Postmarketing surveillance of medications and pregnancy outcomes: clarithromycin and birth malformations

Pregnancy outcomes following maternal macrolide use: A systematic review and meta-analysis

To determine whether gestational use of all or specific macrolides (azithromycin, clarithromycin, roxithromycin or erythromycin) lead to an increase in rates of overall major congenital malformations, organ-specific malformations, and other adverse pregnancy outcomes in infants. PubMed/MEDLINE, Cochrane Central Register of Controlled Trials and Reprotox® databases were searched. Dichotomous outcomes or calculated log odds ratios and standard errors from observational studies are combined using the random-effects method in Review Manager 5.3. No significant increased risks for major congenital malformation (OR 1.06 [95% CI 0.99, 1.13]) and congenital heart defect (OR 1.05 [95% CI 0.92, 1.19]) following all macrolides use during the first trimester were detected. Prenatal azithromycin use was associated with a significantly increased risk of major congenital malformations in the analysis of cohort studies (OR 1.21 [95% CI 1.08-1.36]). This significance was also present in the sensitivity analysis. There were no statistically significant associations between the risk of organ specific malformations and all or specific macrolide exposures except for the decreased risk in hypospadias following erythromycin use in the meta-analysis of case-control studies (OR 0.38 [95% CI 0.18, 0.81]. Also, a significant 1.5-fold increased risk for spontaneous abortion following macrolide use was detected. A slight yet significantly increased rate of major congenital malformation with azithromycin exposure during pregnancy may be associated with maternal confounders. Nevertheless, level II ultrasound can be suggested following maternal azithromycin use during the first trimester. Future studies should take into account the inclusion of a disease-matched control group and accurate classification of the malformations.

The Management of Pregnancy Complicated with the Previable Preterm and Preterm Premature Rupture of the Membranes: What about a Limit of Neonatal Viability?—A Review

Preterm premature rupture of the membranes (PPROM) at the limit of viability is associated with low neonatal survival rates and a high rate of neonatal complications in survivors. It carries a major risk of maternal morbidity and mortality. The limit of viability can be defined as the earliest stage of fetal maturity when a fetus has a reasonable chance, although not a high likelihood, for extra-uterine survival. The study reviews available data on preventing preterm delivery caused by the previable PPROM, pregnancy latency, therapeutic options including the use of antibiotics and steroids, neonatal outcomes, and future directions and opportunities.

Clarithromycin use for adjunct surgical prophylaxis before non-elective cesarean deliveries to adapt to azithromycin shortages in COVID-19 pandemic

OBJECTIVE

This study aimed to evaluate safety and effectiveness of clarithromycin as adjunctive antibiotic prophylaxis for patients undergoing non-elective cesarean delivery in comparison with no macrolides, to adapt to azithromycin shortages in COVID-19 pandemic.

STUDY DESIGN

We conducted a multi-center, prospective observational cohort study from March 23, 2020 through June 1, 2020. We followed all women receiving either clarithromycin or no macrolide antibiotic for adjunct surgical prophylaxis for non-elective cesarean deliveries. The primary outcome was development of postpartum endometritis. Secondary outcomes included meconium-stained amniotic fluid at time of cesarean delivery, neonatal sepsis, neonatal intensive care unit admission, and neonatal acute respiratory distress syndrome. All patients in this study were tested for SARS-CoV-2 infection and resulted negative.

RESULTS

This study included 240 patients, with 133 patients receiving clarithromycin and 107 patients receiving no adjunct macrolide prophylaxis. Patients receiving clarithromycin were noted to have significantly lower rates of postpartum endometritis as compared to those who did not receive adjunct prophylaxis (4.5% versus 11.2%, p = 0.025). In crude (unadjusted) analysis, a significantly lower risk of developing endometritis was noted in the clarithromycin group as compared to the control group (66% decreased risk, 95% CI 0.12 to 0.95, p = 0.040). When adjusted for perceived confounders, a significant difference was again noted (67% decreased risk, 95% CI 0.11 to 0.97, p = 0.034). Stratified analysis of significantly different demographic factors including Black race, BMI, and age was performed. A significantly decreased risk of development of endometritis when taking clarithromycin versus no adjunct macrolide was noted for Black race women in crude and adjusted models (crude: 87% decreased risk, 95% CI 0.08 to 0.83, p = 0.032; adjusted: 91% decreased risk, 95% CI 0.06 to 0.79, p = 0.026). This was also noted for women aged 18-29 years in crude and adjusted models (crude: model, 79% decreased risk, 95% CI 0.06 to 0.80, p = 0.014; adjusted model: 75% decreased risk, 95% CI 0.06 to 0.94, p = 0.028). All other stratified analyses did not yield significant differences in endometritis risk.

CONCLUSION

Our study suggests that administration of clarithromycin for adjunctive surgical prophylaxis for non-elective cesarean deliveries may be a safe option that may provide suitable endometritis prophylaxis in cases where azithromycin is unavailable, as was the case during the start of COVID-19 pandemic, most especially for Black race women and women ages 18-29 years.

A Review of Antibiotic Use in Pregnancy

During pregnancy, untreated sexually transmitted or urinary tract infections are associated with significant morbidity, including low birth weight, preterm birth, and spontaneous abortion. Approximately one in four women will be prescribed an antibiotic during pregnancy, accounting for nearly 80% of prescription medications in pregnant women. Antibiotic exposures during pregnancy have been associated with both short-term (e.g., congenital abnormalities) and long-term effects (e.g., changes in gut microbiome, asthma, atopic dermatitis) in the newborn. However, it is estimated that only 10% of medications have sufficient data related to safe and effective use in pregnancy. Antibiotics such as beta-lactams, vancomycin, nitrofurantoin, metronidazole, clindamycin, and fosfomycin are generally considered safe and effective in pregnancy. Fluoroquinolones and tetracyclines are generally avoided in pregnancy. Physiologic changes in pregnancy lead to an increase in glomerular filtration rate, increase in total body volume, and enhanced cardiac output. These changes may lead to pharmacokinetic alterations in antibiotics that require dose adjustment or careful monitoring and assessment.

Safety of antimicrobial treatment during pregnancy: a current review of resistance, immunomodulation and teratogenicity

INTRODUCTION

The extent of antibiotic use in pregnancy remains unknown but may occur in > 40% of pregnant women for various indications, at different gestational ages from different sources.

AREAS COVERED

Antibiotic resistance, alterations to the neonatal immune system causing allergy, asthma and atopic disease in later life and teratogenicity.

EXPERT OPINION

Although teratogenesis is not a major concern, it is important, and ignorance and complacency cast a long shadow. Robust evidence exists to guide clinicians in their choice of a safe agent with respect to teratogenicity. Antibiotic resistance is a major safety concern, and together with decreased research and development of new antibiotic agents, it has required legal initiatives to encourage Big Pharma to search for safe alternatives. New information from culture-independent, molecular-based techniques has resulted in a greater understanding of the adverse effects of antepartum/intrapartum antibiotics on the maternal vaginal microbiome and the neonatal gut microbiome. As this might adversely affect the development of the immature immune system and lead to asthma, allergy and atopic disease in later life, new research merits support in scrutinizing the safety of antibiotic use in pregnancy.

Fetal safety of macrolides

Macrolide antibiotics are largely used in pregnancy for different bacterial infections. Their fetal safety has been studied by several groups, yielding opposing results. In particular, there have been studies claiming an association between macrolides and cardiovascular malformations. Exposure in early infancy has been associated with pyloric stenosis and intussusception. This has led to an avoidance in prescribing macrolides to pregnant women in several Scandinavian countries. The Objectives of the present study was to investigate the fetal safety of this class of drug by linking a large administrative database of drug dispensing and pregnancy outcome in Southern Israel. A computerized database of medications dispensed from 1999 to 2009 to all women registered in the Clalit health maintenance organization in southern Israel was linked with two computerized databases containing maternal and infant hospitalization records. Also, medical pregnancy termination data were analyzed. The following confounders were controlled for: maternal age, ethnicity, maternal pregestational diabetes, parity, and the year the mother gave birth or went through medical pregnancy termination. First- and third-trimester exposures to macrolide antibiotics as a group and to individual drugs were analyzed. During the study period there were 105,492 pregnancies among Clalit women that met the inclusion criteria. Of these, 104,380 ended in live births or dead fetuses and 1,112 in abortion due to medical reasons. In the first trimester of pregnancy, 1,033 women were exposed to macrolides. There was no association between macrolides and either major malformations [odds ratio (OR), 1.08; 95% confidence interval (CI), 0.84 to 1.38)] or specific malformations, after accounting for maternal age, parity, ethnicity, prepregnancy diabetes, and year of exposure. During the third trimester of pregnancy, 959 women were exposed to macrolides. There was no association between such exposure and perinatal mortality, low birth weight, low Apgar score, or preterm delivery. Similarly, no associations were demonstrated with pyloric stenosis or intussusception. Use of macrolides in the first trimester of pregnancy is not associated with an increased risk of major malformations. Exposure in the third trimester is not likely to increase neonatal risks for pyloric stenosis or intussusception in a clinically meaningful manner.

Clarithromycin in early pregnancy and the risk of miscarriage and malformation: a register based nationwide cohort study

Background

The antibiotic clarithromycin has been associated with fetal loss in animals and a study has found a doubling in the frequency of miscarriages among women using clarithromycin in pregnancy. The aim of the study was to investigate whether clarithromycin use in early pregnancy was associated with an increased risk for miscarriages and major malformations.

Methods

We conducted a nationwide cohort study including all women in Denmark with a known conception between 1997 and 2007. The Fertility Database was used to identify all women giving birth and the National Hospital Register was used to identify all women with a record of miscarriage or induced abortion. Prescription data was obtained from the National Prescription Register. The primary outcome was the number of miscarriages and offspring with major congenital malformations among users of clarithromycin compared to non-users.

Results

We identified 931 504 pregnancies (705 837 live births, 77 553 miscarriages, and 148 114 induced abortions). 401 women redeemed a prescription of clarithromycin in the first trimester of which 40 (10.0%) experienced a miscarriage and among the live born nine (3.6%) had offspring with malformations. The hazard ratio (HR) of having a miscarriage after exposure to clarithromycin was 1.56 (CI95% 1.14–2.13). There was no increased hazard of having a miscarriage when being exposed to penicillin or erythromycin. There was no increased prevalence (OR = 1.03 (CI95% 0.52–2.00)) of having offspring with malformations after exposure to clarithromycin.

Conclusions

We found an increased hazard of miscarriage but no increased prevalance of having offspring with malformations among women redeeming a prescription of clarithromycin in early pregnancy. This is supported by previous studies in animals and humans. However, further research is required to explore the possible effect of treatment indication on the associations found.

Pregnancy outcome after gestational exposure to erythromycin - a population-based register study from Norway

AIMS

Erythromycin is a macrolide antibiotic indicated for respiratory tract infections, genital chlamydia and skin infections. It has recently been suggested that erythromycin use in the first trimester of pregnancy can increase the risk of congenital cardiovascular malformations. This study aimed to determine whether erythromycin exposure in the first trimester is associated with cardiovascular or other malformations.

METHODS

We studied 180 120 women in Norway who were pregnant during 2004-2007. Data on all live births stillbirths and induced abortions after 12 gestational weeks from The Medical Birth Registry of Norway (MBRN) were linked to information from the Norwegian prescription database (NorPD). We compared the pregnancy outcomes of women who had taken erythromycin (n= 1786, 1.0%), penicillin V (n= 4921, 2.7%) or amoxicillin (n= 1599, 0.9%) in their first trimester with outcomes of women who had not taken any systemic antibiotics (n= 163 653, 90.9%) during this period.

RESULTS

The risk of cardiovascular malformations was not significantly different with or without exposure to erythromycin in the first trimester (adjusted OR = 1.2 [95% CI 0.8, 1.8]) or in the most vulnerable period of heart formation (adjusted OR = 1.6 [95% CI 0.9-3.0]). Sub-analyses showed that the risk for any specific malformations was not increased with erythromycin, macrolides, penicillin V or amoxicillin compared with no antibiotic use in first trimester.

CONCLUSIONS

This large, population-based register study did not find that exposure to erythromycin or macrolides in the first trimester of pregnancy was associated with fetal cardiovascular or other malformations. These results suggest that the risk of erythromycin use during early pregnancy, if any, is low.

When one drug affects 2 patients: a review of medication for the management of nonlabor-related pain, sedation, infection, and hypertension in the hospitalized pregnant patient

One of the most difficult challenges health care providers encounter is drug selection for pregnant patients. Drug selection can be complex as efficacy and maternal side effects must be weighed against potential risk to the embryo or fetus. Verification of an individual drug's fetal safety is limited as most evidence is deduced from epidemiologic, prospective cohort, or case-control studies. Medication selection for the pregnant inpatient is a particularly complex task as the illnesses and conditions that require hospitalization mandate different medications, and the risk versus benefit ratio can vary significantly compared to the outpatient setting. Some degree of acute pain is not uncommon among inpatients. Acetaminophen is generally considered the drug of choice in pregnancy for mild to moderate acute pain, while most opioids are thought to be safe for short-term use to manage moderate to severe pain. Providing sedation is particularly challenging as the few options available for the general population are further limited by either known increased risk of congenital malformations or very limited human pregnancy data. Propofol is the only agent recommended for continuous sedation, which has a Food and Drug Administration classification as a pregnancy category B medication. Treatment of infections in hospitalized patients requires balancing the microbiology profile against the fetal risk. Older antimicrobials proven generally safe include beta-lactams, and those with proven fetal risks include tetracyclines. However, little to no information regarding gestational use is available on the newer antimicrobials that are frequently employed to treat resistant infections more commonly found in the inpatient setting. Management of maternal blood pressure is based on the severity of blood pressure elevations and not the hypertensive classification. Agents generally considered safe to use in hypertensive pregnant patients include methyldopa, labetolol, and hydralazine, while angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, hydrochlorothiazide, and atenolol should be avoided.

Investigation of developmental toxicity and teratogenicity of macrolide antibiotics in cultured rat embryos

Macrolides are considered to be one of the safest anti-infective groups in clinical use, with severe adverse reactions being rare. However, there are limited data about their embryotoxicity and teratogenicity. We aimed to investigate and compare the effects of these agents on embryonic growth and development. Rat embryos were cultured in vitro for 48 h in rat serum. Whole rat serum was used as a culture medium for the control group while different concentrations of spiramycin and azithromycin (1.25-6.25 microg/ml), and clarithromycin (2.5-30 microg/ml) were added to rat serum for the experimental groups. Dose-dependent effects of macrolides on embryonic developmental parameters were compared using morphological methods. Embryos were evaluated for the presence of any malformations. After morphological examination of the embryos, total DNA was extracted from the cells using standard procedures to determine fragmentation of nuclear DNA of embryonic cells. When compared with the control embryos, the macrolides significantly decreased all growth and developmental parameters dose dependently. While clarithromycin was found to cause more developmental toxicity than spiramycin and azithromycin, azitromycin was determined to have more teratogenicity potential. Compared with controls, there was no difference regarding the fragmentation of nuclear DNA of all the agents used. According to these results, when the toxic and teratogenic potential of the used agents compared, because of the lower toxic and teratogenic effects observed with spiramycin, this agent may be preferred for parturients.

Paroxetine in the first trimester and the prevalence of congenital malformations

PURPOSE

To refine a preliminary analysis identifying a possibly increased prevalence of malformations among infants born to women exposed to paroxetine in the first trimester.

METHODS

This study used data from UnitedHealthcare, a large U.S. insurer, using datasets originally for a study of bupropion in pregnancy. We identified women with a live-born delivery between January 1995 and September 2004. We classified women according to their first trimester mono- or mono/polytherapy exposure to paroxetine and other antidepressants. We confirmed malformation cases by medical record abstraction. We calculated the adjusted odds ratios (AORs) through logistic regression.

RESULTS

For paroxetine, there were 815 infants among 791 women exposed as monotherapy, and 1020 infants among 989 women exposed as mono- or polytherapy. For other antidepressants, there were 4198 infants among 4072 women exposed as monotherapy, and 4936 infants among 4767 women exposed as mono- or polytherapy. AORs for all congenital malformations associated with paroxetine were 1.89 (95%CI 1.20-2.98) for monotherapy, and 1.76 (95%CI 1.18-2.64) for mono- or polytherapy. AORs for cardiovascular malformations associated with paroxetine were 1.46 (95%CI 0.74-2.88) for monotherapy, and 1.68 (95%CI 0.95-2.97) for mono- or polytherapy.

CONCLUSIONS

These more detailed paroxetine findings confirm previous findings of analyses of these data among women exposed to all types of antidepressants. The present findings are consistent with other recent results suggesting the possibility of a modestly increased occurrence of congenital malformations following first trimester exposure to paroxetine compared to other antidepressants.

Gastrointestinal medications in pregnancy

Management of the pregnant patient presents unique challenges to the treating physician. Current Food and Drug Administration classifications do not necessarily reflect clinical experience or recent literature. Ideally, one should use the lowest-risk drug possible, with attention to the appropriate level of efficacy for the patient's condition, the stage of pregnancy and dose adjustment. Every treatment decision should be fully discussed with the patient and a multidisciplinary team that should include the obstetrician and, if appropriate, the paediatrician. This review will cover the medications commonly used to treat gastrointestinal disease. The majority of medications can be categorised as 'low risk' or 'should be avoided'. The following medications should never be used during pregnancy due to the clear risk of teratogenicity or adverse events: bismuth, castor oil, sodium bicarbonate, methotrexate, ribavirin, doxycycline, tetracycline, and thalidomide.

Bupropion in pregnancy and the prevalence of congenital malformations

PURPOSE

Reports from the GlaxoSmithKline Bupropion Pregnancy Registry suggested an increase in cardiovascular defects following exposure to bupropion during pregnancy. We conducted a study of congenital malformations among infants born to women exposed to bupropion during their first trimester.

METHODS

The study used data from UnitedHealthcare between January 1995 and September 2004. We calculated the prevalence of all congenital malformations and cardiovascular malformations associated with bupropion exposure in the estimated first trimester (1213 infants), compared with (1) other antidepressant exposure in the first trimester (4743 infants) and (2) bupropion exposure outside the first trimester (1049 infants). Malformation cases were confirmed through medical record abstraction. We calculated adjusted odds ratios (AORs) using the GEE form of logistic regression.

RESULTS

For all congenital malformations, the prevalence associated with bupropion first trimester was 23.1 per 1000 infants. The AORs were 0.95 (95%CI 0.62-1.45) and 1.00 (95%CI 0.57-1.73) in comparison to other antidepressants (prevalence 23.2 per 1000) and bupropion outside the first trimester (prevalence 21.9 per 1000), respectively. For cardiovascular malformations, the prevalence associated with bupropion first trimester was 10.7 per 1000 infants. The AORs were 0.97 (95%CI 0.52-1.80) and 1.07 (95%CI 0.48-2.40) in comparison to other antidepressants (prevalence 10.8 per 1000) and bupropion outside the first trimester (prevalence 9.5 per 1000), respectively.

CONCLUSIONS

Results do not support a hypothesis of a teratogenic effect of first trimester bupropion exposure. The prevalence of malformations associated with bupropion exposure in the first trimester was not increased relative to the comparison groups.

American gastroenterological association institute technical review on the use of gastrointestinal medications in pregnancy

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Institute Clinical Practice and Economics Committee. The paper was approved by the Committee on February 22, 2006 and by the AGA Institute Governing Board on April 20, 2006.

The pregnant wilderness traveler

BACKGROUND

Travel during pregnancy, especially, when it involves potentially hazardous activities in remote areas, often raises serious concerns regarding the health and safety risks involved.

METHOD

The authors have researched the available medical literature to identify these risks and present the current recommendations for their prevention and treatment.

RESULTS

Topics addressed include some political and social issues, insurance, basic comfort measures, complications of pregnancy, infectious diseases, environmental exposures, and trauma. Preventive measures include pre-travel evaluation and teaching, possible modifications of the itinerary, vaccinations and medications. Also briefly discussed are the handling of obstetrical emergencies in the field and medical evacuation of the pregnant patient.

CONCLUSIONS

The authors conclude that many trips of this nature can be made relatively safe for the pregnant traveler, but she may need to accept some precautions and modifications of the itinerary that might not otherwise be necessary.

Evaluation of gestational age and admission date assumptions used to determine prenatal drug exposure from administrative data

OBJECTIVE

Our aim was to evaluate the 270-day gestational age and delivery date assumptions used in an administrative dataset study assessing prenatal drug exposure compared to information contained in a birth registry.

STUDY DESIGN AND SETTING

Kaiser Permanente Colorado (KPCO), a member of the Health Maintenance Organization (HMO) Research Network Center for Education and Research in Therapeutics (CERTs), previously participated in a CERTs study that used claims data to assess prenatal drug exposure. In the current study, gestational age and deliveries information from the CERTs study dataset, the Prescribing Safely during Pregnancy Dataset (PSDPD), was compared to information in the KPCO Birth Registry. Sensitivity and positive predictive value (PPV) of the claims data for deliveries were assessed. The effect of gestational age and delivery date assumptions on classification of prenatal drug exposure was evaluated.

RESULTS

The mean gestational age in the Birth Registry was 273 (median = 275) days. Sensitivity of claims data at identifying deliveries was 97.6%, PPV was 98.2%. Of deliveries identified in only one dataset, 45% were related to the gestational age assumption and 36% were due to claims data issues. The effect on estimates of prevalence of prescribing during pregnancy was an absolute change of 1% or less for all drug exposure categories. For Category X, drug exposures during the first trimester, the relative change in prescribing prevalence was 13.7% (p = 0.014).

CONCLUSION

Administrative databases can be useful for assessing prenatal drug exposure, but gestational age assumptions can result in a small proportion of misclassification.

Treatment of multidrug-resistant tuberculosis during pregnancy: a report of 7 cases

Multidrug-resistant tuberculosis (MDR-TB) is a global public health problem affecting women of childbearing age. Little is known, however, about the safety of the drugs used to treat MDR-TB during pregnancy. We describe 7 patients who were treated for MDR-TB during pregnancy. These patients had chronic tuberculosis that had caused extensive parenchymal damage and had high-grade resistance to antituberculous drugs. All patients received individualized antituberculous therapy prior to delivery of healthy term infants. Neither obstetrical complications nor perinatal transmission of MDB-TB was observed. One patient experienced treatment failure, and another abandoned therapy. The other 5 patients are currently cured or in treatment and have culture-negative status. In each of these 7 cases, excellent treatment outcomes were obtained for the women and their children. Under certain circumstances, MDR-TB can be successfully treated during pregnancy.