A changing pattern in the association of oral contraceptives and the different groups of congenital limb deficiencies.

A case-control study on different groups of isolated congenital limb deficiency was performed in a ten-year population-based and revised Hungarian data set. A higher rate of one contraceptive pill type with relatively high dose (ethynodiol diacetate 1.0 mg + ethinyloestradiol 0.05 mg) used in the periconceptional period was found in the mothers of cases with terminal transverse defect (adjusted relative odds 1.9 with 95% confidence interval of 1.1-3.4). This risk is minimised by the use of recent low-dose pills.