
- 15 percent were taking medicine and were in therapy
- 39 percent weren’t getting treatment
What did the research team do?
The research team looked at health record data on depression treatment, timing of birth, and birth weight and size. The team looked for a link between women’s depression and treatment and risk of health problems in their babies.
Providers, patient groups, and pregnant women with depression gave input during the study.
What were the limits of the study?
This study included only one California health system. Results may differ in other health systems. The research team didn’t assign treatment to the women by chance. For this reason, the team can’t be sure that the risk of babies’ health problems was due to women having depression, getting treatment, or something else. Also, this study didn’t look at the different medicines or types of therapy that women may have been using.
Future research could look at whether specific kinds of depression or types of therapy have clear effects on babies’ health. Researchers could also look at pregnant women who live in other places.
How can people use the results?
Women and their doctors can use the results when considering options for treating depression during pregnancy.
Professional Abstract
Objective
(1) To measure risk to fetal health associated with maternal depression; (2) To determine whether medication and/or psychotherapy for pregnant women experiencing depression is associated with greater fetal risk than untreated depression in the context of psychiatric comorbidity
Study Design
| Design Elements | Description |
|---|---|
| Design | Observational: cohort study |
| Population | 91,084 women who gave birth between January 2014 and January 2017 |
| Interventions/ Comparators |
|
| Outcomes | Preterm delivery (before 37 weeks), low birth weight, small or gestational age |
| Timeframe | Up to 15-month follow-up for study outcomes |
In this study, researchers examined whether women with and without maternal depression differed in risk of preterm delivery (PTD), low birth weight (LBW), or being small for gestational age (SGA). Then, researchers explored whether different treatments for maternal depression—antidepressant medications and/or psychotherapy—affected risk of PTD, LBW, and SGA compared with untreated depression and no depression in relation to the presence or absence of other nondepressive mental disorders.
The study included 91,084 women who gave birth at a hospital in an integrated delivery system in California between January 2014 and January 2017. Of these, 37% were white, 25% were Asian, 6% were African American, and 5% were another or unknown race; 26% were Hispanic. In addition, 13% of women were ages 18–24, 63% were ages 25–34, and 24% were age 35 or older.
Of the total sample, 21% had been clinically diagnosed with depression or screened positive for depressive symptoms as part of a universal peripartum depression screening program. Researchers grouped these women into four categories: 7% took antidepressants, 39% received psychotherapy, 15% received a combination of antidepressants and psychotherapy, and 39% were not receiving any treatment.
Researchers used health records to track depression status, psychotherapy, and antidepressant medication, as well as birth outcomes. Statistical analyses accounted for possible confounders, such as maternal age, substance use, and infections during pregnancy.
An advisory board of patient organizations, women diagnosed with depression during pregnancy, and healthcare providers provided input on the study.
Results
Compared with women without depression, women with a clinical diagnosis or positive screening of depression who did not receive any treatment
- Were at higher risk of PTD (adjusted hazard ratio [aHR]=1.19; 95% confidence interval [CI]: 1.091.31)
- Were not at increased risk of having babies with LBW or who were SGA
When comparing women in treatment with those not in treatment among those with a clinical diagnosis or positive screening of depression
- Women in psychotherapy alone did not differ in risk of PTD (aHR=0.94; 95% CI: 0.83, 1.07).
- Women who used antidepressants (aHR=1.40; 95% CI: 1.16, 1.70) or a combination of antidepressants and psychotherapy (aHR=1.19; 95% CI: 1.02, 1.39) had a higher risk of PTD.
- Neither antidepressant medication nor psychotherapy during pregnancy had any significant association with LBW or SGA.
Limitations
This study took place in California; results may be different elsewhere. Researchers did not randomly assign the women with depression to receive different treatments, nor did they account for type or duration of depression or medication dosages. These differences may affect risk to fetal health. In addition, researchers did not examine different types of psychotherapy.
Conclusions and Relevance
In this study, maternal depression, compared with no depression, was associated with an increased risk of PTD. The use of antidepressants in pregnancy further strengthened the association with PTD.
Future Research Needs
Future research could examine the effectiveness of different types of psychotherapy in mitigating risk of PTD. Studies could consider duration and severity of depression and medication dosages. Researchers could examine associations between depression and birth outcomes in other locations.
Final Research Report
View this project's final research report.
Peer-Review Summary
Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.
The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments.
Peer reviewers commented, and the researchers made changes or provided responses. The comments and responses included the following:
- The reviewers expressed concern about the interpretation of the study findings given the statistical limitations that exist when testing multiple outcomes. The researchers acknowledged that the number of comparisons could increase the chance of a false-positive result and added this as a limitation of the study.
- Reviewers suggested stratifying patients by their Patient Health Questionnaire-9 scores, a measure of depression severity. The researchers stated that the scores could not be used as a marker of depression severity in this case, since they collected the measures after treatment started. The researchers explained that the initiation of treatment could have affected depression severity. The researchers added a limitation regarding the lack of a pretreatment measure of depression severity, which could confound the interpretation of study results.