Reproductive medicine is as the Roman god Janus, the god of gates, of beginnings and endings, and hence represented with a double-faced head looking in opposite direction. He was worshipped at the beginning of important events in a person's life. When infertility is involved, the system can circumvent the problem or can even be stimulated in the right direction. When contraception is requested, the same system ( & ) can be inhibited. Clinical questions such as whether treatments in infertility and contraception are doing more good than harm are addressed. As part of the Cochrane Collaboration, our international group develops systematic reviews on fertility regulation. Other issues we are addressing: * the peri- and postnatal outcome of assisted reproduction methods; * the mechanism behind the poor outcome by studying, for example, the maternal angiogenesis process (as part of the maternal embryo discussion) and recurrent abortion; * the relationship between the haemostatic system and hormones (as in hormonal contraception) which can lead to thrombosis.
The title of his inaugural lecture was 'Werking, bijwerking en de balans'.