Risk of drug-induced congenital defects

Folate deficiency increases the incidence of dolutegravir-associated foetal defects in a mouse pregnancy model

BACKGROUND

Dolutegravir (DTG) is a recommended first-line regimen for all people with Human Immunodeficiency Virus (HIV) infection. Initial findings from Botswana, a country with no folate fortification program, showed an elevated prevalence of neural tube defects (NTDs) with peri-conceptional exposure to DTG. Here we explore whether a low folate diet influences the risk of DTG-associated foetal anomalies in a mouse model.

METHODS

C57BL/6 mice fed a folate-deficient diet for 2 weeks, were mated and then randomly allocated to control (water), or 1xDTG (2.5 mg/kg), or 5xDTG (12.5 mg/kg) both administered orally with 50 mg/kg tenofovir disoproxil fumarate 33.3 mg/kg emtricitabine. Treatment was administered once daily from gestational day (GD) 0.5 to sacrifice (GD15.5). Foetuses were assessed for gross anomalies. Maternal and foetal folate levels were quantified.

FINDINGS

313 litters (103 control, 106 1xDTG, 104 5xDTG) were assessed. Viability, placental weight, and foetal weight did not differ between groups. NTDs were only observed in the DTG groups (litter rate: 0% control; 1.0% 1xDTG; 1.3% 5xDTG). Tail, abdominal wall, limb, craniofacial, and bleeding defects all occurred at higher rates in the DTG groups versus control. Compared with our previous findings on DTG usage in folate-replete mouse pregnancies, folate deficiency was associated with higher rates of several defects, including NTDs, but in the DTG groups only. We observed a severe left-right asymmetry phenotype that was more frequent in DTG groups than controls.

INTERPRETATION

Maternal folate deficiency may increase the risk for DTG-associated foetal defects. Periconceptional folic acid supplementation could be considered for women with HIV taking DTG during pregnancy, particularly in countries lacking folate fortification programs.

FUNDING

This project has been funded by Federal funds from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN275201800001I and award #R01HD104553. LS is supported by a Tier 1 Canada Research Chair in Maternal-Child Health and HIV. HM is supported by a Junior Investigator award from the Ontario HIV Treatment Network.

Toxicology knowledge graph for structural birth defects

BACKGROUND

Birth defects are functional and structural abnormalities that impact about 1 in 33 births in the United States. They have been attributed to genetic and other factors such as drugs, cosmetics, food, and environmental pollutants during pregnancy, but for most birth defects there are no known causes.

METHODS

To further characterize associations between small molecule compounds and their potential to induce specific birth abnormalities, we gathered knowledge from multiple sources to construct a reproductive toxicity Knowledge Graph (ReproTox-KG) with a focus on associations between birth defects, drugs, and genes. Specifically, we gathered data from drug/birth-defect associations from co-mentions in published abstracts, gene/birth-defect associations from genetic studies, drug- and preclinical-compound-induced gene expression changes in cell lines, known drug targets, genetic burden scores for human genes, and placental crossing scores for small molecules.

RESULTS

Using ReproTox-KG and semi-supervised learning (SSL), we scored >30,000 preclinical small molecules for their potential to cross the placenta and induce birth defects, and identified >500 birth-defect/gene/drug cliques that can be used to explain molecular mechanisms for drug-induced birth defects. The ReproTox-KG can be accessed via a web-based user interface available at https://maayanlab.cloud/reprotox-kg . This site enables users to explore the associations between birth defects, approved and preclinical drugs, and all human genes.

CONCLUSIONS

ReproTox-KG provides a resource for exploring knowledge about the molecular mechanisms of birth defects with the potential of predicting the likelihood of genes and preclinical small molecules to induce birth defects.

Comparative Genomics Identifies Putative Interspecies Mechanisms Underlying Crbn-Sall4-Linked Thalidomide Embryopathy

The identification of thalidomide–Cereblon-induced SALL4 degradation has brought new understanding for thalidomide embryopathy (TE) differences across species. Some questions, however, regarding species variability, still remain. The aim of this study was to detect sequence divergences between species, affected or not by TE, and to evaluate the regulated gene co-expression in a murine model. Here, we performed a comparative analysis of proteins experimentally established as affected by thalidomide exposure, evaluating 14 species. The comparative analysis, regarding synteny, neighborhood, and protein conservation, was performed in 42 selected genes. Differential co-expression analysis was performed, using a publicly available assay, GSE61306, which evaluated mouse embryonic stem cells (mESC) exposed to thalidomide. The comparative analyses evidenced 20 genes in the upstream neighborhood of NOS3, which are different between the species who develop, or not, the classic TE phenotype. Considering protein sequence alignments, RECQL4, SALL4, CDH5, KDR, and NOS2 proteins had the biggest number of variants reported in unaffected species. In co-expression analysis, Crbn was a gene identified as a driver of the co-expression of other genes implicated in genetic, non-teratogenic, limb reduction defects (LRD), such as Tbx5, Esco2, Recql4, and Sall4; Crbn and Sall4 were shown to have a moderate co-expression correlation, which is affected after thalidomide exposure. Hence, even though the classic TE phenotype is not identified in mice, a deregulatory Crbn-induced mechanism is suggested in this animal. Functional studies are necessary, especially evaluating the genes responsible for LRD syndromes and their interaction with thalidomide–Cereblon.

Anticonvulsants and Chromatin-Genes Expression: A Systems Biology Investigation

Embryofetal development is a critical process that needs a strict epigenetic control, however, perturbations in this balance might lead to the occurrence of congenital anomalies. It is known that anticonvulsants potentially affect epigenetics-related genes, however, it is not comprehended whether this unbalance could explain the anticonvulsants-induced fetal syndromes. In the present study, we aimed to evaluate the expression of epigenetics-related genes in valproic acid, carbamazepine, or phenytoin exposure. We selected these three anticonvulsants exposure assays, which used murine or human embryonic stem-cells and were publicly available in genomic databases. We performed a differential gene expression (DGE) and weighted gene co-expression network analysis (WGCNA), focusing on epigenetics-related genes. Few epigenetics genes were differentially expressed in the anticonvulsants' exposure, however, the WGCNA strategy demonstrated a high enrichment of chromatin remodeling genes for the three drugs. We also identified an association of 46 genes related to Fetal Valproate Syndrome, containing SMARCA2 and SMARCA4, and nine genes to Fetal Hydantoin Syndrome, including PAX6, NEUROD1, and TSHZ1. The evaluation of stem-cells under drug exposure can bring many insights to understand the drug-induced damage to the embryofetal development. The candidate genes here presented are potential biomarkers that could help in future strategies for the prevention of congenital anomalies.

Assembling systems biology, embryo development and teratogenesis: What do we know so far and where to go next?

The recognition of molecular mechanisms of a teratogen can provide insights to understand its embryopathy, and later to plan strategies for the prevention of new exposures. In this context, experimental research is the most invested approach. Despite its relevance, these assays require financial and time investment. Hence, the evaluation of such mechanisms through systems biology rise as an alternative for this conventional methodology. Systems biology is an integrative field that connects experimental and computational analyses, assembling interaction networks between genes, proteins, and even teratogens. It is a valid strategy to generate new hypotheses, that can later be confirmed in experimental assays. Here, we present a literature review of the application of systems biology in embryo development and teratogenesis studies. We provide a glance at the data available in public databases, and evaluate common mechanisms between different teratogens. Finally, we discuss the advantages of using this strategy in future teratogenesis researches.

Pharmacoepidemiology in pregnancy

Taking a medication is usually a challenge for a pregnant woman as the beneficial drug effect on the mother has to be considered regarding its potential adverse effects, not only for her but also for her unborn child. As medication use is common in pregnant women, by chance or necessity, it gives the opportunity to evaluate the consequences of prenatal drug exposure in real life through pharmacoepidemiological studies. This paper provides an overview of data sources, study designs and data analysis methods that can be used for pregnancy medication safety studies. In the future, the implementation of responsive international networks may be the keystones of drug evaluation in pregnancy.

The importance of pharmacoepidemiology in pregnancy-implications for safety

INTRODUCTION

Prescription of medications to pregnant women is usually a challenge as the drug benefit has to be considered regarding its potential adverse effects. As medication use is common in pregnant women, by chance or necessity, it gives the opportunity to evaluate the consequences of prenatal drug exposure in real life through pharmacoepidemiologic studies. Area covered: Data sources are numerous. Some of them have been created for the particular purpose of assessing medications during pregnancy. Augmented databases enable the study of delayed effects in late childhood and provide information on potential confounders. Each data source exhibits strengths and weaknesses. Several designs can be used to assess the safety of medications during pregnancy. Innovative designs have been developed in order to bypass major limits of classical methods. Expert opinion: An efficient system could follow up each pregnant woman, who had taken a medication, and consider her as a precious information for the knowledge of drug potential adverse actions against the child, who must be followed up to identify long term-effects. The diversity of data sources and approaches of pharmacoepidemiologic studies, the implementation of international networks as well as the improvement of adverse signal detection are the keystones of such an evaluation.

Patterns of prescription drugs use among pregnant women at Sultan Qaboos University Hospital and Sultan Qaboos University Hospital Family and Community Medicine Clinic, Oman

Objective:

This study evaluates the patterns of prescription drugs use among women attending antenatal clinic at Sultan Qaboos University Hospital (SQUH) and SQUH Family and Community Medicine clinic (FAMCO), Oman.

Methods:

The study was a descriptive retrospective cross-sectional study on pregnant women who attended the antenatal clinic at SQUH and FAMCO from February to April 2014 and received a prescription containing at least one drug. Patients’ information was extracted from SQUH electronic records.

Results:

A total of 105 pregnant women were included in the study. Among the recruited pregnant women, 35 (33.3%) had at least one chronic disease. The average number of drugs prescribed per patient per prescription during the period of pregnancy was 2.33 ± 1.43. Vitamins and minerals were the most frequently prescribed class of drugs (30.60%) followed by analgesics (11.19%) and antidiabetic drugs (10.13%). According to the Food and Drug Administration risk classification, most of the prescribed drugs were from category B (30.0%) and C (27.14%). No drug was prescribed from category X. There was a significant decrease in prescribing category A drugs over the three trimesters (20.7%, 12.7%, and 9.3%, respectively) (P < 0.047).

Conclusion:

The study gives an overview of the extent of drug prescription during pregnancy and increases the awareness of health-care providers and women about the potential risks of drug use during pregnancy.

Angiogenesis-related genes and thalidomide teratogenesis in humans: an approach on genetic variation and review of past in vitro studies

Thalidomide embryopathy (TE) has affected more than 10,000 babies worldwide. The hypothesis of antiangiogenesis as the teratogenic mechanism of thalidomide has been investigated in several experimental models; but, in humans, it has only been accessed by in vitro studies. Here, we hypothesized the effect of thalidomide upon angiogenesis-related molecules or proteins, previously identified in human embryonic cells, through the in silico STRING-tool. We also investigated ten polymorphisms in angiogenesis-related genes in 38 Brazilian TE individuals and 136 non-affected Brazilians. NOS2, PTGS2, and VEGFA polymorphisms were chosen for genotyping. The STRING-tool suggested nitric oxide and β-catenin as the central angiogenesis-related molecules affected by thalidomide's antiangiogenic property. We did not identify a significant difference of allelic, genotypic or haplotypic frequencies between the groups. We could not predict a risk allele or a protective one for TE in NOS2, PTGS2, or VEGFA, although other genes should be analyzed in larger samples. The role of nitric oxide and β-catenin must be further evaluated, regarding thalidomide teratogenesis complex etiology.

Analysis of agreement between Visual Analogue Scales (VAS) and numerical questions to assess perception of teratogenic risks in treatment with drugs and radiotherapy in women

Objectives: to evaluate the agreement between Visual Analogue Scales (VAS) and numerical questions as a way of assessing the perception of teratogenic risk of treatment with drugs and radiotherapy. Methods: the sample comprised 144 pregnant and 143 non-pregnant women consecutively recruited at public health centers in Porto Alegre, in the State of Rio Grande do Sul, from February to August 2011. The perception of risk for congenital malformations in the general population and the perceptions of teratogenic risk for exposure to acetaminophen, meto-clopramide, misoprostol and radiotherapy were measured using VAS and numerical questions. The agreement between the results of the two techniques was tested using a Bland-Altman plot. Results: the medians for the perceptions measured using VAS were higher than those obtained using numerical questions for all variables. The perception of risk for acetaminophen showed the lower bias of the two techniques (bias=13.17; p<0.001) and exposure to radiotherapy, the higher (bias=25.02; p<0.001). Conclusion: there was no agreement between the measurements obtained using the two techniques for any of the risk perceptions under study. Risk perceptions were higher using VAS, for all kinds of exposure. Studies should be conducted to assess whether there is overestimation in other situations and social contexts owing to the use of VAS.

Perceptions by pregnant and childbearing-age women in southern Brazil towards teratogenic risk from medicines and radiotherapy

Mistaken perception of teratogenic risk can keep pregnant women from using safe medicines. The current study analyzed women’s concepts and perceptions towards teratogenic risk from medicines and exposure to radiotherapy during pregnancy. The quantitative data resulted from interviews with 287 pregnant and non-pregnant women. Two qualitative focus groups were conducted. No significant differences were observed between the two groups in terms of perceptions of teratogenic risk. Median perceptions of non-teratogenic exposures (paracetamol and metoclopramide) were close to the expected values, while higher values were found for teratogenic exposures (misoprostol and radiotherapy). The logic women used to estimate risk was classification of medicines as “strong” or “weak”. Medicines perceived as “weak” by the women do not pose any teratogenic risk, as shown by the median perceptions close to the true values. Meanwhile, “strong” medicines were viewed as dangerous, thus explaining the high median perceptions of teratogenic exposures.

Folic acid use in planned pregnancy: an Italian survey

It is well known that periconceptional folic acid supplementation decreases the risk of neural tube defects. The aim of this study was to evaluate the attitudes and practices of women with planned pregnancies regarding periconceptional folic acid intake and to identify factors associated with the use of this supplement. During 2 years of observation, we surveyed women with planned pregnancies who called our Teratology Information Service. A total of 500 women were surveyed: 217 (43.4%) took folic acid before becoming pregnant, and 283 (56.6%) did not take it. The women who took folic acid before becoming pregnant had a high education level and received preconception counselling. Our results suggest that less than half of Italian women took folic acid before they became pregnant although they were trying to conceive. Knowledge about the benefits of this vitamin is inadequate also among women who planned the pregnancy and the level of information received from their physicians.

Smoke, alcohol consumption and illicit drug use in an Italian population of pregnant women

OBJECTIVE

High-risk behaviours are associated with an increased risk of adverse pregnancy outcomes. Exposure to drugs, infection or radiation is a cause of concern for pregnant women, who contact Teratology Information Services (TIS) to have a counseling but with an accurate medical history is possible to detect additional behavioural risk factors that can significantly interfere with pregnancy outcome. The aim of this study is to describe risk behaviours in a population of Italian women calling our TIS and to identify related maternal factors.

STUDY DESIGN

Between December 2008 and January 2010 we collected data from 503 pregnant women calling our TIS (Telefono Rosso, Rome). We investigated about smoke, alcohol and abuse substances addiction and we also collected demographic data.

RESULTS

Of the 503 women consenting to participate 34% were found to have an additional risk marker during the current pregnancy. Within this group were 22.7% (n=119) who reported smoking, the 17.7% (n=89) admitted to drink and 2 women (0.4%) used illicit drugs. In 13.7% of cases (n=69) reason for calling represented an exposure to teratogenic agents. Unmarried status and previous induced abortion represent a risk factor for all high-risk behaviours. Lower education (p<0.001) and use of neurological drugs (p<0.001) are related with cigarette consumption. A lower parity was a risk factor for alcohol assumption (p=0.04). Women with high-risk behaviours tend to be exposed to more than a risk factor.

CONCLUSIONS

Teratogen Information Services are an important system to identify women with pregnancy risk markers. These services should have the ability to provide risk reduction information to women who smoke cigarettes or with alcohol or drug use. In addition to the phone based information these women may benefit from referral back to their physician for assessment and management of substance use/abuse during pregnancy. Substance abuse risks are often underestimated by pregnant women. Single mothers or women with an history of terminations of pregnancy represents an high-risk population. Physicians should inform their patients about possible risks related to high-risk behaviours during preconception counseling or during the first obstetric visit.

Pregnancy and Commonly Used Drugs in Hematology Practice

When a woman suffering from a hematological condition is contemplating pregnancy, she may need to continue the use of medications that do not have sufficient evidence of fetal safety. We discuss the evidence existing for some therapies of major hematological conditions in the context of major principles in clinical teratology. It is critical to always balance the potential fetal risks of the drug in question against the maternal and fetal risks of the untreated hematological condition.

Use of the Internet by women seeking information about potentially teratogenic agents

OBJECTIVE

The aim of this study was to evaluate if the Internet provides evidence-based information to women seeking information about teratogenic risk factors and women's risk perception. Furthermore, we evaluated the possible risk related to teratogen exposure in the study sample and analysed age, gravidity, educational level, geographic location, marital status and type of exposure compared to a control group made up of women who did not use the Internet to search for teratogen-related information.

STUDY DESIGN

Between October 2008 and June 2009, a questionnaire was administered to pregnant women calling our Teratology Information Service concerning a suspected teratogenic exposure.

RESULTS

Fifty-seven percent (n=116) of callers had used the Internet to find medical information about their exposure, while 43% (n=87) had not. Internet users had a medium-high level of education and consulted the Internet because of its convenience, usually early in their pregnancy. We verified the accuracy of the information the women obtained from the Internet and found that 59.5% (n=69) of women received evidence-based answers; 18.1% (n=21) were informed that their exposure was dangerous when it was not; 4.3% (n=5) were wrongly reassured; and the rest (n=18) were not able to interpret the data they found or found no relevant information.

CONCLUSIONS

Internet use during pregnancy is a widespread phenomenon as the Internet offers the opportunity to share apprehensions and doubts with other women, but it can often lead to increased and unjustified anxiety. Medical information published on websites cannot be considered a substitute for informed medical advice, and patients should not take any action before consulting with a health care professional.

Human Teratogens and Evidence-based Teratogen Risk Counseling: The Motherisk Approach

There are only a limited number of drugs proven to be human teratogens including thalidomide, isotretinoin, coumarin derivates, valproic acid, and folate antagonists. In some cases, the combination of 2 drugs may increase the teratogenic risk. The risk of birth defects may also vary with the time at which the drug is administered during pregnancy and the dose. There are some examples of drugs in which the dose has proven to be a major determinant of their teratogenicity in humans. There is more safety information for older than for newer drugs. Proactive teratogen risk counseling should include a critical appraisal of all available data including the consequences of the untreated maternal condition.

Drug utilization and teratogenicity risk categories during pregnancy

A limited number of studies have investigated in detail the use of drugs during pregnancy. Researchers in the present study investigated the details of drug utilization in pregnant women during the month before pregnancy, at the time that they became aware of the pregnancy, and during the first trimester. Face-to-face interviews were conducted with 359 pregnant women who were admitted to the fetal medicine unit at a university hospital for diagnosis and follow-up. A questionnaire was used to document sociodemographic characteristics and details of drug use. Drugs were categorized according to the US Food and Drug Administration fetal risk classification. Mean maternal age was 29.9+/-5.1 y, and mean gestational age was 19.6+/-9.5 wk. Many of the pregnant women studied (46.6%) were university graduates, and most (61.9%) had a relatively high annual income. Mean gestational age when participants first learned of their pregnancy was 39.8+/-16.4 d. One hundred seventeen participants (32.6%) used drugs during the month before conception, 54 (15%) at the time when they learned of their pregnancy, 180 (50.1%) at the time of the interview, and 289 (80.5%) during the first trimester. The percentages of drugs in categories D and X used by these subjects were 14%, 13.5%, 2.9%, and 5.9%, respectively. Most of the drugs were hormones. The total rate of drug utilization was not high before and during the first trimester of pregnancy. A considerable number of women were using drugs from the D and X categories; however, these numbers decreased significantly when women learned of their pregnancies. Intake of folic acid, vitamins, and iron was very low during the preconception period and was not high enough during the first trimester; this suggests that particular attention should be paid to the use of beneficial "safe" drugs during the preconception and early pregnancy periods.

Safety of medications prescribed before and during early pregnancy in a cohort of 81 975 mothers from the UK General Practice Research Database

PURPOSE

To demonstrate a linkage methodology for mother and baby automated medical records, and describe frequency, type, and pregnancy risk level of medications prescribed during pregnancy in a GPRD cohort, 1991-1999.

METHODS

We linked records using a two-stage algorithm and selected pairs with > or = 7 months prenatal records and > or = 2 records in baby's first year of life. Periods of interest were: 90 days prior to a woman's earliest identified pregnancy record (Period I), and this record plus 70 days (Period II, approximate early pregnancy). Medications were classified using the British National Formulary and US Food and Drug Administration Pregnancy Risk Categories.

RESULTS

We achieved over 80% record linkage and defined a cohort of 81,975. Sixty-five per cent of mothers had > or = 1 prescription during both periods combined. Most frequent medications in Period I were anti-bacterial, contraceptive, topical steroid, and bronchodilator. In Period II, they were folic acid, anti-bacterial, antacid, and gynecological anti-infective. In Period I, 4% were FDA category A (considered safest), 34% B, and 49% C and D combined. By Period II, prescription of category A medications increased (folic acid, iron) while other categories declined. Category X medications, with potential teratogenic risk that outweighs maternal benefit, were prescribed to 5714 (7%) women in Period I, and 501 (0.6%) women in Period II (46% progesterone).

CONCLUSIONS

One in every 164 women received a category X prescription in early pregnancy. The visit when pregnancy is first medically recognized represents an opportunity to review prescribed medications in light of contraindication and/or fetal risk.

Quality and content of abstracts in papers reporting about drug exposures during pregnancy

BACKGROUND

Most clinicians read only the abstract of papers in scientific journals. Therefore, it is very important that abstracts contain as much information as possible, to summarize the data succinctly. Our objectives were to evaluate the quality of information in abstracts reporting human fetal outcomes following drug exposure during pregnancy.

METHODS

We developed quality criteria based on previous work, modifying them for use with pregnancy outcomes. Quality scores were calculated as present/absent for all of the equally weighted criteria, then expressed as percentages (present/[present + absent]). We examined a random sample of 100 abstracts obtained through searches of MEDLINE, EMBASE, and the Web of Science databases from 1990 to 2005. Average quality scores were compared across designs (cohort, case-control, meta-analysis, and mixed design) Using Kruskal-Wallis ANOVA and structured/unstructured formats using Student's t test.

RESULTS

The overall average quality was 59.2% +/- 14% (median, 61.5%; range, 15.4-83.3%). Quality was not significantly different across designs (P = .16) or between structured and unstructured abstracts (P = .44). Quality scores increased over time (Rho = 0.23, P = .02). Most frequently absent were baseline risk (94%), drug dose (91%), nonsignificant P values (72%), confounders (69%), significant P values (57%), and risk difference (48%).

CONCLUSIONS

Abstracts provide insufficient information, particularly baseline risk values, for readers to make evidence-based decisions regarding drug use during pregnancy. Efforts need to be made to improve the quality of abstracts and include critical information such as baseline risk.