학술논문

Antidepressants in pregnancy: applying causal epidemiological methods to understand service-use outcomes in women and long-term neurodevelopmental outcomes in exposed children
Document Type
article
Source
Health Technology Assessment, Vol 27, Iss 15 (2023)
Subject
humans
child
cohort studies
female
pregnancy
united kingdom
patient admission
mothers
depression
depressive disorder, major
outpatients
pregnancy outcome
pregnant women
live birth
secondary care
inpatients
attention deficit disorder with hyperactivity
intellectual disability
propensity score
autism spectrum disorder
autistic disorder
follow-up studies
mental health
antidepressive agents
self-injurious behavior
medical records
primary health care
emergency service, hospital
hospitals
prescriptions
receptors, serotonin
socioeconomic factors
confidence intervals
regression analysis
referral and consultation
delivery of health care
cognition
decision making
Medical technology
R855-855.5
Language
English
ISSN
1366-5278
2046-4924
Abstract
Background Antidepressants are commonly prescribed during pregnancy, despite a lack of evidence from randomised trials on the benefits or risks. Some studies have reported associations of antidepressants during pregnancy with adverse offspring neurodevelopment, but whether or not such associations are causal is unclear. Objectives To study the associations of antidepressants for depression in pregnancy with outcomes using multiple methods to strengthen causal inference. Design This was an observational cohort design using multiple methods to strengthen causal inference, including multivariable regression, propensity score matching, instrumental variable analysis, negative control exposures, comparison across indications and exposure discordant pregnancies analysis. Setting This took place in UK general practice. Participants Participants were pregnant women with depression. Interventions The interventions were initiation of antidepressants in pregnancy compared with no initiation, and continuation of antidepressants in pregnancy compared with discontinuation. Main outcome measures The maternal outcome measures were the use of primary care and secondary mental health services during pregnancy, and during four 6-month follow-up periods up to 24 months after pregnancy, and antidepressant prescription status 24 months following pregnancy. The child outcome measures were diagnosis of autism, diagnosis of attention deficit hyperactivity disorder and intellectual disability. Data sources UK Clinical Practice Research Datalink. Results Data on 80,103 pregnancies were used to study maternal primary care outcomes and were linked to 34,274 children with at least 4-year follow-up for neurodevelopmental outcomes. Women who initiated or continued antidepressants during pregnancy were more likely to have contact with primary and secondary health-care services during and after pregnancy and more likely to be prescribed an antidepressant 2 years following the end of pregnancy than women who did not initiate or continue antidepressants during pregnancy (odds ratioinitiation 2.16, 95% confidence interval 1.95 to 2.39; odds ratiocontinuation 2.40, 95% confidence interval 2.27 to 2.53). There was little evidence for any substantial association with autism (odds ratiomultivariableregression 1.10, 95% confidence interval 0.90 to 1.35; odds ratiopropensityscore 1.06, 95% confidence interval 0.84 to 1.32), attention deficit hyperactivity disorder (odds ratiomultivariableregression 1.02, 95% confidence interval 0.80 to 1.29; odds ratiopropensityscore 0.97, 95% confidence interval 0.75 to 1.25) or intellectual disability (odds ratiomultivariableregression 0.81, 95% confidence interval 0.55 to 1.19; odds ratiopropensityscore 0.89, 95% confidence interval 0.61 to 1.31) in children of women who continued antidepressants compared with those who discontinued antidepressants. There was inconsistent evidence of an association between initiation of antidepressants in pregnancy and diagnosis of autism in offspring (odds ratiomultivariableregression 1.23, 95% confidence interval 0.85 to 1.78; odds ratiopropensityscore 1.64, 95% confidence interval 1.01 to 2.66) but not attention deficit hyperactivity disorder or intellectual disability; however, but results were imprecise owing to smaller numbers. Limitations Several causal-inference analyses lacked precision owing to limited numbers. In addition, adherence to the prescribed treatment was not measured. Conclusions Women prescribed antidepressants during pregnancy had greater service use during and after pregnancy than those not prescribed antidepressants. The evidence against any substantial association with autism, attention deficit hyperactivity disorder or intellectual disability in the children of women who continued compared with those who discontinued antidepressants in pregnancy is reassuring. Potential association of initiation of antidepressants during pregnancy with offspring autism needs further investigation. Future work Further research on larger samples could increase the robustness and precision of these findings. These methods applied could be a template for future pharmaco-epidemiological investigation of other pregnancy-related prescribing safety concerns. Funding This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (15/80/19) and will be published in full in Health Technology Assessment; Vol. 27, No. 15. See the NIHR Journals Library website for further project information. Plain language summary About one in seven women experience depression during pregnancy. Left untreated, this may harm them and their unborn babies. However, the decision to take antidepressants during pregnancy is difficult because women often worry about the risks to their unborn baby. Research findings have been inconsistent, so women often do not have clear information to enable them to make informed decisions. We studied women’s and children’s outcomes after starting (compared with not starting) or continuing (compared with stopping) antidepressants in pregnancy. We used a large UK primary care database and several novel methods of analysis. We tracked 80,103 pregnancies of women with depression for up to 2 years after pregnancy. We also tracked 34,274 children from these pregnancies for at least 4 years to check for developmental outcomes. Women prescribed antidepressants were more likely than women not prescribed antidepressants to use general practice and mental health services during and after pregnancy, and to be prescribed antidepressants 2 years after pregnancy. This suggests that antidepressants were being prescribed to women with greater clinical need. Women who continued antidepressants in pregnancy had no higher likelihood than those who discontinued antidepressants of autism, attention deficit hyperactivity disorder or intellectual disability in their children. This should reassure women making the decision to continue taking their medications in pregnancy. Women who started antidepressants in pregnancy may possibly have had a slightly higher likelihood of autism in their children than those who did not start them. These findings were not seen in all analyses and were based on smaller numbers; therefore, they should be viewed with caution. Importantly, over 98 in every 100 children of women who initiated or continued antidepressants in pregnancy did not receive an autism diagnosis. The findings may help women and clinicians make informed decisions on treatment with antidepressants in pregnancy. Scientific summary Background Depression is common in women of childbearing age and up to one in seven women experience depression during pregnancy. Untreated depression may have serious consequences, such as distress, self-neglect and suicidal behaviour, in affected women and birth complications in their babies. Many women with depression may, therefore, encounter a situation in which they need to decide whether to start or continue an antidepressant during their pregnancy; however, the potential for resulting harm to the neurodevelopment of their offspring is a common concern. In the absence of randomised controlled trials, the information available to guide these decisions is based on observational data, which are subject to confounding. Given that maternal depression may itself lead to adverse outcomes, isolating any effect of antidepressants from the underlying depression is particularly difficult: a problem known as confounding by indication. In the absence of randomised trials, studies designed to emulate such trials and using methods to account for confounding may help triangulate results and strengthen causal inference. Objectives This research aimed to simulate two scenarios that could be tested in pregnant women with depression in a hypothetical target randomised controlled trial asking the following research questions: Does the initiation of antidepressants for depression during pregnancy affect maternal service use outcomes and childhood neurodevelopmental outcomes? Does the continuation of antidepressant use during pregnancy for depression affect maternal service use outcomes and childhood neurodevelopmental outcomes? The data were interrogated using several methods of causal inference, and assessed in relation to dose response, timing of exposure and type of antidepressants according to class and their serotonin-receptor affinity. Methods Design: This was an observational cohort design, with use of multiple methods to strengthen causal inference. Setting and participants: This took place in UK general practice. Participants were UK primary care patients, specifically pregnant women with depression. Data sources: This study used data from the Clinical Practice Research Datalink (CPRD), a large ongoing database of anonymised primary care medical records in the UK. The CPRD’s pregnancy register was used to identify the dates and stages of pregnancy, and the CPRD mother–baby link allowed for the linkage of the records of pregnant women with their live born offspring. For consenting CPRD practices in England, the primary care records were linked to Hospital Episode Statistics, which include registers for inpatient admissions, outpatient care and accident and emergency (A&E) attendance in England, and with mortality data from the Office for National Statistics and Census small-area socioeconomic data. Eligible patients: The data extract covered dates between 1 January 1995 and 31 December 2017. Within this time frame, we identified 344,720 pregnancies in the pregnancy register for which there was evidence of depressive symptoms, or prescription of an antidepressant up to 1 year before or during pregnancy. From this sample, we constructed two cohorts: (1) the pregnant women’s cohort, which contained all pregnancies for which women could be followed up for at least 2 years beyond the pregnancy end date, regardless of the pregnancy outcome or ability to link to the child; (2) the mother and child cohort, which consisted of pregnancies followed up at least until delivery that could be linked with the patient records of the children arising from these pregnancies. The pregnant women’s cohort: The exclusion criteria were (1) records for which the general practice was not yet up to standard, as defined by CPRD (n = 61,704); (2) where the patient had not yet registered with her current general practice 1 year prior to conception (n = 93,638); (3) records suggesting that the woman had transferred out of the general practice while still pregnant (n = 15,627); (4) records with