Use of Prescription Antiemetics Among US Commercially Insured Pregnant Patients, 2005-2019

This cohort study investigates prescription antiemetic treatment patterns considering monotherapy, switching, and combination therapy during the first trimester of pregnancy and evaluates factors associated with ondansetron use.

Signal mining of adverse reactions in the antiemetic drug ondansetron during pregnancy: A real-world analysis of the FDA adverse event reporting system (FAERS)

BACKGROUND

The aim of this study is to assess the risks associated with the use of ondansetron in pregnant women in real-world based on the Food and Drug Administration adverse Event Reporting System (FAERS).

METHODS

The FAERS data from the 2017Q1 to the 2023Q1, which was used by the ratio-of-reporting (ROR) and Bayesian confidence interval progressive neural network (BCPNN) to assess the safety of ondansetron in pregnancy.

RESULTS

A total of 15,727 pregnancy population reports were reported, with a total of 1,064 reports of adverse reactions with ondansetron as the primary suspected drug. Ondansetron was involved in a total of 10 system organ classifications (SOCs) of signal generation, and the top three signal intensities were Congenital, familial, and genetic disorders (ROR = 19.1, ROR025 = 17.03; IC = 1.23, IC025 = 1.16), Ear and labyrinth disorders (ROR = 17.11, ROR025 = 12.46; IC = 1.22, IC025 = 1.03), and Cardiac disorders (ROR = 9.48, ROR025 = 8.38; IC = 1.12, IC025 = 1.03); signals of adverse reactions obtained of 216, of which the main ones were Anhedonia (IC = 1.34, IC025 = 1.08), Injury (IC = 1.34, IC025 = 1.19), Left-to-right cardiac shunt (IC = 1.33, IC025 = 1.05).

CONCLUSION

The adverse reactions of Ondansetron involve multiple systems and organs, which should cause clinical vigilance. However, due to the limitations of the data, the causal relationship and risk level of adverse reactions cannot be accurately inferred.

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.

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.

Association of Commonly Prescribed Antepartum Medications and Incidence of Orofacial Clefting

BACKGROUND

Pharmacologic agents are often used in the antepartum period, however, studies on their effect on fetal development are limited. Thus, this study aims to examine the effect of commonly prescribed antepartum medications on the development of orofacial clefting.

METHODS

Utilizing EPIC Cosmos deidentified data from approximately 180 US institutions was queried. Patients born between January 1, 2013, to January 1, 2023, were included. Eight OC cohorts were identified. Gestational medication use was identified by medications prescribed, provider-administered, or reported use by mothers. Medications used in at least 1 in 10,000 pregnancies were included in this analysis.

RESULTS

A total of 12 098 newborns with available maternal pharmacologic data were born with any type of orofacial clefting. Prevalence for all oral clefts, any cleft palate, and any cleft lip were 20.56, 18.10, and 10.60 per 10 000 individuals, respectively. Notable significant exposures include most anticonvulsants, such as lamotrigine (OR1.33, CI 1.10-1.62), and topiramate (OR1.35, CI 1.13-1.62), as well as nearly all SSRIs/SNRIs, including fluoxetine (OR1.34, CI 1.19-1.51), sertraline (OR1.25, CI 1.16-1.34), and citalopram (OR1.28, CI 1.11-1.47). Corticosteroids were also correlated including dexamethasone (OR1.19, CI 1.12-1.27), and betamethasone (OR1.64, CI 1.55-1.73), as were antibiotics, including amoxicillin (OR1.22, CI 1.14-1.30), doxycycline (OR1.29, CI 1.10-1.52), and nitrofuran derivatives (OR1.10, CI 1.03-1.17).

CONCLUSION

New associations between commonly prescribed antepartum medications and orofacial clefting were found. These findings should be confirmed as causality is not assessed in this report. Practitioners should be aware of the potential increased risk associated with these medications.

A patterned human primitive heart organoid model generated by pluripotent stem cell self-organization

Pluripotent stem cell-derived organoids can recapitulate significant features of organ development in vitro. We hypothesized that creating human heart organoids by mimicking aspects of in utero gestation (e.g., addition of metabolic and hormonal factors) would lead to higher physiological and anatomical relevance. We find that heart organoids produced using this self-organization-driven developmental induction strategy are remarkably similar transcriptionally and morphologically to age-matched human embryonic hearts. We also show that they recapitulate several aspects of cardiac development, including large atrial and ventricular chambers, proepicardial organ formation, and retinoic acid-mediated anterior-posterior patterning, mimicking the developmental processes found in the post-heart tube stage primitive heart. Moreover, we provide proof-of-concept demonstration of the value of this system for disease modeling by exploring the effects of ondansetron, a drug administered to pregnant women and associated with congenital heart defects. These findings constitute a significant technical advance for synthetic heart development and provide a powerful tool for cardiac disease modeling.

Embryo-fetal safety evaluation of ondansetron in rats

BACKGROUND

Ondansetron is a 5HT3 receptor antagonist, used to mitigate the effects of nausea and vomiting after chemotherapy or surgery. Since nausea and vomiting are common experiences during the first trimester of pregnancy, this antiemetic has been the main drug used during this period.

METHODS

To evaluate the effects of ondansetron on the embryo-fetal development, which are still very contradictory, pregnant rats were exposed to therapeutic doses of ondansetron (1.7 or 2.5 mg/kg) daily, from gestational day (GD) 6 to 15.

RESULTS

No clinical signs of toxicity were observed in dams during the treatment. Although the hemato-biochemical parameters were similar among the groups, histological changes, as well as a reduction in the weight of kidney were found in the treated dams. After fetal examination, no visceral and skeletal abnormalities were observed in treated fetuses.

CONCLUSION

In conclusion, therapeutic doses of ondansetron have low teratogenic potential in rats. These data provide important information about the drug safety during pregnancy.

Patterns of antiemetic medication use during pregnancy: A multi-country retrospective cohort study

OBJECTIVE

To compare patterns in use of different antiemetics during pregnancy in Canada, the United Kingdom, and the United States, between 2002 and 2014.

METHODS

We constructed population-based cohorts of pregnant women using administrative healthcare data from five Canadian provinces (Alberta, British Columbia, Manitoba, Ontario, and Saskatchewan), the Clinical Practice Research Datalink from the United Kingdom, and the IBM MarketScan Research Databases from the United States. We included pregnancies ending in live births, stillbirth, spontaneous abortion, or induced abortion. We determined maternal use of antiemetics from pharmacy claims in Canada and the United States and from prescriptions in the United Kingdom.

RESULTS

The most common outcome of 3 848 734 included pregnancies (started 2002-2014) was live birth (66.7% of all pregnancies) followed by spontaneous abortion (20.2%). Use of antiemetics during pregnancy increased over time in all three countries. Canada had the highest prevalence of use of prescription antiemetics during pregnancy (17.7% of pregnancies overall, 13.2% of pregnancies in 2002, and 18.9% in 2014), followed by the United States (14.0% overall, 8.9% in 2007, and 18.1% in 2014), and the United Kingdom (5.0% overall, 4.2% in 2002, and 6.5% in 2014). Besides use of antiemetic drugs being considerably lower in the United Kingdom, the increase in its use over time was more modest. The most commonly used antiemetic was combination doxylamine/pyridoxine in Canada (95.2% of pregnancies treated with antiemetics), ondansetron in the United States (72.2%), and prochlorperazine in the United Kingdom (63.5%).

CONCLUSIONS

In this large cohort study, we observed an overall increase in antiemetic use during pregnancy, and patterns of use varied across jurisdictions. Continued monitoring of antiemetic use and further research are warranted to better understand the reasons for differences in use of these medications and to assess their benefit-risk profile in this population.

Time-related biases in perinatal pharmacoepidemiology: A systematic review of observational studies

BACKGROUND

Time-related biases, such as immortal time and time-window bias, frequently occur in pharmacoepidemiologic research. However, the prevalence of these biases in perinatal pharmacoepidemiology is not well understood.

OBJECTIVE

To describe the frequency of time-related biases in observational studies of medications commonly used during pregnancy (antibiotic, antifungal, and antiemetic drugs) via systematic review.

METHOD

We searched Medline and EMBASE for observational studies published between January 2013 and September 2020 and examining the association between antibiotic, antifungal, or antiemetic drugs and adverse pregnancy outcomes, including spontaneous abortion, stillbirth, preterm delivery, small-for-gestational age, pre-eclampsia, and gestational diabetes. The proportion of studies with time-related biases was estimated overall and by type (immortal time bias, time-window bias).

RESULTS

Our systematic review included 20 studies (16 cohort studies, 3 nested case-control studies, and 1 case-control study), of which 12 examined antibiotic, 6 antiemetic, and 2 anti-fungal drugs. Eleven studies (55%) had immortal time bias due to the misclassification of unexposed, event-free person-time between cohort entry and exposure initiation as exposed. No included study had time-window bias. The direction of effect varied for both studies with and without time-related bias, with many studies reporting very wide confidence intervals around the effect estimates, thus making the direction of effect less interpretable. However, studies with time-related bias were more likely to show protective or null associations compared with studies without time-related bias.

CONCLUSION

Time-related biases occur frequently in observational studies of drug effects during pregnancy. The use of appropriate study design and analytical approaches is needed to prevent time-related biases and ensure study validity.

Safety evaluation of ondansetron after gestational exposure on male reproductive parameters in rats

Ondansetron is a 5HT3 receptor antagonist widely used to treat hyperemesis gravidarum, although its safety is still questionable. Since 5HT3 receptors, which are the target of this drug, can interfere with brain development through changes in neurotransmitter levels, this study evaluated whether the prenatal exposure to this drug could compromise reproductive and behavioral parameters in male offspring. Pregnant rats were treated with ondansetron (1.7 and 2.5 mg/kg/body weight; gavage), from gestational day 1-21. No exposure-related changes in clinical signs, body weight, food consumption, pregnancy length, and necropsy findings were observed in dams. Ondansetron exposure did not alter the anogenital distance or age of preputial separation in male offspring. Similarly, males exposed to therapeutic doses of ondansetron did not exhibit changes in play behavior. In adulthood, there were no changes in sperm parameters, as well as in testosterone level, sexual behavior and fertility. Furthermore, ondansetron did not interfere with testicular and epididymal histology, and with androgen receptor expression in hypothalamus. In conclusion, prenatal exposure to ondansetron did not cause maternal toxicity, as well as did not interfere with reproductive parameters of male offspring, indicating its safety after gestational exposure in rats.

The US Food and Drug Administration Sentinel System: a national resource for a learning health system

The US Food and Drug Administration (FDA) created the Sentinel System in response to a requirement in the FDA Amendments Act of 2007 that the agency establish a system for monitoring risks associated with drug and biologic products using data from disparate sources. The Sentinel System has completed hundreds of analyses, including many that have directly informed regulatory decisions. The Sentinel System also was designed to support a national infrastructure for a learning health system. Sentinel governance and guiding principles were designed to facilitate Sentinel's role as a national resource. The Sentinel System infrastructure now supports multiple non-FDA projects for stakeholders ranging from regulated industry to other federal agencies, international regulators, and academics. The Sentinel System is a working example of a learning health system that is expanding with the potential to create a global learning health system that can support medical product safety assessments and other research.

Risk of abnormal pregnancy outcomes after using ondansetron during pregnancy: A systematic review and meta-analysis

Background: Hyperemesis gravidarum is a serious pregnancy complication that affects approximately 1% of pregnancies worldwide.

Objective: To determine whether the use of ondansetron during pregnancy is associated with abnormal pregnancy outcomes.

Search strategy: PubMed, Cochrane Library, CINAHL, Embase, CNKI, CBM, WANFANG, and ClinicalTrials.gov were searched for citations published in any language from inception to 15 December 2021.

Selection criteria: Eligible studies included any observational study.

Data collection and analysis: Odds ratio (OR) and 95% confidence interval (CI) were used as indicators to examine the association between ondansetron and abnormal pregnancy outcomes.

Main results: Twenty articles from 1,558 citations were included. Our preliminary analysis showed that compared with the unexposed group, the use of ondansetron during pregnancy may be associated with an increased incidence of cardiac defects (OR = 1.06, 95% CI: 1.01–1.10), neural tube defects (OR = 1.12, 95% CI: 1.05–1.18), and chest cleft (OR = 1.21, 95% CI: 1.07–1.37). Further sensitivity analysis showed no significant association between ondansetron and cardiac defects (OR = 1.15,95% CI: 0.94–1.40) or neural tube defects (OR = 0.87,95% CI: 0.46–1.66). When controversial studies were eliminated, the results for the chest defects disappeared. Simultaneously, we found that the use of ondansetron was associated with a reduced incidence of miscarriage (OR = 0.53, 95% CI: 0.31–0.89). Ondansetron was not associated with orofacial clefts (OR = 1.09,95% CI: 0.95–1.25), spinal limb defects (OR = 1.14,95% CI: 0.89–1.46), urinary tract deformities (OR = 1.06,95% CI: 0.97–1.15), any congenital malformations (OR = 1.03,95% CI: 0.98–1.09), stillbirth (OR = 0.97,95% CI: 0.83–1.15), preterm birth (OR = 1.22,95% CI: 0.80–1.85), neonatal asphyxia (OR = 1.05,95% CI: 0.72–1.54), or neonatal development (OR = 1.18,95% CI: 0.96–1.44) in our primary analysis.

Conclusion: In our analysis, using ondansetron during pregnancy was not associated with abnormal pregnancy outcomes. Although our study did not find sufficient evidence of ondansetron and adverse pregnancy outcomes, future studies including the exposure period and dose of ondansetron, as well as controlling for disease status, may be useful to truly elucidate the potential risks and benefits of ondansetron.

Ondansetron use in nausea and vomiting during pregnancy: a descriptive analysis of prescription patterns and patient characteristics in UK general practice

Aims

The objective of this study was to describe ondansetron drug utilization patterns during pregnancy to treat nausea and vomiting in pregnancy (NVP). Moreover, we aimed to describe the maternal factors associated with NVP and antiemetic use.

Methods

The data consist of pregnancies with a live birth(s) within an IMRD‐UK registered GP practice. Descriptive statistics were used to investigate patterns of ondansetron use in pregnancy and to describe maternal characteristics associated with NVP and antiemetic drug utilization. We differentiate first‐ from second‐line use during pregnancy using antiemetic prescription pathways.

Results

The dataset included 733 633 recorded complete pregnancies from 2005 to 2019. NVP diagnosis and ondansetron prescription prevalence increased from 2.7% and 0.1% in 2005 to 4.8% and 2.5% in 2019 respectively. Over the period 2015–2019, the most common oral daily dosages were 4 mg/d (8.5%), 8 mg/d (37.1%), 12 mg/d (37.5%) and between 16 and 24 mg/d (16.9%). Prescription of ondansetron was initiated during the first trimester of pregnancy in 40% of the cases and was moderately used as a first‐line therapy (2.8%), but preferred choice of second‐line therapy. Women with mental health disorders, asthma and/or prescribed folic acid were more likely to experience NVP and use antiemetics in pregnancy than their counterparts.

Conclusion

This study confirms that ondansetron is increasingly used off‐label to treat NVP during pregnancy, also in the first trimester and before other prescription antiemetics have been prescribed. Several maternal comorbidities and folic acid use were more common among women experiencing NVP and using antiemetics, including ondansetron.

Clinician perspectives of pregnant women's participation in antiemetic decision-making: A qualitative study

This study explored clinician perceptions of women's participation in decision-making about antiemetic treatments during pregnancy, and the suitability of the five Choosing Wisely questions to increase women's involvement. The qualitative interpretive descriptive design used semi-structured interviews to capture data. Participants were six obstetricians and six midwives experienced in providing care for pregnant women seeking support for nausea and vomiting at a single private, obstetrician-led maternity health service in Australia. Thematic analysis revealed four themes that captured clinician perspectives about women's participation in decision-making about antiemetic treatments: (i) information gathering; (ii) developing an understanding; (iii) using knowledge; and (iv) making decisions. Clinician attitudes and perspectives, as well as their self-reported styles of communication and negotiation, influenced how they engaged with women during decision-making. While unfamiliar with the five Choosing Wisely questions, almost all participants considered them potentially useful, but for other clinicians. Strategies to actively involve women in decision-making about antiemetics were inconsistently used. The five Choosing Wisely questions may provide a useful tool for clinicians, but further research is needed to better understand women's perspectives and clinician-related barriers to shared decision-making.

Prescription medication use and baseline health status of women with live-birth deliveries in a national data network

BACKGROUND

The US Food and Drug Administration increasingly uses administrative databases to conduct surveillance of medications used during pregnancy. To assess adverse fetal effects, administrative records must be linked between the mother and infant. The Sentinel Initiative's Mother-Infant Linkage Table provides a large cohort of linked deliveries from national, regional, and public insurance claims in the United States for the US Food and Drug Administration to conduct surveillance.

OBJECTIVE

This study aimed to describe baseline health conditions and prescription medication use during pregnancy in cohorts of women with a live-birth delivery linked and not linked to an infant.

STUDY DESIGN

Live-birth deliveries in women aged 10 to 54 years with at least 391 days of medical and drug coverage before delivery were identified in the Sentinel Mother-Infant Linkage Table from 2000 to 2019. Two cohorts were created for analysis: deliveries linked to infant records (linked deliveries, n=2,320,805) and deliveries unable to be linked to an infant (not-linked deliveries, n=504,785). Baseline health conditions, pregnancy history, healthcare utilization, and pregnancy conditions were defined using International Classification of Diseases, Ninth Revision, and International Classification of Diseases, Tenth Revision, diagnosis and procedure codes. Medication exposure was identified in a 90-day prepregnancy period and in each trimester.

RESULTS

Few notable differences were observed between the linked and not-linked deliveries except for maternal age and preterm birth; the not-linked cohort was 3.4 years younger on average and more likely to have a preterm delivery. At baseline among the linked deliveries, the most common conditions were depression and anxiety (5.2% each), acquired hypothyroidism (5.0%), pain conditions (3.9%), and asthma (2.8%). Among linked deliveries, 6.9% had evidence of gestational diabetes mellitus, 3.9% had gestational hypertension, and 4.5% had preeclampsia or eclampsia. The most commonly used medications during pregnancy in the linked deliveries were antibacterials (41.6%) and antiemetics (21.5%); similar medication use patterns were observed in the not-linked cohort. Age trends were observed for some medication groups; anti-infectives, pain medications, and antiemetics were more common in younger mothers, whereas endocrine medications were more common in older mothers.

CONCLUSION

Similarities between the linked and not-linked cohorts suggested that the ability to link mother and infant records is not influenced by maternal health status. In the linked cohort, the prevalence of specific pregnancy complications and medication use were similar to previously reported national estimates. Some baseline comorbidities, such as obesity and smoking, may be underestimated in the Sentinel Mother-Infant Linkage.

Validation of an ICD-10-based algorithm to identify stillbirth in the Sentinel System

PURPOSE

To develop and validate an International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM)-based algorithm to identify cases of stillbirth using electronic healthcare data.

METHODS

We conducted a retrospective study using claims data from three Data Partners (healthcare systems and insurers) in the Sentinel Distributed Database. Algorithms were developed using ICD-10-CM diagnosis codes to identify potential stillbirths among females aged 12-55 years between July 2016 and June 2018. A random sample of medical charts (N = 169) was identified for chart abstraction and adjudication. Two physician adjudicators reviewed potential cases to determine whether a stillbirth event was definite/probable, the date of the event, and the gestational age at delivery. Positive predictive values (PPVs) were calculated for the algorithms. Among confirmed cases, agreement between the claims data and medical charts was determined for the outcome date and gestational age at stillbirth.

RESULTS

Of the 110 potential cases identified, adjudicators determined that 54 were stillbirth events. Criteria for the algorithm with the highest PPV (82.5%; 95% CI, 70.9%-91.0%) included the presence of a diagnosis code indicating gestational age ≥20 weeks and occurrence of either >1 stillbirth-related code or no other pregnancy outcome code (i.e., livebirth, spontaneous abortion, induced abortion) recorded on the index date. We found ≥90% agreement within 7 days between the claims data and medical charts for both the outcome date and gestational age at stillbirth.

CONCLUSIONS

Our results suggest that electronic healthcare data may be useful for signal detection of medical product exposures potentially associated with stillbirth.

What changes in prescription patterns of antiemetic medications in pregnant women in France?

BACKGROUND

In France, few data are available on the prescription patterns of antiemetic medications in pregnant women.

OBJECTIVES

The purpose of this study was to describe antiemetic medication prescriptions and trends over time. Can we observe significant changes in pregnant woman prescriptions in recent years?

METHODS

We conducted a drug utilization study among pregnant women using data from the EFEMERIS database, including 135 574 pregnant women who had a pregnancy outcome between 2004 and 2017 in Haute-Garonne (France).

RESULTS

During the study period, 40 028 women (29.5%) received at least one antiemetic prescription during pregnancy. Metoclopramide (56.6%), domperidone (34.9%), and metopimazine (28.5%) were the most commonly prescribed antiemetics, whatever the trimester of pregnancy. Prescriptions of ondansetron only concerned 53 women (0.1%). The prevalence of women who received at least one prescription for an antiemetic decreased from 32.5% in 2010 to 21.6% in 2017. This decline mainly concerned domperidone prescriptions (from 13.1% in 2010 to 1.2% in 2017). Metoclopramide prescriptions also decreased slightly (18.3% in 2010 and 14.0% in 2017). Metopimazine prescriptions increased lowly (8.0% in 2010 and 9.0% in 2017).

CONCLUSION

This study showed a decrease of antiemetic prescriptions between 2010 and 2017, linked to the sharp decrease in domperidone use from 2011, probably related to warnings about the risk of cardiovascular adverse effects following exposure to domperidone. We could not observe real switches to other antiemetic medications. No switches to ondansetron could be noted either, with only rare exposure during pregnancy, contrary to other countries, like the United States.

Comparison of Pregnancy Outcomes of Patients Treated With Ondansetron vs Alternative Antiemetic Medications in a Multinational, Population-Based Cohort

IMPORTANCE

Ondansetron is frequently used to treat nausea and vomiting during pregnancy. Although some studies reported important safety signals, few studies have been sufficiently large to assess rare pregnancy outcomes.

OBJECTIVE

To study the association between ondansetron exposure during pregnancy and the risks of spontaneous abortion, stillbirth, and major congenital malformations.

DESIGN, SETTING, AND PARTICIPANTS

This is a cohort study conducted in 3 countries, with a meta-analysis. Participants included women and girls aged 12 to 55 years who experienced spontaneous abortion, induced abortion, stillbirth, or live birth between April 2002 and March 2016, as recorded in administrative data from 5 Canadian provinces (British Columbia, Alberta, Saskatchewan, Manitoba, and Ontario), the US IBM MarketScan Research Databases, and the UK Clinical Practice Research Datalink. The statistical analysis was completed in October 2020.

EXPOSURES

Exposure to ondansetron during pregnancy was compared with exposure to other commonly used antiemetics to minimize confounding by indication.

MAIN OUTCOMES AND MEASURES

The primary outcome was fetal death, defined as either spontaneous abortion or stillbirth. Secondary outcomes were the 2 components of the primary outcome and major congenital malformations identified during the year after a live birth. Adjusted hazard ratios were estimated using Cox proportional hazards models with time-dependent drug exposures and were adjusted using high-dimensional propensity scores. For major congenital malformations, adjusted odds ratios were estimated from logistic models. Site-level results were pooled using random-effects meta-analysis. Sensitivity analyses considered second-line antiemetic exposure and exposure specifically during 4 to 10 weeks of gestation.

RESULTS

Data from 456 963 pregnancies were included in this study of fetal death (249 787 [54.7%] in Canada, 197 913 [43.3%] in the US, and 9263 [2.0%] in the UK; maternal age, ≤24 years, 93 201 patients [20.4%]; 25-29 years, 149 117 patients [32.6%]; 30-34 years, 142 442 patients [31.2%]; and ≥35 years, 72 203 patients [15.8%]). Fetal death occurred in 12 907 (7.9%) of 163 810 pregnancies exposed to ondansetron, and 17 476 (5.7%) of 306 766 pregnancies exposed to other antiemetics. The adjusted hazard ratios were 0.91 (95% CI, 0.67-1.23) for fetal death with time-dependent ondansetron exposure during pregnancy, 0.82 (95% CI, 0.64-1.04) for spontaneous abortion, and 0.97 (95% CI, 0.79-1.20) for stillbirth. For major congenital malformations, the estimated odds ratio was 1.06 (95% CI, 0.91-1.22). Results of sensitivity analyses were generally consistent with those of the primary analyses.

CONCLUSIONS AND RELEVANCE

In this large, multicenter cohort study, there was no association between ondansetron exposure during pregnancy and increased risk of fetal death, spontaneous abortion, stillbirth, or major congenital malformations compared with exposure to other antiemetic drugs.

Ondansetron use in the first trimester of pregnancy and the risk of neonatal ventricular septal defect

BACKGROUND

Literature is divided regarding the risk of neonatal ventricular septal defect (VSD) associated with first trimester ondansetron use in pregnancy.

METHODS

We evaluated the risk of VSD associated with first trimester exposure to intravenous or oral ondansetron in 33 677 deliveries at Magee-Womens Hospital in Pittsburgh, PA (2006-2014). Using log-binomial regression, we evaluated the risk: (1) in the full cohort, (2) using propensity score designs with both matching and inverse probability weighting and (3) utilizing clustered trajectory analysis evaluating the role of dose. Sensitivity analyses assessed the association between ondansetron and all recorded birth defects in aggregate.

RESULTS

A total of 3733 (11%) pregnancies were exposed to ondansetron in the first trimester (dose range: 2.4-1008 mg). Ondansetron was associated with increased risk of VSD with risk ratios ranging from 1.7 [95% confidence interval (CI) 1.0-2.9] to 2.1 (95% CI 1.1-4.0) across methods. Risks correspond to one additional VSD for approximately every 330 pregnancies exposed in the first trimester. The association was dose-dependent with increased risk in women receiving highest cumulative doses compared with lowest doses [adjusted risk ratio: 3.2 (95% CI 1.0-9.9)]. The association between ondansetron and congenital malformations was diluted as the outcome included additional birth defects.

CONCLUSIONS

First trimester ondansetron use is associated with an increased risk of neonatal VSD potentially driven by higher doses. This risk should be viewed in the context of risks attributable to severe untreated nausea and vomiting of pregnancy.

Antiemetic Prescription Fills in Pregnancy: A Drug Utilization Study Among 762,437 Pregnancies in Norway

Objective

To determine antiemetic prescription fill patterns during pregnancy in Norway, with special focus on the use of ondansetron and recurrent use in subsequent pregnancies.

Methods

We conducted a population-based registry study based on data from the Medical Birth Registry of Norway linked to the Norwegian Prescription Database for 762,437 pregnancies >12 gestational weeks ending in live or non-live births between 2005 and 2017. Prescription fills of medications used for nausea and vomiting of pregnancy were summarized in treatment pathways to determine drug utilization patterns. Logistic regression analyses were used to estimate associations between maternal and pregnancy characteristics and antiemetic prescription fills.

Results

The prescription fill rate for antiemetic medication during pregnancy was 7.6%. However, prescription fill rates were 35.5% in the second pregnancy after filling an antiemetic prescription in the first pregnancy and 53.5% for women who filled antiemetic prescriptions in the previous 2 pregnancies. Among pregnancies with antiemetic prescription fills, 62.2% were dispensed metoclopramide, 28.2% meclizine, and 17.2% promethazine. First-line treatment started with monotherapy in 97.4% of these pregnancies, which was the only treatment received in 78.7%. Prescriptions for ondansetron were filled in 0.3% of pregnancies, with 76.9% being initially filled in the first trimester. Ondansetron as first-line prescription medication and/or use in the first trimester was associated with proxies for more severe nausea and vomiting of pregnancy, including a diagnosis of hyperemesis gravidarum, multiple gestations, a higher obstetric comorbidity index, and concomitant use of medication for gastroesophageal reflux disease and nervous system medications. Women who filled an antiemetic prescription in their first pregnancy were less likely to have subsequent pregnancies than women who did not fill an antiemetic prescription in their first pregnancy (OR 0.93, 95% CI 0.90–0.96).

Conclusion

Complex patterns of antiemetic prescription fills in pregnancy may mirror the challenge of optimal management of nausea and vomiting of pregnancy in clinical practice, especially for women with severe symptoms.

Trends in first-trimester nausea and vomiting of pregnancy and use of select treatments: Findings from the National Birth Defects Prevention Study

BACKGROUND

Although nausea and vomiting of pregnancy (NVP) is common, the secular and demographic trends of NVP and its treatments are not well-studied.

OBJECTIVES

To describe the prevalence and patterns of first-trimester NVP and selected treatments among controls in the National Birth Defects Prevention Study (NBDPS).

METHODS

National Birth Defects Prevention Study is a population-based case-control study of birth defects in the United States (1997-2011). We collected self-reported data about NVP and use of commonly reported pharmacological and herbal/natural treatments (ondansetron, promethazine, pyridoxine, metoclopramide, doxylamine succinate, ginger, phosphorated carbohydrate solution, and prochlorperazine) from mothers of non-malformed control infants. We estimated the prevalence of NVP and selected treatments and examined secular and demographic trends (education, race/ethnicity, and maternal age) for such use, adjusting for study centre.

RESULTS

Among 10 540 mothers of controls, 7393 women (70.1%) reported first-trimester NVP, and 12.2% of those used one or more of the commonly reported treatments. Specific treatment use varied after adjustment for study centre (ondansetron: 3.4%; promethazine: 4.2%; pyridoxine: 3.2%; metoclopramide: 0.7%; doxylamine succinate: 1.7%; ginger: 1.0%; phosphorated carbohydrate solution: 0.4%; and prochlorperazine: 0.3%). Treatment use increased for each agent over the study period. Women with more years of education reported more NVP and treatment use. White (72%), Hispanic (71%), and other race (73%) women reported more NVP than Black women (67%); White women used selected NVP treatments most frequently, and Black women used them more than Hispanic women. Though women aged 25-34 years reported more NVP (72%) than younger (69%) or older (67%) women, the frequency of medication use was similar among women aged 25-34 and ≥35, and lower among women aged <25 years.

CONCLUSIONS

National Birth Defects Prevention Study controls reported NVP at frequencies similar to those previously reported. Of note, we observed an increase in use of selected treatments over time, and variations in NVP and treatments by study site and demographic factors.

Ondansetron in pregnancy revisited: Assessment and pregnancy labelling by the European Medicines Agency (EMA) & Pharmacovigilance Risk Assessment Committee (PRAC)

Ondansetron is an effective antiemetic that is being widely used as a second-line treatment option for severe nausea and vomiting of pregnancy in accordance with clinical guidelines. The safety of ondansetron during pregnancy has-following publication of controversial and seemingly contradictory results-been subject to considerable academic turmoil, specifically with respect to the risk of congenital cardiac malformations and oral cleft. In July 2019, the European Medicines Agency (EMA) Pharmacovigilance Risk Assessment Committee (PRAC) released an updated, comprehensive assessment report on the use of ondansetron in the first trimester. The ensuing Summary of Product Characteristics (SmPC) was updated in November 2019 with important changes to section on "Fertility, pregnancy and lactation." The SmPC now states that ondansetron should not be used in the first trimester of pregnancy. ENTIS, The European Network of Teratology Information Services, believes that the implementation of this regulatory step-which has important clinical consequences-is insufficiently substantiated and is not serving the interest of pregnant women with severe nausea and vomiting. Herein, we discuss the underlying evidence and argue the case against the EMA decision.

Pregnancy outcome following in-utero exposure to ondansetron: A prospective comparative observational study

The objective of the study was to evaluate the rate of major congenital anomalies after first trimester exposure to ondansetron for nausea and vomiting of pregnancy (NVP). The design is a prospective, comparative, observational cohort study, performed at the Israeli Teratology Information Service between 2010 and 2014. Follow-up was obtained for 195 ondansetron-exposed, 110 metoclopramide-exposed, and 778 pregnancies with non-teratogenic exposure (NTE). The overall rate of major anomalies did not significantly differ between the groups [4/200 = 2.0 % (ondansetron), 1/109 = 0.9 % (metoclopramide), and 13/731 = 1.8 % (NTE)]. All the anomalies in both the ondansetron and metoclopramide groups, and 6/13 anomalies in the NTE group, were cardiac septal defects most of which spontaneously resolved. Both ondansetron (adjHR = 0.29, 95 % CI 0.10-0.80) and metoclopramide (adjHR = 0.27, 95 % CI 0.08-0.86) were associated with lower miscarriage rate compared to NTE. Based on the present study, ondansetron during pregnancy is not associated with an increased risk for overall major anomalies, nor for clinically important cardiac defects. It may be a reasonable alternative for women with severe NVP who do not respond to first line medications.

Ondansetron use in early pregnancy and the risk of late pregnancy outcomes

BACKGROUND

The effects of ondansetron, used off-label to treat nausea and vomiting during pregnancy, on common pregnancy complications are understudied. Modest effects of a commonly used drug could result in adverse events for large numbers of pregnant women. Therefore, our objective was to compare the risk of stillbirth, preterm birth, gestational hypertensive disorders, small for gestational age, and differences in birth weight between women prescribed ondansetron and women prescribed alternative antiemetics in early pregnancy.

METHODS

A cohort of pregnant women receiving a prescription for ondansetron or comparator antiemetics (metoclopramide or promethazine) during the first 20 weeks of pregnancy was identified using electronic health record data from a health care system in North Carolina, USA. Confounding by multiple covariates was controlled using stabilized inverse probability of treatment weights. Weighted hazard ratios (HR) and 95% confidence intervals (CI) accounted for competing events.

RESULTS

We identified 2677 eligible pregnancies with antiemetic orders, 66% for ondansetron. The small number of stillbirths (n = 15) resulted in an imprecise estimate of the association with ondansetron (HR = 1.60; 95%CI 0.51, 4.97). No association was observed for preterm birth (HR = 0.90; 95%CI 0.67, 1.20) or gestational hypertensive disorders (HR = 0.87; 95%CI 0.68, 1.12). We observed an association with small for gestational age (HR = 1.37; 95%CI 0.98, 1.90), however mean birth weight among term births was similar between groups.

CONCLUSIONS

Our results do not suggest that ondansetron increases the risk of preterm birth or gestational hypertensive disorders. The weak association observed between ondansetron use and small for gestational age warrants further investigation.

Ondansetron use in early pregnancy and the risk of miscarriage

BACKGROUND

Ondansetron is commonly used to treat nausea and vomiting in pregnancy despite inconclusive evidence of its safety. Previous studies have reported no increase in risk of miscarriage but relied on methods that failed to account for gestational weeks at risk and non-user comparators, which may increase the potential for unmeasured confounding. Our objective was to estimate the risk of miscarriage among women prescribed ondansetron vs alternative antiemetics during the first 20 weeks of pregnancy.

METHODS

A pregnancy cohort was created using electronic health record data from a health care system in North Carolina. Women were classified as exposed to either ondansetron or comparator antiemetics (metoclopramide or promethazine) based on the first antiemetic prescription received in the first 20 weeks of gestation. Cumulative incidence of miscarriage at 20 weeks was estimated in each antiemetic group. Hazard ratios (HR) were estimated with 95% confidence intervals and measured confounding was controlled using inverse probability of treatment weights. Sensitivity analyses assessed the potential impact of exposure misclassification, latency period, and selection bias.

RESULTS

We identified 2620 eligible pregnancies with antiemetic orders; 65% had a first ondansetron order and 35% had a first comparator antiemetic order. In total, 95 women had a miscarriage. After adjustment, there was no difference in risk of miscarriage (HR 1.21, 95% CI 0.77, 1.90). Results from the per-protocol and other sensitivity analyses were similar to the main analysis.

CONCLUSIONS

We did not observe an increase in the risk of miscarriage for pregnancies exposed to ondansetron vs comparator antiemetics.

The impact of intrauterine growth restriction on cytochrome P450 enzyme expression and activity

With the increased prevalence of non-communicable disease and availability of medications to treat these and other conditions, a pregnancy free from prescribed medication exposure is rare. Up to 99% of women take at least one medication during pregnancy. These medications can be divided into those used to improve maternal health and wellbeing (e.g., analgesics, antidepressants, antidiabetics, antiasthmatics), and those used to promote the baby's wellbeing in either fetal (e.g., anti-arrhythmics) or postnatal life (e.g., antenatal glucocorticoids). These medications are needed for pre-existing or coincidental illnesses in the mother, maternal conditions induced by the pregnancy itself through to conditions that arise in the fetus or that will be encountered by the newborn. Thus, medications administered to the mother may be used to treat the mother, the fetus or both. Metabolism of medications is regulated by a range of physiological processes that change during pregnancy. Other pathological processes such as placental insufficiency can in turn have both immediate and lifelong adverse health consequences for babies. Individuals born growth restricted are more likely to require medications but may also have an altered ability to metabolise these medications in fetal and postnatal life. This review aims to determine the effect of suboptimal fetal growth on the fetal expression of the drug metabolising enzymes (DMEs) that convert medications into active or inactive metabolites, and the transporters that remove both these medications and their metabolites from the fetal compartment.

Validating the effect of Ondansetron and Mirtazapine In Treating hyperemesis gravidarum (VOMIT): protocol for a randomised placebo-controlled trial

INTRODUCTION

Current pharmacological treatment options for hyperemesis gravidarum have been introduced based on scarce evidence and are often not sufficiently effective. Several case reports suggest that mirtazapine, an antidepressant, may be an effective treatment for hyperemesis gravidarum, but so far there are no controlled trials investigating the potential effect of mirtazapine on hyperemesis gravidarum. The antiemetic ondansetron is currently widely used to treat hyperemesis gravidarum despite sparse evidence of effect in pregnant women. This study aims to investigate the effect of mirtazapine on hyperemesis gravidarum while also providing data on the effect of ondansetron.

METHODS AND ANALYSIS

This randomised double-blind placebo-controlled multicentre trial will be conducted in eight Danish hospitals. One hundred and eighty pregnant women referred to secondary care for hyperemesis gravidarum will be randomly allocated to 14-day treatment with either mirtazapine, ondansetron or placebo. Main inclusion criterion will be Pregnancy Unique Quantification of Emesis (PUQE-24) score ≥13 or PUQE-24 score ≥7 if accompanied by weight loss >5% of pre-pregnancy weight or hospitalisation. Participants are eligible regardless of whether other antiemetics, including ondansetron, have been tried. The coprimary outcomes are effects of mirtazapine and ondansetron, respectively, on PUQE-24 score tested hierarchically on day 2 and day 14. Secondary outcomes include, but are not limited to, differences between the three groups in number of daily vomiting episodes, dropout due to treatment failure, use of rescue medication, weight change and side effects.

ETHICS AND DISSEMINATION

The trial has been approved by the Regional Committees on Health Research Ethics in the Capital Region of Denmark, the Danish Medicines Agency and the Danish Data Protection Agency. Results will be published in peer-reviewed journals and submitted to relevant conferences.

TRIAL REGISTRATION NUMBER

NCT03785691.

Pharmacogenomic Testing In Pediatrics: Navigating The Ethical, Social, And Legal Challenges

For the past several years, the implementation of pharmacogenetic (PGx) testing has become widespread in several centers and clinical practice settings. PGx testing may be ordered at the point-of-care when treatment is needed or in advance of treatment for future use. The potential benefits of PGx testing are not limited to adult patients, as children are increasingly using medications more often and at earlier ages. This review provides some background on the use of PGx testing in children as well as mothers (prenatally and post-natally) and discusses the challenges, benefits, and the ethical, legal, and social implications of providing PGx testing to children.

Nausea and vomiting of pregnancy and hyperemesis gravidarum

Nausea and vomiting of pregnancy (NVP) is a common condition that affects as many as 70% of pregnant women. Although no consensus definition is available for hyperemesis gravidarum (HG), it is typically viewed as the severe form of NVP and has been reported to occur in 0.3-10.8% of pregnant women. HG can be associated with poor maternal, fetal and child outcomes. The majority of women with NVP can be managed with dietary and lifestyle changes, but more than one-third of patients experience clinically relevant symptoms that may require fluid and vitamin supplementation and/or antiemetic therapy such as, for example, combined doxylamine/pyridoxine, which is not teratogenic and may be effective in treating NVP. Ondansetron is commonly used to treat HG, but studies are urgently needed to determine whether it is safer and more effective than using first-line antiemetics. Thiamine (vitamin B1) should be introduced following protocols to prevent refeeding syndrome and Wernicke encephalopathy. Recent advances in the genetic study of NVP and HG suggest a placental component to the aetiology by implicating common variants in genes encoding placental proteins (namely GDF15 and IGFBP7) and hormone receptors (namely GFRAL and PGR). New studies on aetiology, diagnosis, management and treatment are under way. In the next decade, progress in these areas may improve maternal quality of life and limit the adverse outcomes associated with HG.

New evidence for concern over the risk of birth defects from medications for nausea and vomitting of pregnancy

OBJECTIVES

The aim of the study was to quantify the risk of major congenital malformations (MCM) associated with first-trimester exposure to antiemetics.

STUDY DESIGN AND SETTING

Using the Quebec Pregnancy Cohort (1998-2015), first-trimester doxylamine-pyridoxine, metoclopramide, and ondansetron exposures were assessed for their association with MCM. Generalized estimating equations were used to estimate odds ratios (OR), adjusting for potential confounders (aOR).

RESULTS

Within 17 years of follow-up, the prevalence of antiemetic use during pregnancy increased by 76%. Within our cohort, 45,623 pregnancies were exposed to doxylamine-pyridoxine, 958 to metoclopramide, and 31 to ondansetron. Doxylamine-pyridoxine and metoclopramide use were associated with an increased risk of overall MCM (aOR 1.07, 95% confidence interval [CI]: 1.03-1.11; 3,945 exposed cases) and (aOR 1.27, 95% CI: 1.03-1.57; 105 exposed cases), respectively. Doxylamine-pyridoxine exposure was associated with increased risks of spina bifida (aOR 1.87, 95% CI: 1.11-3.14; 23 exposed cases), nervous system (aOR 1.25, 95% CI: 1.06-1.47; 225 exposed cases), and musculoskeletal system defects (aOR 1.08, 95% CI: 1.02-1.14; 1,735 exposed cases). Metoclopramide exposure was associated with an increased risk of genital organ defects (aOR 2.26, 95% CI: 1.14-4.48; 10 exposed cases). No statistically significant association was found between ondansetron exposure and the risk of overall MCM.

CONCLUSION

First-trimester doxylamine-pyridoxine and metoclopramide exposure was associated with a significantly increased risk of overall and specific MCM.

Medications that Cause Fetal Anomalies and Possible Prevention Strategies

Many conditions that require frequent medication use are common during pregnancy. The purpose of this article is to list some of the most common of these disorders and to discuss the risk to the developing fetus of the medications used most frequently to treat them. Included are drugs used for the treatment of asthma, nausea and vomiting, hyperthyroidism, pain and fever, and depression during pregnancy.

Use of ondansetron during pregnancy and the risk of major congenital malformations: A systematic review and meta-analysis

AIMS

To investigate whether ondansetron use during pregnancy is associated with increased rates of major or subgroups of malformations.

METHODS

PubMed/MEDLINE, Cochrane and Reprotox^® databases were searched. Observational studies comprising an exposed and control group (healthy and/or disease-matched) were included.

RESULTS

No significant increased risk for major malformations, heart defects, orofacial clefts, genitourinary malformations or hypospadias were identified in our primary analysis. A significant heterogeneity existed for isolated cleft palate. Elevated point estimates and altered statistical significances were present for some of the outcomes among secondary analyses.

CONCLUSIONS

Ondansetron use during pregnancy was not associated with a significant increase in rate of major or selected subgroups of malformations in our primary analysis. However, results of the secondary analyses warrant the need for continued surveillance. These results may be reassuring for pregnant women in whom ondansetron use is clinically indicated since the absolute risks of possible concerns appear to be low.

Effects of prenatal education on complaints during pregnancy and on quality of life

OBJECTIVE

The study was conducted to determine the effects of prenatal education on quality of life and complaints during pregnancy.

METHODS

This study is a quasi-experimental research with a control group. Personal Information Form and Scale of Complaints during Pregnancy and their Effects on Quality of Life (SCPEQL) were used to collect the data. Thirty participants were included in both the control and the intervention groups (N = 60).

RESULTS

The mean scores of SCPEQL of the intervention group was 46.2 ± 21.1 and the mean scores of SCPEQL of the control group was 99.8 ± 21.6 in 2nd trimester. In the 3rd trimester, the mean score of SCPEQL of the intervention group was 43.5 ± 16.4, and the mean score of SCPEQL of the control group was 108.0 ± 16.8. The difference between the groups was statistically significant in 2nd and 3rd trimesters (p < 0.05).

CONCLUSION

Findings of the study suggest that providing prenatal education reduces complaints and increases quality of life of pregnant women.

PRACTICE IMPLICATIONS

Assessing complaints during pregnancy by nurses is a part of the prenatal care. Therefore, nurses should evaluate pregnancy-related complaints. Quality of life should be increased by giving effective education about complaints during pregnancy.

Association of Maternal First-Trimester Ondansetron Use With Cardiac Malformations and Oral Clefts in Offspring

IMPORTANCE

Evidence for the fetal safety of ondansetron, a 5-HT3 receptor antagonist that is commonly prescribed for nausea and vomiting during pregnancy, is limited and conflicting.

OBJECTIVE

To evaluate the association between ondansetron exposure during pregnancy and risk of congenital malformations.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study nested in the 2000-2013 nationwide Medicaid Analytic eXtract. The cohort consisted of 1 816 414 pregnancies contributed by 1 502 895 women enrolled in Medicaid from 3 months before the last menstrual period through 1 month or longer after delivery; infants were enrolled in Medicaid for at least 3 months after birth. The final date of follow-up was December 31, 2013. Analyses were conducted between November 1, 2017, and June 30, 2018. Propensity score stratification was used to control for treatment indication and other confounders.

EXPOSURES

Ondansetron dispensing during the first trimester, the period of organogenesis.

MAIN OUTCOMES AND MEASURES

Primary outcomes were cardiac malformations and oral clefts diagnosed during the first 90 days after delivery. Secondary outcomes included congenital malformations overall and subgroups of cardiac malformations and oral clefts.

RESULTS

Among 1 816 414 pregnancies (mean age of mothers, 24.3 [5.8] years), 88 467 (4.9%) were exposed to ondansetron during the first trimester. Overall, 14 577 of 1 727 947 unexposed and 835 of 88 467 exposed infants were diagnosed with a cardiac malformation, for an absolute risk of 84.4 (95% CI, 83.0 to 85.7) and 94.4 (95% CI, 88.0 to 100.8) per 10 000 births respectively. The absolute risk of oral clefts was 11.1 per 10 000 births (95% CI, 10.6 to 11.6; 1921 unexposed infants) and was 14.0 per 10 000 births (95% CI, 11.6 to 16.5; 124 exposed infants). The risk of any congenital malformation was 313.5 per 10 000 births (95% CI, 310.9 to 316.1; 54 174 unexposed infants) and was 370.4 (95% CI, 358.0 to 382.9; 3277 exposed infants). The adjusted relative risk (RR) for cardiac malformations was 0.99 (95% CI, 0.93 to 1.06) and the adjusted risk difference (RD) was -0.8 (95% CI, -7.3 to 5.7 per 10 000 births). For oral clefts, the adjusted RR was 1.24 (95% CI, 1.03 to 1.48) and the RD was 2.7 (95% CI, 0.2 to 5.2 per 10 000 births). The adjusted estimate for congenital malformations overall was an RR of 1.01 (95% CI, 0.98 to 1.05) and an RD of 5.4 (95% CI, -7.3 to 18.2 per 10 000 births).

CONCLUSIONS AND RELEVANCE

Among offspring of mothers enrolled in Medicaid, first-trimester exposure to ondansetron was not associated with cardiac malformations or congenital malformations overall after accounting for measured confounders but was associated with a small increased risk of oral clefts.

First trimester ondansetron exposure and risk of structural birth defects

This study investigates risk of specific structural birth defects associated with ondansetron exposure during the first trimester in a large US commercially-insured population. Medical claims data were obtained from Truven Health Analytics for 864,083 mother-infant pairs from 2000 to 2014. Logistic regression was used to measure the association between first trimester exposure to ondansetron and risk of cardiac defects, orofacial clefts and other specific structural defects in offspring. First trimester exposure to ondansetron was associated with increased risk of cardiac (OR: 1.52 95% CI: 1.35-1.70) and orofacial cleft defects (OR: 1.32 95% CI: 0.76-2.28) in offspring compared to women with no antiemetic exposure during pregnancy. This analysis addresses limitations of prior studies including limited power, exposure misclassification, and generalizability to the US population. In a large, US population we found a statistically significant association between early pregnancy ondansetron exposure and specific structural birth defects in offspring.

Ondansetron in Pregnancy and the Risk of Congenital Malformations: A Systematic Review

OBJECTIVE

Ondansetron, not approved for use in pregnancy, is increasingly being prescribed for nausea and vomiting in pregnancy and hyperemesis gravidarum. A number of recent lawsuits have highlighted the possibility that ondansetron may cause congenital malformations. The aim of this study was to systematically review epidemiological evidence on the potential association of prenatal exposure to ondansetron and congenital malformations.

METHODS

Systematic searches in Medline and Embase were performed in June 2017 using controlled vocabulary and key words, and references of search results were reviewed. Full papers (RCTs, cohort, and case-control studies) were eligible for inclusion if they reported fetal outcomes of prenatal ondansetron exposure in humans. Excluded were: case reports, studies involving pre-medication with ondansetron prior to CS, animal studies, and foreign languages studies.

RESULTS

Ten epidemiologic studies were included: five large retrospective cohort studies, two prospective observational studies, two population-based case-controls. and a retrospective case series. Sample sizes ranged from 17 to 1 501 434 infants exposed to ondansetron. A case-control study identified an association between prenatal exposure to ondansetron and cleft palate, and one cohort study found an increased risk of cardiovascular defects. These findings were not reproduced in the other studies.

CONCLUSION

While further investigation of the literature is needed, our results highlight the paucity of evidence linking prenatal exposure to ondansetron to an increased risk of congenital malformations. There is a need for additional epidemiologic studies to confirm whether ondansetron represents a safe and effective alternative treatment for nausea and vomiting in pregnancy and hyperemesis gravidarum.

Serotonin Receptor 5-HT3A Affects Development of Bladder Innervation and Urinary Bladder Function

The autonomic and sensory nervous systems are required for proper function of all visceral organs, including the lower urinary tract (LUT). Despite the wide prevalence of bladder dysfunction, effective treatment options remain limited. Pelvic innervation regenerative strategies are promising, but surprisingly little is known about the molecular factors driving the development of bladder innervation. Given prior evidence that serotonin receptor 5-HT3A is expressed early in LUT development and is an important mediator of adult bladder function, we sought to determine if 5-HT3A is required for the development of autonomic innervation of the bladder. We found that 5-HT3A is expressed early in fetal mouse pelvic ganglia and is maintained through adulthood. Htr3a knockout male mice, but not females, exhibit increased urinary voiding frequency compared to wild type littermates. Analysis of LUT function via anesthetized cystometry revealed decreased voiding efficiency in male Htr3a mutants. Htr3a-/- mutant animals exhibit a transient disturbance of autonomic neuronal subtype markers (tyrosine hydroxylase and choline acetyl transferase) within the fetal pelvic ganglia, although the imbalance of neuronal subtype markers assayed is no longer apparent in adulthood. Loss of 5-HT3A activity results in a higher density of autonomic and sensory neuronal fibers supplying bladder smooth muscle in both fetal and adult mice. Collectively, our findings highlight 5-HT3A as a critical component in the autonomic control of micturition and identify a novel role for this serotonin receptor in peripheral nervous system development.

Preventing nausea and vomiting in women undergoing regional anesthesia for cesarean section: challenges and solutions

BACKGROUND

Intraoperative nausea and vomiting (IONV) or postoperative nausea and vomiting (PONV) affecting women undergoing regional anesthesia for cesarean section is an important clinical problem since these techniques are used widely. There are burdens of literature about IONV/PONV and several in parturient and cesarean. However, it needs more attention. The underlying mechanisms of IONV and PONV in the obstetrical setting mainly include hypotension due to sympathicolysis during neuraxial anesthesia, bradycardia owing to an increased vagal tone, the visceral stimulation via the surgical procedure and intravenously administered opioids.

METHODS

Given the high and even increasing rate of cesarean sections and the sparse information on the etiology, incidence and severity of nausea and vomiting and the impact of prophylactic measures on the incidence of PONV/IONV, this article aims to review the available information and provide pragmatic suggestions on how to prevent nausea and vomiting in this patient cohort. Current literature and guidelines were identified by electronic database searching (MEDLINE via PubMed and Cochrane database of systematic reviews) up to present, searching through reference lists of included literature and personal contact with experts.

DISCUSSION AND CONCLUSION

Taking into account the current guidelines and literature as well as everyday clinical experience, the first step for decreasing the incidence of IONV and PONV is a comprehensive management of circulatory parameters. This management includes liberal perioperative fluid administration and the application of vasopressors as the circumstances require. By using low-dose local anesthetics, an additional application of intrathecal or spinal opioids or hyperbaric solutions for a sufficient controllability of neuraxial distribution, maternal hypotension might be reduced. Performing a combined spinal-epidural anesthesia or epidural anesthesia may be considered as an alternative to spinal anesthesia. Antiemetic drugs may be administered restrainedly due to off-label use in pregnant women for IONV or PONV prophylaxis and may be reserved for treatment.