Branching out: Specialties and subspecialties in medical genetics
Peter S. Harper in The Evolution of Medical Genetics, 2019
Most of these early dysmorphologists were strongly clinical in their approach, but they were keenly aware that a detailed knowledge of embryology and teratology was essential for the understanding of congenital malformations and that the disorders resulting from environmental factors were intimately related to those caused by genetic defects. They also recognised the value of studying malformations in other species, which could provide homologues for human malformations and were more amenable to experimental approaches. In this they were greatly helped by experimental studies, largely on mice, notably the early work of Hans Grüneberg, based at University College London, part of the constellation of talent in genetics there represented by Penrose, RA Fisher, JBS Haldane and others (see Chapters 1 and 2). Grüneberg, like his American counterpart Josef Warkany, was a refugee from Nazi-controlled Europe, and his book Animal Genetics in Medicine (Grüneberg 1947) gave a firm foundation on which later more clinical workers could build. A number of these early workers, especially in America, were primarily pathologists and regarded themselves as ‘teratologists’, focusing more on the developmental basis of malformations than on their diagnosis during life.
Preconceptual Health
Michelle Tollefson, Nancy Eriksen, Neha Pathak in Improving Women's Health Across the Lifespan, 2021
The six basic principles of teratology were outlined in the 1970s and provide a framework for evaluating the teratogenic propensity of an exposure. Based on these principles, a teratogen is expected to demonstrate variable effects based on genetic susceptibility, gestational timing, and the degree of tissue exposure. It should manifest a spectrum of outcomes, with a dose–response effect ranging from no observable effect to lethality. It is also expected to act via specific mechanisms, thus leading to a characteristic pattern of findings.52,53 When post-market drug surveillance demonstrates a data signal consistent with these principles, a more directed study is warranted.
Birth defects
Frank J. Dye in Human Life Before Birth, 2019
Teratology is the study of abnormal development. The agents that cause abnormal development (teratogens) may be chemical, physical, or biological. Perhaps the best-known chemical teratogen is thalidomide, which, when administered to pregnant women at a particular time, resulted in phocomelia (severe limb abnormalities) in their offspring (Figure 19.10). The use of the antibiotic tetracycline can cause stained teeth. Although the effects are much less dramatic than thalidomide, tetracycline should be avoided by expectant mothers.
Review of Ilana Löwy, Imperfect Pregnancies: A History of Birth Defects & Prenatal Diagnosis
Published in The American Journal of Bioethics, 2019
Kirsten A. Riggan
Chapter 3 examines the identification of and concerns over environmental teratogens in the 1960s. This includes the rubella and thalidomide crises, which generated much concern in women who feared they would give birth to a malformed child, and ultimately led to greater sympathy and public acceptance of abortion. Löwy places her discussion in the broader context of the efforts by scientists interested in fetal malformation to rename the field of teratology as dysmorphology, with the hope it would destigmatize birth defects previously labeled as “monstrosities.” At this time, visibility of birth defects was increasing through national and international registries, created to identify unusual anomalies potentially caused by environmental teratogens. As a consequence, eliminating birth defects became a public health concern. This chapter also discusses the increase in obstetric ultrasound to identify structural fetal malformations in the 1970s and 1980s as ultrasound resolution increased and it became a routine component of prenatal care.
Comparison of the groups treated with mirtazapine and selective serotonine reuptake inhibitors with respect to birth outcomes and severity of psychiatric disorder
Published in Psychiatry and Clinical Psychopharmacology, 2019
Buket Belkız Güngör, Nalan Öztürk, Ayça Öngel Atar, Nazan Aydın
The widespread usage of SSRIs provides knowledge related to the effects of SSRIs on the developing fetus during pregnancy and on neonatal outcomes after delivery. However, there is limited information related to mirtazapine usage and its effects on pregnancy outcomes. The off label use of mirtazapine for morning sickness has been increasing gradually in pregnant women [11]. More information is needed about its use in pregnant women with psychiatric symptoms. The literature offers insufficient information about the comparison of SSRI and mirtazapine usage in pregnancy, including the clinical course of mental disorders and birth outcomes. Although two studies compared a mirtazapine and an SSRI group according to the rates of congenital malformations and birth outcomes, the data of this study was obtained from a Teratology Information Service and contained no information related with the psychiatric follow up and the characteristics of the psychiatric patient group [12,13].
Pharmaceutical strategies for smoking cessation during pregnancy
Published in Expert Opinion on Pharmacotherapy, 2018
Jose Barboza
Richardson compared major congenital malformations (MCM) of infants exposed to (1) varenicline (2) NRT or bupropion, and (3) non-teratogenic medications in a multi-center, prospective, observational comparative cohort trial using surveillance data from the European Network of Teratology Information [57]. Two MCM were identified in 89 first-trimester varenicline exposed infants, 2.25%, which was within the author’s expected 2–4% incident background rate. A non-significant increase in MCM rates was seen with varenicline compared to NRT or bupropion, 1.3%, aOR: 0.874(CI: 0.0620–12.3) and to infants not exposed to teratogenic medications 0.7%, aOR: 2.02(CI: 0.166–17.9). Additionally, there was a significant higher rate of elective termination of pregnancy with the varenicline exposed group, 11.2%, compared to the non-teratogenic group, 2.25%, HR: 4.57(CI: 1.66–12.6). Mothers responded that concerns over varenicline exposure was a reason for elective termination. The small sample size caused imprecise risk estimates and wide confidence intervals. Duration of therapy was also a limitation, 72.1%, had stopped varenicline before the sixth gestational week, shorter than the recommended 12 weeks. Self-reported smoking rates during pregnancy were 41.2% for varenicline, 63.2% for NRT or bupropion, and 9.4% for the non-teratogenic group. There were sources of potential bias with this trial, including recall bias and confounding with smoking during pregnancy. Overall, there was no significantly increased risk of MCM, yet it is difficult to draw conclusions regarding the safety of varenicline in pregnancy from this evidence.
Related Knowledge Centers
- Birth Defect
- Developmental Toxicity
- Dysmorphic Feature
- Fetus
- Toxicity
- Embryo
- Development of The Human Body
- Medical Genetics
- Insult
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