First trimester ondansetron exposure and risk of structural birth defects

Efficacy and safety of acupressure in nausea and vomiting during pregnancy: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety of acupressure on nausea and vomiting during pregnancy.

METHODS

PubMed, Embase, Springer, Web of Science, and the Cochrane Library were searched for all randomized controlled trials (RCT) of treating nausea and vomiting during pregnancy by acupressure from the inception date of database to July 31st, 2023. Study selection, data extraction, and risk of bias assessment were conducted independently by researchers. The methodological quality of included studies was evaluated by the Cochrane Collaboration's bias risk assessment tool, meta-analysis by Stata 17.0 software, and publication bias by Begg's test.

RESULTS

A total of 11 RCTs involving 1378 pregnant women were included in this review, which was assessed to be moderate quality. 10 RCTs involving 1298 pregnant women were assessed for the meta-analysis. The results revealed that acupressure showed significant difference on improvement in symptom score compared with sham acupressure (pooled MD, - 1.33; 95%CI [- 2.06, - 0.61]; P < 0.001) or control group (pooled MD, - 0.73; 95%CI [- 1.08, - 0.39]; P < 0.001), and incidence of effective rate compared with sham acupressure group (pooled RR, 1.78; 95%CI [1.03, 3.07]; P = 0.039). However, no statistical significance was found between acupressure and control group (pooled RR, 4.53; 95%CI [0.67, 30.48]; P = 0.120) on effective rate. On comparing acupressure with sham acupressure, there was no beneficial effect on preventing nausea and vomiting during pregnancy (pooled RR, 0.83; 95%CI [0.50, 1.38]; P = 0.476), shortening the duration of hospital stay (pooled MD, - 0.78; 95%CI [- 1.98, 0.41]; P = 0.199) and improving patient satisfaction (pooled RR, 1.36; 95%CI [0.47, 3.91]; P = 0.570). Begg's test did not reveal any publication bias. Only one RCT reported minimal acupressure-related adverse events.

CONCLUSION

Acupressure may have potential favorable or encouraging effect on treating nausea and vomiting during pregnancy, but strong supportive data are not yet available. Well-designed and large-scale RCTs should be conducted for assessing and confirming the efficacy and safety of acupressure in nausea and vomiting during pregnancy.

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.

Epidemiological Profile of Neonates in Hearing Screening at a Maternity of a Tertiary Hospital in the state of Santa Catarina, Brazil

Introduction  The newborn hearing screening (NHS) test aims the early diagnostic of hearing deficits that may also harm the full development of communication and learning of the affected child. Objective  Trace the clinical and epidemiological profile of children born between July 2016 and July 2019; in addition to the outcome of the NHSs and factors related to failure in the hearing tests at a maternity of a tertiary hospital in Santa Catarina, Brazil. Methods  The present is a cross-sectional study. A census of those born in the period defined for study was performed and a script was developed for the review of medical records, based on the literature. Results  The sample can be considered homogeneous in relation to gender and age. The pregnant women had an average of 30.9 years. There were 30 neonates (1.9%) that did not undergo NHS. New evaluations were required in 288 patients (18.2%). Finally, 24 (1.5% of the population) remained with insufficient results in the retest. The following variables achieved statistical relevance with higher failure rates in tests and/or retests: natural delivery ( p  = 0.007), arterial hypertension present ( p  = 0.002), use of hydralazine ( p  = 0.038), and use of dipyrone in the test ( p  = 0.041) and retest ( p  = 0.003). Younger mothers had higher levels of normality in the test ( p  = 0.003) and retest ( p  = 0.161). The correlations between the other variables and the outcomes were not statistically significant. Conclusion  False positives (62.8%) in the first test showed a value higher than the ideal goal; those who did not undergo the NHS (1.9%) and who needed evaluation by a specialist, due to failure in the retest (1.5%), are within the quality goals defined by the Joint Committee on Infant Hearing (JCIH) in 2007.

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.

Ondansetron Use During Pregnancy: Birth Defects and Obstetric Outcomes

Ondansetron is a widely administered medication for nausea and vomiting of pregnancy. Further examination of its teratogenic capacity is necessary. This study examines the association between ondansetron treatment during pregnancy and birth defects and adverse obstetric outcomes. Patient data were extracted from Clalit Health Services, Israel. A propensity-score analysis was performed matching those exposed to ondansetron with those who were not. Findings identified 774 women exposed to ondansetron, matched 1:1 with unexposed control patients. No significant differences were found between the groups for: cleft palate, cardiovascular congenital abnormalities, spina bifida occulta, preterm delivery, or small for gestational age. Ondansetron may be a useful and safe alternative as treatment for women who suffer from hyperemesis gravidarum and do not respond to other antiemetic drugs. Notwithstanding, additional prospectively designed research is needed to establish the safety of ondansetron treatment during pregnancy.

The association of nausea and vomiting of pregnancy, its treatments, and select birth defects: Findings from the National Birth Defect Prevention Study

BACKGROUND

Nausea and vomiting of pregnancy (NVP) occurs in approximately 70% of pregnant people. Treatments include pharmacologic and herbal/natural products. Research on the associations between NVP and its treatments and birth defects is limited.

METHODS

We used data from the case-control National Birth Defects Prevention Study (1997-2011) to examine whether first-trimester NVP or its specific treatments were associated with 37 major birth defects. Odds ratios (aOR) and 95% confidence intervals (CIs) were adjusted for sociodemographic and reproductive factors.

RESULTS

Mothers of 66.6% of 28,628 cases and 69.9% of 11,083 controls reported first-trimester NVP. Compared to no NVP, mothers with NVP had ≥10% reduction in risk of cardiac and noncardiac defects overall, and of 18 specific defects. Over-the-counter antiemetic use, compared to untreated NVP, was associated with ≥10% increase in risk for nine defect groups (heterotaxy, hypoplastic left heart syndrome [HLHS], aortic stenosis, cataracts, anophthalmos/microphthalmos, biliary atresia, transverse limb deficiency, omphalocele, and gastroschisis), whereas use of prescription antiemetics increased risk ≥10% for seven defect groups (tetralogy of Fallot, HLHS, spina bifida, anopthlamos/microphthalmos, cleft palate, craniosynostosis, and diaphragmatic hernia). We observed increased risks for promethazine and tetralogy of Fallot (aOR: 1.49, 95% CI: 1.05-2.10), promethazine and craniosynostosis (1.44, 1.08-1.92), ondansetron and cleft palate (1.66, 1.18-2.31), pyridoxine and heterotaxy (3.91, 1.49-10.27), and pyridoxine and cataracts (2.57, 1.12-5.88).

CONCLUSIONS

NVP does not increase risks of birth defects. Our findings that some treatments for NVP increase risk of specific birth defects should be investigated further before clinical recommendations are made.

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.

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.

Emerging Progress in Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum: Challenges and Opportunities

Nausea and vomiting of pregnancy (NVP) is a common condition that affects up to 70% of pregnant women. Hyperemesis gravidarum (HG) is considered the serious form of NVP, which is reported in 0.3–10.8% of pregnant women. NVP has a relatively benign course, but HG can be linked with some poor maternal, fetal, and offspring outcomes. The exact causes of NVP and HG are unknown, but various factors have been hypothesized to be associated with pathogenesis. With the advance of precision medicine and molecular biology, some genetic factors such as growth/differentiation factor 15 (GDF15) have become therapeutic targets. In our review, we summarize the historical hypotheses of the pathogenesis of NVP and HG including hormonal factors, Helicobacter pylori, gastrointestinal dysmotility, placenta-related factors, psychosocial factors, and new factors identified by genetics. We also highlight some approaches to the management of NVP and HG, including pharmacological treatment, complementary treatment, and some supporting treatments. Looking to the future, progress in understanding NVP and HG may reduce the adverse outcomes and improve the maternal quality of life during pregnancy.

[Nausea and vomiting in pregnancy: A place for ondansetron?]

Although there is no recommendation in France relating to the treatment of nausea and vomiting of pregnancy, there are some in other countries, where ondansetron, widely used, appears to be an effective second-line treatment option behind doxylamine/vitamin B6 association and metoclopramide. However, based on some recent publication suggesting an increased risk of orofacial clefts and congenital heart defects in fetuses exposed in utero to ondansetron in the 1st trimester of pregnancy, the European Medicines Agency now states that this drug should not longer be used during this period. This 2019 decision is controversial and whether ondansetron can be used in pregnant women with severe vomiting during pregnancy is still in question.

Ondansetron and metoclopramide as second-line antiemetics in women with nausea and vomiting in pregnancy: the EMPOWER pilot factorial RCT

BACKGROUND

Around one-third of pregnant women suffer from moderate to severe nausea and vomiting, causing physical and emotional distress and reducing their quality of life. There is no cure for nausea and vomiting in pregnancy. Management focuses on relieving symptoms and preventing morbidity, and often requires antiemetic therapy. National guidelines make recommendations about first-, second- and third-line antiemetic therapies, although care varies in different hospitals and women report feeling unsupported, dissatisfied and depressed.

OBJECTIVES

To determine whether or not, in addition to intravenous rehydration, ondansetron compared with no ondansetron and metoclopramide compared with no metoclopramide reduced the rate of treatment failure up to 10 days after drug initiation; improved symptom severity at 2, 5 and 10 days after drug initiation; improved quality of life at 10 days after drug initiation; and had an acceptable side effect and safety profile. To estimate the incremental cost per treatment failure avoided and the net monetary benefits from the perspectives of the NHS and women.

DESIGN

This was a multicentre, double-dummy, randomised, double-blinded, dummy-controlled 2 × 2 factorial trial (with an internal pilot phase), with qualitative and health economic evaluations.

PARTICIPANTS

Thirty-three patients (who were < 17 weeks pregnant and who attended hospital with nausea and vomiting after little or no improvement with first-line antiemetic medication) who attended 12 secondary care NHS trusts in England, 22 health-care professionals and 21 women participated in the qualitative evaluation.

INTERVENTIONS

Participants were randomly allocated to one of four treatment groups (1 : 1 : 1: 1 ratio): (1) metoclopramide and dummy ondansetron; (2) ondansetron and dummy metoclopramide; (3) metoclopramide and ondansetron; or (4) double dummy. Trial medication was initially given intravenously and then continued orally once women were able to tolerate oral fluids for a maximum of 10 days of treatment.

MAIN OUTCOME MEASURES

The primary end point was the number of participants who experienced treatment failure, which was defined as the need for further treatment because symptoms had worsened between 12 hours and 10 days post treatment. The main economic outcomes were incremental cost per additional successful treatment and incremental net benefit.

RESULTS

Of the 592 patients screened, 122 were considered eligible and 33 were recruited into the internal pilot (metoclopramide and dummy ondansetron, n = 8; ondansetron and dummy metoclopramide, n = 8; metoclopramide and ondansetron, n = 8; double dummy, n = 9). Owing to slow recruitment, the trial did not progress beyond the pilot. Fifteen out of 30 evaluable participants experienced treatment failure. No statistical analyses were performed. The main reason for ineligibility was prior treatment with trial drugs, reflecting an unpredicted change in prescribing practice at several points along the care pathway. The qualitative evaluation identified the requirements of the study protocol, in relation to guidelines on anti-sickness drugs, and the diversity of pathways to care as key hurdles to recruitment while the role of research staff was a key enabler. No important adverse events or side effects were reported.

LIMITATIONS

The pilot trial failed to achieve the recruitment target owing to unforeseen changes in the provision of care.

CONCLUSIONS

The trial was unable to provide evidence to support clinician decisions about the best choice of second-line antiemetic for nausea and vomiting in pregnancy.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN16924692 and EudraCT 2017-001651-31.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 63. See the NIHR Journals Library website for further project information.

A systematic review of quantitative bias analysis applied to epidemiological research

BACKGROUND

Quantitative bias analysis (QBA) measures study errors in terms of direction, magnitude and uncertainty. This systematic review aimed to describe how QBA has been applied in epidemiological research in 2006-19.

METHODS

We searched PubMed for English peer-reviewed studies applying QBA to real-data applications. We also included studies citing selected sources or which were identified in a previous QBA review in pharmacoepidemiology. For each study, we extracted the rationale, methodology, bias-adjusted results and interpretation and assessed factors associated with reproducibility.

RESULTS

Of the 238 studies, the majority were embedded within papers whose main inferences were drawn from conventional approaches as secondary (sensitivity) analyses to quantity-specific biases (52%) or to assess the extent of bias required to shift the point estimate to the null (25%); 10% were standalone papers. The most common approach was probabilistic (57%). Misclassification was modelled in 57%, uncontrolled confounder(s) in 40% and selection bias in 17%. Most did not consider multiple biases or correlations between errors. When specified, bias parameters came from the literature (48%) more often than internal validation studies (29%). The majority (60%) of analyses resulted in >10% change from the conventional point estimate; however, most investigators (63%) did not alter their original interpretation. Degree of reproducibility related to inclusion of code, formulas, sensitivity analyses and supplementary materials, as well as the QBA rationale.

CONCLUSIONS

QBA applications were rare though increased over time. Future investigators should reference good practices and include details to promote transparency and to serve as a reference for other researchers.

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.

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.

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.

Patterns of prescription medicine dispensing before and during pregnancy in New Zealand, 2005-2015

Objective

To describe prescription medicine dispensing before and during pregnancy in New Zealand, 2005–2015.

Methods

Members of the New Zealand Pregnancy Cohort were linked with their dispensing records in a national database of prescription products dispensed from community pharmacies. We identified the proportion of pregnancies during which at least one prescription medicine was dispensed, the number of different medicines used and the most commonly dispensed medicine groups both during pregnancy and in the 270 days before conception. Dispensing during pregnancy was assessed by several maternal characteristics.

Results

874,884 pregnancies were included. Over the study timeframe, the proportion of pregnancies exposed to a non-supplement prescription medicine increased from 38.5% to 67.2%. The mean number of different non-supplement medicines dispensed during pregnancy increased from 2.5 to 3.2. Dispensing during pregnancy was weakly associated with body mass index, smoking status and ethnicity. Pregnancy exposure was highest for Antibacterials (26.0%), Analgesics (16.7%) and Antinausea & Vertigo Agents (11.0%).

Conclusions

From 2005–2015, both the proportion of exposed pregnancies and the number of different medicines dispensed to pregnant women in New Zealand increased.

Intravenous Ondansetron in Pregnancy and Risk of Congenital Malformations

This pharmacoepidemiology study uses Medicaid data to estimate associations between first-trimester use of intravenous ondansetron and risk of cardiac malformations and oral cleft in children of exposed mothers.

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.

Cancer in Pregnancy

Cancer in pregnancy may be increasing in incidence with advancing maternal age and higher rates of obesity. The diagnosis of cancer in pregnancy provokes complex management issues balancing short- and long-term risks for both mother and baby. Every case needs to be individualized, with a multidisciplinary team of midwives, obstetricians, oncologists, surgeons, radiation oncologists, and neonatologists assisting the family to make informed decisions regarding the best treatment course for the mother and baby. The present article reviews the evidence regarding the safety of diagnostic imaging, procedures and treatment modalities for cancer for the pregnant woman and fetus. The efficacy of novel anticancer therapies highlight the need for International Registries to accumulate safety data for these agents in pregnancy as expeditiously as possible.

The effect of anti-emetic drugs on rat embryonic heart activity

Nausea and vomiting of pregnancy (NVP) is the most common medical complaint during pregnancy affecting up to 70% of pregnant women worldwide. Some antiemetic medications (AEM) (droperidol, domperidone, granisetron, metoclopramide and trifluoperazine) used to treat NVP have the unwanted side effect of hERG blockade. The hERG potassium channel is essential for normal heart rhythm in both the adult human and the human and rat embryo. Animal studies show hERG blockade in the embryo causes bradycardia and arrhythmia leading to cardiovascular malformations and other birth defects. Whole rat embryo in vitro culture was used to determine the effect of the above listed AEM and meclizine on the heart rate of Gestational day 13 rat embryos. These embryos are similar in size and heart development to 5-6-week human embryo. The results showed that all of the AEMs caused a concentration-dependent bradycardia. Droperidol had the lowest margin of safety.

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.