Obstetrical, pregnancy and socio-economic predictors for new onset severe postpartum psychiatric disorders in primiparous women
Disclaimer: This study details predictors of severe postpartum disorders and is not limited to postpartum psychosis. Although it did not find significant predictors for postpartum psychosis, the other findings may be relevant for future studies.
To improve methods of screening for and treating severe postpartum psychiatric disorders, it is necessary to consider the role that obstetrical complications and socioeconomic factors play in the development of such illnesses. In a 2017 study, researchers evaluated the extent to which medical complications associated with pregnancy/childbirth and a woman’s demographics impact the development of the following severe disorders:
postpartum depression (PPD)
postpartum acute stress reactions (PAS), and
postpartum psychosis (PP).
Investigating how these variables may contribute to rates and severity of illness will allow clinicians to better understand what causes these disorders, enabling them to create more targeted approaches for patient screening and treatment.
Using the Danish Civil Population Registration, 392,458 subjects were identified for this study. To control for confounding variables, researchers only enrolled women who were delivering their first child and had no history of psychiatric disorders prior to pregnancy. Researchers calculated the rates of illness onset based on the psychiatric contact these women had with medical professionals in their first year after childbirth. Of the 392,459 subjects, 2,941 had a record of PPD, PP, or PAS within their first year postpartum. This 0.8% prevalence is consistent with past register-based incidence estimates of the same severe illnesses (Munk-Olsen et al. 2006). However, the incidence reported here is lower than it is in comparable studies in which women self-identify for PP illness.
Based on existing literature of common medical complications associated with childbirth/pregnancy and Denmark’s Medical Birth and National Patient Register, researchers considered the following pregnancy and obstetrical complications for the study:
● Pre-eclampsia
● Eclampsia
● Gestational diabetes and/or hypertension
● Postpartum hemorrhage
● Emergency C-section
● Hyperemesis gravidarum (excessive nausea and/or vomiting)
● Fetal stress
● Preterm labor and delivery
Furthermore, socioeconomic variables such as paternal/maternal annual income, age, civil status at date of childbirth, and education level were evaluated for their influence over the development of severe postpartum psychiatric disorders.
While each woman’s psychiatric contact with medical professionals was tracked their entire first year postpartum, the majority of women experienced an onset of illness in the immediate three months following childbirth. Rates of illness onset generally declined from that point on, with the least risk for developing illness present in the last three months of the first year postpartum. The most notable observation, though, is that the types of postpartum illnesses appeared to be significantly associated with specific pregnancy/delivery-related medical complication(s) they experienced. Drawing these particular connections is useful in parsing out the possible different causes among PPD, PP, and postpartum acute stress reactions.
Factors Related to Postpartum Depression
When evaluating pregnancy and obstetrical challenges in the subgroup of women with PPD, the following factors appeared to increase susceptibility to illness:
hyperemesis gravidarum (IRR 2.69, 95% CI 1.93–3.73),
gestational hypertension (IRR 1.84, 95% CI 1.33–2.55),
preeclampsia (IRR 1.45, 95% CI 1.14–1.84) and
C-section (IRR 1.32, 95% CI 1.13–1.53).
Having experienced hyperemesis gravidarum almost tripled the risk one had for developing PPD. Additionally, young age and low income were the two greatest socioeconomic risk factors associated with PPD.
Factors Related to Postpartum Acute Stress Reaction
For postpartum acute stress reactions, the obstetrical and pregnancy complications that were significantly associated with a heightened rate of illness included the following:
hyperemesis gravidarum (IRR 1.93, 95% CI 1.38–2.71),
preterm birth (IRR 1.51, 95% CI 1.30–1.75),
gestational diabetes (IRR 1.42, 95% CI 1.03–1.97),
C-section (IRR 1.36, 95% CI 1.20–1.55),
fetal stress (IRR 1.25, 95% CI 1.10–1.41) and
postpartum hemorrhage (IRR 1.23, 95% CI 1.01–1.49).
Similarly to PPD, the experience of hyperemesis gravidarum conferred double the amount of risk for postpartum acute stress reactions when compared with women in reference categories who did not experience this complication. As for demographics, single mothers (IRR 1.15, 95% CI 1.02–1.29) and mothers who had only completed elementary school (IRR 1.52, 95% CI 1.27–1.83) were the most susceptible to the acute stress reaction.
Interestingly enough, no associations were found between the risk of developing PP and specific medical complications during pregnancy/delivery or particular demographic variables. This could potentially be due to the structure and limitations of the study and should be explored further with severe PP-focused research. The declined illness incidence rate trend following the first three months after childbirth remained consistent for all of the postpartum psychiatric disorders in question, including PP.
Limitations and Discussion:
This study has numerous limitations. First, researchers excluded subjects who had prior psychiatric history or had given birth more than once. This technique was useful in controlling for potentially confounding risk factors and further isolating obstetrical and socioeconomic variables as the only independent variables. However, previous deliveries and previous psychiatric contact are crucial predictors for the onset of PPD, postpartum acute stress, and PP, so excluding these participants could very possibly have impacted this study’s results. Another limitation encountered was the mere rarity of PP, as only 170 cases of PP were identified in the present study. This limited statistical power could potentially explain the rate discrepancies between the different disorders based on pregnancy complications and demographics. Aside from these limitations, this study had notable strengths. For example, the use of population registers for subject selection minimized sampling bias within the study cohort. With that being said, obtaining population data from other countries in addition to Denmark would have diversified the subject group much more. Lastly, a remarkable strength of the study is that it allowed for the mental health assessment of hundreds of thousands of women without requiring them to discuss their sensitive, potentially traumatic experiences.
Overall, the fact that pregnancy/obstetrical complications and socioeconomic variables disproportionately contributed to rates of illness PPD/postpartum acute stress reactions over PP begs the question, how distinct is the etiology underlying these seemingly similar postpartum disorders? Despite sharing many of the same risk factors, these illnesses clearly diverge in their pathology in ways we cannot yet confidently attribute to psychological, environmental, or biological reasons. By expanding our understanding of these disorders’ potential predictors, like obstetrical complications, we can further distinguish the biological causes underlying these disorders and create more targeted approaches for identification and treatment of susceptible mothers. In the meantime, clinicians must recognize the particularly vulnerable states of women with compromising pregnancies or socioeconomic statuses and provide such patients with meaningful support and careful monitoring to ensure proper health.
Written by Dhiya Sani, Clinical Research Intern
Meltzer-Brody, S., Maegbaek, M. L., Medland, S. E., Miller, W. C., Sullivan, P., & Munk-Olsen, T. (2017, June). Obstetrical, pregnancy and socio-economic predictors for new-onset severe postpartum psychiatric disorders in primiparous women. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429203/
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