Human teratogens update 2011: can we ensure safety during pregnancy?

Detection of major congenital malformations depends on length of follow-up in Swedish National Health Register Data: Implications for pharmacoepidemiological research on medication safety in pregnancy

BACKGROUND

In observational medication pregnancy safety studies, children are often followed from birth to 1 year of age. However, some major congenital malformations (MCM) may take longer to diagnose.

OBJECTIVES

We aimed to investigate the proportion of children with detected MCMs at different lengths of follow-up and compare them to the proportion detected at 1 year after birth.

METHODS

This population-based register study included all singleton children liveborn in Sweden from 2006 to 2016. MCM were identified by ICD-10 codes in the Medical Birth Register and National Patient Register, aligned to the EUROCAT classification system. Cumulative proportion of children with detected MCM at birth, 90 days, 1, 2, and 3 years was calculated and compared between children born preterm and at term.

RESULTS

In 1,138,113 liveborn children, the cumulative proportion of children with a detected MCM increased from 1.9% at birth to 3.1%, 3.9%, 4.4% and 4.7% at 90 days, 1, 2, and 3 years after birth, respectively, and varied by MCM subgroup. MCMs of the eye, ear-face-neck, nervous system and genitals were detected with the longest delay, with 31%-59% more detected at 3- versus 1-year follow-up. Compared to children born at term, the proportion of children with any MCM was 2.5 times higher amongst preterm children, with a higher proportion detected over the first 90 days for most MCM subgroups.

CONCLUSIONS

The proportion of children with a detected MCM varied by MCM subgroup and follow-up time. In pharmacoepidemiology studies of medication safety in pregnancy using Swedish national data, the length of child follow-up should be chosen in accordance with the expected age at detection if a specific subgroup of MCM is under investigation, for example, eye and genital MCM require longer follow-up for detection than abdominal wall and digestive system MCM. However, in most circumstances, 1 year of follow-up is sufficient.

Drug-induced fetal and offspring disorders, beyond birth defects

Studies on drug utilization in western countries disclosed that about nine over ten women use at least one or more drugs during pregnancy. Determining whether a drug is safe or not in pregnant women is a challenge of all times. As a developing organism, the fetus is particularly vulnerable to effects of drugs used by the mother. Historically, research has predominantly focused on birth defects, which represent the most studied adverse pregnancy outcomes. However, drugs can also alter the ongoing process of pregnancy and impede the general growth of the fetus. Finally, adverse drug reactions can theoretically damage all developing systems, organs or tissues, such as the central nervous system or the immune system. This extensive review focuses on different aspects of drug-induced damages affecting the fetus or the newborn/infant, beyond birth defects, which are not addressed here.

Machine Learning to Predict Teratogenicity: Theory and Practice

Machine learning (ML) is a subfield of artificial intelligence (AI) that consists of developing algorithms that can automatically learn patterns and relationships from data, without being explicitly programmed. It continues to advance with the development of more sophisticated algorithms, increased computational power, and larger datasets, leading to significant advancements in AI technology. With the significant progress made in ML, the need to apply these systems in the area of teratogenicity is growing. It is sought as robust boosting methods to overcome many limitations and restrictions facing the experimental studies. By performing tasks such as classification, regression, clustering, anomaly detection, and decision systems, ML can be used to assess whether an agent is teratogen or not or to determine its teratogenic potential. It may also be used for the purpose of deciding on the use of medicinal products. In this chapter, we describe how ML can be used to investigate teratogenicity.

Maternal long-term inhalation exposure to perchloroethylene and prenatal teratogenicity: morphometric, hormonal, and histological study

Some commonly used chemicals have teratogenic effects. Perchloroethylene (PCE) is a liquid that is widely used in various industries and drying clothes. In this study, the teratogenic effects of PCE in rat embryos were investigated. In this experimental study, 32 adult Wistar female rats in the weight range of 230-250 g were used. Female rats were randomly divided into 4 groups (n = 8). Control group (without PCE inhalation), experimental group G(I) (exposed to PCE 18 days prior to mating), experimental group G(II) (exposed to PCE 18 days after mating) and experimental group G(III) (exposed to PCE 18 days before and 18 days after mating). Pregnant rats were anesthetized on the 18th day of gestation and then serum and embryos were removed for the required studies. Embryos were examined for number, weight, sex, morphometric parameters of organs, and tissue samples were prepared for histological studies. Serum isolated from dams were evaluated for sexual and gonadal hormones. The results of this study showed that PCE has teratogenic effects on rat embryos. Infertility and reduced birth rate were other effects of PCE in rats. PCE has teratogenic effects and impairs the reproductive system of rats.

Prevalence, determinants and attitude towards herbal medicine use in the first trimester of pregnancy in Cameroon: A survey in 20 hospitals

To examine the prevalence, determinants and attitude towards herbal medication (HM) use in the first trimester of pregnancy in Cameroon women. Between March to August 2015, we surveyed 795 pregnant women attending 20 randomly selected urban or rural hospitals in South West Cameroon on first trimester orthodox medication (OM) and HM use. Data was obtained by interviews using structured questionnaires. First trimester HM use was reported by 293 (36∙9%) women, 76% of whom used it in combination with OM. The most frequent indication for taking HM was prevention/treatment of anaemia (26∙3%). The HM were usually self-prescribed (33∙3%) or by family (56∙2%), and obtained from the woman's own garden (69∙3%). Twenty percent of women believed that HM was always safe to take in pregnancy, compared to 69.3% for OM. Intake of HM was significantly influenced by women's opinion on OM or HM safety-the odds of taking HM was 3 time higher among women who were unsure about the safety of OM (AOR: 3∙0, 95%CI = 1∙5-6∙1), while women who thought HM were never safe or who were unsure about its safety, were 91% or 84% respectively less likely to take HM compared to women who believed HM were always safe. We identified a high prevalence of HM use and concomitant use with OM, strongly influenced by women's perception of HM and OM safety. These findings indicate the need for WHO to specifically address safety in pregnancy in its policy to integrate traditional medicine use into existing healthcare systems in Africa.

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.

Identification and quantification of gold engineered nanomaterials and impaired fluid transfer across the rat placenta via ex vivo perfusion

Development and implementation of products incorporating nanoparticles are occurring at a rapid pace. These particles are widely utilized in domestic, occupational, and biomedical applications. Currently, it is unclear if pregnant women will be able to take advantage of the potential biomedical nanoproducts out of concerns associated with placental transfer and fetal interactions. We recently developed an ex vivo rat placental perfusion technique to allow for the evaluation of xenobiotic transfer and placental physiological perturbations. In this study, a segment of the uterine horn and associated placenta was isolated from pregnant (gestational day 20) Sprague-Dawley rats and placed into a modified pressure myography vessel chamber. The proximal and distal ends of the maternal uterine artery and the vessels of the umbilical cord were cannulated, secured, and perfused with physiological salt solution (PSS). The proximal uterine artery and umbilical artery were pressurized at 80 mmHg and 50 mmHg, respectively, to allow countercurrent flow through the placenta. After equilibration, a single 900 μL bolus dose of 20 nm gold engineered nanoparticles (Au-ENM) was introduced into the proximal maternal artery. Distal uterine and umbilical vein effluents were collected every 10 min for 180 min to measure placental fluid dynamics. The quantification of Au-ENM transfer was conducted via inductively coupled plasma mass spectrometry (ICP-MS). Overall, we were able to measure Au-ENM within uterine and umbilical effluent with 20 min of material infusion. This novel methodology may be widely incorporated into studies of pharmacology, toxicology, and placental physiology.

Hospital based surveillance of congenital rubella syndrome cases in the pre-vaccine era in Amhara Regional State, Ethiopia: A base line information for the country

Background

Rubella virus infection in early pregnancy lead to serious multi-organ birth defects known as congenital rubella syndrome (CRS). The incidence of CRS varies in different populations and the highest burden is found in developing countries in which rubella vaccination is not included in their national immunization programs. In Ethiopia, there is scarcity of data about congenital rubella syndrome. Therefore, the aim of this study was to determine the burden of CRS-related birth defects and its incidence in the pre-vaccine era in Amhara Regional State, Ethiopia.

Materials and methods

A cross sectional study was conducted in Dessie, Felege-Hiwot and University of Gondar Referral Hospitals, from December 2015 to August 2017. After getting informed assent from each parent/guardian, blood was collected from infants < 1 year of age for laboratory determination of anti-rubella virus antibodies. Their socio-demographic data and clinical information compatible with congenital rubella syndrome were collected using WHO guideline.

Results

During the study period, a total of 50 infants suspected for congenital rubella syndrome were included in the study. All infants suspected for CRS were tested against rubella specific IgM and IgG [for infants ≥ 6 months of age] antibodies using ELISA method. Of these, 9/50 (18%) and 4/14 (28.6%) of them were laboratory confirmed and potential CRS cases, respectively. In the present study, the most common laboratory confirmed defect was ocular manifestations 6 (66.7%) followed by heart related problems 5 (55.6%). In the present study, most of the laboratory confirmed cases (66.7%) were reported among 1–5 months of age infants. In addition, 5 (55.6%) of the infants with laboratory confirmed CRS cases were male and 6 (66.7%) of them were from urban settings. In this study, the incidence of CRS was 0.4 per 1000 live births.

Conclusion

In this study, nearly one fifth of the infants had laboratory confirmed congenital rubella syndrome and most of them had multiple rubella associated congenital defects at a time. Most of these congenital anomalies were reported among infants ≥ 1 month of age. Based on our result, the incidence of the CRS was line with the global incidence of the CRS in the pre-vaccine era. Therefore, establishing strong rubella/CRS surveillance system as well as introducing the rubella containing vaccine in the national immunization program might be important to reduce the burden of rubella and CRS in the country.

Adverse effect of valproic acid on an in vitro gastrulation model entails activation of retinoic acid signaling

Valproic acid (VPA), an antiepileptic drug, is a teratogen that causes neural tube and axial skeletal defects, although the mechanisms are not fully understood. We previously established a gastrulation model using mouse P19C5 stem cell embryoid bodies (EBs), which exhibits axial patterning and elongation morphogenesis in vitro. Here, we investigated the effects of VPA on the EB axial morphogenesis to gain insights into its teratogenic mechanisms. Axial elongation and patterning of EBs were inhibited by VPA at therapeutic concentrations. VPA elevated expression levels of various developmental regulators, including Cdx1 and Hoxa1, known transcriptional targets of retinoic acid (RA) signaling. Co-treatment of EBs with VPA and BMS493, an RA receptor antagonist, partially rescued axial elongation as well as gene expression profiles. These results suggest that VPA requires active RA signaling to interfere with EB morphogenesis.

Female gender as a susceptibility factor for drug-induced liver injury

Adverse drug reactions (ADRs) can involve all tissues and organs, but liver injuries are considered among the most serious. A number of prospective, multicenter studies have confirmed a higher risk of ADRs in general among female subjects compared to a male cohort. Although drug-induced liver injury (DILI) is infrequently encountered, the preponderance of evidence suggests that women appear to be more susceptible than men to fulminate hepatic/acute liver failure especially in response to some anti-infective drugs and to autoimmune-like hepatitis following exposure to certain other therapeutic drugs. A number of hypotheses have been proposed to explain this sex difference in susceptibility to DILI. Collectively, these hypotheses suggest three basic sex-dependent mechanisms that include differences in various aspects of drug pharmacokinetics (PK) or pharmacodynamics following the administration of certain drugs; specific hormonal effects or interactions with immunomodulating agents or signaling molecules; and differences in the adverse response of the immune system to some drugs, reactive drug metabolites, or drug-protein adducts. At the preclinical drug safety stage, there is a need for more research on hormonal effects on drug PK and for additional research on gender differences in aberrant immune responses that may lead to idiosyncratic DILI in some female patients. Because the detection of rare but serious hepatic ADRs requires the exposure of very large patient populations, pharmacovigilance networks will continue to play a key role in the postmarketing surveillance for their detection and reporting.

Effects of fetal exposure to maternal chemotherapy

Approximately 1 in 1,000-2,000 pregnancies are complicated by cancer. Today, different treatment options are considered as safe during pregnancy: chemotherapy, radiotherapy, surgery, or a combination of these. Surgery is considered safe during all trimesters of pregnancy; radiotherapy can be administered during the first and the second trimester, and chemotherapy after the first trimester of pregnancy. The placenta, acting as a barrier between the mother and the fetus, plays a key role in the safe administration of chemotherapy during pregnancy. A few studies have investigated the short- as well as the long-term health, general development, and cognitive and cardiac outcomes on children exposed to chemotherapy in utero. In general, these results were reassuring. Nevertheless, better safety data are required. This means data with longer follow-up periods and comparison with appropriate control groups. Moreover, important biasing factors should be taken into account when interpreting these results. Firstly, a great proportion of children were born prematurely due to the maternal condition. Preterm birth in general has been associated with cognitive impairment. Secondly, cancer during pregnancy is clearly a stressful situation, and maternal stress is associated with attention deficits. In sum, we state that chemotherapy can be administered safely after the first trimester of pregnancy. Moreover, iatrogenic prematurity in order to start postpartum administration of chemotherapy should be avoided. Nonetheless, decisions concerning treatment in these specific cases should always be made in a multidisciplinary setting with internationally recognized expertise in the coexistence of cancer and pregnancy.

Seroprevalence of anti-rubella and anti-measles IgG antibodies in pregnant women in Shiraz, Southern Iran: outcomes of a nationwide measles-rubella mass vaccination campaign

OBJECTIVE

Nonimmune pregnant women are at risk of developing congenital rubella syndrome and measles complications. We aimed to identify pregnant women susceptible to rubella or measles in order to determine the need for immunity screening and supplemental immunization in women of childbearing age.

METHOD

This seroprevalence survey was conducted by convenience sampling in obstetric hospitals affiliated with Shiraz University of Medical Sciences (southern Iran). Serum IgG levels were measured by ELISA.

RESULT

Mean age of the 175 pregnant women was 27.3±5.3 (range 16 to 42) years. The geometric mean concentration of anti-rubella IgG was 14.9 IU/mL (CI 95%,14.1-15.5), and that of anti-measles IgG was 13.8 IU/mL (CI 95%, 13-14.5). One hundred sixty-eight women (96%) had a protective serologic level (>11 IU/mL) of IgG against rubella, and 143 (81.7%) had a protective level against measles. Except for a significant inverse correlation that was showed by univariate analysis between anti-rubella IgG and the women's age (P = 0.01), immunity did not correlate with demographic or obstetric characteristics or medical history. There was no significant correlation between anti-rubella and anti-measles IgG levels (P = 0.25).

CONCLUSION

Nearly a decade after Iran's nationwide measles-rubella vaccination campaign for the population aged 5-25 years, most pregnant women up to 34 years of age had humoral immunity against rubella. We recommend rubella immunity screening or catch-up immunization for women older than 35 years who wish to become pregnant, and measles immunity screening and appropriate vaccination for all women of childbearing age.