Personal care product use patterns in association with phthalate and replacement biomarkers across pregnancy.

BACKGROUND: Humans are exposed to phthalates, a class of non-persistent chemicals, through multiple products, including personal care and cosmetics. Associations between specific phthalates and product use have been inconsistent. However, determining these connections could provide avenues for exposure reduction. OBJECTIVE: Examine the association between patterns of personal care product use and associations with phthalate and replacement biomarkers. METHODS: In the Human Placenta and Phthalates Study, 303 women were enrolled in early pregnancy and followed for up to 8 visits across gestation. At each visit, women completed a questionnaire about product use in the prior 24 hours and contributed urine samples, subsequently analyzed for 18 phthalate and replacement metabolites. At early, mid-, and late pregnancy, questionnaire responses were condensed and repeated metabolite concentrations were averaged. Latent class analysis (LCA) was used to determine groups of women with similar use patterns, and weighted associations between group membership and biomarker concentrations were assessed. RESULTS: LCA sorted women into groups which largely corresponded to: (1) low fragranced product use (16-23% of women); (2) fragranced product and low body wash use (22-26%); 3) fragranced product and low bar soap use (26-51%); and (4) low product use (7-34%). Monoethyl phthalate (MEP) urinary concentrations were 7-10% lower and concentrations of summed di(2-ethylhexyl) terephthalate metabolites were 15-21% lower among women in the "low fragranced product use" group compared to the population mean. Few other consistent associations between group and biomarker concentrations were noted. IMPACT STATEMENT: Personal care products and cosmetics are a known exposure source for phthalates and potentially represent one of the most accessible intervention targets for exposure reduction. However, in this analysis accounting for concurrent use and fragranced status of products, we did not find any use patterns that corresponded to universally lower levels.

Maternal exposure to zolpidem and risk of specific birth defects.

Zolpidem is a non-benzodiazepine agent indicated for treatment of insomnia. While zolpidem crosses the placenta, little is known about its safety in pregnancy. We assessed associations between self-reported zolpidem use 1 month before pregnancy through to the end of the third month ("early pregnancy") and specific birth defects using data from two multi-site case-control studies: National Birth Defects Prevention Study and Slone Epidemiology Center Birth Defects Study. Analysis included 39,711 birth defect cases and 23,035 controls without a birth defect. For defects with ≥ 5 exposed cases, we used logistic regression with Firth's penalised likelihood to estimate adjusted odds ratios and 95% confidence intervals, considering age at delivery, race/ethnicity, education, body mass index, parity, early-pregnancy antipsychotic, anxiolytic, antidepressant use, early-pregnancy opioid use, early-pregnancy smoking, and study as potential covariates. For defects with three-four exposed cases, we estimated crude odds ratios and 95% confidence intervals. Additionally, we explored differences in odds ratios using propensity score-adjustment and conducted a probabilistic bias analysis of exposure misclassification. Overall, 84 (0.2%) cases and 46 (0.2%) controls reported early-pregnancy zolpidem use. Seven defects had sufficient sample size to calculate adjusted odds ratios, which ranged from 0.76 for cleft lip to 2.18 for gastroschisis. Four defects had odds ratios > 1.8. All confidence intervals included the null. Zolpidem use was rare. We could not calculate adjusted odds ratios for most defects and estimates are imprecise. Results do not support a large increase in risk, but smaller increases in risk for certain defects cannot be ruled out.

Characteristics and Outcomes of Patients With Pregnancy-Related End-Stage Kidney Disease.

Importance: The incidence of pregnancy-related acute kidney injury is increasing and is associated with significant maternal morbidity including progression to end-stage kidney disease (ESKD). Little is known about characteristics and long-term outcomes of patients who develop pregnancy-related ESKD. Objectives: To examine the characteristics and clinical outcomes of patients with pregnancy-related ESKD and to investigate associations between pre-ESKD nephrology care and outcomes. Design, Setting, and Participants: This was a cohort study of 183 640 reproductive-aged women with incident ESKD between January 1, 2000, and November 20, 2020, from the US Renal Data System and maternal data from births captured in the US Centers for Disease Control and Prevention publicly available natality data. Data were analyzed from December 2022 to June 2023. Exposure: Pregnancy-related primary cause of ESKD, per International Classification of Diseases, Ninth Revision (ICD-9) and ICD-10 codes reported at ESKD onset by the primary nephrologist on Centers for Medicare and Medicaid Services form 2728. Main Outcomes Measures: Multivariable Cox proportional hazards and competing risk models were constructed to examine time to (1) mortality, (2) access to kidney transplant (joining the waiting list or receiving a live donor transplant), and (3) receipt of transplant after joining the waitlist. Results: A total of 341 patients with a pregnancy-related primary cause of ESKD were identified (mean [SD] age 30.2 [7.3]). Compared with the general US birthing population, Black patients were overrepresented among those with pregnancy-related ESKD (109 patients [31.9%] vs 585 268 patients [16.2%]). In adjusted analyses, patients with pregnancy-related ESKD had similar or lower hazards of mortality compared with those with glomerulonephritis or cystic kidney disease (adjusted hazard ratio [aHR], 0.96; 95% CI, 0.76-1.19), diabetes or hypertension (aHR, 0.49; 95% CI, 0.39-0.61), or other or unknown primary causes of ESKD (aHR, 0.60; 95% CI, 0.48-0.75). Despite this, patients with pregnancy-related ESKD had significantly lower access to kidney transplant compared with those with other causes of ESKD, including (1) glomerulonephritis or cystic kidney disease (adjusted subhazard ratio [aSHR], 0.51; 95% CI, 0.43-0.66), (2) diabetes or hypertension (aSHR, 0.81; 95% CI, 0.67-0.98), and (3) other or unkown cause (aSHR, 0.82; 95% CI, 0.67-0.99). Those with pregnancy-related ESKD were less likely to have nephrology care or have a graft or arteriovenous fistula placed before ESKD onset (nephrology care: adjusted relative risk [aRR], 0.47; 95% CI, 0.40-0.56; graft or arteriovenous fistula placed: aRR, 0.31; 95% CI, 0.17-0.57). Conclusion and Relevance: In this study, those with pregnancy-related ESKD had reduced access to transplant and nephrology care, which could exacerbate existing disparities in a disproportionately Black population. Increased access to care could improve quality of life and health outcomes among these young adults with high potential for long-term survival.

Bias analyses to investigate the impact of differential participation: Application to a birth defects case-control study.

BACKGROUND: Certain associations observed in the National Birth Defects Prevention Study (NBDPS) contrasted with other research or were from areas with mixed findings, including no decrease in odds of spina bifida with periconceptional folic acid supplementation, moderately increased cleft palate odds with ondansetron use and reduced hypospadias odds with maternal smoking. OBJECTIVES: To investigate the plausibility and extent of differential participation to produce effect estimates observed in NBDPS. METHODS: We searched the literature for factors related to these exposures and participation and conducted deterministic quantitative bias analyses. We estimated case-control participation and expected exposure prevalence based on internal and external reports, respectively. For the folic acid-spina bifida and ondansetron-cleft palate analyses, we hypothesized the true odds ratio (OR) based on prior studies and quantified the degree of exposure over- (or under-) representation to produce the crude OR (cOR) in NBDPS. For the smoking-hypospadias analysis, we estimated the extent of selection bias needed to nullify the association as well as the maximum potential harmful OR. RESULTS: Under our assumptions (participation, exposure prevalence, true OR), there was overrepresentation of folic acid use and underrepresentation of ondansetron use and smoking among participants. Folic acid-exposed spina bifida cases would need to have been ≥1.2× more likely to participate than exposed controls to yield the observed null cOR. Ondansetron-exposed cleft palate cases would need to have been 1.6× more likely to participate than exposed controls if the true OR is null. Smoking-exposed hypospadias cases would need to have been ≥1.2 times less likely to participate than exposed controls for the association to falsely appear protective (upper bound of selection bias adjusted smoking-hypospadias OR = 2.02). CONCLUSIONS: Differential participation could partly explain certain associations observed in NBDPS, but questions remain about why. Potential impacts of other systematic errors (e.g. exposure misclassification) could be informed by additional research.

The Carolina hysterectomy cohort (CHC): a novel case series of reproductive-aged hysterectomy patients across 10 hospitals in the US south.

BACKGROUND: Hysterectomy is a common surgery among reproductive-aged U.S. patients, with rates highest among Black patients in the South. There is limited insight on causes of these racial differences. In the U.S., electronic medical records (EMR) data can offer richer detail on factors driving surgical decision-making among reproductive-aged populations than insurance claims-based data. Our objective in this cohort profile paper is to describe the Carolina Hysterectomy Cohort (CHC), a large EMR-based case-series of premenopausal hysterectomy patients in the U.S. South, supplemented with census and surgeon licensing data. To demonstrate one strength of the data, we evaluate whether patient and surgeon characteristics differ by insurance payor type. METHODS: We used structured and abstracted EMR data to identify and characterize patients aged 18-44 years who received hysterectomies for non-cancerous conditions between 10/02/2014-12/31/2017 in a large health care system comprised of 10 hospitals in North Carolina. We used Chi-squared and Kruskal Wallis tests to compare whether patients' socio-demographic and relevant clinical characteristics, and surgeon characteristics differed by patient insurance payor (public, private, uninsured). RESULTS: Of 1857 patients (including 55% non-Hispanic White, 30% non-Hispanic Black, 9% Hispanic), 75% were privately-insured, 17% were publicly-insured, and 7% were uninsured. Menorrhagia was more prevalent among the publicly-insured (74% vs 68% overall). Fibroids were more prevalent among the privately-insured (62%) and the uninsured (68%). Most privately insured patients were treated at non-academic hospitals (65%) whereas most publicly insured and uninsured patients were treated at academic centers (66 and 86%, respectively). Publicly insured and uninsured patients had higher median bleeding (public: 7.0, uninsured: 9.0, private: 5.0) and pain (public: 6.0, uninsured: 6.0, private: 3.0) symptom scores than the privately insured. There were no statistical differences in surgeon characteristics by payor groups. CONCLUSION: This novel study design, a large EMR-based case series of hysterectomies linked to physician licensing data and manually abstracted data from unstructured clinical notes, enabled identification and characterization of a diverse reproductive-aged patient population more comprehensively than claims data would allow. In subsequent phases of this research, the CHC will leverage these rich clinical data to investigate multilevel drivers of hysterectomy in an ethnoracially, economically, and clinically diverse series of hysterectomy patients.

Incidence of new outpatient long-acting reversible contraceptive insertions among a commercially insured, US population from 2010 to 2020.

Objectives: Characterize new use of long-acting reversible contraceptives (LARCs), highly effective contraceptive methods, in a broad population over time. Study Design: We constructed a retrospective cohort of commercially insured individuals aged 15 to 54 years from 2010 to 2020 and estimated monthly incidence of new LARC insertions. Results: The monthly standardized incidence increased from 6.0 insertions per 10,000 individuals in January 2010 to 14.1 in December 2020, with a dip in insertions after March 2020. Hormonal intrauterine devices were consistently the most inserted LARC; implants were increasingly favored over time. Conclusions: LARCs are increasingly popular forms of contraception among commercially insured individuals. Implications: Given the increasing popularity, ensuring access to LARCs is critical.

Variability and Longitudinal Trajectories of Phthalate and Replacement Biomarkers across Pregnancy in the Human Placenta and Phthalates Study.

Human exposure to phthalates is widespread, but assessment of variability across pregnancy has been hampered by short half-lives of phthalate biomarkers and a few repeated measures in prior studies. We aimed to characterize the variability and longitudinal profiles of phthalate and replacement biomarkers across pregnancy. Within the Human Placenta and Phthalates Study, 303 pregnant women provided urine samples at up to 8 visits across gestation. Concentrations of 14 metabolites of phthalates and 4 metabolites of replacements were quantified in each sample, and subject-specific averages within each trimester were calculated. We examined variability in individual biomarker concentrations across the 8 visits, within trimesters, and across trimester-specific averages using intraclass correlation coefficients (ICCs). To explore longitudinal exposure biomarker profiles, we applied group-based trajectory modeling to trimester-specific averages over pregnancy. Pooling multiple visits into trimester-specific averages improved the ICCs for all biomarkers. Most biomarkers generally showed stable concentrations across gestation, i.e., high-, medium-, and low-concentration profiles, with small proportions of participants falling into the "high"-exposure groups. Variability over pregnancy is likely attributable to random fluctuations around a baseline exposure rather than true changes in concentrations over time.

Ethnoracial Differences in Premenopausal Hysterectomy: The Role of Symptom Severity.

OBJECTIVE: To evaluate whether greater symptom severity can explain higher hysterectomy rates among premenopausal non-Hispanic Black compared with White patients in the U.S. South rather than potential overtreatment of Black patients. METHODS: Using electronic health record data from 1,703 patients who underwent hysterectomy in a large health care system in the U.S. South between 2014 and 2017, we assessed symptom severity to account for differences in hysterectomy rates for noncancerous conditions among premenopausal non-Hispanic Black, non-Hispanic White, and Hispanic patients. We used Poisson generalized linear mixed modeling to estimate symptom severity (greater than the 75th percentile on composite symptom severity scores of bleeding, bulk, or pelvic pain) as a function of race-ethnicity. We calculated prevalence ratios (PRs). We controlled for factors both contra-indicating and contributing to hysterectomy. RESULTS: The overall median age of non-Hispanic White (n=1,050), non-Hispanic Black (n=565), and Hispanic (n=158) patients was 40 years. The White and Black patients were mostly insured (insured greater than 95%), whereas the Hispanic patients were often uninsured (insured 58.9%). White and Black patients were mostly treated outside academic medical centers (nonmedical center: 63.7% and 58.4%, respectively); the opposite was true for Hispanic patients (nonmedical center: 34.2%). Black patients had higher bleeding severity scores compared with Hispanic and White patients (median 8, 7, and 4 respectively) and higher bulk scores (median 3, 1, and 0, respectively), but pain scores differed (median 3, 5, and 4, respectively). Black and Hispanic patients were disproportionately likely to have severe symptoms documented on two or more symptoms (referent: not severe on any symptoms) (adjusted PR [Black vs White] 3.02, 95% CI 2.29-3.99; adjusted PR [Hispanic vs White] 2.61, 95% CI 1.78-3.83). Although Black and Hispanic patients were more likely to experience severe symptoms, we found no racial and ethnic differences in the number of alternative treatments attempted before hysterectomy. CONCLUSION: We did not find evidence of overtreatment of Black patients. Our findings suggest potential undertreatment of Black and Hispanic patients with uterine-sparing alternatives earlier in their disease progression.

Association of Prenatal Exposure to Benzodiazepines and Z-Hypnotics With Risk of Attention-Deficit/Hyperactivity Disorder in Childhood.

Importance: Evidence is limited regarding the safety of prenatal benzodiazepine and z-hypnotic exposure and its association with long-term neurodevelopment in childhood. Objective: To quantify the associations of the timing and number of intervals of prenatal exposure to benzodiazepines and/or z-hypnotics with the risk of attention-deficit/hyperactivity disorder (ADHD) in childhood. Design, Setting, and Participants: This cohort study used data from the 1999 to 2008 population-based Norwegian Mother, Father and Child Cohort Study, which are linked to the Medical Birth Registry of Norway, Norwegian Patient Registry, and Norwegian Prescription Database. Two populations of participants were created: a full sample and a mental health sample. The full sample included mothers and their live-born singletons, whereas the mental health sample was restricted to offspring of mothers who reported anxiety, depression, or sleeping problems during pregnancy or 6 months before pregnancy. Data were analyzed from September 2021 to February 2022. Exposures: Maternal self-report of benzodiazepine and/or z-hypnotic use during pregnancy was grouped into early pregnancy exposure and middle and/or late pregnancy exposure for analysis of the association with timing of exposure, and number of 4-week intervals of exposure was classified (single [1] vs multiple [≥2]) for analysis of the association with number of exposed intervals. Main Outcome and Measures: The outcome was ADHD, defined as time to ADHD diagnosis or filled prescription for ADHD medication. To control for confounding, inverse probability of treatment-weighted Cox proportional hazards regression models were used. Hazard ratios and 95% CIs were estimated. The weights were derived from propensity score modeling of the probability of benzodiazepine and/or z-hypnotic exposure as a function of potential confounders between the exposure and the outcome, including maternal symptoms of depression and anxiety. Results: The full sample comprised 82 201 pregnancies, and the mental health sample included 19 585 pregnancies. In total, 681 offspring (0.8%) in the full sample and 468 offspring (2.4%) in the mental health sample were prenatally exposed to benzodiazepines and/or z-hypnotics. After weighting, exposure in early (hazard ratio, 0.74; 95% CI, 0.39-1.94) and middle and/or late (hazard ratio, 0.76; 95% CI, 0.35-1.61) pregnancy was not associated with increased risk of childhood ADHD. There was no evidence of substantial association between the number of exposed intervals during pregnancy and childhood ADHD. Conclusions and Relevance: Results of this study suggest that there may be no increased risk of childhood ADHD associated with prenatal exposure to benzodiazepines and/or z-hypnotics, regardless of timing of exposure and number of exposed intervals. However, these findings should be interpreted with caution due to low study power.

DAG With Omitted Objects Displayed (DAGWOOD): a framework for revealing causal assumptions in DAGs.

Directed acyclic graphs (DAGs) are frequently used in epidemiology as a method to encode causal inference assumptions. We propose the DAGWOOD framework to bring many of those encoded assumptions to the forefront. DAGWOOD combines a root DAG (the DAG in the proposed analysis) and a set of branch DAGs (alternative hidden assumptions to the root DAG). All branch DAGs share a common ruleset, and must 1) change the root DAG, 2) be a valid DAG, and either 3a) change the minimally sufficient adjustment set or 3b) change the number of frontdoor paths. Branch DAGs comprise a list of assumptions which must be justified as negligible. We define two types of branch DAGs: exclusion branch DAGs add a single- or bidirectional pathway between two nodes in the root DAG (e.g., direct pathways and colliders), while misdirection branch DAGs represent alternative pathways that could be drawn between objects (e.g., creating a collider by reversing the direction of causation for a controlled confounder). The DAGWOOD framework 1) organizes causal model assumptions, 2) reinforces best DAG practices, 3) provides a framework for evaluation of causal models, and 4) can be used for generating causal models.

Longitudinal Methods for Modeling Exposures in Pharmacoepidemiologic Studies in Pregnancy.

In many perinatal pharmacoepidemiologic studies, exposure to a medication is classified as "ever exposed" versus "never exposed" within each trimester or even over the entire pregnancy. This approach is often far from real-world exposure patterns, may lead to exposure misclassification, and does not to incorporate important aspects such as dosage, timing of exposure, and treatment duration. Alternative exposure modeling methods can better summarize complex, individual-level medication use trajectories or time-varying exposures from information on medication dosage, gestational timing of use, and frequency of use. We provide an overview of commonly used methods for more refined definitions of real-world exposure to medication use during pregnancy, focusing on the major strengths and limitations of the techniques, including the potential for method-specific biases. Unsupervised clustering methods, including k-means clustering, group-based trajectory models, and hierarchical cluster analysis, are of interest because they enable visual examination of medication use trajectories over time in pregnancy and complex individual-level exposures, as well as providing insight into comedication and drug-switching patterns. Analytical techniques for time-varying exposure methods, such as extended Cox models and Robins' generalized methods, are useful tools when medication exposure is not static during pregnancy. We propose that where appropriate, combining unsupervised clustering techniques with causal modeling approaches may be a powerful approach to understanding medication safety in pregnancy, and this framework can also be applied in other areas of epidemiology.

The use of glucose-lowering medications for the treatment of type 2 diabetes mellitus during pregnancy in the United States.

INTRODUCTION: Some guidelines allow for the use of either insulin or noninsulin antidiabetic agents for gestational diabetes, but only insulin is recommended for pregnant women with preexisting type 2 diabetes mellitus (T2DM). We aimed to document treatment patterns in routine care for women with preexisting T2DM. METHODS: We identified pregnancy cohorts within 2 US claims databases for publicly and privately insured individuals: the Medicaid Analytical eXtract (2000-2014) and OptumClinformatics (2004-2014). T2DM was classified with a validated algorithm using ICD-9-CM and CPT codes. We assessed medication usage over the years of the study, and changes in medication use before and after the beginning of pregnancy, using prescription fills as a proxy for the use of insulin, metformin, sulphonylureas and other noninsulin antidiabetic agents before pregnancy and during each trimester. RESULTS: Among 12,631 women with T2DM, insulin use in pregnancy was stable over the study years (55%-60% in the 2nd trimester), but 2nd trimester use of metformin increased from <5% to 20%. Over the study period, 41% of women filled a prescription for metformin before pregnancy, 37% in the 1st trimester and 17% in the 2nd trimester. By the 2nd trimester, few women used sulphonylureas (11%) or other noninsulin antidiabetic agents (1%). Of the women on metformin only before pregnancy, 36% switched to insulin only by 2nd trimester, 11% added insulin and 16% continued on metformin only. Of the women on metformin and insulin before pregnancy, 61% switched to insulin only by 2nd trimester, 22% continued with metformin and insulin and <5% used only metformin. CONCLUSION: The use of insulin-metformin combinations and other noninsulin antidiabetic drugs during pregnancy has increased. Safety studies for these medication regimens are needed.

Validation of a Claims-based Algorithm to Identify Pregestational Diabetes Among Pregnant Women in the United States.

BACKGROUND: Identifying pregestational diabetes in pregnant women using administrative claims databases is important for studies of the safety of antidiabetic treatment in pregnancy, but limited data are available on the validity of case-identifying algorithms. The purpose of this study was to evaluate the validity of an administrative claims-based algorithm to identify pregestational diabetes. METHODS: Using a cohort of pregnant women nested within the Medicaid Analytic Extract (MAX) database, we developed an algorithm to identify pregestational type 1 and type 2 diabetes, distinct from gestational diabetes. Within a single large healthcare system in the Boston area, we identified women who delivered an infant between 2000 and 2010 and were covered by Medicaid, and linked their electronic health records to their Medicaid claims within MAX. Medical records were reviewed by two physicians blinded to the algorithm classification to confirm or rule out pregestational diabetes, with disagreements resolved by discussion. We calculated positive predictive values with 95% confidence intervals using the medical record as the reference standard. RESULTS: We identified 49 pregnancies classified by the claims-based algorithm as pregestational diabetes that were linked to the electronic health records and had records available for review. The PPV for any pregestational diabetes was 92% [95% confidence interval (CI) 82%, 97%], type 2 diabetes 87% (68%, 95%), and type 1 diabetes 57% (37%, 75%). CONCLUSIONS: The claims-based algorithm for pregestational diabetes and type 2 diabetes performed well; however, the PPV was low for type 1 diabetes.

The Patterns of Use of Medications for Inflammatory Bowel Disease During Pregnancy in the US and Sweden Are Changing.

BACKGROUND: Population-level data spanning different countries describing oral and parenteral treatment in pregnant women with inflammatory bowel disease (IBD) are scarce. We studied treatment with sulfasalazine/5-aminosalicylates, corticosteroids, thiopurines/immunomodulators, and tumor necrosis factor (TNF)-inhibitors in the United States (Optum Clinformatics Data Mart and the Medicaid Analytics Extract [MAX]) and in the Swedish national health registers. METHODS: We identified 2975 pregnant women in Optum (2004-2013), 3219 women in MAX (2001-2013), and 1713 women in Sweden (2006-2015) with a recorded diagnosis of IBD. We assessed patterns of use for each drug class according to filled prescriptions, assessing frequency of treatment continuation in those that were treated in the prepregnancy period. RESULTS: The proportion of women with Crohn's disease and ulcerative colitis on any treatment during pregnancy was 56.1% and 56.3% in Optum, 47.5% and 49.3% in MAX, and 61.3% and 64.7% in Sweden, respectively, and remained stable over time. Sulfasalazine/5-aminosalicylates was the most commonly used treatment in Crohn's disease, ranging from 25.1% in MAX to 31.8% in Optum, and in ulcerative colitis, ranging from 34.9% in MAX to 53.6% in Sweden. From 2006 to 2012, the TNF-inhibitor use increased from 5.0% to 15.5% in Optum, from 3.6% to 8.5% in MAX, and from 0.7% to 8.3% in Sweden. Continuing TNF-inhibitor treatment throughout pregnancy was more common in Optum (55.8%) and in MAX (43.0%) than in Sweden (11.8%). CONCLUSIONS: In this population-based study from 2 countries, the proportion of women with IBD treatment in pregnancy remained relatively constant. TNF-inhibitor use increased substantially in both countries.

Polypharmacy and comorbidities during pregnancy in a cohort of women with migraine.

OBJECTIVE: To describe longitudinal patterns of medication use throughout pregnancy in women with migraine. METHODS: We used the IBM MarketScan healthcare claims database in the US to create a cohort of pregnancies enrolled between 2011-2015 resulting in live or stillbirth. Migraine headache was identified based on ICD-9-CM diagnosis codes or procedure codes recorded in clinical encounters. Outcomes were patterns of prescriptions filled for medications that may be used to prevent migraine (antiepileptics, antihypertensives, antidepressants) or treat acute episodes (opioids, triptans, acetaminophen) and of other comorbid conditions (hypertension, psychiatric diagnoses, epilepsy). We used group-based multi-trajectory models to cluster women into similar longitudinal patterns of prescription fills. RESULTS: Of 859,501 pregnancies, 8168 had migraine. Within migraineurs, before pregnancy, the most commonly filled prescription was for a triptan (43.2%), followed by opioids (26.7%), acetaminophen (26.2%), antidepressants (24.9%), antiepileptics (18.6%) and antihypertensives (12.3%). Antiepileptics, antidepressants, and triptans were frequently discontinued early in pregnancy with few new users, while antihypertensives were discontinued by some users, but continued or initiated by a minority of users late in pregnancy. Opioids and acetaminophen were used intermittently throughout pregnancy. Comorbidities included hypertension (10.8%), epilepsy (4.7%), depression (14.0%), and anxiety (15.6%). Polypharmacy involving both preventive and acute medications was most common before pregnancy (31.4%) and declined in first trimester (14.7%). In all, 25.9% of women filled prescriptions for two or more acute medications before pregnancy. CONCLUSIONS: Medication use patterns during pregnancy for women with migraine are complex. Patterns of polypharmacy and comorbidity during pregnancy highlight an under-studied area relevant for maternal and child health outcomes.