Читать книгу Assisted Reproduction Techniques - Группа авторов - Страница 65

Drugs may be harmful in pregnancy, with women and clinicians alike fearing their impact upon fetal development and growth. Congenital developmental disorders have been the subject of tales dating all the way back to prehistoric times and were initially attributed to supernatural causes [1]. In the 19th century, the concept of teratology as the study of developmental malformations in an embryo or fetus was first introduced by I. G. de Saint‐Hillaire [2]. Later on, in the 1930s, Hale described a set of experiments where pigs deprived of vitamin A exhibited a lack of eyeballs, pioneering experimental teratology as a modern science aimed at identifying possible causes of congenital defects [3]. The widely known thalidomide episode in the 1960s, where pregnant women exposed to this antiemetic gave birth to babies with limb deformities, remains a prime example of drug toxicity and its potential catastrophic effects in the offspring of healthy mothers [4].

Today, caution is advised to clinicians prescribing drugs for women who are pregnant or trying to conceive. This stems, to an extent, from a paucity of good‐quality data on safety of medications in pregnant women, who are often excluded from preapproval drug studies [5]. Yet pregnant women, and those trying to conceive, are frequently prescribed drugs with teratogenic potential. This may be due to preexisting medical conditions where the therapeutic benefits of a certain drug are thought to outweigh the teratogenic risk attributed to the medication [6–13]. For example, in the UK, 1 in every 164 women received a United States Food and Drug Administration (FDA) Pregnancy Risk category X prescription in early pregnancy between 1991 and 1999 [6]. Furthermore, over‐the‐counter medications are also used by a majority of women in early pregnancy [14,15].

Women planning to get pregnant, and particularly those undergoing assisted reproductive technology (ART) treatment, often present to their clinicians asking about drug safety in the preconception period and early pregnancy.