Human chorionic gonadotropin and hyperemesis gravidarum

There are a number of reasons for considering the association of human chor ionic gonadotropin (hCG) with hyperemesis gravidarum. The temporal relation ship between peak hCG levels and the most common time of nausea and vomitin g has long been noted. More recently, the relationship of hCG to transient hyperthyroidism of hyperemesis gravidarum (THHG) has been described. Severa l experiments of nature have suggested that hCG plays a role. Let us consid er these interrelated lines of evidence, beginning with the latter.