Toxicology

Teratogenicity

TRTeratojenite
Also known as:Teratogenic effect · Teratogenic potential

The capacity of a drug or other agent to cause structural malformations or functional abnormalities in the embryo or fetus when exposure occurs during pregnancy.

In depth

Effects depend on the agent, the level of exposure, maternal and fetal genotype and, above all, timing. Exposure in the first 2 weeks after conception tends to have an all-or-none effect; organogenesis (about weeks 3–8 after conception) is the period of greatest susceptibility to major malformations; later exposure affects growth and function, e.g. fetal renal failure with ACE inhibitors or ductus arteriosus constriction with NSAIDs. Mechanisms include folate antagonism, disrupted retinoid signaling, neural crest injury and vascular disruption.

Established teratogens include isotretinoin, valproate, thalidomide, mycophenolate, methotrexate and warfarin. Pregnancy risk is described in section 4.6 of the SmPC (KÜB in Turkey), and pregnancy prevention programs apply to valproate and isotretinoin.

Clinical pearl

Many exposures occur before pregnancy is recognized: women of childbearing potential taking known teratogens need effective contraception and pre-conception review, and an inadvertent exposure calls for individual risk assessment by timing and agent.

Example drugs

Isotretinoin Valproic acid Thalidomide Mycophenolate mofetil Methotrexate Warfarin
TRIn Turkish

Teratojenite

Bir ilacın ya da başka bir etkenin, gebelik sırasında maruziyet olduğunda embriyo veya fetüste yapısal malformasyon ya da işlevsel bozukluk oluşturabilme özelliğidir.

Etki; etkene, maruziyet düzeyine, anne ve fetüsün genotipine ve özellikle zamanlamaya bağlıdır. Döllenmeyi izleyen ilk 2 haftadaki maruziyet genellikle “ya hep ya hiç” biçiminde etki gösterir; organogenez dönemi (döllenmeden sonra yaklaşık 3.–8. haftalar) majör malformasyonlara duyarlılığın en yüksek olduğu dönemdir; daha geç maruziyet büyümeyi ve işlevi etkiler (ör. ACE inhibitörleriyle fetal böbrek yetmezliği, NSAİİ’lerle duktus arteriyozusun daralması). Mekanizmalar arasında folat antagonizması, retinoid sinyal yolunun bozulması, nöral krista hasarı ve vasküler bozulma yer alır.

Kanıtlanmış teratojenler arasında izotretinoin, valproat, talidomid, mikofenolat, metotreksat ve varfarin bulunur. Gebelikteki risk KÜB’ün 4.6 bölümünde (Gebelik ve laktasyon) belirtilir; valproat ve izotretinoin için gebelik önleme programları uygulanır.

Pek çok maruziyet gebelik fark edilmeden gerçekleşir: bilinen teratojen kullanan doğurganlık çağındaki kadınlarda etkili kontrasepsiyon ve gebelik öncesi tedavi değerlendirmesi gerekir; istenmeden olan maruziyette risk, zamanlama ve etkene göre bireysel değerlendirilmelidir.

Diğer adları:Teratojenik etki · Teratojenisite
Updated 24.09.2026 1 views Educational reference — verify against current sources before clinical use.

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