Prevalence and risk factors for postnatal mental health problems in mothers of infants admitted to neonatal care: analysis of two population-based surveys in England

BACKGROUND

Previous research suggests that mothers whose infants are admitted to neonatal units (NNU) experience higher rates of mental health problems compared to the general perinatal population. This study examined the prevalence and factors associated with postnatal depression, anxiety, post-traumatic stress (PTS), and comorbidity of these mental health problems for mothers of infants admitted to NNU, six months after childbirth.

METHODS

This was a secondary analysis of two cross-sectional, population-based National Maternity Surveys in England in 2018 and 2020. Postnatal depression, anxiety, and PTS were assessed using standardised measures. Associations between sociodemographic, pregnancy- and birth-related factors and postnatal depression, anxiety, PTS, and comorbidity of these mental health problems were explored using modified Poisson regression and multinomial logistic regression.

RESULTS

Eight thousand five hundred thirty-nine women were included in the analysis, of whom 935 were mothers of infants admitted to NNU. Prevalence of postnatal mental health problems among mothers of infants admitted to NNU was 23.7% (95%CI: 20.6-27.2) for depression, 16.0% (95%CI: 13.4-19.0) for anxiety, 14.6% (95%CI: 12.2-17.5) for PTS, 8.2% (95%CI: 6.5-10.3) for two comorbid mental health problems, and 7.5% (95%CI: 5.7-10.0) for three comorbid mental health problems six months after giving birth. These rates were consistently higher compared to mothers whose infants were not admitted to NNU (19.3% (95%CI: 18.3-20.4) for depression, 14.0% (95%CI: 13.1-15.0) for anxiety, 10.3% (95%CI: 9.5-11.1) for PTS, 8.5% (95%CI: 7.8-9.3) for two comorbid mental health problems, and 4.2% (95%CI: 3.6-4.8) for three comorbid mental health problems six months after giving birth. Among mothers of infants admitted to NNU (N = 935), the strongest risk factors for mental health problems were having a long-term mental health problem and antenatal anxiety, while social support and satisfaction with birth were protective.

CONCLUSIONS

Prevalence of postnatal mental health problems was higher in mothers of infants admitted to NNU, compared to mothers of infants not admitted to NNU six months after giving birth. Experiencing previous mental health problems increased the risk of postnatal depression, anxiety, and PTS whereas social support and satisfaction with birth were protective. The findings highlight the importance of routine and repeated mental health assessments and ongoing support for mothers of infants admitted to NNU.

The impact of the Covid-19 pandemic on postnatal depression: analysis of three population-based national maternity surveys in England (2014-2020)

Background

Few studies have evaluated postnatal depression before and during the Covid-19 pandemic using comparable data across time. We used data from three national maternity surveys in England to compare prevalence and risk factors for postnatal depression before and during the pandemic.

Methods

Analysis was conducted using population-based surveys carried out in 2014 (n = 4571), 2018 (n = 4509), and 2020 (n = 4611). Weighted prevalence estimates for postnatal depression (EPDS score ≥13) were compared across surveys. Modified Poisson regression was used to estimate adjusted risk ratios (aRR) for the association between sociodemographic, pregnancy- and birth-related, and biopsychosocial factors, and postnatal depression.

Findings

Prevalence of postnatal depression increased from 10.3% in 2014 to 16.0% in 2018 (difference = +5.7% (95% CI: 4.0-7.4); RR = 1.55 (95% CI: 1.36-1.77)) and to 23.9% in 2020 (difference = +7.9% (95% CI: 5.9-9.9); RR = 1.49 (95% CI: 1.34-1.66)). Having a long-term mental health problem (aRR range = 1.48-2.02), antenatal anxiety (aRR range = 1.73-2.12) and antenatal depression (aRR range = 1.44-2.24) were associated with increased risk of postnatal depression, whereas satisfaction with birth (aRR range = 0.89-0.92) and social support (aRR range = 0.73-0.78) were associated with decreased risk before and during the pandemic.

Interpretation

This analysis indicates that Covid-19 had an important negative impact on postnatal women's mental health and may have accelerated an existing trend of increasing prevalence of postnatal depression. Risk factors for postnatal depression were consistent before and during the pandemic. Timely identification, intervention and follow-up are key to supporting women at risk, and it is essential that mechanisms to support women are strengthened during times of heightened risk such as the pandemic.

Funding

NIHR Policy Research Programme.

Trends in response rates and respondent characteristics in five National Maternity Surveys in England during 1995-2018

Background

The National Perinatal Epidemiology Unit in England has conducted five National Maternity Surveys (NMS) at varying intervals since 1995. This paper aims to describe the changes in NMS response rates over time and to compare the demographic characteristics of respondents to each NMS.

Methods

This paper is based on secondary data analysis of the NMS (cross-sectional postal surveys) from 1995 to 2018. All women aged 16 years and over who gave birth in England (and Wales in 1995) during specified time periods from 1995 to 2018 were eligible to be selected. For each survey, between 3570 and 16,000 women who were 3–6 months postpartum were selected at random by the Office for National Statistics, using birth registrations. Women could participate on paper, by telephone (from 2006) or online (from 2010).

Results

The response rate to the NMS decreased from 67% in 1995 to 29% in 2018. The decline was evident across demographic groups. In all NMS, response rates were higher in women who were older (crude prevalence ratios (PR) for 16–24 years versus 30–34 years = 0.51–0.73 (across surveys)), married (crude PR for sole versus married registrants = 0.41–0.62), born in the UK (crude PR for non UK-born versus UK-born = 0.70–0.84), and living in less deprived areas (crude PR for least versus most deprived = 0.42–0.63). However, the association between each demographic characteristic and response varied across surveys, with the youngest women, women who registered the birth of the baby in their sole name, and women living in the most deprived areas becoming relatively less likely to respond over time. In multivariable analysis in 2014 and 2018, the effects of age, marital status, country of birth and level of area deprivation on response were attenuated but all four demographic characteristics remained statistically significantly associated with response.

Conclusions

Response rates to the NMS have declined significantly during the last 23 years. The demographic characteristics associated with response were consistent across surveys, but the size of the effect varied significantly, with underrepresented groups becoming relatively less likely to participate over time. It is important to find strategies to increase response rates, particularly amongst underrepresented groups, and to validate the data collected.