Antipsychotic use during pregnancy and risk of specific neurodevelopmental disorders and learning difficulties in children: a multinational cohort study.

Background: Antipsychotics are commonly prescribed to treat a range of psychiatric conditions in women of reproductive age and during pregnancy, including schizophrenia, bipolar disorder, anxiety, depression, autism spectrum disorder, and insomnia. This study aimed to evaluate whether children exposed to antipsychotic medication prenatally are at increased risk of specific neurodevelopmental disorders and learning difficulties. Methods: Our population-based cohort study used nationwide register data (1 January 2000-31 December 2020) on pregnant women diagnosed with a psychiatric disorder and their live-born singletons from Denmark, Finland, Iceland, Norway, and Sweden. Cox proportional hazard regression yielded propensity score-weighted hazard ratios (aHRs) and 95% confidence intervals (CIs) for risk of intellectual-, speech or language-, learning-developmental disorders, and a composite outcome of the listed disorders. We defined poor performance as scoring within the lowest quartile on national school tests in mathematics and language arts. We estimated propensity score-weighted risk ratios (aRRs) using Poisson regression. We analysed data from Denmark separately and pooled results using random effects meta-analysis. Findings: Among 213,302 children (median follow-up: 6.7 years), 11 626 (5.5%) were exposed to antipsychotics prenatally. Adjusted risk estimates did not suggest an increased risk of neurodevelopmental disorders: aHR of 1.06 (95% CI 0.94-1.20) for the composite outcome, or for poor academic performance: aRR of 1.04 (95% CI 0.91-1.18) in mathematics, and of 1.00 (95% CI 0.87-1.15) in language arts. Results were generally consistent across individual medications, trimesters of exposure, sibling- and sensitivity analyses. Interpretation: The findings of this large multinational cohort study suggest there is little to no increased risk of child neurodevelopmental disorders or learning difficulties after prenatal exposure to antipsychotics. Our findings can assist clinicians and women managing mental illness during pregnancy. Funding: This study was funded by the NordForsk Nordic Program on Health and Welfare (Nordic Pregnancy Drug Safety Studies, project No. 83539), by the Research Council of Norway (International Pregnancy Drug Safety Studies, project No. 273366) and by the Research Council of Norway through its Centres of Excellence funding scheme (project No. 262700), and UNSW Scientia Programme Awards (PS46019, PS46019-A).

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.

Comparative Risk of Major Congenital Malformations With Antiseizure Medication Combinations vs Valproate Monotherapy in Pregnancy.

BACKGROUND AND OBJECTIVES: Valproate should be avoided in pregnancy, but it is the most effective drug for generalized epilepsies. Alternative treatment may require combinations of other drugs. Our objectives were to describe first trimester use of antiseizure medication (ASM) combinations that are relevant alternatives to valproate and determine whether specific combinations were associated with a lower risk of major congenital malformations (MCM) compared with valproate monotherapy. METHODS: We conducted a population-based cohort study using linked national registers from Denmark, Finland, Iceland, Norway, and Sweden and administrative health care data from the United States and New South Wales, Australia. We described first trimester use of ASM combinations among pregnant people with epilepsy from 2000 to 2020. We compared the risk of MCM after first trimester exposure to ASM combinations vs valproate monotherapy and low-dose valproate plus lamotrigine or levetiracetam vs high-dose valproate (≥1,000 mg/d). We used log-binomial regression with propensity score weights to calculate adjusted risk ratios (aRRs) and 95% CIs for each dataset. Results were pooled using fixed-effects meta-analysis. RESULTS: Among 50,905 pregnancies in people with epilepsy identified from 7.8 million total pregnancies, 788 used lamotrigine and levetiracetam, 291 used lamotrigine and topiramate, 208 used levetiracetam and topiramate, 80 used lamotrigine and zonisamide, and 91 used levetiracetam and zonisamide. After excluding pregnancies with use of other ASMs, known teratogens, or a child diagnosed with MCM of infectious or genetic cause, we compared 587 exposed to lamotrigine-levetiracetam duotherapy and 186 exposed to lamotrigine-topiramate duotherapy with 1959 exposed to valproate monotherapy. Pooled aRRs were 0.41 (95% CI 0.24-0.69) and 1.26 (0.71-2.23), respectively. Duotherapy combinations containing low-dose valproate were infrequent, and comparisons with high-dose valproate monotherapy were inconclusive but suggested a lower risk for combination therapy. Other combinations were too rare for comparative safety analyses. DISCUSSION: Lamotrigine-levetiracetam duotherapy in first trimester was associated with a 60% lower risk of MCM than valproate monotherapy, while lamotrigine-topiramate was not associated with a reduced risk. Duotherapy with lamotrigine and levetiracetam may be favored to treat epilepsy in people with childbearing potential compared with valproate regarding MCM, but whether this combination is as effective as valproate remains to be determined. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in people with epilepsy treated in the first trimester of pregnancy, the risk of major congenital malformations is lower with lamotrigine-levetiracetam duotherapy than with valproate alone, but similar with lamotrigine-topiramate.

Safety of GLP-1 Receptor Agonists and Other Second-Line Antidiabetics in Early Pregnancy.

Importance: Increasing use of second-line noninsulin antidiabetic medication (ADM) in pregnant individuals with type 2 diabetes (T2D) may result in fetal exposure, but their teratogenic risk is unknown. Objective: To evaluate periconceptional use of second-line noninsulin ADMs and whether it is associated with increased risk of major congenital malformations (MCMs) in the infant. Design, Setting, and Participants: This observational population-based cohort study used data from 4 Nordic countries (2009-2020), the US MarketScan Database (2012-2021), and the Israeli Maccabi Health Services database (2009-2020). Pregnant women with T2D were identified and their live-born infants were followed until up to 1 year after birth. Exposure: Periconceptional exposure was defined as 1 or more prescription fill of sulfonylureas, dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide 1 (GLP-1) receptor agonists, and sodium-glucose cotransporter 2 (SGLT2) inhibitors, or insulin (active comparator) from 90 days before pregnancy to end of first trimester. Main Outcomes and Measures: Relative risks (RRs) and 95% CIs for MCMs were estimated using log-binomial regression models, adjusting for key confounders in each cohort and meta-analyzed. Results: Periconceptional exposure to second-line noninsulin ADMs differed between countries (32, 295, and 73 per 100 000 pregnancies in the Nordics, US, and Israel, respectively), and increased over the study period, especially in the US. The standardized prevalence of MCMs was 3.7% in all infants (n = 3 514 865), 5.3% in the infants born to women with T2D (n = 51 826), and among infants exposed to sulfonylureas was 9.7% (n = 1362); DPP-4 inhibitors, 6.1% (n = 687); GLP-1 receptor agonists, 8.3% (n = 938); SGLT2 inhibitors, 7.0% (n = 335); and insulin, 7.8% (n = 5078). Compared with insulin, adjusted RRs for MCMs were 1.18 (95% CI, 0.94-1.48), 0.83 (95% CI, 0.64-1.06), 0.95 (95% CI, 0.72-1.26), and 0.98 (95% CI, 0.65-1.46) for infants exposed to sulfonylureas, DPP-4 inhibitors, GLP-1 receptor agonists, and SGLT2 inhibitors, respectively. Conclusions and Relevance: Use of second-line noninsulin ADMs is rapidly increasing for treatment of T2D and other indications, resulting in an increasing number of exposed pregnancies. Although some estimates were imprecise, results did not indicate a large increased risk of MCMs above the risk conferred by maternal T2D requiring second-line treatment. Although reassuring, confirmation from other studies is needed, and continuous monitoring will provide more precise estimates as data accumulate.

Characteristics and hormonal contraception use patterns of levonorgestrel 13.5 mg intrauterine device users in Sweden 2014-2016.

OBJECTIVES: The levonorgestrel-releasing intrauterine device containing 13.5 mg of levonorgestrel (LNG 13.5 mg IUD), Jaydess, was approved for contraception by the European Medicines Agency in 2013. We aimed to describe the characteristics of new users of LNG 13.5 mg IUD in Sweden within the first 3 years after approval (2014-2016). STUDY DESIGN: We conducted an observational, population-based study using data from the Swedish national registers. Women with the first pharmacy dispensation of LNG 13.5 mg IUD between 2014 and 2016 were followed until December 31, 2020. Descriptive analyses included demographic characteristics, duration of the use of first-time LNG 13.5 mg IUD, and contraceptive switching patterns. RESULTS: We included 38,327 women, with mean age at first-time LNG 13.5 mg IUD use of 26 (SD: 7) years. Over 80% were prescribed LNG 13.5 mg IUD by a midwife. The most common comorbidities in the year prior to LNG 13.5 mg IUD use (2%-3% prevalence) were depression, anxiety, premenstrual syndrome, and menorrhagia. The median duration of first-time LNG 13.5 mg IUD use was 2.6 years, and after use, more than 50% of women opted to continue using a hormonal intrauterine device. CONCLUSIONS: In this postmarketing drug utilization study, there were over 38,000 first-time LNG 13.5 mg IUD users in Sweden between 2014 and 2016, with an estimated median duration of use of 2.6 years. First-time LNG 13.5 mg IUD users consisted mostly of young, healthy individuals with a history of hormonal contraceptive use. Over half of the women continued using a hormonal IUD after the first LNG 13.5 mg IUD. IMPLICATIONS: The median duration of LNG 13.5 mg IUD use was 2.6 years, approaching the 3-year indicated use limit. The majority of users continued with another hormonal intrauterine device after LNG 13.5 mg IUD use.

Detection of major congenital malformations depends on length of follow-up in Swedish National Health Register Data: Implications for pharmacoepidemiological research on medication safety in pregnancy.

BACKGROUND: In observational medication pregnancy safety studies, children are often followed from birth to 1 year of age. However, some major congenital malformations (MCM) may take longer to diagnose. OBJECTIVES: We aimed to investigate the proportion of children with detected MCMs at different lengths of follow-up and compare them to the proportion detected at 1 year after birth. METHODS: This population-based register study included all singleton children liveborn in Sweden from 2006 to 2016. MCM were identified by ICD-10 codes in the Medical Birth Register and National Patient Register, aligned to the EUROCAT classification system. Cumulative proportion of children with detected MCM at birth, 90 days, 1, 2, and 3 years was calculated and compared between children born preterm and at term. RESULTS: In 1,138,113 liveborn children, the cumulative proportion of children with a detected MCM increased from 1.9% at birth to 3.1%, 3.9%, 4.4% and 4.7% at 90 days, 1, 2, and 3 years after birth, respectively, and varied by MCM subgroup. MCMs of the eye, ear-face-neck, nervous system and genitals were detected with the longest delay, with 31%-59% more detected at 3- versus 1-year follow-up. Compared to children born at term, the proportion of children with any MCM was 2.5 times higher amongst preterm children, with a higher proportion detected over the first 90 days for most MCM subgroups. CONCLUSIONS: The proportion of children with a detected MCM varied by MCM subgroup and follow-up time. In pharmacoepidemiology studies of medication safety in pregnancy using Swedish national data, the length of child follow-up should be chosen in accordance with the expected age at detection if a specific subgroup of MCM is under investigation, for example, eye and genital MCM require longer follow-up for detection than abdominal wall and digestive system MCM. However, in most circumstances, 1 year of follow-up is sufficient.

Achieving comparability in glycemic control between antidiabetic treatment strategies in pregnancy when using real world data.

PURPOSE: Healthcare utilization databases often lack information on glycemic control, a key confounder when studying the safety of antidiabetic treatments, since patients with worse control are channeled to second-line agents, in particular insulin, versus first-line agents such as metformin. We evaluated whether adjustment for measured characteristics attains balance in glycemic control when comparing antidiabetic treatment strategies in pregnant women with pregestational type 2 diabetes (T2DM). METHODS: In a US insurance claims database, we identified 3360 women with T2DM pregnant between 2004 and 2015, of whom a subset of 996 had data on hemoglobin A1c (HbA1c ) levels. We selected insulin only as the comparator group and used propensity score (PS)-matching on comorbidities and proxies of diabetes severity, but not on HbA1c , to adjust for confounding. We used standardized differences (st.diff) to assess balance in claims-based covariates and mean HbA1c (% ± SD) in the subset. RESULTS: There were imbalances in claims-based covariates before PS-matching, with smaller differences when both treatment strategies included insulin. After PS-matching, balance was achieved in most claims-based covariates (st.diff <0.1). Mean HbA1c was similar before and after PS-matching when both treatments included insulin (e.g., 7.1 ± 1.5 vs. 7.7 ± 1.8 and 7.1 ± 1.5 vs. 7.5 ± 1.7, respectively, for metformin + insulin vs. insulin only). Differences in mean HbA1c remained after PS-matching when non-insulin treatments were compared to treatments including insulin (e.g., 6.3 ± 1.1 vs. 7.6 ± 1.7 for metformin only vs. insulin only). CONCLUSIONS: Balance in both claims-based characteristics and glycemic control was attained after restricting the population to women with T2DM and comparing treatment strategies indicated for patients with similar diabetes severity. When comparing treatment strategies with versus without insulin, differences in glycemic control persisted after PS-matching even when balance was attained for other measured characteristics.

Trajectories of ADHD medication use before, during, and after pregnancy: A population-based study from Norway and Sweden.

PURPOSE: To describe ADHD medication use trajectories around pregnancy in Norway and Sweden. METHODS: We identified pregnancies resulting in births using linked data from birth and prescribed drug registers of Norway (2006-2019, N = 813 107) and Sweden (2007-2018, N = 1 269 146). We restricted to women who filled prescriptions for ADHD medication during pregnancy or in the year before or after. We described exposure as use versus no use, and total amount of drug dispensed in defined daily doses (DDDs). Group-based trajectory modeling was used to identify distinct medication use trajectories. RESULTS: In total, 13 286 women (0.64%) filled a prescription for ADHD medication. We identified four trajectory groups: continuers (5.7%), interrupters (23.8%), discontinuers (49.5%), and late initiators (21.0%). Discontinuers were younger, continuers were older on average. More women continued medication in recent years (2014-2019). Most discontinuers (60.7%) were nulliparous; more initiators and continuers had one or multiple previous births, respectively. Continuers were least likely to live with a partner (65.8%). Discontinuers were least likely (24.7%) and continuers most likely (37.6%) to smoke at the beginning of pregnancy. More continuers used amphetamine derivatives and were most likely to use other psychotropics. On modeling continuers, we identified three dose-trajectory groups which suggested that most women reduced medication dose during pregnancy. CONCLUSIONS: Most pregnant women discontinued or interrupted their ADHD medication during pregnancy, but more continued in recent years. Continuers were more likely to have had previous births, less likely to have lived with a partner, and may have had additional comorbidities warranting the use of other psychotropics.

Metformin Versus Insulin and Risk of Major Congenital Malformations in Pregnancies With Type 2 Diabetes: A Nordic Register-Based Cohort Study.

OBJECTIVE: To assess the risk of major congenital malformations with metformin versus insulin in pregnancies with type 2 diabetes. RESEARCH DESIGN AND METHODS: This cohort study used four Nordic countries' nationwide registers of live and stillborn infants exposed to metformin or insulin during first trimester organogenesis. Main exclusion criteria were type 1 diabetes, polycystic ovary syndrome, fertility treatment, and exposure to other diabetes drugs. Adjusted risk ratios (RRs) and 95% CIs were estimated for any and cardiac malformations. RESULTS: Of 3,734,125 infants in the source population, 25,956 were exposed to metformin or insulin in the first trimester, and 4,023 singleton infants were included. A malformation was diagnosed in 147 (4.7%) of 3,145 infants with exposure to any metformin (alone or in addition to insulin) and 50 (5.7%) of 878 infants with exposure to insulin alone (RR 0.84, 95% CI 0.46-1.54). Among 2,852 infants exposed to metformin alone and 293 infants exposed to metformin in addition to insulin 127 (4.4%) and 20 (6.8%), respectively, had a malformation. The adjusted risk was not increased for either metformin alone (0.83, 0.44-1.58) or both metformin and insulin (0.98, 0.56-1.69) versus insulin alone. Corresponding RRs for cardiac malformations were 1.01 (0.55-1.84) for any metformin, 0.92 (0.47-1.81) for metformin alone, and 1.72 (0.76-3.91) for both metformin and insulin. CONCLUSIONS: No evidence of an increased malformation risk with metformin versus insulin in the first trimester was found. Results should be interpreted with caution since information on glycemic control was missing.

Comparative Safety of Antiseizure Medication Monotherapy for Major Malformations.

OBJECTIVE: This study was undertaken to examine the comparative safety of antiseizure medication (ASM) monotherapy in pregnancy with respect to risk of major congenital malformations (MCMs), overall and by MCM subtype. METHODS: We conducted a population-based cohort study using national health register data from Denmark, Finland, Iceland, Norway, and Sweden (1996-2020). We compared pregnancies with first trimester exposure to lamotrigine monotherapy to ASM-unexposed, carbamazepine, valproate, oxcarbazepine, levetiracetam, and topiramate to lamotrigine monotherapy, and stratified monotherapy groups by dose. The outcome was nongenetic MCM and specific subtypes. We estimated adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) with log-binomial regression and propensity score weights. RESULTS: There was a higher crude risk of any MCM in pregnancies exposed to lamotrigine monotherapy (n = 8,339) compared to ASM-unexposed pregnancies (n = 4,866,362), but not after confounder adjustment (aRR = 0.97, 95% CI = 0.87-1.08). Compared to lamotrigine, there was an increased risk of malformations associated with valproate (n = 2,031, aRR = 2.05, 95% CI = 1.70-2.46) and topiramate (n = 509, aRR = 1.81, 95% CI = 1.26-2.60), which increased in a dose-dependent manner. We found no differences in malformation risk for carbamazepine (n = 2,674, aRR = 0.91, 95% CI = 0.72-1.15), oxcarbazepine (n = 1,313, aRR = 1.09, 95% CI = 0.83-1.44), or levetiracetam (n = 1,040, aRR = 0.78, 95% CI = 0.53-1.13). Valproate was associated with several malformation subtypes, including nervous system, cardiac, oral clefts, clubfoot, and hypospadias, whereas lamotrigine and carbamazepine were not. INTERPRETATION: Topiramate is associated with an increased risk of MCM similar to that associated with valproate, but lower doses may mitigate the risks for both drugs. Conversely, we found no increased risks for lamotrigine, carbamazepine, oxcarbazepine, or levetiracetam, which is reassuring. ANN NEUROL 2023;93:551-562.

Prevalence trends and individual patterns of ADHD medication use in pregnancy in Norway and Sweden, 2010-2019.

PURPOSE: This study aimed to describe recent trends in ADHD medication use in pregnancy in Norway and Sweden, including prevalence, individual characteristics, and patterns of use. METHODS: We studied ADHD medication use (amphetamine, dexamphetamine, methylphenidate, atomoxetine, lisdexamfetamine, guanfacine) by year and age in pregnancies from 2010 to 2019 identified from the medical birth registers (gestational age ≥ 22 weeks) linked to prescribed drug registers (Norway, N = 577,116; Sweden, N = 1,118,988). We compared characteristics of those who used any ADHD medication in pregnancy to no use in pregnancy. Discontinuation was defined as no use after first trimester. RESULTS: ADHD medication use increased from 2010 to 2019 by 3.0 users per 1000 pregnancies in Norway (from 2.5 to 5.5/1000) and by 6.3 per 1000 in Sweden (from 1.6 to 7.9/1000), mainly driven by methylphenidate and since 2015 by lisdexamfetamine. Medication use has increased among pregnant individuals of all age groups, with higher use among the youngest. Pregnant individuals who used ADHD medication were less likely to be married/cohabiting, more likely be nulliparous and to smoke. They had particularly high use of co-medication with antidepressants, anxiolytics/hypnotics, and opioids: 42% in Norway and 65% in Sweden used at least one additional class of psychotropic medication. Most individuals discontinued ADHD medication in pregnancy (85% Norway, 78% Sweden). CONCLUSION: ADHD medication use during pregnancy increased in Norway and Sweden in the last decade. However, discontinuation rates during pregnancy were high. Those who used ADHD medication had more risk factors for pregnancy complications including low parity, smoking, and other psychotropic drug use.

Utilization of antidepressants, anxiolytics, and hypnotics during the COVID-19 pandemic in Scandinavia.

OBJECTIVE: To study patterns of antidepressant, anxiolytic, and hypnotic drug utilization in Denmark, Norway, and Sweden during the first year of the COVID-19 pandemic. METHODS: The monthly observed number of prescription fills of antidepressants, benzodiazepines and benzodiazepine-related hypnotics (BZ), and other anxiolytics and hypnotics (OAH) per population in 2020 were compared with predicted numbers based on analysis of covariance of prescription fills during 2015-2019. RESULTS: In March 2020, there was an increased number of prescription fills for antidepressants, anxiolytics, and hypnotics in youths and adults aged 20-59 years in Denmark, Norway, and Sweden. Antidepressant prescription fills increased between 13.5 % and 31.3 % at the end of 2020 in all age groups in Denmark and 17.4 % in youths in Norway. BZ drug prescription fills increased by 20.8 % at the end of 2020 in the 20-59 year age group in Denmark and decreased by 16.7 % in youths in Sweden. A general increase of prescription fills of OAH at the end of 2020 was observed in all countries (range 24.0-80.0 % in Denmark, 11.5-30.8 % in Norway, and 9.1-12.1 % in Sweden). Increases of prescription fills of OAH occurred earlier in Denmark. LIMITATIONS: Aggregated data with lack of information on indications. CONCLUSIONS: Peaks of utilization of antidepressants, anxiolytics, and hypnotics observed in March 2020 may reflect medication stock piling. Increased antidepressant drug utilization in Denmark and in Norwegian youths together with the general increase in OAH utilization in the Scandinavian countries in late 2020 may indicate an increase of symptoms of depression and anxiety, as well as disturbed sleep.

Association of In Utero Antipsychotic Medication Exposure With Risk of Congenital Malformations in Nordic Countries and the US.

Importance: Psychiatric disorders are common among female individuals of reproductive age. While antipsychotic medication use is increasing, the safety of such medications in pregnancy is an area with large evidence gaps. Objective: To evaluate the risk of first-trimester antipsychotic exposure with respect to congenital malformations, focusing on individual drugs and specific malformation subtypes. Design, Setting, and Participants: This cohort study used data from nationwide health registers from the 5 Nordic countries and the US and spanned 1996 to 2018. The Nordic cohort included all pregnancies resulting in singleton live-born infants, and the US cohort consisted of publicly insured mothers linked to their live-born infants nested in the nationwide Medicaid Analytic eXtract. Data were analyzed from November 2020 to April 2022. Exposures: One or more first-trimester dispensing of any atypical, any typical, and individual antipsychotic drugs. Main Outcomes and Measures: Any major congenital malformation and specific malformation subtypes previously suggested to be associated with antipsychotic exposure in utero: cardiovascular malformations, oral clefts, neural tube defects, hip dysplasia, limb reduction defects, anorectal atresia/stenosis, gastroschisis, hydrocephalus, other specific brain anomalies, and esophageal disorders. Propensity score stratification was used to control for potential confounders. Pooled adjusted estimates were calculated using indirect standardization. Results: A total of 6 455 324 unexposed mothers (mean maternal age range across countries: 24-31 years), 21 751 mothers exposed to atypical antipsychotic drugs (mean age range, 26-31 years), and 6371 mothers exposed to typical antipsychotic drugs (mean age range, 27-32 years) were included in the study cohort. Prevalence of any major malformation was 2.7% (95% CI, 2.7%-2.8%) in unexposed infants, 4.3% (95% CI, 4.1%-4.6%) in infants with atypical antipsychotic drug exposure, and 3.1% (95% CI, 2.7%-3.5%) in infants with typical antipsychotic drug exposure in utero. Among the most prevalent exposure-outcome combinations, adjusted relative risks (aRR) were generally close to the null. One exception was olanzapine exposure and oral cleft (aRR, 2.1 [95% CI, 1.1-4.3]); however, estimates varied across sensitivity analyses. Among moderately prevalent combinations, increased risks were observed for gastroschisis and other specific brain anomalies after atypical antipsychotic exposure (aRR, 1.5 [95% CI, 0.8-2.6] and 1.9 [95% CI, 1.1-3.0]) and for cardiac malformations after chlorprothixene exposure (aRR, 1.6 [95% CI, 1.0-2.7]). While the association direction was consistent across sensitivity analyses, confidence intervals were wide, prohibiting firm conclusions. Conclusions and Relevance: In this study, considering the evidence from primary and sensitivity analyses and inevitable statistical noise for very rare exposure-outcome combinations, in utero antipsychotic exposure generally was not meaningfully associated with an increased risk of malformations. The observed increased risks of oral clefts associated with olanzapine, gastroschisis, and other specific brain anomalies with atypical antipsychotics and cardiac malformations with chlorprothixene requires confirmation as evidence continues to accumulate.

Trends in use of attention deficit hyperactivity disorder medication among children and adolescents in Scandinavia in 2010-2020.

The objective of the study was to compare the use of attention deficit hyperactivity disorder (ADHD) medication among children and adolescents in Scandinavia 2010-2020. Using aggregated prescription data for individuals aged 5-19 years, we calculated annual prevalence proportions of ADHD medication (users/1000 inhabitants) for each country, overall and stratified by age and sex. Overall, use of ADHD medication increased during 2010-2020 in all countries. The increase was pronounced in Sweden reaching 35 users/1000 inhabitants in 2020 (119% increase), whereas it reached 22/1000 in Denmark and Norway (equivalent to a 38% and 16% increase, respectively). Methylphenidate was the most frequently used drug and Sweden had the highest use reaching 25/1000 in 2020 compared to 16/1000 and 18/1000 in Denmark and Norway, respectively. Lisdexamfetamine use increased steadily and was also highest in Sweden (13/1000 in 2020). In 2020, atomoxetine use was higher in Sweden (4.6/1000) and Denmark (4.5/1000) compared to Norway (2.2/1000). From 2015, use of guanfacine increased in Sweden reaching 4.4/1000 in 2020 but remained low in Denmark (0.4/1000) and Norway (0.7/1000). Use of dexamphetamine was low (ranging from 0.47 to 0.75/1000 in 2020) in the three countries. ADHD medication use was highest in Sweden across all age groups. In all countries, the prevalence was higher in males compared to females. In conclusion, use of ADHD medication among children and adolescents in Scandinavia is increasing. The prevalence of use is higher in Sweden for all drug groups compared to Norway and Denmark.

Association between folic acid use during pregnancy and gestational diabetes mellitus: Two population-based Nordic cohort studies.

INTRODUCTION: Inconsistent results have been reported on the association between folic acid use in pregnancy and risk of GDM. The aim of this study was to estimate the association between folic acid use and GDM in two population-based Nordic cohorts. MATERIAL AND METHODS: Two cohort studies were conducted using data from the national population registers in Norway (2005-2018, n = 791,709) and Sweden (2006-2016, n = 1,112,817). Logistic regression was used to estimate the associations between GDM and self-reported folic acid use and prescribed folic acid use, compared to non-users, adjusting for covariates. To quantify how potential unmeasured confounders may affect the estimates, E-values were reported. An exposure misclassification bias analysis was also performed. RESULTS: In Norwegian and Swedish cohorts, adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for maternal self-reported folic acid use were 1.10 (1.06-1.14) and 0.89 (0.85-0.93), with E-values of 1.43 (1.31) and 1.50 (1.36), respectively. For prescribed folic acid use, ORs were 1.33 (1.15-1.53) and 1.56 (1.41-1.74), with E-values of 1.99 (1.57) and 2.49 (2.17), in Norway and Sweden respectively. CONCLUSIONS: The slightly higher or lower odds for GDM in self-reported users of folic acid in Norway and Sweden respectively, are likely not of clinical relevance and recommendations for folic acid use in pregnancy should remain unchanged. The two Nordic cohorts showed different directions of the association between self-reported folic acid use and GDM, but based on bias analysis, exposure misclassification is an unlikely explanation since there may still be differences in prevalence of use and residual confounding. Prescribed folic acid is used by women with specific comorbidities and co-medications, which likely underlies the higher odds for GDM.

Antimicrobial use in Sweden during the COVID-19 pandemic: prescription fill and inpatient care requisition patterns.

BACKGROUND: Increased and inappropriate antimicrobial use are the key drivers of the emergence of antimicrobial resistance, and there have been widespread concerns around potential antimicrobial misuse, overuse and their consequences during the COVID-19 pandemic. To better understand the impact of the pandemic on antimicrobial use, particularly in light of the resurgence of COVID-19 cases since the summer of 2020, we assessed trends in antimicrobial prescription fills and hospital requisitions in Sweden during 2020 against those of preceding years. METHODS: We performed a descriptive study using population-based data from the Swedish Prescribed Drug Register and the Swedish e-Health Agency. The weekly number of prescriptions filled and the total volume sold to inpatient care institutions in defined daily doses (DDDs) per 1000 inhabitants for systemic antibacterials (Anatomical Therapeutic Chemical therapeutic subgroup J01 excluding J01XX), antimycotics (J02), antivirals (J05) and antiprotozoals (P01) were computed and evaluated from time series graphs. A time series linear regression with ordinary least squares (OLS) estimation was used to model 2015-2019 data and predict the expected number of prescriptions filled and volumes sold in DDDs per 1000 inhabitants during 2020 with 95% confidence limits. RESULTS: From mid-March 2020, the weekly rate of antibiotic and antiprotozoal prescriptions filled plummeted to unprecedentedly low levels for the rest of the year; while unprecedentedly high numbers of antiviral prescriptions were filled weekly between mid-February and mid-March 2020. There was a net reduction in annual dispensing of antibiotics by 17%; of antiprotozoals by 21%; and of antivirals by 0.3% during 2020 compared to 2019. Inpatient care requisitions of antiprotozoals and antibiotics surged to 6-year highs during March 2020, resulting in a 127% increase in DDDs of antiprotozoals sold from 2019. The volume of antibiotics and antivirals sold to inpatient care institutions in 2020 decreased by 3% and 13% compared to 2019, respectively. CONCLUSIONS: The overall decline in antimicrobial prescriptions filled in Sweden during 2020 were in part, collateral dividends of the COVID-19 pandemic.

Method of Hormonal Contraception and Protective Effects Against Ectopic Pregnancy.

OBJECTIVE: To estimate the incidence rates for ectopic pregnancy by contraceptive method in a cohort of women using hormonal contraception in Sweden between 2005 and 2016. METHOD: Women aged 15-49 years with a filled prescription for a hormonal contraceptive in the Swedish Prescribed Drug Register between 2005 and 2016 were included. For each woman, all exposed woman-years were allocated to treatment episodes depending on the method of contraception. Treatment time started on the day the prescription was filled and ended on the first day of the end of supply, new eligible dispensing, pregnancy-related diagnosis and its associated estimated last menstrual period, or removal procedure. Ectopic pregnancy was defined as having at least two records of International Classification of Diseases, Tenth Revision code O00-, including O00.0, O00.1, O00.2, O00.8, O00.9, within 30 days or one episode of O00- and one surgical procedure for ectopic pregnancy (NOMESCO Classification of Surgical Procedures code LBA, LBC, LBD, LBE, LBW). Incidence rates per 1,000 woman-years and 95% CIs were calculated for each method of contraception. RESULTS: The study included 1,663,242 women and 1,915 events of ectopic pregnancy. The incidence rate (95% CI) for ectopic pregnancy per method of hormonal contraception was estimated: 13.5-mg levonorgestrel (LNG) hormonal intrauterine device (IUD), 2.76 (2.26-3.35) per 1,000 woman-years; 52-mg LNG hormonal IUD, 0.30 (0.28-0.33) per 1,000 woman-years; combined oral contraception, 0.20 (0.19-0.22) per 1,000 woman-years; progestogen implants, 0.31 (0.26-0.37) per 1,000 woman-years; oral medium-dose progestogen (desogestrel 75 mg), 0.24 per 1,000 woman-years, (0.21-0.27); and oral low-dose progestogen (norethisterone 0.35 mg and lynestrenol 0.5 mg), 0.81 (0.70-0.93) per 1,000 woman-years. CONCLUSION: Hormonal contraception lowers the risk of ectopic pregnancy markedly. The incidence rate of ectopic pregnancy among women using a low-dose hormonal IUD (13.5 mg LNG) was substantially higher than that in women using other types of hormonal contraception. This study provides real-world evidence to inform best clinical practice for women-centered contraceptive counseling.

Antipsychotic use in pregnancy and risk of attention/deficit-hyperactivity disorder and autism spectrum disorder: a Nordic cohort study.

BACKGROUND: Antipsychotics are increasingly used among women of childbearing age and during pregnancy. OBJECTIVE: To determine whether children exposed to antipsychotics in utero are at increased risk of attention-deficit/hyperactivity disorder (ADHD) or autism spectrum disorder (ASD), accounting for maternal diagnoses of bipolar, psychotic and other psychiatric disorders. Design Population-based cohort study, including a sibling analysis. Setting Nationwide data on all pregnant women and their live-born singletons in Denmark (1997-2017), Finland (1996-2016), Iceland (2004-2017), Norway (2004-2017), and Sweden (2006-2016). Participants 4 324 086 children were eligible for inclusion to the study cohort. Intervention Antipsychotic exposure in utero, assessed by pregnancy trimester, type of antipsychotic, and varying patterns of use. Main outcome measures Non-mutually exclusive diagnoses of ADHD and ASD. We used Cox proportional hazard models to calculate hazard ratios (HRs) controlling for maternal psychiatric disorders and other potential confounding factors. FINDINGS: Among 4 324 086 singleton births, 15 466 (0.4%) were exposed to antipsychotics in utero. During a median follow-up of 10 years, we identified 72 257 children with ADHD and 38 674 children with ASD. Unadjusted HRs were raised for both outcomes but shifted substantially towards the null after adjustment; 1.10 (95%CI 1.00 to 1.27) for ADHD and 1.12 (0.97 to 1.29) for ASD. Adjusted HRs remained consistent by trimester of exposure and type of antipsychotic. Comparing in utero exposure with pre-pregnancy use yielded HRs of 0.74 (0.62 to 0.87) for ADHD and 0.88 (0.70 to 1.10) for ASD. Sibling analyses yielded HRs of 1.14 (0.79 to 1.64) for ADHD and 1.34 (0.75 to 2.39) for ASD. DISCUSSION: Our findings suggest little or no increased risk of child ADHD or ASD after in utero exposure to antipsychotics. CLINICAL IMPLICATIONS: Results regarding child neurodevelopment are reassuring for women who need antipsychotics during pregnancy.

Investigating the association between prenatal exposure to folic acid and risk of neonatal diabetes/hyperglycemia and type 1 diabetes: A Norwegian register-based study.

BACKGROUND: Experimental animal studies suggest a novel role for the folate receptor 1 in ß-cell differentiation in the pancreas, with potential implications for glycemic control. We tested the hypothesis of a protective association between prenatal folic acid use and neonatal diabetes or hyperglycemia and type 1 diabetes in an observational cohort study using data from the national population health registers in Norway. METHODS: All singleton pregnancies resulting in live births from 2005 to 2018 were identified. Prenatal exposure to folic acid was determined based on maternal report at antenatal care in early pregnancy. Diagnoses of neonatal diabetes, hyperglycemia, and type 1 diabetes for the children were identified. Associations were estimated with logistic regression or Cox proportional hazard model and included crude and adjusted estimates. RESULTS: Among 781,567 children, 69% had prenatal exposure to folic acid, 264 were diagnosed with neonatal diabetes or hyperglycemia, and 1390 with type 1 diabetes. Compared to children with no prenatal exposure to folic acid, children with prenatal exposure to folic acid had similar odds of having a neonatal diabetes or hyperglycemia diagnosis (adjusted odds ratio 0.95, 95% confidence interval [CI] 0.72, 1.25) and similar risk of being diagnosed with type 1 diabetes (adjusted hazard ratio 1.05, 95% CI 0.93, 1.18). CONCLUSIONS: No association between prenatal folic acid exposure and neonatal diabetes/hyperglycemia or type 1 diabetes was found. These findings do not rule out a translational effect of the experimental results and future studies with longer follow-up and more precise information on the window of prenatal exposure are needed.