The
thalidomide tragedy of the late 1950s clearly proved the need for caution, and questionable
drug use should always be avoided. The teratogenic potential of a
drug is related to dosage and time of administration. During blastogenesis,
fetal death may occur; during embryogenesis,
deformity may develop; and during the last trimester, functional anomalies or "covert
embryopathy" may be seen. Finally, the benefit to risk ratio of every
drug must be carefully weighed, and only those with proved safety to the feto-maternal unit should be prescribed.
Aspirin may be administered to the pregnant woman as an
anti-inflammatory agent but in the lowest therapeutic dosage. In the later stages of pregnancy, however,
aspirin should be avoided since it may prolong labor, lead to greater blood loss during delivery, and increase the incidence of
stillbirths. The
pyrazolones, although not associated with teratogenic side effects, may lead to sometimes fatal
agranulocytosis and, accordingly, are not recommended in pregnancy.
Acetaminophen is the
analgesic and
antipyretic of choice during all phases of pregnancy.