Disruption of buds
Phocomelia occurs when the limb buds(arms & legs) are interrupted in fetal development & one or more do not form.In some countries, thalidomide
was used for nausea
If taken between week 4 and 7 (when the limb buds come out) up to 30% of exposed infants were affected. This experience led to the largest us study of meds in pregnancy with > 50, 000 studied & changes in the view of meds.