Advances in Epidemiological Methods and Utilisation of Large Databases: A Methodological Review of Observational Studies on Central Nervous System Drug Use in Pregnancy and Central Nervous System Outcomes in Children

The Methodological Quality of Observational Studies Examining the Risk of Pregnancy Drug Use on Congenital Malformations Needs Substantial Improvement: A Cross-Sectional Survey

BACKGROUND AND OBJECTIVE

An increasing number of observational studies have investigated the risk of using drugs during pregnancy on congenital malformations. However, the credibility of the causal relationships drawn from these studies remains uncertain. This study aims to evaluate the potential methodological issues in existing observational studies.

METHODS

We used a stepwise approach to investigate this issue. First, we identified observational studies published in 2020 that examined the risk of congenital malformations associated with medication use during pregnancy. We assessed the methodological characteristics for establishing causality, including study design, confounding control, and sensitivity analysis, and compared them between "core clinical journals" and "general journals." For studies reporting an increased risk of congenital malformations in core clinical journals, we searched for subsequent studies addressing the same research question published between January 2021 and May 2023 to assess the consistency of the literature.

RESULTS

A total of 40 eligible studies were published in 2020, primarily focused on the safety of vitamin B12 and folic acid (n = 4), antidepressants (n = 4), and others (n = 32). Our findings suggest that only two (5.00%) studies used causal models to guide the identification of confounding, and only eight (20.00%) studies assessed the potential dose-response relationship. In all, 15 (37.50%) studies used propensity score analysis strategy to achieve "mimic-randomization." In addition, 22 studies (55.00%) performed sensitivity analyses, while 10 (45.45%) showed inconsistency with the primary outcome. Furthermore, 5 studies reported positive outcomes, whereas only 1 out of 11 studies demonstrated a positive correlation between drug usage during pregnancy and major malformations in subsequent studies.

CONCLUSION

A significant portion of the studies has failed to sufficiently consider the essential methodological characteristics required to improve the credibility of causal inferences. The increased risk of congenital malformations documented in core clinical journal was not adequately replicated in subsequent studies.

Maternal diabetes and risk of attention-deficit/hyperactivity disorder in offspring in a multinational cohort of 3.6 million mother-child pairs

Previous studies report an association between maternal diabetes mellitus (MDM) and attention-deficit/hyperactivity disorder (ADHD), often overlooking unmeasured confounders such as shared genetics and environmental factors. We therefore conducted a multinational cohort study with linked mother-child pairs data in Hong Kong, New Zealand, Taiwan, Finland, Iceland, Norway and Sweden to evaluate associations between different MDM (any MDM, gestational diabetes mellitus (GDM) and pregestational diabetes mellitus (PGDM)) and ADHD using Cox proportional hazards regression. We included over 3.6 million mother-child pairs between 2001 and 2014 with follow-up until 2020. Children who were born to mothers with any type of diabetes during pregnancy had a higher risk of ADHD than unexposed children (pooled hazard ratio (HR) = 1.16, 95% confidence interval (CI) = 1.08-1.24). Higher risks of ADHD were also observed for both GDM (pooled HR = 1.10, 95% CI = 1.04-1.17) and PGDM (pooled HR = 1.39, 95% CI = 1.25-1.55). However, siblings with discordant exposure to GDM in pregnancy had similar risks of ADHD (pooled HR = 1.05, 95% CI = 0.94-1.17), suggesting potential confounding by unmeasured, shared familial factors. Our findings indicate that there is a small-to-moderate association between MDM and ADHD, whereas the association between GDM and ADHD is unlikely to be causal. This finding contrast with previous studies, which reported substantially higher risk estimates, and underscores the need to reevaluate the precise roles of hyperglycemia and genetic factors in the relationship between MDM and ADHD.

Association between prenatal antipsychotic exposure and the risk of attention-deficit/hyperactivity disorder and autism spectrum disorder: a systematic review and meta-analysis

The paucity of evidence regarding the safety of gestational antipsychotic exposure has led to treatment discontinuation in pregnant women with severe mental health conditions. This systematic review and meta-analysis aimed to summarise the current evidence on the association between gestational antipsychotic exposure and attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in children (Study protocol registered in PROSPERO:CRD42022311354). Five studies included in our meta-analysis with around 8.6 million pregnancy episodes in nine different countries/regions. Results from our meta-analysis indicate that the heightened risks of ASD and ADHD in children gestationally exposed to antipsychotics appear to be attributable to maternal characteristics, rather than having a causal relationship with the antipsychotic exposure during pregnancy. The results underscore the importance of meticulously monitoring the neurodevelopment of children born to mothers with mental illnesses, which can facilitate early interventions and provide requisite support.

A Methodological Review of Drug-Related Toxicological Studies in Saudi Arabia

This study aimed to conduct a methodological review of drug-related toxicological studies in Saudi Arabia. A systematic review and a methodological analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline and Embase were searched for all types of studies reporting toxicological studies in the English language published until January 10, 2022. The search was conducted using both keywords and Medical Subject Headings (MeSH) terms. The methodological analysis of included studies was assessed using the Newcastle-Ottawa Scale. A total of 3,750 studies were extracted and screened. Of these, 30 observational studies (seven cohort studies and 23 cross-sectional studies) met the inclusion criteria. The methodological scores ranged from five to seven out of 10 possible points. Twelve studies had high quality, and 18 studies had moderate quality. Eight studies focused on adverse drug reactions, eight explored poisoning, four explored drug-related hospitalizations, nine explored drug-induced toxicity, and one explored drug overdose. This research project revealed that most of the drug-related toxicological studies conducted in Saudi Arabia were observational studies of moderate quality. Future studies should focus on the quality of the design and reporting.

Association Between Prenatal Exposure to Antipsychotics and Attention-Deficit/Hyperactivity Disorder, Autism Spectrum Disorder, Preterm Birth, and Small for Gestational Age

IMPORTANCE

The risk of birth and neurodevelopmental complications with prenatal exposure to antipsychotics is unclear.

OBJECTIVE

To evaluate the association between prenatal antipsychotics exposure and the risk of birth and neurodevelopmental problems.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included children born between January 2001 and January 2015 with follow-up to December 2019 who were identified by the Hong Kong Clinical Data Analysis and Reporting System. Pregnancies with maternal antidepressant/lithium exposure were removed. Primary analyses compared gestationally exposed and gestationally nonexposed individuals with propensity score fine stratification. Additional analyses included gestationally exposed individuals vs those with past exposure and a sibling-matched analysis to evaluate the effect of confounding by indication.

EXPOSURES

Prenatal antipsychotic exposure.

MAIN OUTCOMES AND MEASURES

Preterm birth (<37 gestational weeks), small for gestational age (birth weight <2 standard deviations below the mean for gestational age), and first diagnosis of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in children.

RESULTS

The cohorts included 333 749 mother-child pairs for ADHD (mean [SD] maternal age at delivery, 31.46 [5.03] years) and 411 251 pairs for ASD, preterm birth, and small for gestational age analyses (mean [SD] maternal age at delivery, 31.56 [5.01] years). There were 13 196 children (3.95%) with a diagnosis of ADHD, 8715 (2.12%) with ASD, 33 891 (8.24%) preterm, and 7009 (1.70%) who were small for gestational age. The weighted hazard ratio (wHR) was 1.16 (95% CI, 0.83-1.61) for ADHD and 1.06 (95% CI, 0.70-1.60) for ASD, while the weighted odds ratio (wOR) was 1.40 (95% CI, 1.13-1.75) for preterm birth and 1.36 (95% CI, 0.86-2.14) for small for gestational age when comparing gestationally exposed with gestationally nonexposed individuals. Additional analyses showed no association when comparing gestationally exposed individuals with those with past exposure (ADHD: wHR, 0.99; 95% CI, 0.60-1.61; ASD: wHR, 1.10; 95% CI, 0.58-2.08; preterm birth: wOR, 0.93; 95% CI, 0.70-1.24; small for gestational age: wOR, 1.21; 95% CI, 0.66-2.20) and in a sibling-matched analysis (ADHD: wHR, 0.41; 95% CI, 0.04-4.93; ASD: wHR, 0.90; 95% CI, 0.40-2.01; preterm birth: wOR, 1.25; 95% CI, 0.85-1.82; small for gestational age: wOR, 0.86, 95% CI, 0.32-2.31).

CONCLUSIONS AND RELEVANCE

In this cohort study, the findings did not suggest that prenatal antipsychotics exposure increased the risk of ADHD, ASD, or small for gestational age. In the primary analysis, there was a small increased risk of preterm birth, but additional analyses comparing gestationally exposed individuals with those with past exposure and comparing gestationally exposed with gestationally nonexposed siblings did not support an increased risk. Given the benefits of treating psychosis during pregnancy, our findings do not support a recommendation for women to discontinue receipt of their regular antipsychotic treatment during pregnancy.

The use of antipsychotic agents during pregnancy and the risk of gestational diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

Previous studies have found contradicting results with regard to the use of antipsychotics during pregnancy and the risk of gestational diabetes mellitus (GDM). We aimed to evaluate the association between antipsychotic use in pregnancy and GDM.

METHODS

A systematic literature search was conducted in PubMed, EMBASE, PsycINFO and Cochrane Library databases up to March 2019, for data from observational studies assessing the association between gestational antipsychotic use and GDM. Non-English studies, animal studies, case reports, conference abstracts, book chapters, reviews and summaries were excluded. The primary outcome was GDM. Estimates were pooled using a random effect model, with the I2 statistic used to estimate heterogeneity of results. Our study protocol was registered with PROSPERO number: CRD42018095014.

RESULTS

In total 10 cohort studies met the inclusion criteria in our systematic review with 6642 exposed and 1 860 290 unexposed pregnancies. Six studies were included in the meta-analysis with a pooled adjusted relative risk of 1.24 overall [95% confidence interval (CI) 1.09-1.42]. The I2 result suggested low heterogeneity between studies (I2 = 6.7%, p = 0.373).

CONCLUSION

We found that the use of antipsychotic medications during pregnancy is associated with an increased risk of GDM in mothers. However, the evidence is still insufficient, especially for specific drug classes. We recommend more studies to investigate this association for specific drug classes, dosages and comorbidities to help clinicians to manage the risk of GDM if initiation or continuation of antipsychotic prescriptions during pregnancy is needed.

Prenatal exposure to antipsychotic agents and the risk of congenital malformations in children: A systematic review and meta-analysis

OBJECTIVE

To evaluate the association between antipsychotic use in pregnancy and the risk of congenital malformations in children.

DATA SOURCES

Searches of PubMed, EMBASE, PsycINFO and Cochrane Library were conducted from inception to 06 January 2020 using keywords: antipsychotics, pregnancy, pregnancy complication and congenital abnormalities.

STUDY SELECTION

Of 38 reports initially identified as being of potential interest, 13 studies met our inclusion criteria: English observational studies that examined the association between gestational antipsychotic use and congenital malformations in children.

DATA EXTRACTION

Data were extracted independently by 2 investigators including the publication year, study site, study period, data source, study design, sample size, medication exposure, exposure period and pregnancy definition, exposure as well as outcome ascertainment, selection of study and comparison group, confounding adjustment, statistical analysis, and method of linkage between mother and children. Risk estimates were pooled using a random-effect model and the I² statistic was used to evaluate the degree of heterogeneity.

RESULTS

Thirteen studies met our systematic review inclusion criteria. Six studies with a total of 2 515 272 pregnancy episodes were included in our meta-analysis, which provided a pooled adjusted risk ratio of 1.23, 95% confidence interval: 0.96-1.58. The I² result showed moderate heterogeneity between studies (I² = 35.2%, P = .173).

CONCLUSION

We did not find strong evidence of an association between prenatal exposure to antipsychotic medications and the risk of congenital malformations in children. We recommend further studies investigate this association, focusing on specific medication classes and dose responses, which would help clinicians decide whether to prescribe certain antipsychotics during pregnancy.

Association between antipsychotic use in pregnancy and the risk of gestational diabetes: Population-based cohort studies from the United Kingdom and Hong Kong and an updated meta-analysis

AIMS

To investigate whether exposure to antipsychotic medications during pregnancy is associated with gestational diabetes mellitus (GDM) in United Kingdom (UK) and Hong Kong (HK) population cohorts.

METHODS

Two population-based cohort studies were conducted using data from the UK The Health Improvement Network (THIN) and HK Clinical Data Analysis and Reporting System (CDARS). Nondiabetic women who received any type of antipsychotic medicine before their first pregnancy were included in our cohorts. The exposed group comprised women who continued using antipsychotics from the start of pregnancy to delivery (continuers), while the comparison group included women who were prescribed antipsychotics before the start of pregnancy but stopped during pregnancy (discontinuers). GDM was identified using GDM diagnosis and/or clinicians reported GDM. Odds ratios (ORs) with a 95% confidence interval (CI) were calculated to assess the association between antipsychotic use during pregnancy and GDM. Propensity Score fine-stratification weighting was used to adjust for potential confounding factors.

RESULTS

3114 women with registered first pregnancies (2351 in THIN and 763 in CDARS) were included. 5.49% (2.55% in THIN and 14.55% in CDARS) were diagnosed with GDM. The adjusted OR of GDM in continuers was 0.73 (95% CI: 0.43-1.25) in THIN and 1.16 (95% CI: 0.78-1.73) in CDARS compared with discontinuers.

CONCLUSIONS

Our results do not suggest an increased risk of GDM in women who continued using antipsychotics during pregnancy compared to women who stopped. Based on these results, women should not stop their regular antipsychotics prescriptions in pregnancy due to the fear of GDM.

Associations of Prescribed ADHD Medication in Pregnancy with Pregnancy-Related and Offspring Outcomes: A Systematic Review

BACKGROUND

Increasing numbers of reproductive-aged women are using attention-deficit/hyperactivity disorder (ADHD) medications. Findings from studies exploring the safety of these medications during pregnancy are mixed, and it is unclear whether associations reflect causal effects or could be partially or fully explained by other factors that differ between exposed and unexposed offspring.

OBJECTIVES

The aim of this systematic review was to evaluate the adverse pregnancy-related and offspring outcomes associated with exposure to prescribed ADHD medication during pregnancy with a focus on how studies to date have handled the influence of confounding.

METHODS

We searched PubMed, Embase, PsycINFO, and Web of Science up to 1 July 2019 without any restrictions on language or date of publication. We included all observational studies (e.g., cohort studies, case-control studies, case-crossover studies, cross-sectional studies, and registry-based studies) with pregnant women of any age or from any setting who were prescribed ADHD medications and evaluated any outcome, including both short- and long-term maternal and offspring outcomes. Two independent authors then used the Newcastle-Ottawa Scale to rate the quality of the included studies.

RESULTS

Eight cohort studies that estimated adverse pregnancy-related and offspring outcomes associated with exposure to ADHD medication during pregnancy were included in the qualitative review. The included studies had substantial methodological differences in data sources, type of medications examined, definitions of studied pregnancy-related and offspring outcomes, types of control groups, and confounding adjustment. There was no convincing evidence for teratogenic effects according to the relative risk of pregnancy-related and offspring outcomes, and the observed differences in absolute risks were overall small in magnitude. Adjustment for confounding was inadequate in most studies, and none of the included studies adjusted for ADHD severity in the mothers.

CONCLUSION

The current evidence does not suggest that the use of ADHD medication during pregnancy results in significant adverse consequences for mother or offspring. However, the data are too limited to make an unequivocal recommendation. Therefore, physicians should consider whether the advantages of using ADHD medication outweigh the potential risks for the developing fetus according to each woman's specific circumstances. Future research should attempt to triangulate research findings based on a combination of different designs that differ in their underlying strengths and limitations and should investigate specific confounding factors, the potential impact of timing of exposure, and potential long-term outcomes in the offspring.

Real-world data on healthcare resource consumption and costs before and after kidney transplantation

End-stage renal disease (ESRD) is increasing worldwide as a consequence of population aging and increasing chronic illness. Treatment consists mostly of dialysis and kidney transplantation (KTx), and KTx offers advantages for life expectancy and long-term cost reductions compared with dialysis. This study uses the administrative database of the Lombardy Region to analyze the costs of a cohort of patients with ESRD receiving KTx, covering a time period of 24 months before transplant to 12 months after. During 2011, 276 patients underwent kidney transplantation (8.7% preemptive and 91.3% non-preemptive). In the period before transplantation, the main cost driver was dialysis (66.6% for the period from -24 to -12 months and 73.8% for the period from -12 to 0 months), while in the 12 months after KTx, the most relevant cost was surgery. The total cost -24 to -12 months pre-KTx was 35 049.2€; the cost -12 to 0 months was 36 745.9€; and the cost 12 months after KTx was 43 805.8€. Non-preemptive patients showed much higher costs both pre- and post-KTx than preemptive patients. This study highlights how KTx modifies the resource consumption and costs composition of patients with ESRD vs those undergoing dialysis treatment and how KTx may be economically beneficial, especially preemptive intervention.

Use and validity of child neurodevelopment outcome measures in studies on prenatal exposure to psychotropic and analgesic medications - A systematic review

In recent years there has been increased attention to child neurodevelopment in studies on medication safety in pregnancy. Neurodevelopment is a multifactorial outcome that can be assessed by various assessors, using different measures. This has given rise to a debate on the validity of various measures of neurodevelopment. The aim of this review was twofold. Firstly we aimed to give an overview of studies on child neurodevelopment after prenatal exposure to central nervous system acting medications using psychotropics and analgesics as examples, giving special focus on the use and validity of outcome measures. Secondly, we aimed to give guidance on how to conduct and interpret medication safety studies with neurodevelopment outcomes. We conducted a systematic review in the MEDLINE, Embase, PsycINFO, Web of Science, Scopus, and Cochrane databases from inception to April 2019, including controlled studies on prenatal exposure to psychotropics or analgesics and child neurodevelopment, measured with standardised psychometric instruments or by diagnosis of neurodevelopmental disorder. The review management tool Covidence was used for data-extraction. Outcomes were grouped as motor skills, cognition, behaviour, emotionality, or "other". We identified 110 eligible papers (psychotropics, 82 papers, analgesics, 29 papers). A variety of neurodevelopmental outcome measures were used, including 27 different psychometric instruments administered by health care professionals, 15 different instruments completed by parents, and 13 different diagnostic categories. In 23 papers, no comments were made on the validity of the outcome measure. In conclusion, establishing neurodevelopmental safety includes assessing a wide variety of outcomes important for the child's daily functioning including motor skills, cognition, behaviour, and emotionality, with valid and reliable measures from infancy through to adolescence. Consensus is needed in the scientific community on how neurodevelopment should be assessed in medication safety in pregnancy studies. Review registration number: CRD42018086101 in the PROSPERO database.