What are the differences in risks of adverse pregnancy outcomes based on the level of pre-pregnancy specialist mental health care?

In a recent study published in the Lancet Psychiatry, researchers screened data of two million women aged ≥18 years registered in England’s National Health Service (NHS) to review the evidence on the effects of pre-existing maternal mental health illnesses on increased risk of adverse obstetric and neonatal outcomes, such as preterm births, babies small for gestational age (SGA), stillbirth, and fetal and neonatal death compared to women without a history of mental illnesses.

Specifically, they stratified risks from composite indicators for neonatal adverse outcomes and maternal morbidity according to the highest level of pre-pregnancy specialist mental health care sought by these women (as a proxy for the severity of illness).

Examples include psychiatric hospital admission, crisis resolution team (CRT) contact, or specialist community care contact, and the time of the most recent care contact seven years before pregnancy. This helped the researchers distinguish pregnant women’s mental health histories.

Study: Obstetric and neonatal outcomes in pregnant women with and without a history of specialist mental health care: a national population-based cohort study using linked routinely collected data in England. Image Credit: Iryna Inshyna/Shutterstock.com

Background

Previously, multiple reviews investigating the effects of mental illnesses in pregnant women and their impact on obstetric and neonatal outcomes in most administrative datasets have fetched incomplete and inconsistent evidence, especially for depressive disorders and anxiety.

This data is crucial to identify women most likely to benefit from community perinatal mental health models of care integrated with midwifery care.

About the study

In the present study, researchers searched the MEDLINE database from inception to May 21, 2023, to identify women with a gestation period of at least 24 weeks and who gave a singleton birth between April 1, 2014, and March 31, 2018, from the England NHS dataset.

Further, they categorized specialist mental healthcare experiences into the highest, middle, and lowest levels. Seeking admission to a psychiatric ward was considered the highest level of care, and community-based care was the lowest level. Likewise, the team noted the time of most recent mental healthcare contact, ranging between >5 to <1 year before pregnancy.

Hospital Episode Statistics (HES) records all care episodes in general NHS hospitals. So, the researchers used HES data to know the maternal age, parity, ethnicity, and pre-existing morbidities.

They derived their socioeconomic deprivation status from rankings of the Index of Multiple Deprivation 2019 (IMD).

The England NHS maintains a national dataset of its specialist mental health care programs, which remains linked at the patient level to the HES and the personal demographics service (PDS) birth notifications. This health service delivery data is collected routinely.

The primary study outcomes were two composite adverse outcome indicators capturing neonatal and maternal morbidity, preterm birth before 37 weeks of gestation, a baby born SGA, and neonatal death within seven days of delivery.

Finally, the team used a logistic regression model to estimate odds ratios (ORs), adjusted ORs, and their 95% confidence intervals (CIs).

Results

Of the 2,081,043 women constituting the analytic sample of this study, 151,770, i.e., 7·3%, at least once contacted a specialist mental health care before pregnancy onset. There were 7,247 severe mental illness cases as they sought admission to a psychiatric hospital at least once. 29,770 and 114,753 women also had at least one CRT contact, and one specialist community contact, respectively.

More recent and one-on-one contact with specialist mental health care before pregnancy onset increased risks of adverse obstetric and neonatal outcomes as that reflected a more severe mental illness.

Intriguingly, these associations remained significant even after accounting for these women’s age, parity, ethnicity, maternal comorbidities, and socioeconomic status.

Conclusions

The UK’s National Health Service (NHS) has set up specialist community perinatal mental health teams to provide care and counseling to women with severe mental illnesses. Women can seek these services in the pre-pregnancy, pregnancy, and postnatal periods. 

However, moving forward, asking mothers about contacting specialist mental healthcare services during the initial obstetric risk assessment or before the onset of pregnancy could help identify women at the highest risk and provide care to women with complex medical and social needs. 

To conclude, a timely and detailed causal mediation analysis to assess a woman’s overall health is key to preventing adverse obstetric and neonatal outcomes.