Validation of maternal recall of early pregnancy medication exposure using prospective diary data

The timing, duration, and severity of nausea and vomiting of pregnancy and adverse birth outcomes among controls without birth defects in the National Birth Defects Prevention Study

BACKGROUND

Nausea and vomiting of pregnancy (NVP) occurs in approximately 70% of pregnant people, with varying severity and duration. Treatments include pharmacologic and herbal/natural medications. The associations between NVP and birth outcomes, including preterm birth, small for gestational age (SGA), and low birth weight are inconclusive.

OBJECTIVE

To determine whether NVP and reported medications are associated with adverse birth outcomes.

METHODS

We used data from the population-based, multisite National Birth Defects Prevention Study (1997-2011) to evaluate whether self-reported NVP according to timing, duration, and severity or its specific treatments were associated with preterm birth, SGA, and low birth weight among controls without birth defects. Odds ratios (aOR) and 95% confidence intervals (CI) were adjusted for sociodemographic, reproductive, and medical factors. For any NVP, duration, treatment use, and severity score analyses, the comparison group was participants with no reported NVP. For timing analyses, the comparison group was women with no reported NVP in the same trimester of pregnancy.

RESULTS

Among 6018 participants, 4339 (72.1%) reported any NVP. Among those with NVP, moderate or severe symptoms were more common than mild symptoms. Any versus no NVP was not associated with any of the outcomes of interest. NVP in months 4-6 (aOR 1.21, 95% CI: 1.00, 1.47) and 7-9 (aOR 1.57, 95% CI: 1.22, 2.01) of pregnancy were associated with an increase in the risk of preterm birth. NVP lasting one trimester in duration was associated with decrease in risk of SGA (aOR: 0.74, 95% CI: 0.58, 0.95), and NVP present in every trimester of pregnancy had a 50% increase in risk of preterm birth (aOR: 1.50, 95% CI: 1.11, 2.05). For NVP in months 7-9 and preterm birth, ORs were elevated for moderate (aOR: 1.82, 95% CI: 1.26, 2.63), and severe (aOR: 1.53, 95% CI: 1.06, 2.19) symptoms. NVP was not significantly associated with low birth weight. Our analyses of medications were limited by small numbers, but none suggested increased risk of adverse outcomes associated with use of the medication.

CONCLUSION

Mild NVP and NVP limited to early pregnancy appear to have no effect or a small protective effect on birth outcomes. Long-lasting NVP, severe NVP, and NVP later in pregnancy may increase risk of preterm birth and SGA.

Agreement between maternal report and medical records on use of medications during early pregnancy in New York

BACKGROUND

Studies evaluating associations between medication use in pregnancy and birth outcomes rely on various sources of exposure information. We sought to assess agreement between self-reported use of medications during early pregnancy and medication information in prenatal medical records to understand the reliability of each of these information sources.

METHODS

We compared self-reported prescription medication use in early pregnancy to medical records from 184 New York women with deliveries in 2018 who participated in the Birth Defects Study To Evaluate Pregnancy exposureS. We assessed medications used chronically and episodically, and medications within 12 therapeutic groups. We calculated agreement using kappa (κ) coefficients, sensitivity, and specificity. We assessed differences by case/control status, maternal age, education, time to interview, and interview language.

RESULTS

Medications used chronically showed substantial agreement between self-report and medical records (κ = 0.75, 0.61-0.88), with agreement for therapeutic groups used chronically ranging from κ = 0.61 for antidiabetics to κ = 1.00 for antihypertensives. Prescription medications used episodically showed worse agreement (κ = 0.40, 0.25-0.54), with the lowest agreement for opioid analgesics (κ = 0.20) and anti-infectives (κ = 0.33). Agreement did not differ by the characteristics examined, although we observed potential differences by interview language.

CONCLUSIONS

Among our sample, we observed good agreement between self-report and medical records for medications used chronically and substantially less agreement for medications used episodically. Differences by source may be due to poor recall in self-reports, non-adherence with prescribed medications and lack of complete prescription information within medical records. Limitations should be considered when assessing prescription medication exposures during early pregnancy in epidemiologic studies.

Critical assessment of the current indicator for antenatal iron‐containing supplementation coverage: Insights from a mixed‐methods study

Daily consumption of iron‐containing supplements is recommended for all pregnant women but there is no approved global standard indicator for assessing supplementation coverage. Furthermore, the validity of commonly used coverage indicators for iron‐containing supplement consumption is questionable. The WHO–UNICEF Technical Expert Advisory Group on Nutrition Monitoring, and partners, have systematically worked to identify a feasible and valid indicator of iron‐containing supplement coverage for reporting by countries. In 2019, we conducted key informant interviews with respondents in eight countries, fielded an online survey (in three languages using SurveyMonkey) to which 142 nutrition professionals from 52 countries responded, and used Demographic and Health Surveys (DHS) data from four countries to assess determinants of the quality of iron‐containing supplement coverage data. Less than half (45%) of online survey respondents were satisfied with the current methods for collecting iron‐containing supplement coverage data in their context. Recommended changes by study respondents include recall period <5 years, adding questions about counselling, including other beneficiary groups, and assessing supply chain functionality. The DHS analysis suggested an association between time since pregnancy and data quality. Data heaping on multiples of 30 was observed in 40%–75% of data. There is a clear demand for a revised indicator and measurement guidance for coverage of iron‐containing supplementation during pregnancy. Future research should continue the development and validation of a global indicator, to more precisely validate the quality of recall data, including the distinction between distribution and consumption using various question formulations.

Health and nutrition professionals have described concerns with current methods for reporting coverage of daily iron‐containing supplementation in pregnant women.

The long recall period (5 years) of commonly used iron‐containing supplement consumption indicators calls into question the validity of these indicators.

Our study indicates that there is demand for a revised indicator and guidance for data collection.

Determining the Clinical Course of Asthma in Pregnancy

BACKGROUND

Asthma is the most common chronic disease affecting pregnancy, and poor asthma control has been associated with adverse pregnancy outcomes. However, the trajectory of asthma control during pregnancy is not well understood or characterized.

OBJECTIVE

To identify and characterize trajectories of gestational asthma control in a US-based prospective pregnancy cohort.

METHODS

A k-means algorithm for joint longitudinal data was used to cluster pregnant women with and without asthma into gestational asthma control trajectories on the basis of daily activity limitation, nighttime symptoms, inhaler use, and respiratory symptoms.

RESULTS

Among 308 women with asthma, 2 trajectories of gestational asthma control were identified and labeled "same" (n = 184; 59.5%) or "worse" (n = 124; 40.5%). Contrary to previous studies, we did not observe women with better asthma control in pregnancy. Women belonging to the "worse" trajectory experienced frequent and stable activity limitation and inhaler use, as well as frequent and increasing nighttime symptoms (∼3 d/gestational week) and respiratory symptoms (∼5 times/wk). Women belonging to the "same" trajectory experienced infrequent and stable activity limitation, inhaler use, and respiratory symptoms, as well as infrequent and slightly increasing (∼1 d/gestational week) nighttime symptoms. Results from pregnant women without asthma (n = 107) suggest that pregnancy alone was not responsible for changes in symptoms over time.

CONCLUSIONS

In this US-based obstetric cohort receiving care according to standard clinical practice, gestational asthma control worsened for about 40% of women.

Intra-Individual Variability in Self-Reported Use of Non-Steroidal Anti-Inflammatory and Analgesic Medicines Depending on Mode of Data Collection - Observations from the Population Study of Women in Gothenburg, Sweden

Background

Self-report by questionnaire is one of the main methods to collect data on drug utilization. There are several modes of data collection by questionnaire, differing in the way of delivering the questionnaire to respondents and in the administration of the questions, both influencing the recall and participation rates. The aim of this study was to compare different modes of data collection for self-reported use of non-steroidal anti-inflammatory (NSAIDs) and analgesic medicines.

Methods

Data on 573 women (38 or 50 years) were retrieved from the Population Study of Women in Gothenburg. Data on medicine use were collected using two different modes: (1) a self-administered questionnaire with closed-ended medicine-specific questions; and (2) an interviewer-administered questionnaire with open-ended questions. Cohen’s kappa statistics were applied to assess the agreement of the two modes.

Results

The proportion of participants that reported use of NSAIDs and analgesics was higher with the self-administered questionnaire compared with the interviewer-administered questionnaire (69.3% vs 58.5%, p <0.001). The overall agreement between the two modes of data collection was fair (Ⱪ=0.27), ranging from none for antimigraine preparations to fair (Ⱪ=0.36) for NSAIDs. A higher proportion of the participants aged 38 years reported use of NSAIDs and analgesics compared with the 50-year olds. In the regression model using data from the self-administered questionnaire, all four categories of bodily pain were significant predictors for use of NSAIDs and analgesics. The most severe reported bodily pain was the only significant predictor in the model using data from the interviewer-administered questionnaire.

Conclusion

This study showed that use of a self-administered questionnaire with closed-ended medicine-specific questions identified more users of NSAIDs and analgesic medicines compared with an interviewer-administered questionnaire with open-ended questions. Reported use according to the self-administered questionnaire was also more strongly associated with experienced pain.

Prenatal exposure to non-steroidal anti-inflammatory drugs and risk of attention-deficit/hyperactivity disorder: A follow-up study in the Norwegian mother, father and child cohort

PURPOSE

To estimate the association between Attention-Deficit/Hyperactivity Disorder (ADHD) in children in preschool and primary school, and prenatal exposure to non-steroidal anti-inflammatory drugs (NSAIDs) by timing and duration.

METHODS

This study was based on the Norwegian Mother, Father and Child Cohort Study linked to the Medical Birth Registry of Norway, the Norwegian Patient Registry (NPR) and the Norwegian Prescription Database (NorPD). NSAID exposure was identified by maternal self-report in pregnancy. Child diagnosis of ADHD was obtained from NPR and NorPD. Symptoms of ADHD at age 5 years were measured using Conners' Parent Rating Scale-Revised, where higher scores correspond to more symptoms. To account for time-varying exposure and confounders, marginal structural models were fitted to estimate hazard ratios and mean difference in z-scores.

RESULTS

The analyses on ADHD diagnosis and ADHD symptoms included 56 340 and 34 961 children respectively. Children exposed to NSAIDs prenatally had no increased risk of ADHD diagnosis (first trimester: HR 1.12, 95% CI 0.86;1.45, second trimester: HR 0.98, 95% CI 0.69;1.38, third trimester: HR 0.68, 95% CI 0.31; 1.46) or ADHD symptoms (first trimester: standardized mean difference 0.03, 95% CI -0.03;0.09, second trimester: standardized mean difference 0.03, 95% CI -0.04;0.11, third trimester: standardized mean difference 0.11, 95% CI -0.03; 0.25). There was no duration-response relationship for either outcome.

CONCLUSION

Though non-differential misclassification of the exposure may have attenuated results, these findings are reassuring and suggest no substantially increased risk of ADHD diagnosis or symptoms in children prenatally exposed to NSAIDs, regardless of timing or duration.

Caffeine exposure during pregnancy: Is it safe?

Numerous studies have examined the association between maternal caffeine consumption and infant and childhood health outcomes and the results have been inconsistent. The study of maternal caffeine intake and infant and childhood health outcomes is prone to methodologic challenges. In this review, we examine the existing evidence juxtaposed with the epidemiologic design challenges that color the interpretation of the study results presented. In light of methodologic/interpretation challenges, it seems reasonable to infer that exposure to low levels of caffeine is probably not associated with substantial infant and childhood adversities. However, more research is needed using well designed studies that address methodologic challenges.

Recalled maternal lifestyle behaviors associated with anti-müllerian hormone of adult female offspring

Anti-müllerian hormone (AMH) is an established marker of ovarian reserve that decreases with age. Though the pool of ovarian follicles is established during fetal development, impacts of in utero exposures on AMH are uncertain. Thus, we sought to evaluate associations of in utero exposures with AMH of adult daughters with a prospective cohort study of adult daughters at university medical centers. Women noted their mother's reported use of diethylstilbestrol (DES), vitamins, tobacco, alcohol, and caffeine during pregnancy, and their mother's occupation during pregnancy. All participants were reproductive age women (18-40 years) enrolled in the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial. Serum AMH concentrations were measured at baseline prior to conception and categorized using clinical guidelines. Multinomial regression models estimated associations between each exposure and high (>3.5 ng/mL) and low (<1.0 ng/mL) versus normal AMH (1.0-3.5 ng/mL), adjusting for participant's age, mother's age, mother's history of fertility treatment, and mother's use of vitamins. In 1202 women with available data, maternal caffeine use was associated with an increased risk of low AMH, compared to normal (relative risk [RR] 1.90, 95 % confidence interval [CI] 1.09, 3.30). Vitamins were associated with an increased risk of high AMH compared to normal (RR 1.93, 95 % CI 1.24, 3.00). Other exposures were not associated with AMH concentrations in offspring. Maternal caffeine and vitamin use during pregnancy may be associated with ovarian reserve in adult offspring, highlighting the potential importance of pregnancy lifestyle on the reproductive health of daughters.

Factors Associated with Unplanned Primary Cesarean Birth: Secondary Analysis of the Listening to Mothers in California Survey

BACKGROUND

In many countries, cesarean section has become the most common major surgical procedure. Most nations have high cesarean birth rates, suggesting overuse. Due to the excess harm and expense associated with unneeded cesareans, many health systems are seeking approaches to safe reduction of cesarean rates. Surveys of childbearing women are a distinctive and underutilized source of data for examining factors that may contribute to cesarean reduction.

METHODS

To identify factors associated with unplanned primary cesarean birth, we carried out a secondary analysis of the Listening to Mothers in California Survey, limited to the subgroup who had not had a previous cesarean birth and did not have a planned primary cesarean (n = 1,964). Participants were identified through birth certificate sampling and contacted initially by mail and then by telephone, text message and email, as available. Sampled women could participate in English or Spanish, on any device or with a telephone interviewer. Following bivariate demographic, knowledge and attitude, and labor management analyses, we carried out multivariable analyses to adjust with covariates and identify factors associated with unplanned primary cesarean birth.

RESULTS

Whereas knowledge, attitudes, preferences and behaviors of the survey participants were not associated with having an unplanned primary cesarean birth, their experience of pressure from a health professional to have a cesarean and a series of labor management practices were strongly associated with how they gave birth. These practices included attempted induction of labor, early hospital admission, and labor augmentation. Women's reports of pressure from a health professional to have a primary cesarean were strongly related to the likelihood of cesarean birth.

CONCLUSIONS

While women largely wish to avoid unneeded childbirth interventions, their knowledge, preferences and care arrangement practices did not appear to impact their likelihood of an unplanned primary cesarean birth. By contrast, a series of labor management practices and perceived health professional pressure to have a cesarean were associated with unplanned primary cesarean birth. Improving ways to engage childbearing women and implementing changes in labor management and communication practices may be needed to reduce unwarranted cesarean birth.

Association between First Trimester Antidepressant Use and Risk of Spontaneous Abortion

STUDY OBJECTIVE

The potential for maternal antidepressant use to influence the risk of spontaneous abortion, one of the most important adverse pregnancy outcomes, is not clear. We aimed to assess whether first trimester antidepressant exposure was associated with an increased risk of spontaneous abortion.

DESIGN

Community-based prospective cohort study (Right from the Start).

SETTING

Eight metropolitan areas in North Carolina, Tennessee, and Texas.

PARTICIPANTS

A total of 5451 women (18 years of age or older) who were planning to conceive or were pregnant (before 12 weeks of completed gestation) and were enrolled in the study between 2000 and 2012; of those women, 223 used antidepressants (selective serotonin reuptake inhibitors [SSRIs] only [170], SSRIs and non-SSRIs [9], and non-SSRIs only [44]) during their first trimester, and 5228 did not (never users). Measurements and Main Results First trimester antidepressant use was determined during a first trimester telephone interview. Spontaneous abortion was self-reported and verified by medical records. The association of first trimester antidepressant use and spontaneous abortion was assessed by using Cox proportional hazard regression. Among the 5451 women enrolled, 223 (4%) reported first trimester antidepressant use, and 659 (12%) experienced a spontaneous abortion. SSRIs were the most common class of antidepressants used (179 [80%]). Compared with women who never used antidepressants during the first trimester of pregnancy, women who reported antidepressant use were 34% (adjusted hazard ratio [aHR] 1.34, 95% confidence interval [CI] 0.97-1.85) more likely to experience a spontaneous abortion after adjusting for covariates. Women who reported ever using SSRIs were 45% (aHR 1.45, 95% CI 1.02-2.06) more likely to experience a spontaneous abortion compared with never users. When time of loss relative to the time of interview was taken into consideration, the association between first trimester SSRI use and spontaneous abortion was significant only among those with losses before the interview (aHR 1.49, 95% CI 1.04-2.13) but was not significant among those with losses after the interview (aHR 0.43, 95% CI 0.06-3.15).

CONCLUSION

The association between use of first trimester antidepressants, particularly SSRI use, and spontaneous abortion was significant only among women whose exposure status was assessed after loss. In this instance, reporting bias may create a spurious association. Future studies should take the timing of data collection relative to the timing of loss into consideration.

Assessment of medication use during pregnancy by Web-based questionnaires, pharmacy records and serum screening

OBJECTIVE

To compare assessment of early pregnancy medication exposure using three methods of data collection.

METHODS

Serum samples were obtained from 752 women participating in the PRegnancy and Infant DEvelopment (PRIDE) Study before gestational week 17. For 52 women using medication at the date of blood sampling according to Web-based questionnaires or pharmacy records, we analysed serum samples using untargeted liquid chromatography time-of-flight spectrometry.

RESULTS

Medication was detected in 18 serum samples (35%). Medications taken orally for chronic conditions reported in the questionnaire were detected in serum and vice versa. Pharmacy records did not identify additional exposed women, but missed exposure in 5 women mainly due to unavailability. We observed substantial discordance between the three methods for inhaled medication, dermatological preparations, and medications for short-term use, which went often undetected in serum.

CONCLUSIONS

It remains challenging to assess medication use in large-scale studies as no 'gold standard' is currently available.

Implementation and Effects of Risk-Dependent Obstetric Care in the Netherlands (Expect Study II): Protocol for an Impact Study

BACKGROUND

Recently, validated risk models predicting adverse obstetric outcomes combined with risk-dependent care paths have been made available for early antenatal care in the southeastern part of the Netherlands. This study will evaluate implementation progress and impact of the new approach in obstetric care.

OBJECTIVE

The objective of this paper is to describe the design of a study evaluating the impact of implementing risk-dependent care. Validated first-trimester prediction models are embedded in daily clinical practice and combined with risk-dependent obstetric care paths.

METHODS

A multicenter prospective cohort study consisting of women who receive risk-dependent care is being performed from April 2017 to April 2018 (Expect Study II). Obstetric risk profiles will be calculated using a Web-based tool, the Expect prediction tool. The primary outcomes are the adherence of health care professionals and compliance of women. Secondary outcomes are patient satisfaction and cost-effectiveness. Outcome measures will be established using Web-based questionnaires. The secondary outcomes of the risk-dependent care cohort (Expect II) will be compared with the outcomes of a similar prospective cohort (Expect I). Women of this similar cohort received former care-as-usual and were prospectively included between July 1, 2013 and December 31, 2015 (Expect I).

RESULTS

Currently, women are being recruited for the Expect Study II, and a total of 300 women are enrolled.

CONCLUSIONS

This study will provide information about the implementation and impact of a new approach in obstetric care using prediction models and risk-dependent obstetric care paths.

TRIAL REGISTRATION

Netherlands Trial Register NTR4143; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4143 (Archived by WebCite at http://www.webcitation.org/6t8ijtpd9).

Bayesian Correction for Misclassification in Multilevel Count Data Models

Covariate misclassification is well known to yield biased estimates in single level regression models. The impact on hierarchical count models has been less studied. A fully Bayesian approach to modeling both the misclassified covariate and the hierarchical response is proposed. Models with a single diagnostic test and with multiple diagnostic tests are considered. Simulation studies show the ability of the proposed model to appropriately account for the misclassification by reducing bias and improving performance of interval estimators. A real data example further demonstrated the consequences of ignoring the misclassification. Ignoring misclassification yielded a model that indicated there was a significant, positive impact on the number of children of females who observed spousal abuse between their parents. When the misclassification was accounted for, the relationship switched to negative, but not significant. Ignoring misclassification in standard linear and generalized linear models is well known to lead to biased results. We provide an approach to extend misclassification modeling to the important area of hierarchical generalized linear models.

Agreement between paternal self-reported medication use and records from a national prescription database

PURPOSE

Father's medication use is of interest in fertility studies and as negative control exposures in pregnancy medication safety studies. We sought to compare self-report to prescription records to understand how reliably each of these sources of information may be used.

METHODS

We compared self-reported medication use in the 6 months prior to pregnancy from fathers participating in the Norwegian Mother and Child Cohort Study to records of dispensed prescriptions from the Norwegian Prescription Database that overlapped in time. Medications from 3 main categories were assessed: prescription medications used chronically, prescription medications used episodically, and over-the-counter/prescription medications (predominantly obtained without prescription). We calculated agreement between self-report and dispensing records using Cohen's kappa statistic.

RESULTS

We included 42 848 pregnancies with the father's prescription data available for the 9 months before pregnancy. Prescription medications used chronically including antiepileptics, antipsychotics, and antidepressants showed substantial agreement between self-report and prescription records: kappa statistics 0.87, 0.63, and 0.74, respectively. Prescription medications used episodically like anti-infectives, opioids, anxiolytics, and hypnotics and sedatives showed worse agreement: kappa 0.19, 0.32, 0.40, 0.32. Over-the-counter/prescription medications like paracetamol and nonsteroidal anti-inflammatory drugs had slight agreement: kappa 0.02 and 0.20.

CONCLUSIONS

There is good agreement between paternal self-report and prescription data for prescribed medications used chronically and substantially less for medications used episodically. Suboptimal agreement for episodic medications suggests poor recall (for questionnaires) or false positives due to noncompliance (prescription data). Not surprisingly, use of medications available both with and without a prescription is not well captured using prescription databases alone.

Using Web-Based Questionnaires to Assess Medication Use During Pregnancy: A Validation Study in 2 Prospectively Enrolled Cohorts

Medication use is often underreported in paper-based questionnaires or interviews. Web-based questionnaires may improve recall of medication use, but data on their validity are currently lacking. Participants in the Pregnancy and Infant Development (PRIDE) Study (2014-2016; n = 557) and the Pregnancy Drug Registry (pREGnant) (2015-2016; n = 169) completed a 6-week paper-based medication diary during gestational weeks 19-24 or 26-31. In week 34, they completed a Web-based questionnaire with questions on medication names, time period and frequency of use, and quantity taken. To assess the degree of underreporting, we calculated the questionnaire's sensitivity using the medication diary as the reference standard. Sensitivity was high for many medication groups, including antiepileptic medication (sensitivity (Sn) = 0.96, 95% confidence interval (CI): 0.89, 1.00), antacids (Sn = 0.89, 95% CI: 0.86, 0.93), and iron preparations (Sn = 0.81, 95% CI: 0.64, 0.98). However, medications for short-term use were underreported more frequently, with sensitivities of 0.54 (95% CI: 0.35, 0.72) for antihistamines, 0.63 (95% CI: 0.57, 0.69) for analgesic and antipyretic agents, and 0.57 (95% CI: 0.51, 0.64) for acetaminophen. Shortening the period of time between exposure and questionnaire administration increased sensitivity substantially. In conclusion, underreporting in Web-based questionnaires is limited for many medication groups. In prospective studies, underreporting of medications for short-term use may be reduced by decreasing the interval between consecutive questionnaires.

Administrative Claims Data Versus Augmented Pregnancy Data for the Study of Pharmaceutical Treatments in Pregnancy

Purpose of Review

Administrative claims databases, which collect reimbursement-related information generated from healthcare encounters, are increasingly used to evaluate medication safety in pregnancy. We reviewed the strengths and limitations of claims-only databases and how other data sources may be used to improve the accuracy and completeness of information critical for studying medication safety in pregnancy.

Recent Findings

Research on medication safety in pregnancy requires information on pregnancy episodes, mother-infant linkage, medication exposure, gestational age, maternal and birth outcomes, confounding factors, and (in some studies) long-term follow-up data. Claims data reliably identifies live births and possibly other pregnancies. It allows mother-infant linkage and has prospectively collected prescription medication information. Its diagnosis and procedure information allows estimation of gestational age. It captures maternal medical conditions but generally has incomplete data on reproductive and lifestyle factors. It has information on certain, typically short-term maternal and infant outcomes that may require chart review confirmation. Other data sources including electronic health records and birth registries can augment claims data or be analyzed alone. Interviews, surveys, or biological samples provide additional information. Nationwide and regional birth and pregnancy registries, such as those in several European and North American countries, generally contain more complete information essential for pregnancy research compared to claims-only databases.

Summary

Claims data offers several advantages in medication safety in pregnancy research. Its limitations can be partially addressed by linking it with other data sources or supplementing with primary data collection. Rigorous assessment of data quality and completeness is recommended regardless of data sources.