Internal validation of gestational age estimation algorithms in healthcare databases using pregnancies conceived with fertility procedures.

Fertility procedures recorded in healthcare databases can be used to estimate the start of pregnancy, which can serve as a reference standard to validate gestational age estimates based on International Classification of Diseases (ICD) codes. In a cohort of 17,398 pregnancies conceived by fertility procedures in MarketScan (2011-2020), we estimated gestational age at the end of pregnancy using algorithms based on (1) days since fertility procedure (the reference); (2) ICD-9/ICD-10 (before/after October 2015) codes indicating gestational length recorded at the end of pregnancy (method A); and (3) ICD-10 enhanced with Z3A codes denoting specific gestation weeks recorded at prenatal visits (method B). We calculated the proportion of pregnancies with an estimated gestational age within 14 days of the reference. Method A accuracy was similar for ICD-9 and ICD-10 codes. After 2015, method B was more accurate than method A: For term births, within-14-day-agreements were 90.8% for method A and 98.7% for method B. Corresponding estimates were 70.1% and 95.6% for preterm births; 35.3% and 92.6% for stillbirths; 54.3% and 64.2% for spontaneous abortions; and 16.7% and 84.6% for elective terminations. ICD-10-based algorithms that incorporate Z3A codes improve the accuracy of gestational age estimation in healthcare databases, especially for preterm and non-live births.

Risk of Autism after Prenatal Topiramate, Valproate, or Lamotrigine Exposure.

BACKGROUND: Maternal use of valproate during pregnancy has been associated with an increased risk of neurodevelopmental disorders in children. Although most studies of other antiseizure medications have not shown increased risks of these disorders, there are limited and conflicting data regarding the risk of autism spectrum disorder associated with maternal topiramate use. METHODS: We identified a population-based cohort of pregnant women and their children within two health care utilization databases in the United States, with data from 2000 through 2020. Exposure to specific antiseizure medications was defined on the basis of prescription fills from gestational week 19 until delivery. Children who had been exposed to topiramate during the second half of pregnancy were compared with those unexposed to any antiseizure medication during pregnancy with respect to the risk of autism spectrum disorder. Valproate was used as a positive control, and lamotrigine was used as a negative control. RESULTS: The estimated cumulative incidence of autism spectrum disorder at 8 years of age was 1.9% for the full population of children who had not been exposed to antiseizure medication (4,199,796 children). With restriction to children born to mothers with epilepsy, the incidence was 4.2% with no exposure to antiseizure medication (8815 children), 6.2% with exposure to topiramate (1030 children), 10.5% with exposure to valproate (800 children), and 4.1% with exposure to lamotrigine (4205 children). Propensity score-adjusted hazard ratios in a comparison with no exposure to antiseizure medication were 0.96 (95% confidence interval [CI], 0.56 to 1.65) for exposure to topiramate, 2.67 (95% CI, 1.69 to 4.20) for exposure to valproate, and 1.00 (95% CI, 0.69 to 1.46) for exposure to lamotrigine. CONCLUSIONS: The incidence of autism spectrum disorder was higher among children prenatally exposed to the studied antiseizure medications than in the general population. However, after adjustment for indication and other confounders, the association was substantially attenuated for topiramate and lamotrigine, whereas an increased risk remained for valproate. (Funded by the National Institute of Mental Health.).

Prediction of pregnancy-related complications in women undergoing assisted reproduction, using machine learning methods.

OBJECTIVE: To use machine learning methods to develop prediction models of pregnancy complications in women who conceived with assisted reproductive techniques (ART). DESIGN: A nation-wide register-based cohort study with prospectively collected data. SETTING: Swedish national registers and nationwide quality IVF register. PATIENT(S): all nulliparous women who achieved birth within the first 3 ART treatment cycles between 2008 and 2016 in Sweden. INTERVENTION(S): Characteristics before the use of ART, such as demographics and medical history, were considered potential predictors in the development of before treatment prediction models. ART treatment details were further included in after treatment prediction models. MAIN OUTCOME MEASURE(S): Potential diagnoses of preeclampsia, placental complications (previa, accreta, and abruption), and postpartum hemorrhage were identified using the International Classification of Diseases recorded in the Swedish Medical Birth and Patient registers, respectively. Multiple prediction model algorithms were performed and compared for each outcome and treatment cycle, including logistic regression, decision tree model, naïve Bayes classification, support vector machine, random forest, and gradient boosting. The performance of each model was assessed with C statistic, and nested cross-validation was used to aid model selection and hyperparameter tuning. RESULT(S): A total of 14,732 women gave birth after the first (N = 7,302), second (N = 4,688), or third (N = 2,742) ART cycle, representing birth rates of 24.1%, 23.8%, and 22.0%. Overall prediction performance did not vary much across the different methods used. In the first cycle, the before treatment prediction performance was at best 66%, 66%, and 60% for preeclampsia, placental complications, and postpartum hemorrhage, respectively. Inclusion of after treatment characteristics conferred slight improvement (approximately 1%-5%), as did prediction in later cycles (approximately 1%-5%). The top influential and consistent predictors included age, region of residence, infertility diagnosis, and type of embryo transfer (fresh or frozen) in the later (2nd and 3rd) cycles. Body mass index was a top predictor of preeclampsia and was also influential for placental complications but not for postpartum hemorrhage. CONCLUSION(S): The combined use of demographics, medical history, and ART treatment information was not enough to confidently predict serious pregnancy complications in women who conceived with ART. Future studies are needed to assess if additional longitudinal follow-up during pregnancy can improve the prediction to allow clinical protocol development.

Accounting for Twins and Other Multiple Births in Perinatal Studies Conducted Using Healthcare Administration Data.

The analysis of perinatal studies is complicated by twins and other multiple births even when they are not the exposure, outcome, or a confounder of interest. Common approaches to handling multiples in studies of infant outcomes include restriction to singletons, counting outcomes at the pregnancy-level (i.e., by counting if at least one twin experienced a binary outcome), or infant-level analysis including all infants and, typically, accounting for clustering of outcomes by using generalised estimating equations or mixed effects models. Several healthcare administration databases only support restriction to singletons or pregnancy-level approaches. For example, in MarketScan insurance claims data, diagnoses in twins are often assigned to a single infant identifier, thereby preventing ascertainment of infant-level outcomes among multiples. Different approaches correspond to different causal questions, produce different estimands, and often rely on different assumptions. We demonstrate the differences that can arise from these different approaches using Monte Carlo simulations, algebraic formulas, and an applied example. Furthermore, we provide guidance on the handling of multiples in perinatal studies when using healthcare administration data.

First Trimester Use of Buprenorphine or Methadone and the Risk of Congenital Malformations.

Importance: Use of buprenorphine or methadone to treat opioid use disorder is recommended in pregnancy; however, their teratogenic potential is largely unknown. Objective: To compare the risk of congenital malformations following in utero exposure to buprenorphine vs methadone. Design, Setting, and Participants: This population-based cohort study used health care utilization data from publicly insured Medicaid beneficiaries in the US from 2000 to 2018. A total of 13 360 pregnancies with enrollment from 90 days prior to pregnancy start through 1 month after delivery and first trimester use of buprenorphine or methadone were included and linked to infants. Data were analyzed from July to December 2022. Exposure: A pharmacy dispensing of buprenorphine or a code for administration of methadone in the first trimester. Main Outcomes and Measures: Primary outcomes included major malformations overall and malformations previously associated with opioids (any cardiac malformations, ventricular septal defect, secundum atrial septal defect/nonprematurity-related patent foramen ovale, neural tube defects, clubfoot, and oral clefts). Secondary outcomes included other organ system-specific malformations. Risk differences and risk ratios (RRs) were estimated comparing buprenorphine with methadone, adjusting for confounders with propensity score overlap weights. Results: The cohort included 9514 pregnancies with first-trimester buprenorphine exposure (mean [SD] maternal age, 28.4 [4.6] years) and 3846 with methadone exposure (mean [SD] maternal age, 28.8 [4.7] years). The risk of malformations overall was 50.9 (95% CI, 46.5-55.3) per 1000 pregnancies for buprenorphine and 60.6 (95% CI, 53.0-68.1) per 1000 pregnancies for methadone. After confounding adjustment, buprenorphine was associated with a lower risk of malformations compared with methadone (RR, 0.82; 95% CI, 0.69-0.97). Risk was lower with buprenorphine for cardiac malformations (RR, 0.63; 95% CI, 0.47-0.85), including both ventricular septal defect (RR, 0.62; 95% CI, 0.39-0.98) and secundum atrial septal defect/nonprematurity-related patent foramen ovale (RR, 0.54; 95% CI, 0.30-0.97), oral clefts (RR, 0.65; 95% CI, 0.35-1.19), and clubfoot (RR, 0.55; 95% CI, 0.32-0.94). Results for neural tube defects were uncertain given low event counts. In secondary analyses, buprenorphine was associated with a decreased risk of central nervous system, urinary, and limb malformations but a greater risk of gastrointestinal malformations compared with methadone. These findings were consistent in sensitivity and bias analyses. Conclusions and Relevance: In this cohort study, the risk of most malformations previously associated with opioid exposure was lower in buprenorphine-exposed infants compared with methadone-exposed infants, independent of measured confounders. Malformation risk is one factor that informs the individualized patient decision regarding medications for opioid use disorder in pregnancy.

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.

Short-Term Increases in NO2 and O3 Concentrations during Pregnancy and Stillbirth Risk in the U.S.: A Time-Stratified Case-Crossover Study.

Associations between gaseous pollutant exposure and stillbirth have focused on exposures averaged over trimesters or gestation. We investigated the association between short-term increases in nitrogen dioxide (NO2) and ozone (O3) concentrations and stillbirth risk among a national sample of 116 788 Medicaid enrollees from 2000 to 2014. A time-stratified case-crossover design was used to estimate distributed (lag 0-lag 6) and cumulative lag effects, which were adjusted for PM2.5 concentration and temperature. Effect modification by race/ethnicity and proximity to hydraulic fracturing (fracking) wells was assessed. Short-term increases in the NO2 and O3 concentrations were not associated with stillbirth in the overall sample. Among American Indian individuals (n = 1694), a 10 ppb increase in NO2 concentrations was associated with increased stillbirth odds at lag 0 (5.66%, 95%CI: [0.57%, 11.01%], p = 0.03) and lag 1 (4.08%, 95%CI: [0.22%, 8.09%], p = 0.04) but not lag 0-6 (7.12%, 95%CI: [-9.83%, 27.27%], p = 0.43). Among participants living in zip codes within 15 km of active fracking wells (n = 9486), a 10 ppb increase in NO2 concentration was associated with increased stillbirth odds in single-day lags (2.42%, 95%CI: [0.37%, 4.52%], p = 0.02 for lag 0 and 1.83%, 95%CI: [0.25%, 3.43%], p = 0.03 for lag 1) but not the cumulative lag (lag 0-6) (4.62%, 95%CI: [-2.75%, 12.55%], p = 0.22). Odds ratios were close to the null in zip codes distant from fracking wells. Future studies should investigate the role of air pollutants emitted from fracking and potential racial disparities in the relationship between short-term increases in NO2 concentrations and stillbirth.

Prescription Stimulant Use During Pregnancy and Risk of Neurodevelopmental Disorders in Children.

Importance: Use of medications for attention-deficit/hyperactivity disorder (ADHD) during pregnancy is increasing in the US. Whether exposure to these medications in utero impacts the risk of neurodevelopmental disorders in children is uncertain. Objective: To evaluate the association of childhood neurodevelopmental disorders with in utero exposure to stimulant medications for ADHD. Design, Setting, and Participants: This cohort study included health care utilization data from publicly insured (Medicaid data from 2000 to 2018) and commercially insured (MarketScan Commercial Claims Database data from 2003 to 2020) pregnant individuals aged 12 to 55 years in the US with enrollment from 3 months prior to pregnancy through 1 month after delivery, linked to children. Children were monitored from birth until outcome diagnosis, disenrollment, death, or end of the study (December 2018 for Medicaid and December 2020 for MarketScan). Exposures: Dispensing of amphetamine/dextroamphetamine or methylphenidate in the second half of pregnancy. Main Outcomes and Measures: Autism spectrum disorder, ADHD, and a composite of any neurodevelopmental disorder were defined using validated algorithms. Hazard ratios were estimated comparing amphetamine/dextroamphetamine and methylphenidate to no exposure. Results: The publicly insured cohort included 2 496 771 stimulant-unexposed, 4693 amphetamine/dextroamphetamine-exposed, and 786 methylphenidate-exposed pregnancies with a mean (SD) age of 25.2 (6.0) years. The commercially insured cohort included 1 773 501 stimulant-unexposed, 2372 amphetamine/dextroamphetamine-exposed, and 337 methylphenidate-exposed pregnancies with a mean (SD) age of 31.6 (4.6) years. In unadjusted analyses, amphetamine/dextroamphetamine and methylphenidate exposure were associated with a 2- to 3-fold increased risk of the neurodevelopmental outcomes considered. After adjustment for measured confounders, amphetamine/dextroamphetamine exposure was not associated with any outcome (autism spectrum disorder: hazard ratio [HR], 0.80; 95% CI, 0.56-1.14]; ADHD: HR, 1.07; 95% CI, 0.89-1.28; any neurodevelopmental disorder: HR, 0.91; 95% CI, 0.81-1.28). Methylphenidate exposure was associated with an increased risk of ADHD (HR, 1.43; 95% CI, 1.12-1.82]) but not other outcomes after adjustment (autism spectrum disorder: HR, 1.06; 95% CI, 0.62-1.81; any neurodevelopmental disorder: HR, 1.15; 95% CI, 0.97-1.36). The association between methylphenidate and ADHD did not persist in sensitivity analyses with stricter control for confounding by maternal ADHD. Conclusions and Relevance: The findings in this study suggest that amphetamine/dextroamphetamine and methylphenidate exposure in utero are not likely to meaningfully increase the risk of childhood neurodevelopmental disorders.

The COVID-19 International Drug Pregnancy Registry (COVID-PR): Protocol Considerations.

BACKGROUND AND OBJECTIVE: Over the past 2 years, several drugs have been approved for coronavirus disease 2019 (COVID-19) treatment, but their safety during pregnancy remains poorly understood. This study aims to assess the relative risk of obstetric, neonatal, and infant outcomes associated with the use of drugs specifically indicated for the treatment of COVID-19 compared with other drug treatment strategies. The purpose of this article is to present elements of the study protocol. METHODS: The COVID-19 International Drug Pregnancy Registry (COVID-PR) is a noninterventional, postmarketing cohort study. Pregnant women receiving treatment with monoclonal antibodies (mAbs) or antiviral drugs for mild, moderate, or severe COVID-19 are matched 1:1 with pregnant women not receiving these study-specific drugs, based on calendar time, country, gestational age at enrollment, and COVID-19 severity. Participants complete online questionnaires at enrollment, during pregnancy, and for 12 months after delivery of liveborn infants. The study began enrolling participants on 1 December 2021 and is set to span 5 years for each drug of interest. DISCUSSION: The COVID-PR is designed to evaluate the safety profile of each studied drug. Additionally, it may allow for an analysis of the effects of COVID-19 drug exposure during relevant gestational periods on specific neonatal outcomes. Although the sample size will be too small to detect associations with rare outcomes, the study has the potential to generate hypotheses for future research. Ultimately, these data can provide valuable insights for evidence-based decisions about COVID-19 treatment during pregnancy. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05013632. EU PAS EUPAS42517.

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.

Overweight or obesity in children born after assisted reproductive technologies in Denmark: A population-based cohort study.

BACKGROUND: The association between assisted reproductive technologies (ARTs) and the body mass index (BMI) of children remains controversial. Confounding by morbidity and other factors associated with parental infertility may have biased studies comparing children born after ART with children born after no treatment. We investigated the associations between different fertility treatments and BMI in children at age 5 to 8 years, adjusting for and stratifying by causes of parental infertility. METHODS AND FINDINGS: This Danish cohort study included 327,301 children born between 2007 and 2012 (51% males, median age at follow-up 7 years). Of these, 13,675 were born after ART, 7,728 were born after ovulation induction with or without intrauterine insemination [OI/IUI], and 305,898 were born after no fertility treatments. Using the International Obesity Task Force (IOTF) standards, we defined overweight (BMI ≥ IOTF-25) and obesity (BMI ≥ IOTF-30). We compared children born after ART versus OI/IUI; intracytoplasmic sperm injection (ICSI) versus conventional in vitro fertilization (IVF); and frozen-thawed versus fresh embryo transfer and estimated crude and adjusted prevalences of children with overweight or obesity at age 5 to 8 years, prevalence odds ratios (PORs), and differences in mean BMI z-scores. Adjustment was performed using stabilized inverse probability of treatment weights, including parity, year of conception, parental causes of infertility, age, educational level, comorbidities, maternal country of origin, BMI, and smoking as covariates. The crude prevalence of obesity was 1.9% in children born after ART, 2.0% in those born after OI/IUI, and 2.7% in those born after no fertility treatment. After adjustment, children born after ART and OI/IUI had the same prevalence of being overweight (11%; POR 1.00, 95% confidence interval [CI] 0.91 to 1.11; p = 0.95) or obese (1.9%; POR 1.01, 95% CI 0.79 to 1.29; p = 0.94). Comparison of ICSI with conventional IVF yielded similar pattern (POR 0.95, 95% CI 0.83 to 1.07; p = 0.39 for overweight and POR 1.16, 95% CI 0.84 to 1.61; p = 0.36 for obesity). Obesity was more prevalent after frozen-thawed (2.7%) than fresh embryo transfer (1.8%) (POR 1.54, 95% CI 1.09 to 2.17; p = 0.01). The associations between fertility treatments and BMI were only modestly different in subgroups defined by the cause of infertility. Study limitations include potential residual confounding, restriction to live births, and lack of detailed technical information about the IVF procedures. CONCLUSIONS: We found no association with BMI at age 5 to 8 years when comparing ART versus OI/IUI or when comparing ICSI versus conventional IVF. However, use of frozen-thawed embryo transfer was associated with a 1.5-fold increased risk of obesity compared to fresh embryo transfer. Despite an elevated relative risk, the absolute risk difference was low.

Prescription medication use during pregnancy in the United States from 2011 to 2020: trends and safety evidence.

BACKGROUND: Medication use during pregnancy has increased in the United States despite the lack of safety data for many medications. OBJECTIVE: This study aimed to inform research priorities by examining trends in medication use during pregnancy and identifying gaps in safety information on the most commonly prescribed medications. STUDY DESIGN: We identified population-based cohorts of commercially (MarketScan 2011-2020) and publicly (Medicaid Analytic eXtract/Transformed Medicaid Statistical Information System Analytic Files 2011-2018) insured pregnancies ending in live birth from 2 health care utilization databases. Medication use was based on filled prescriptions between the date of last menstrual period through delivery, as well as the period before the last menstrual period and during specific trimesters. We also included a cross-sectional representative sample of pregnancies ascertained by the National Health and Nutrition Examination Survey (2011-2020), with information on prescription medication use during the preceding month obtained through maternal interviews. Teratogen Information System was used to classify the available evidence on teratogenic risk. RESULTS: Among over 3 million pregnancies, the medications most commonly dispensed at any time during pregnancy were analgesics, antibiotics, and antiemetics. The top medications were ondansetron (16.8%), amoxicillin (13.5%), and azithromycin (12.4%) in MarketScan, nitrofurantoin (22.2%), acetaminophen (21.3%; mostly as part of acetaminophen-hydrocodone products), and ondansetron (19.5%) in Medicaid Analytic eXtract/Transformed Medicaid Statistical Information System Analytic Files, and levothyroxine (5.0%), sertraline (2.9%), and insulin (2.9%) in the National Health and Nutrition Examination Survey group. The most commonly dispensed suspected teratogens during the first trimester were antithyroid medications. The use of antidiabetic and psychotropic medications has continued to increase in the United States during the last decade, opioid dispensation has decreased by half, and antibiotics and antiemetics continue to be common. For one-quarter of medications, there is insufficient evidence available to characterize their safety profile in pregnancy. CONCLUSION: There is a need for more drug research in pregnant patients. Future research should focus on anti-infectives with high utilization and limited level of evidence on safety for use during pregnancy. Although lack of evidence is not evidence of safety concerns, it does not indicate risk either. In many instances, the benefits outweigh the risks when these medications are used clinically, and some of the medications with no proven safety may be necessary to treat patients.

A prospective cohort study of preconception COVID-19 vaccination and miscarriage.

STUDY QUESTION: To what extent is preconception maternal or paternal coronavirus disease 2019 (COVID-19) vaccination associated with miscarriage incidence? SUMMARY ANSWER: COVID-19 vaccination in either partner at any time before conception is not associated with an increased rate of miscarriage. WHAT IS KNOWN ALREADY: Several observational studies have evaluated the safety of COVID-19 vaccination during pregnancy and found no association with miscarriage, though no study prospectively evaluated the risk of early miscarriage (gestational weeks [GW] <8) in relation to COVID-19 vaccination. Moreover, no study has evaluated the role of preconception vaccination in both male and female partners. STUDY DESIGN, SIZE, DURATION: An Internet-based, prospective preconception cohort study of couples residing in the USA and Canada. We analyzed data from 1815 female participants who conceived during December 2020-November 2022, including 1570 couples with data on male partner vaccination. PARTICIPANTS/MATERIALS, SETTING, METHODS: Eligible female participants were aged 21-45 years and were trying to conceive without use of fertility treatment at enrollment. Female participants completed questionnaires at baseline, every 8 weeks until pregnancy, and during early and late pregnancy; they could also invite their male partners to complete a baseline questionnaire. We collected data on COVID-19 vaccination (brand and date of doses), history of SARS-CoV-2 infection (yes/no and date of positive test), potential confounders (demographic, reproductive, and lifestyle characteristics), and pregnancy status on all questionnaires. Vaccination status was categorized as never (0 doses before conception), ever (≥1 dose before conception), having a full primary sequence before conception, and completing the full primary sequence ≤3 months before conception. These categories were not mutually exclusive. Participants were followed up from their first positive pregnancy test until miscarriage or a censoring event (induced abortion, ectopic pregnancy, loss to follow-up, 20 weeks' gestation), whichever occurred first. We estimated incidence rate ratios (IRRs) for miscarriage and corresponding 95% CIs using Cox proportional hazards models with GW as the time scale. We used propensity score fine stratification weights to adjust for confounding. MAIN RESULTS AND THE ROLE OF CHANCE: Among 1815 eligible female participants, 75% had received at least one dose of a COVID-19 vaccine by the time of conception. Almost one-quarter of pregnancies resulted in miscarriage, and 75% of miscarriages occurred <8 weeks' gestation. The propensity score-weighted IRR comparing female participants who received at least one dose any time before conception versus those who had not been vaccinated was 0.85 (95% CI: 0.63, 1.14). COVID-19 vaccination was not associated with increased risk of either early miscarriage (GW: <8) or late miscarriage (GW: 8-19). There was no indication of an increased risk of miscarriage associated with male partner vaccination (IRR = 0.90; 95% CI: 0.56, 1.44). LIMITATIONS, REASONS FOR CAUTION: The present study relied on self-reported vaccination status and infection history. Thus, there may be some non-differential misclassification of exposure status. While misclassification of miscarriage is also possible, the preconception cohort design and high prevalence of home pregnancy testing in this cohort reduced the potential for under-ascertainment of miscarriage. As in all observational studies, residual or unmeasured confounding is possible. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study to evaluate prospectively the relation between preconception COVID-19 vaccination in both partners and miscarriage, with more complete ascertainment of early miscarriages than earlier studies of vaccination. The findings are informative for individuals planning a pregnancy and their healthcare providers. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute of Health [R01-HD086742 (PI: L.A.W.); R01-HD105863S1 (PI: L.A.W. and M.L.E.)], the National Institute of Allergy and Infectious Diseases (R03-AI154544; PI: A.K.R.), and the National Science Foundation (NSF-1914792; PI: L.A.W.). The funders had no role in the study design, data collection, analysis and interpretation of data, writing of the report, or the decision to submit the paper for publication. L.A.W. is a fibroid consultant for AbbVie, Inc. She also receives in-kind donations from Swiss Precision Diagnostics (Clearblue home pregnancy tests) and Kindara.com (fertility apps). M.L.E. received consulting fees from Ro, Hannah, Dadi, VSeat, and Underdog, holds stock in Ro, Hannah, Dadi, and Underdog, is a past president of SSMR, and is a board member of SMRU. K.F.H. reports being an investigator on grants to her institution from UCB and Takeda, unrelated to this study. S.H.-D. reports being an investigator on grants to her institution from Takeda, unrelated to this study, and a methods consultant for UCB and Roche for unrelated drugs. The authors report no other relationships or activities that could appear to have influenced the submitted work. TRIAL REGISTRATION NUMBER: N/A.

Preconception contraceptive use and miscarriage: prospective cohort study.

Objectives: To evaluate the association between preconception contraceptive use and miscarriage. Design: Prospective cohort study. Setting: Residents of the United States of America or Canada, recruited from 2013 until the end of 2022. Participants: 13 460 female identified participants aged 21-45 years who were planning a pregnancy were included, of whom 8899 conceived. Participants reported data for contraceptive history, early pregnancy, miscarriage, and potential confounders during preconception and pregnancy. Main outcome measure: Miscarriage, defined as pregnancy loss before 20 weeks of gestation. Results: Preconception use of combined and progestin-only oral contraceptives, hormonal intrauterine devices, copper intrauterine devices, rings, implants, or natural methods was not associated with miscarriage compared with use of barrier methods. Participants who most recently used patch (incidence rate ratios 1.34 (95% confidence interval 0.81 to 2.21)) or injectable contraceptives (1.44 (0.99 to 2.12)) had higher rates of miscarriage compared with recent users of barrier methods, although results were imprecise due to the small numbers of participants who used patch and injectable contraceptives. Conclusions: Use of most contraceptives before conception was not appreciably associated with miscarriage rate. Individuals who used patch and injectable contraceptives had higher rates of miscarriage relative to users of barrier methods, although these results were imprecise and residual confounding was possible.

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.

Ascertainment of malformations in pregnancy registries: Lessons learned in the North American AED Pregnancy Registry.

BACKGROUND: Pregnancy registries, designed to assess the safety of medications and vaccines for the exposed mother and fetus, have been developed since the 1990s. Malformations present in the exposed liveborn or stillborn infant or fetuses in elective terminations are the outcome of greatest concern. The experiences of the North American AED (antiepileptic drug) Pregnancy Registry (NAAPR) can be used to identify the challenges and limitations of a pregnancy registry in identifying congenital malformations. METHODS: The NAAPR enrolls pregnant women who are taking one or more AEDs for any medical condition, but primarily to prevent seizures, and an unexposed comparison group. Participants are interviewed by clinical research coordinators (CRCs) at enrollment, later in pregnancy and postpartum. Malformations are identified in the mother's reports and her infant's medical records through age 12 weeks. A teratologist, blinded to exposure status, evaluates each potential malformation identified. RESULTS: Among 10,982 pregnancies enrolled between 1997 and 2022, 282 malformations were identified in the 9677 AED-exposed and 15 among the 1305 unexposed infants. Isolated malformations, such as cleft palate, accounted for 84% of the malformations identified. Increased frequencies of oral clefts and myelomeningocele were associated with exposure to several different AEDs. Copies of reports from many diagnostic studies were not obtained and very few pregnancy losses had autopsies. CONCLUSIONS: The evaluation of the AED-exposed infants in a pregnancy registry is indirect. Improvements rely on the rapport established with the mothers by the CRCs and the mothers' willingness to assist in obtaining information from her infants' physicians.

Patterns of Prescription Medication Use during the First Trimester of Pregnancy in the United States, 1997-2018.

The objective of this analysis was to describe patterns of prescription medication use during pregnancy, including secular trends, with consideration of indication, and distributions of use within demographic subgroups. We conducted a descriptive secondary analysis using data from 9,755 women whose infants served as controls in two large United States case-control studies from 1997-2011 and 2014-2018. After excluding vitamin, herbal, mineral, vaccine, i.v. fluid, and topical products and over-the-counter medications, the proportion of women that reported taking at least one prescription medication in the first trimester increased over the study years, from 37% to 50% of women. The corresponding proportions increased with increasing maternal age and years of education, were highest for non-Hispanic White women (47%) and lowest for Hispanic women (24%). The most common indication for first trimester use of a medication was infection (12-15%). Increases were observed across the years for medications used for indications related to nausea/vomiting, depression/anxiety, infertility, thyroid disease, diabetes, and epilepsy. The largest relative increase in use among women was observed for medications to treat nausea/vomiting, which increased from 3.8% in the earliest years of the study (1997-2001) to 14.8% in 2014-2018, driven in large part by ondansetron use. Prescription medication use in the first trimester of pregnancy is common and increasing. Many medical conditions require treatments among pregnant women, often involving pharmacotherapy, which necessitates consideration of the risk and safety profiles for both mother and fetus.

Prenatal opioid exposure and risk of asthma in childhood: a population-based study from Denmark, Norway, and Sweden.

Background: Opioids may modulate the immune function through opioid receptors on immune cells. Long-term consequences of prenatal opioid exposure on the immune system, such as childhood asthma, are unknown. Objectives: To investigate whether prenatal opioid exposure is associated with the risk of childhood asthma. Methods: Cohort study using linked nationwide registers in Denmark (1996-2015), Norway (2005-2015), and Sweden (2006-2013). Children born by mothers who were chronic opioid analgesics users before pregnancy (n = 14,764) or who were receiving opioid maintenance therapy (OMT) before or during pregnancy (n = 1,595) were identified based on information from each of the medical birth registers and prescription registers. Long-term opioid analgesics exposed children were compared to short-term exposed or unexposed, whereas OMT exposed children were compared to OMT unexposed. Asthma among children ≥1 years of age was defined as two or more filled prescriptions of antiasthmatic medication within 365 days, or a diagnosis of asthma. Hazard ratios (HRs) were calculated using Cox proportional hazards regression with attained age as the time scale. Inverse probability of treatment weights based on propensity scores were applied to adjust for measured confounders. Individual level data from Norway and Sweden were pooled, whereas individual level data from Denmark were analyzed separately. For the opioid analgesics comparisons, adjusted HRs (aHR) from the combined Norwegian/Swedish data and the Danish data were pooled in a fixed-effects meta-analysis. Results: For the opioid analgesics cohort, no increased risk of asthma was observed in long-term exposed children neither compared with unexposed [aHR = 0.99 (95% CI 0.87-1.12)], nor compared with short-term exposed [aHR = 0.97 (0.86-1.10)]. No increased risk of asthma was observed in OMT exposed compared with OMT unexposed children [Norway/Sweden: aHR = 1.07 (0.60-1.92), Denmark: aHR = 1.25 (0.87-1.81)]. Results from sensitivity analyses, where potential misclassification of the outcome and misclassification of OMT exposure were assessed, as well as starting follow-up at 6 years of age, showed that the estimates of association were generally robust. Conclusion: We found no association between prenatal exposure to opioids and risk of childhood asthma. Results were consistent across two different opioid exposure groups with different confounder distributions.