Postmarketing surveillance for human teratogenicity: a model approach

COVID-19 in pregnancy-what study designs can we use to assess the risk of congenital anomalies in relation to COVID-19 disease, treatment and vaccination?

BACKGROUND

The COVID-19 pandemic has accelerated pregnancy outcome research, but little attention has been given specifically to the risk of congenital anomalies (CA) and first trimester exposures.

OBJECTIVES

We reviewed the main data sources and study designs used internationally, particularly in Europe, for CA research, and their strengths and limitations for investigating COVID-19 disease, medications and vaccines.

POPULATION

We classify research designs based on four data sources: a) spontaneous adverse event reporting, where study subjects are positive for both exposure and outcome, b) pregnancy exposure registries, where study subjects are positive for exposure, c) congenital anomaly registries, where study subjects are positive for outcome and d) population healthcare data where the entire population of births is included, irrespective of exposure and outcome.

STUDY DESIGN

Each data source allows different study designs, including case series, exposed pregnancy cohorts (with external comparator), ecological studies, case-control studies and population cohort studies (with internal comparator).

METHODS

The quality of data sources for CA studies is reviewed in relation to criteria including diagnostic accuracy of CA data, size of study population, inclusion of terminations of pregnancy for foetal anomaly, inclusion of first trimester COVID-19-related exposures and use of an internal comparator group. Multinational collaboration models are reviewed.

RESULTS

Pregnancy exposure registries have been the main design for COVID-19 pregnancy studies, but lack detail regarding first trimester exposures relevant to CA, or a suitable comparator group. CA registries present opportunities for improving diagnostic accuracy in COVID-19 research, especially when linked to other data sources. Availability of inpatient hospital medication use in population healthcare data is limited. More use of ongoing mother-baby linkage systems would improve research efficiency. Multinational collaboration delivers statistical power.

CONCLUSIONS

Challenges and opportunities exist to improve research on CA in relation to the COVID-19 pandemic and future pandemics.

SARS-CoV-2-specific T cell responses and immune regulation in infected pregnant women

We studied the T cell response to SARS-CoV-2 spike and non-spike peptide epitopes in eight convalescent pregnant women together with the immune monitoring that included innate tolerogenic dendritic cell populations important to maintain the immunological mother/fetus interface to address a potential risk for the antiviral cellular response in the outcome of pregnancy. Four subjects had pre-existing chronic inflammatory conditions that could have potentially affected the SARS-CoV-2-specific T cell response. Seven of eight subjects responded to SARS-CoV-2 peptides with differences within CD4+ T helper (Th) and CD8+ cytotoxic T cells (CTL). SARS-CoV-2-specific inducible regulatory T cells (iTreg) were numerous in circulation. CD4+ T cell memory included central memory T cells (T_CM) and effector memory (T_EM). As far as the CD8+ memory repertoire, T_CM and T_EM were very low or absent in eight of eight subjects and only effector cells that revert to CD45RA+, defined as T_EMRA were measurable in circulation. T cells were in the normal range in all subjects regardless of pre-existing inflammatory conditions. The immune phenotype indicated the expansion and activation of tolerogenic myeloid dendritic cells including CD14+ cDC2 and CD4+ ILT-4+ tmDC. In summary, SARS-CoV-2 infection induced a physiological anti-viral T cell response in pregnant women that included SARS-CoV-2-specific iTreg with no negative effects on the tolerogenic innate dendritic cell repertoire relevant to the immune homeostasis of the maternal-fetal interface. All eight subjects studied delivered full-term, healthy infants.

Birth outcomes in women who have taken hydroxycholoroquine in pregnancy: a prospective cohort study

OBJECTIVE

Previous small studies have been reassuring regarding the pregnancy safety of hydroxychloroquine. One recent report found an increase in major birth defects at doses ≥400 mg/day. This study was undertaken to examine pregnancy outcomes following use of hydroxychloroquine.

METHODS

Pregnant women prospectively enrolled in MotherToBaby/OTIS Pregnancy Studies exposed to hydroxychloroquine were selected. Disease-matched and healthy comparison groups without hydroxychloroquine exposure were randomly selected from the same source using a 1:1 ratio. Data were collected through interviews, medical records, and dysmorphology examinations. Outcomes were major and minor birth defects, spontaneous abortion, preterm delivery and infant growth.

RESULTS

Between 2004 and 2018, 837 pregnancies met criteria for inclusion, 279 exposed to hydroxychloroquine and 279 in each comparison group. Sixty pregnancies (7.2%) were lost-to-follow-up. Among live births, 20/232 (8.6%) with first-trimester hydroxychloroquine exposure had a major birth defect compared to 19/256 (7.4%) in the disease-matched group (Odds Ratio (OR) 1.18, 95% Confidence Interval (CI) 0.61, 2.26), and 13/239 (5.4%) in the healthy group (adjusted OR 0.76, 95% CI 0.28, 2.05). Risks did not differ at doses ≥400 mg/day. No pattern of birth defects was identified. There were no differences in rates of spontaneous abortion or preterm delivery. Growth deficiency measures did not differ in the hydroxychloroquine-exposed vs. disease-matched group, except birth head circumference (adjusted OR 1.85, 95% CI 1.07, 3.20).

CONCLUSIONS

We found no evidence of an increased risk for structural defects or other outcomes with hydroxychloroquine, with the exception of birth head circumference. For women treated with hydroxychloroquine, these findings are reassuring.

A model for human and animal data integration: Weight of evidence strategy

BACKGROUND

Integration of animal and human data to assess potential risks of the use of medications in pregnancy is important. A qualitative weight of evidence process enables all available evidence to be considered in a consistent, systematic manner.

METHODS

We aim to describe the weight of evidence methodology utilized by the authors, a summary of which was presented at the 59th Annual Meeting of the Teratology Society entitled "Integration of Human and Animal Data to Inform Medication Use in Pregnant Women." The qualitative weight of evidence process evaluates data that inform on a potential relationship between an adverse pregnancy outcome and a medication exposure. An interdisciplinary panel evaluates all available human and animal data related to the question of interest. Study quality assessments of both human and animal data are incorporated. The evaluation assesses gaps in the data from the following areas: (a) strength, (b) specificity, (c) consistency, (d) dose response relationship, (e) methodological considerations, and (f) biological plausibility for the potential association of interest.

RESULTS

The panel integrates all the information to arrive at an assessment of the evidence and provides recommendations, which may include obtaining more specific information. We provide examples of how the authors apply this process at a pharmaceutical company for evaluation of potential postmarketing safety issues regarding medications and pregnancy outcomes.

CONCLUSIONS

This weight of evidence method improves the ability to integrate published literature and other data sources to assess the potential risks of medication use in pregnant women and inform future drug safety studies.

Safety evaluation of adverse events following vaccination with Havrix, Engerix-B or Twinrix during pregnancy

BACKGROUND

Vaccination of pregnant women against hepatitis A virus (HAV) or hepatitis B virus (HBV) may benefit the mother and the fetus but is not routinely recommended. However, the risk associated with vaccination should be weighed against the risk of HAV or HBV infection. Data on safety profiles after hepatitis A, B or combined AB immunization during pregnancy are limited.

METHODS

We searched the GSK Worldwide Safety Database for adverse events (AEs) following immunization of pregnant women with HAV (Havrix, GSK), HBV (Engerix-B, GSK) or the combined hepatitis AB (Twinrix, GSK) vaccine since market authorization through 31 January 2018, covering at least 25 years. AE reports (spontaneous, post-marketing surveillance and clinical trial cases) in the GSK Worldwide Safety Database were identified using a systematic search and were reviewed by clinicians to ascertain pregnancy status at time of vaccination and characterize adverse pregnancy outcomes, including pregnancy-related AEs and AEs in infants regardless of the causality assessment.

RESULTS

Overall, 613, 700 and 363 pregnancies with exposure to Havrix, Engerix-B and Twinrix, respectively, were reported. Of these, 378, 339 and 194 were analyzed. The most frequently identified pregnancy outcomes were live infants (288, 223 and 151), spontaneous abortions (43, 57 and 26) and elective terminations (25, 24 and 9). A total of 19, 29 and 10 cases of congenital anomalies were reported. Of these, 17, 20 and 7 were major birth defects. The most commonly reported pregnancy-related AE and AE in infants were premature delivery (28) and jaundice (11), respectively. No maternal deaths were reported. Congenital anomalies were reported in all recorded infant deaths.

CONCLUSIONS

This review did not indicate any concerning pattern of adverse pregnancy outcomes following exposure to any of the 3 vaccines during pregnancy.

Acetaminophen use in pregnancy: Examining prevalence, timing, and indication of use in a prospective birth cohort

BACKGROUND

Previous studies of prenatal acetaminophen use have not addressed what indications and maternal co-factors describe acetaminophen use.

OBJECTIVE

The objective of this study was to describe these parameters in a well-characterised, prospective birth cohort.

METHODS

Data were drawn from the MotherToBaby study of pregnant women enrolled from 2004 to 2018. Daily acetaminophen diaries were calculated for all exposed women with complete dose and duration information. Descriptive statistics were used to assess maternal characteristics associated with acetaminophen use. Prevalence by 2-year interval was described, and linear regression was used to test for trend. Indication of use and dose per indication were summarised.

RESULTS

Of 2441 subjects, 1515 (62%) reported use of acetaminophen. Over the 15-year period, there was a decline in use of 2.5% for each 2-year period (test for trend = 0.001) with 58% reporting acetaminophen use in 2017-2018. Among women with acetaminophen use in pregnancy (n = 1515), 58% reported <10 days of use, 13% reported 10-19 days of use, 9% reported 20-44 days of use, and 9% reported 45 or more days of use. Twelve per cent had undefined duration of use. Increasing duration of exposure was associated with tobacco use, obesity, self-reported depression or anxiety, and antidepressant use. The most frequently reported indication was headache, however, indication varied by duration of use, with more women reporting use for sleep or pain/injury in the categories with the longest duration of use. Median dose per exposed day was highest among those reporting use for sleep, and higher doses were more frequently reported for arthritis, injury, and pain.

CONCLUSION

Acetaminophen is used by the majority of pregnant women, and some continue to use for many weeks in pregnancy. Given the heterogeneity in duration of use, indication, and dose, studies that estimate the risk of adverse outcomes associated with acetaminophen must carefully consider these factors.

Psychological distress in pregnancy and postpartum

PURPOSE

Depression, stress, and anxiety, termed 'psychological distress,' are common in pregnancy and postpartum periods. However, it is unclear whether prenatal psychological distress predicts postpartum psychological distress. We studied the prevalence, comorbidity and associations of maternal depression, stress, and anxiety in the prenatal period in relation to the occurrence of these same measures in the postpartum period.

METHODS

Data originated from the MotherToBaby study of pregnant women residing in the U.S or Canada (2016-2018). Risk ratios and 95% Confidence Intervals using modified-Poisson regression models were used to investigate associations between prenatal psychological distress and postpartum psychological distress.

RESULTS

Of the 288 women in the analysis, 21.2% and 26.7% of women had evidence of prenatal and postnatal psychological distress, respectively. Among those with prenatal psychological distress, 43 (70.5%) also had postpartum psychological distress. Twenty-five (41%) of those with prenatal and 46 (60%) of those with postpartum psychological distress had comorbidity of at least two of the measures. Prenatal measures independently predicted the same postnatal measures; prenatal anxiety also independently predicted postpartum stress. Participants who experienced more types of prenatal psychological distress were at higher risk for postpartum depression, stress, and anxiety.

CONCLUSION

Depression, stress, and anxiety are common in pregnant women and often occur together. Prenatal psychological distress measures are associated with postnatal psychological distress measures, with stronger associations among women with more than one type of psychological distress in pregnancy. Interventions during pregnancy may reduce the risk of postpartum psychological distress.

Oseltamivir use in pregnancy: Risk of birth defects, preterm delivery, and small for gestational age infants

BACKGROUND

Influenza infection during pregnancy increases risks for adverse outcomes for both mother and fetus. For this reason, treatment for infection or postexposure prophylaxis with a neuraminidase inhibitor, such as oseltamivir, may be needed.

METHODS

Between 2009 and 2017, the Organization of Teratology Information Specialists (OTIS) MotherToBaby Pregnancy Studies enrolled pregnant women in the United States and Canada who were or were not treated with oseltamivir in a prospective cohort study. Data were collected on major birth defects, spontaneous abortion, preterm delivery, and small for gestational age birth size. Crude relative risks (RRs) or hazard ratios (HRs) were estimated together with 95% confidence intervals (CIs) for these outcomes.

RESULTS

There were 716 subjects available for analysis; 112 were exposed to oseltamivir sometime in pregnancy and 604 were unexposed. 2/30 (6.7%) first-trimester-exposed pregnancies resulted in a fetus or infant with one or more major birth defects compared to 48/604 (7.9%) in the unexposed cohort (RR 0.84, 95% CI 0.19, 2.80). There were no spontaneous abortions reported. Risk of preterm delivery was not elevated in exposed versus comparison women (HR 0.65, 95% CI 0.26, 1.63). RRs for small for gestational age infants on weight, length, and head circumference following oseltamivir exposure anytime in pregnancy ranged from 0.70 to 1.30 with all 95% CIs including 1.

CONCLUSION

We found no evidence of increased risks with oseltamivir for any of the outcomes evaluated. While numbers are small, these data are reassuring for pregnant women who need to be treated for infection or for postexposure prophylaxis.

Pregnancy After Renal Transplant: Single Center Experience From the Middle East in Patients Using Different Calcineurin Inhibitors

OBJECTIVES

Pregnancy after kidney transplant has a high risk for maternal and fetal complications; however, it can be successful if patients are properly selected. Here, we studied outcomes and complications of pregnancies in kidney transplant recipients who received calcineurin inhibitor-based immunosuppression.

MATERIALS AND METHODS

In this case control study, we reviewed patients who became pregnant between 2004 and 2017. For this analysis, each pregnancy was considered an event. We divided pregnancies into 2 groups according to calcineurin inhibitor-based maintenance immunosuppression: group 1 (49 pregnancies) received cyclosporine, and group 2 (33 pregnancies) received tacrolimus. Patients also received steroids and azathioprine. Patients had regular antenatal follow-up at the Hamed Alessa Organ Transplant Center (Kuwait) and in the maternity hospital (monthly until month 7 and then weekly until delivery).

RESULTS

Of 750 female kidney transplant recipients within childbearing potential, there were 82 pregnancies (10.9%) in 49 recipients (6.5%). Seventy-eight pregnancies were planned, and 4 pregnancies occurred while women were using contraception. There was 1 triple pregnancy, 5 double, and 76 single pregnancies. Two women had preeclampsia as maternal complication, 2 had uncontrolled hypertension, and 7 developed graft dysfunction. Forty-seven women (57.3%) had caesarean section, and the remaining had vaginal deliveries. Of 89 babies, 86 were viable (1 intrauterine fetal death and 2 abortions). Eight babies were delivered prematurely with low birth weight, and 2 needed incubators. Mean serum creatinine levels were 97.9 ± 24, 109 ± 38, 100 ± 39, 120 ± 46, and 115 ± 57 μmol/L at baseline, first, second, and third trimesters, and postpartum, respectively. Twelve patients showed high panel reactive antibodies but without donor-specific antibodies.

CONCLUSIONS

Posttransplant pregnancy can be successful in most renal allograft recipients, but the increased risk of fetal and maternal complications, including low birth weight, spontaneous abortus, and preeclampsia, should be considered.

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.

A nonparametric maximum likelihood approach for survival data with observed cured subjects, left truncation and right-censoring

We consider observational studies in pregnancy where the outcome of interest is spontaneous abortion (SAB). This at first sight is a binary 'yes' or 'no' variable, albeit there is left truncation as well as right-censoring in the data. Women who do not experience SAB by gestational week 20 are 'cured' from SAB by definition, that is, they are no longer at risk. Our data is different from the common cure data in the literature, where the cured subjects are always right-censored and not actually observed to be cured. We consider a commonly used cure rate model, with the likelihood function tailored specifically to our data. We develop a conditional nonparametric maximum likelihood approach. To tackle the computational challenge we adopt an EM algorithm making use of "ghost copies" of the data, and a closed form variance estimator is derived. Under suitable assumptions, we prove the consistency of the resulting estimator which involves an unbounded cumulative baseline hazard function, as well as the asymptotic normality. Simulation results are carried out to evaluate the finite sample performance. We present the analysis of the motivating SAB study to illustrate the advantages of our model addressing both occurrence and timing of SAB, as compared to existing approaches in practice.

Ethical approval for multicenter cohort studies on drug exposure during pregnancy: A survey among members of the European Network of Teratology Information Services (ENTIS)

The European Network of Teratology Information Services (ENTIS) is in a privileged position to perform independent post-marketing surveillance of drugs in pregnancy. The aim of this survey was to describe the legal requirements and procedures involved in obtaining ethical approval for collaborative cohort studies. We sent a survey questionnaire to all 28 Teratology Information Services (TIS), of which 25 (89%) in 18 countries completed our questionnaire. For 15 TIS, specific research ethical approval was mandatory. The review process was estimated to last from 2 up to 16 weeks. Procedures for patients' information and consent were oral (12), written (5) or both (3). Five TIS had no requirement to inform patients and seek consent. Since data on drug exposure during pregnancy are scarce, ENTIS research efforts should be further encouraged, and procedures optimized so that legitimate ethical and legal requirements do not translate into deterrent administrative constraints and costs.

Risk of infantile hemangiomas in the offspring of women with autoimmune disease and the pathogenic implications of these lesions

The purpose of this study was to analyze the risk of maternal autoimmune disease or associated treatments on infantile hemangiomas (IHs), a common benign vascular tumor in infants, and to better understand how maternal chronic inflammation may play a factor in the pathogenesis of these lesions. Eligible women from the United States and Canada who enrolled before 19 weeks' gestation and delivered at least one live born infant were recruited as part of the Organization of Teratology Information Specialists (OTIS) Autoimmune Disease in Pregnancy Project from 2004-2013. A total of 51/969 (5.3%) and 8/240 (3.3%) infants with IH were born to mothers with and without autoimmune disease, respectively (OR 1.61; 95%CI, 0.75-.44). The presence of ulcerative colitis (UC) in the mother was significantly associated with IH in the child (OR 3.46; 95%CI, 1.29-9.26). The five largest IH occurred within the autoimmune disease cohort and to women taking a biologic medication. These results imply that UC may be a risk factor for IH development, and that chronic inflammation may influence the development of these lesions. This potential link between IH and autoimmune disease warrants further investigation.

Autoimmune conditions and comorbid depression in pregnancy: examining the risk of preterm birth and preeclampsia

OBJECTIVE

The objective of this study was to determine whether prenatal depression interacts with autoimmune conditions to further increase the risk of preterm birth or preeclampsia.

STUDY DESIGN

Our sample included 3034 pregnant women with rheumatoid arthritis (RA), Crohn's disease (CD) or psoriasis, or controls that were prospectively enrolled into MothertoBaby pregnancy studies. We estimated the independent and joint effects of the three autoimmune conditions and depression on the select outcomes.

RESULTS

We found an increased risk of preterm birth among women with RA (2.10; 95% confidence interval (CI) 1.54, 2.87), CD (1.87; 95% CI 1.25, 2.81) or psoriasis (1.88; 95% CI 1.27, 2.79) independent of depression status. RA was also independently associated with preeclampsia. Prenatal depression was not independently associated with preterm birth or preeclampsia, nor was there any synergism with autoimmune conditions.

CONCLUSION

If these findings are confirmed, the absence of synergism should be encouraging news to the many women with select autoimmune conditions and depression in pregnancy.

Can We Rely on Pharmacy Claims Databases to Ascertain Maternal Use of Medications during Pregnancy?

BACKGROUND

Administrative databases are increasingly used to measure drug exposure in perinatal pharmacoepidemiology. We aimed to estimate the concordance between records of prescriptions filled in pharmacies and self-reported drug use during pregnancy.

METHODS

Data on self-reported medication use were collected at each trimester of pregnancy among a sub-sample from the Organization of Teratology Information Specialists Antidepressants in Pregnancy Cohort. Women were eligible if they were Quebec resident and provided their pharmacist's contact information. Maternal self-reports were compared with prescriptions filled in pharmacies, which are transferred to pharmaceutical services files of Quebec provincial health plan database (Régie de l'asssurance maladie du Québec). Positive and negative predictive values (PPV and NPV) for medications taken chronically (antidepressants, thyroid hormones), acutely (antibiotics), and as needed (antiemetics, asthma medications) were calculated.

RESULTS

Among the 93 participants (mean age = 30.2 ± 3.8 years), 41.9% (n = 39) took at least one antidepressant during pregnancy according to self-reports, and 39.8% (n = 37) according to pharmacy records. Other commonly used drugs were antiemetics (self-reported 22.6%, pharmacy record 24.7%), antibiotics (20.4%, 16.1%), asthma medications (15.1%, 15.1%), and thyroid hormones (10.8%, 8.6%). PPVs and NPVs were: (1) chronic medication: antidepressants PPV = 100% (95% confidence interval [CI], 100-100%), NPV = 96% (95% CI, 92-100%); thyroid hormones PPV = 100% (95% CI, 100-100%), NPV = 98% (95% CI, 95-100%); (2) Acute medication: antibiotics PPV = 87% (95% CI, 70-100%), NPV = 92% (95% CI, 86-98%); (3) as needed medications: antiemetics: PPV = 78% (95% CI, 62-95%), NPV = 96% (95% CI, 91-100%); asthma: PPV = 33% (95% CI, 3-64%), NPV = 99% (95% CI, 97-100%).

CONCLUSION

The high PPV and NPV validate the use of filled prescription data in large databases as a measure of medication exposure. Birth Defects Research 109:423-431, 2017. © 2017 Wiley Periodicals, Inc.

Overview of Pregnancy in Renal Transplant Patients

Kidney transplantation offers best hope to women with end-stage renal disease who wish to become pregnant. Pregnancy in a kidney transplant recipient continues to remain challenging due to side effects of immunosuppressive medication, risk of deterioration of allograft function, risk of adverse maternal complications of preeclampsia and hypertension, and risk of adverse fetal outcomes of premature birth, low birth weight, and small for gestational age infants. The factors associated with poor pregnancy outcomes include presence of hypertension, serum creatinine greater than 1.4 mg/dL, and proteinuria. The recommended maintenance immunosuppression in pregnant women is calcineurin inhibitors (tacrolimus/cyclosporine), azathioprine, and low dose prednisone; and it is considered safe. Sirolimus and mycophenolate mofetil should be stopped 6 weeks prior to conception. The optimal time to conception continues to remain an area of contention. It is important that counseling for childbearing should start as early as prior to getting a kidney transplant and should be done at every clinic visit after transplant. Breast-feeding is not contraindicated and should not be discouraged. This review will help the physicians in medical optimization and counseling of renal transplant recipients of childbearing age.

Consistency of maternal telephone administration of the asthma control test using postpartum recall compared to repeated measures during pregnancy

BACKGROUND

Suboptimal asthma control during pregnancy may impact perinatal outcomes. U.S. guidelines recommend questionnaires to assess asthma control including the Asthma Control Test (ACT). It is unknown in a research setting to what extent recall differs by the time between symptom occurrence and the administration of the questionnaire.

METHODS

Between 2009-2014, 196 pregnant asthmatic women were recruited by the Organization of Teratology Information Specialists (OTIS) MotherToBaby Pregnancy Studies. Participants were administered the ACT at enrollment, gestational weeks 20 and 32, and shortly after delivery. The same women were also administered the ACT retrospectively at approximately 6 months postpartum.

RESULTS

The Pearson correlation coefficients between the in-pregnancy and retrospective continuous ACT scores for the 1st, 2nd and 3rd trimesters were: 0.67 (95% CI: 0.58, 0.74), 0.61 (0.52, 0.70) and 0.65 (0.56, 0.72), respectively. When dichotomized into well-controlled asthma (ACT score ≥ 20) versus otherwise, the chi-square test for all three trimesters resulted in p values <0.0001. Cohen's Kappa statistics for the same dichotomized scores were 0.51, 0.45 and 0.40 for each trimester respectively. There was no evidence that adverse outcome of pregnancy (recall bias) influenced postpartum responses.

CONCLUSIONS

The retrospectively recalled ACT score obtained postpartum was substantially different compared to in-pregnancy administration of the same questionnaire which could reflect test-retest variability as well as attenuation of recall. Documentation of the magnitude and direction of these differences could be useful in interpretation of the impact of asthma control when the ACT is used in retrospective case-control studies for pregnancy outcomes.

Safety of the 2010-11, 2011-12, 2012-13, and 2013-14 seasonal influenza vaccines in pregnancy: Birth defects, spontaneous abortion, preterm delivery, and small for gestational age infants, a study from the cohort arm of VAMPSS

INTRODUCTION

There is a need for pregnancy safety information overall and for each seasonal formulation of the influenza vaccine.

METHODS

As part of the cohort arm of the Vaccines and Medications in Pregnancy Surveillance System, vaccine-exposed and unexposed women in the U.S. or Canada were recruited during pregnancy in the 2010-2014 vaccine seasons and followed to pregnancy outcome. For the four seasons combined, crude and adjusted relative risks (RRs) were estimated with 95% confidence intervals (CIs) for major birth defects overall and infants small for gestational age. Crude and adjusted hazard ratios (HRs) were estimated with 95% CIs for spontaneous abortion and preterm delivery. Specific influenza season subanalyses were also conducted.

RESULTS

Of 1730 women, 1263 were exposed to an influenza vaccine and 467 were unexposed to any influenza vaccine. Among pregnancies with first-trimester exposure excluding lost-to-follow-up, 26/457 (5.7%) resulted in an infant with a major birth defect compared to 13/427 (3.0%) in the unexposed (RR 1.87, 95% CI 0.97, 3.59). No specific pattern of defects was evident in the vaccine-exposed cohort. The overall risk of spontaneous abortion was not elevated (HR 1.09, 95% CI 0.49, 2.40). Adjusted HRs for preterm delivery approximated 1.0 (adjusted HR 1.23, 95% CI 0.75, 2.02). RRs for small for gestational age infants on weight, length and head circumference ranged from 1.19 to 1.49 with all CIs including 1. Season-by-season analyses resulted in variation by season; however, estimates were based on small numbers.

CONCLUSIONS

Combining the 2010-2014 influenza seasons, we found a moderately elevated RR for major birth defects overall, but no evidence of a specific pattern; 95% CIs included 1, and this finding could be due to chance. In the combined seasons, we found no meaningful evidence of an increased risk for spontaneous abortion or preterm delivery following exposure to the seasonal influenza vaccine.

Field studies versus database studies on the risks and benefits of medication use during pregnancy: Distinct pieces of the same puzzle

Over the past two decades, findings on medication use during pregnancy have been accumulating from observational data. Generally, field studies with prospective recruitment of subjects have better outcome ascertainment, and more control on the longitudinal collection of data, but have lower sample sizes and thus they often lack statistical power to detect increased risks for rare events such as major congenital malformations. In addition, given the rarity of specific drug exposures in a population, even relatively common outcomes, such as low birth weight, may become rare in combination with the specific exposure. On the other hand, administrative databases usually provide larger samples and thus increased statistical power, decrease the probability of selection and recall bias, but often have missing data on potential confounders. Hence, debate amongst researchers, regulators and public health officials has been ongoing with regard to the most appropriate study populations for perinatal epidemiologic research. With this commentary, we aim to highlight the importance of both study populations, which can make complementary and crucial contributions to the iterative determination of causality as well as discuss basic epidemiologic principles that need to be applied in the field of perinatal pharmacoepidemiology for the purpose of causality assessment. This is relevant at present given that the United States Food and Drug Administration (US FDA) has modified their medication label requirements, especially given the international importance of these modifications.

Challenges in Studying Modifiable Risk Factors for Birth Defects

Conducting research to identify modifiable risk factors for birth defects is difficult for a variety of reasons. While some challenges are familiar to researchers across many disciplines, the confluence of issues affecting birth defects research may not be well understood by those outside of the field. This article describes several methodological challenges to the study of birth defects and ways these challenges might be addressed: (1) ascertainment, definition and classification of birth defects; (2) exposure assessment on modifiable risk factors; (3) analytical challenges related to small numbers and multiple statistical tests; (4) the role of genetics, including the collection of specimens and analysis of genetic data; and (5) challenges in translating research and demonstrating public health impact. Understanding these issues is important for researchers planning studies, reviewers evaluating the scientific merit of results from these studies, and consumers of the research, including fellow researchers, policy makers, health care providers, and families.

Assessment of congenital anomalies in infants born to pregnant women enrolled in clinical trials

In 2011 and 2012, the Division of Microbiology and Infectious Diseases at the National Institute of Allergy and Infectious Diseases, National Institutes of Health, held a series of meetings to provide guidance to investigators regarding study design of clinical trials of vaccines and antimicrobial medications that enroll pregnant women. Assessment of congenital anomalies among infants born to women enrolled in these trials was recognized as a challenging issue, and a workgroup with expertise in epidemiology, pediatrics, genetics, dysmorphology, clinical trials, and infectious diseases was formed to address this issue. The workgroup considered 3 approaches for congenital anomalies assessment that have been developed for use in other studies: (1) maternal report combined with medical records review, (2) standardized photographic assessment and physical examination by a health professional who has received specific training in congenital anomalies, and (3) standardized physical examination by a trained dysmorphologist (combined with maternal interview and medical records review). The strengths and limitations of these approaches were discussed with regard to their use in clinical trials. None of the approaches was deemed appropriate for use in all clinical trials. Instead, the workgroup acknowledged that decisions regarding the optimal method of assessment of congenital anomalies will likely vary depending on the clinical trial, its setting, and the agent under study; in some cases, a combination of approaches may be appropriate. The workgroup recognized the need for more research on approaches to the assessment of congenital anomalies to better guide investigators in optimal design of clinical trials that enroll pregnant women.

Time-dependent propensity score for assessing the effect of vaccine exposure on pregnancy outcomes through pregnancy exposure cohort studies

Women are advised to be vaccinated for influenza during pregnancy and may receive vaccine at any time during their pregnancy. In observational studies evaluating vaccine safety in pregnancy, to account for such time-varying vaccine exposure, a time-dependent predictor can be used in a proportional hazards model setting for outcomes such as spontaneous abortion or preterm delivery. Also, due to the observational nature of pregnancy exposure cohort studies and relatively low event rates, propensity score (PS) methods are often used to adjust for potential confounders. Using Monte Carlo simulation experiments, we compare two different ways to model the PS for vaccine exposure: (1) logistic regression treating the exposure status as binary yes or no; (2) Cox regression treating time to exposure as time-to-event. Coverage probability of the nominal 95% confidence interval for the exposure effect is used as the main measure of performance. The performance of the logistic regression PS depends largely on how the exposure data is generated. In contrast, the Cox regression PS consistently performs well across the different data generating mechanisms that we have considered. In addition, the Cox regression PS allows adjusting for potential time-varying confounders such as season of the year or exposure to additional vaccines. The application of the Cox regression PS is illustrated using data from a recent study of the safety of pandemic H1N1 influenza vaccine during pregnancy.

Risks and safety of pandemic H1N1 influenza vaccine in pregnancy: birth defects, spontaneous abortion, preterm delivery, and small for gestational age infants

INTRODUCTION

There is a need for additional information on the fetal risks and relative safety of the pandemic H1N1 monovalent or trivalent influenza (pH1N1)-containing vaccines in women exposed during pregnancy.

METHODS

To assess risks and relative safety of the pH1N1-containing vaccines, we conducted a prospective cohort study of pH1N1-vaccine-exposed and unexposed comparison women residing in the U.S. or Canada who were recruited during pregnancy and followed to outcome between October 2009 and August 2012. For exposure to the pH1N1 vaccine, adjusted relative risks (RRs) and 95% confidence intervals (CIs) were estimated for major birth defects and infants small for gestational age. Adjusted hazard ratios (HRs) and 95% CIs were estimated for spontaneous abortion and preterm delivery for time-varying exposure.

RESULTS

There were 1032 subjects available for analysis; 841 women were exposed to a pH1N1-containing vaccine in pregnancy, and 191 women were unexposed to any influenza vaccine in pregnancy. Nine of 328 (2.7%) first-trimester-exposed pregnancies resulted in an infant with a major birth defect compared to 6/188 (3.2%) in the unexposed (adjusted RR 0.79, 95% CI 0.26-2.42). The HR for spontaneous abortion was not elevated (adjusted HR 0.92, 95% CI 0.31-2.72). Adjusted HRs for preterm delivery were elevated for exposure anytime in pregnancy (3.28, 95% CI 1.25-8.63), specifically with exposure in the 1st or 2nd trimester. However, the mean decrease in gestational age in the exposed pregnancies was approximately three days. Adjusted RRs for small for gestational age infants on weight and length approximated 1.0.

CONCLUSIONS

For the 2009-12 influenza seasons combined, we found no meaningful evidence of increased RR or HR for major birth defects, spontaneous abortion, or small for gestational age infants. There was some evidence of an increased HR for preterm delivery following pH1N1-influenza vaccine exposure; however the decrease in gestational age on average was approximately three days.

Pregnancy, breast-feeding and drugs used in dentistry

BACKGROUND AND OVERVIEW

Despite advances in the study of birth defects related to drug exposures during pregnancy, medication use during pregnancy still causes anxiety and misunderstanding among both members of the public and health care professionals. This may result in a woman's unknowingly taking a medication that may harm the fetus or cause a birth defect or discontinuing medications necessary for treating chronic conditions. Using medications while breast-feeding also represents a challenge for patients and prescribers. Many mothers are told they must stop breast-feeding or "pump and discard" their breast milk if they are taking certain medications; however, in many cases, this advice-based on what may be limited education on the part of the health care provider about breast-feeding and medication use-may be incorrect. The authors review the current evidence regarding drugs that may be safe for pregnant or breast-feeding patients and medications that such patients should avoid.

CONCLUSIONS

When considering prescribing in pregnancy, the dentist must weigh the risk to the fetus versus the benefit to the mother, and the appropriate conclusion should reflect current evidence. In some cases medication dosing should be avoided or altered; however, there are times when it is unnecessary to stop the use of medications. Breast-feeding also represents a clinical challenge, the risks and benefits of which need to be understood by both the patient and practitioner before any medication is administered.

PRACTICE IMPLICATIONS

Dentists should be familiar with the risks and benefits for pregnant or breast-feeding patients posed by five types of medications: analgesics and anti-inflammatories, antibiotics, local anesthetics, sedatives and emergency medications.

Funding for teratology information services: up, down, and all around

Funding for Teratology Information Services has been an ongoing struggle over the 25 years of its existence. Traditional and novel funding mechanisms have been explored with varying success. The importance of providing teratology risk assessment and counseling to all women of reproductive age is now an established health care objective. Sufficient and stable funding for these services is essential.

The CTIS Womb to Classroom Screening Program for the detection of agents with adverse effects on neuropsychological development

Over the last several decades, federal agencies engaged in the screening of environmental or pharmaceutical agents have recognized the need to conduct research in animal models to identify agents that have classic teratogenic effects as well as effects on neural and behavioral development. Many questions typically addressed in rodent models can be further addressed using real-world, everyday human exposures. Although some postmarketing surveillance programs have been put in place to examine the influences on birth characteristics, it is now urgent that programs be launched to examine the long-term risks associated with exposure to the many medications, drugs, and environmental chemicals for which data are currently unavailable and unexplored. The California Teratogen Information Service (CTIS), established in 1983, and its corresponding Clinical Research Program represent the oldest national program directed at identifying pregnancy risk factors and exposures associated with adverse pregnancy outcome, including behavioral dysfunction. In recognition of the rising rates of developmental disorders involving compromised mental ability, in 2007, CTIS committed to the development of a more comprehensive screening program designed to detect relationships between adverse prenatal exposures and compromised human neurobehavioral development. The "CTIS Womb to Classroom Screening Program for the Detection of Agents with Adverse Effects on Neuropsychological Development" is the first program designed to identify agents not yet known to be of concern.

Patterns of prenatal alcohol exposure and associated non-characteristic minor structural malformations: a prospective study

The characteristic facial features of the more severe end of Fetal Alcohol Spectrum Disorders (FASD) include smooth philtrum, thin vermillion of the upper lip, and short palpebral fissures. A systematic evaluation of a comprehensive list of minor structural defects in association with varying patterns of prenatal exposure to alcohol has not been performed. We examined the patterns and timing of prenatal alcohol exposure to minor structural malformations occurring in at least 5% of the sample. Patterns of drinking were evaluated by drinks per day, number of binge episodes, and maximum number of drinks. Timing of exposure was evaluated 0-6 weeks post-conception, 6-12 weeks post-conception, first trimester, second trimester, and third trimester. Naevus flammeus neonatorum is significantly associated with various patterns of drinking during the second half of the first trimester (RR 1.14, 95% CI 1.04, 1.24 for average number of drinks per day; RR 1.04, 95% CI 1.02, 1.07 for number of binge episodes; RR 1.08, 95% CI 1.01, 1.15 for maximum number of drinks in one episode) and similar for number of binge episodes in all categories of timing of exposure and in the second trimester for average number of drinks per day. Other minor malformations occurring in at least 5% of the sample were not found to be significantly associated with prenatal alcohol exposure. Expected minor malformations were not found to be significantly associated with prenatal alcohol exposure. Naevus flammeus neonatorum appears to be part of the spectrum of features associated with prenatal alcohol exposure.

The role of teratology information services in screening for teratogenic exposures: challenges and opportunities

Teratology Information Services (TIS) located throughout the world have long played a key role in screening for potential new human teratogens. Using a basic prospective cohort study design, TIS recruit pregnant women from among callers to the Services who have had an exposure of interest and at the same time identify an unexposed comparison group from the same pool of callers. Women in both groups are followed to pregnancy outcome and a range of adverse outcomes including major congenital anomalies, birth size, pregnancy loss, and preterm delivery are evaluated, while controlling for potential confounding. Particularly for rare exposures or newly marketed medications, TIS may be uniquely suited to gathering this information in a timely and efficient fashion. The primary limitation of these studies is the unknown representativeness of the volunteer sample, and the typical small to moderate sample sizes. Methods to increase the proportion of exposed pregnancies that are recruited should be developed. However, small sample size TIS studies, especially when considering new or rare exposures, often fulfill the important function of providing some reassurance to women who have already had the exposure of interest by ruling out major risks for teratogenicity, that is, on the order of thalidomide. Collaborations across TIS nationally and internationally help to address the sample size challenges. A formal collaboration between the TIS cohort study model with a case-control study design is also underway and will provide complementary strengths.

Value of the small cohort study including a physical examination for minor structural defects in identifying new human teratogens

Most known human teratogens are associated with a unique or characteristic pattern of major and minor malformations and this pattern helps to establish the causal link between the teratogenic exposure and the outcome. Although traditional case-control and cohort study designs can help identify potential teratogens, there is an important role for small cohort studies that include a dysmorphological examination of exposed and unexposed infants for minor structural defects. In combination with other study design approaches, the small cohort study with a specialized physical examination fulfills a necessary function in screening for new potential teratogens and can help to better delineate the spectrum and magnitude of risk for known teratogens.

Birth outcomes in women who have taken leflunomide during pregnancy

OBJECTIVE

In preclinical reproductive studies, leflunomide was found to be embryotoxic and teratogenic. Women treated with leflunomide are advised to avoid pregnancy; those who become pregnant are advised to reduce fetal exposure through a cholestyramine drug elimination procedure. The present study was undertaken to investigate pregnancy outcomes in women who received leflunomide and were treated with cholestyramine during pregnancy.

METHODS

Sixty-four pregnant women with rheumatoid arthritis (RA) who were treated with leflunomide during pregnancy (95.3% of whom received cholestyramine), 108 pregnant women with RA not treated with leflunomide, and 78 healthy pregnant women were enrolled in a prospective cohort study between 1999 and 2009. Information was collected via interview of the mothers, review of medical records, and specialized physical examination of infants.

RESULTS

There were no significant differences in the overall rate of major structural defects in the exposed group (3 of 56 live births [5.4%]) relative to either comparison group (each 4.2%)(P = 0.13). The rate was similar to the 3-4% expected in the general population. There was no specific pattern of major or minor anomalies. Infants in both the leflunomide-exposed and non-leflunomide-exposed RA groups were born smaller and earlier relative to infants of healthy mothers; however, after adjustment for confounding factors, there were no significant differences between the leflunomide-exposed and non-leflunomide-exposed RA groups.

CONCLUSION

Although the sample size is small, these data do not support the notion that there is a substantial increased risk of adverse pregnancy outcomes due to leflunomide exposure among women who undergo cholestyramine elimination procedure early in pregnancy. These findings can provide some reassurance to women who inadvertently become pregnant while taking leflunomide and undergo the washout procedure.

Development and validation of a measure of dysmorphology: useful for autism subgroup classification

Autism spectrum disorders (ASD) comprise a class of neurodevelopmental disorders that can originate from a variety of genetic and environmental causes. To delineate autism's heterogeneity we have looked for biologically-based phenotypes found in consistent proportions of ASD individuals. One informative phenotype is that of generalized dysmorphology, based on whole body examinations by medical geneticists trained in the nuances of anomalous embryologic development. We identified a need for a dysmorphology measure that could be completed by medical clinicians not extensively trained in dysmorphology that would still retain the level of sensitivity and specificity of the comprehensive dysmorphology examination. Based on expert-derived consensus dysmorphology designation of 222 autism patients and a classification validation study of 30 subjects by four dysmorphologists, we determined that dysmorphology designations based on body areas provided superior inter-rater reliability. Using 34 body area designations, we performed a classification and regression tree (CART) analysis to construct a scoring algorithm. Compared to the consensus classification, the model performed with 81% sensitivity and 99% specificity, and classification of a replication dataset of 31 ASD individuals performed well, with 82% sensitivity and 95% specificity. The autism dysmorphology measure (ADM) directs the clinician to score 12 body areas sequentially to arrive at a determination of "dysmorphic" or "nondysmorphic." We anticipate the ADM will permit clinicians to differentiate accurately between dysmorphic and nondysmorphic individuals-allowing better diagnostic classification, prognostication, recurrence risk assessment, and laboratory analysis decisions-and research scientists to better define more homogeneous autism subtypes.

Human pregnancy safety for agents used to treat rheumatoid arthritis: adequacy of available information and strategies for developing post-marketing data

For female patients with rheumatoid arthritis, the availability of a host of new disease modifying antirheumatic drugs has raised important questions about fetal safety if a woman becomes pregnant while she is being treated. In addition, there is limited safety information regarding many of the older medications commonly used to treat rheumatoid arthritis in women of reproductive age. Current summary pregnancy risk information for selected medications used to treat rheumatoid arthritis is reviewed in the context of the pregnancy label category. In addition, the strengths and weaknesses of post-marketing strategies for developing new pregnancy safety information are described.

Do we have a knowledge transfer and translation plan at Teratogen Information Services?

Recently, a new field in science is emerging, which addresses the issue of ensuring that information that is generated from research, reaches the right people in the right format. This has been coined as knowledge transfer and translation and public health leaders worldwide are finding out ways to carry this out effectively. Ultimately, this should ensure greater investment in knowledge syntheses and transfer initiatives, that involve potential users of research to improve the quality of health for everyone. In this brief review/comment, an attempt will be made to help the readers understand the meaning of this new terminology and how it impacts Teratogen Information Services.

How physicians perceive and utilize information from a teratogen information service: the Motherisk Program

BACKGROUND

Teratogen information services have been developed around the world to disseminate information regarding the safety of maternal exposures during pregnancy. The Motherisk Program in Toronto, Canada, fields thousands of these inquiries per year. Our primary objective was to evaluate the perception and utilization of information received from us by physicians. Our secondary objective was to examine their information seeking behavior, in particular regarding teratogen information.

METHODS

A one page survey was sent to physicians who had called Motherisk for information concerning pregnancy exposures in the previous 30 days for three months. Among the questions that were asked were demographics, which included gender, years in practice, specialty, information resources, and how they utilized the information received from Motherisk.

RESULTS

We received 118/200 completed questionnaires (59% response rate). The mean age of the respondents was: 42 +/- 9 years, mean years of practice was: 14 +/- 8 years, males: 46(38%) and females 72(62%) and 95(80%) were family physicians. 56(48%) researched their question prior to calling Motherisk, 106(91%) and passed on the information received to their patient verbatim. The top four resources for information were: 1) The CPS (PDR), 2) textbooks, 3) journals and 4) colleagues. Only 8% used the Medline for gathering information.

CONCLUSIONS

Physicians feel that a teratogen information service is an important component in the management of women exposed to drugs, chemicals, radiation and infections diseases etc. during pregnancy. Despite the advent of the electronic age, a minority of the physicians in our survey elected to use electronic means to seek information.

Pregnancy Exposure Registries

Scientifically valid data on the safety of drug use during pregnancy are a significant public health need. Data are rarely available on the fetal effects of in utero exposure in human pregnancies, particularly when a drug is first marketed. Data from animal reproductive toxicology studies, which function as a screen for potential human teratogenicity, are usually all that is available in a product's labelling. For practising clinicians, translating known animal risks into an accurate assessment of teratogenic risks in their patients is very difficult, if not impossible. Without human data on the effects of in utero drug exposure, it is difficult for physicians and other healthcare providers (e.g. genetic counsellors) to adequately counsel patients about fetal risks. Therefore, a pregnant woman may decide to unnecessarily terminate a wanted pregnancy or forego needed drug therapy. In spite of the lack of data on the safety of drug use during human pregnancies, pregnant women are exposed to drugs either as prescribed therapy or inadvertently before pregnancy is known (over one-half of pregnancies are unplanned). Because little is known about the teratogenic potential of a drug in humans before marketing, post-marketing surveillance of drug use in pregnancy is critical to the detection of drug-induced fetal effects. The existing passive mechanism of spontaneous reporting of adverse drug effects is inadequate to routinely detect drug-induced fetal risks or lack of such risks. Therefore, post-marketing pregnancy exposure registries are being increasingly used to proactively monitor for major fetal effects and to describe margins of safety associated with drug exposure during pregnancy. However, differing methodological rigour has been applied to the development of pregnancy exposure registries. It is important that all pregnancy registries develop epidemiologically sound written study protocols a priori. It is only through the use of rigorous methodology and procedures that data from pregnancy exposure registries will withstand scientific scrutiny. Successful recruitment of an adequate number of exposed pregnancies, aggressive follow-up, and complete and accurate ascertainment of pregnancy outcome are critical attributes of a well-designed registry.