<prompt> Monitoring of β-HCG Useful in Management ofa H.moleb Choriocarcinomac Ectopic Pregnancyd Endodermal Sinus Tumorababcacdbcd  <response>: β-hCG levels are helpful in monitoring:a. H. mole: A method of detecting the persistent mole and development of choriocarcinoma is by estimating hCG is the serumurine.Shaw 14e, p 231b. Chorio carcinoma:β-hCG is a specific marker for choriocarcinoma.The levels of b-hCG are monitored following chemotherapy and complete regression of tumor is indicated when three consecutive weekly radioimmunoassays of hCG in serum are negative.Shaw 14e, p 235c. Ectopic pregrancy:In case of unruptured ectopic pregnancy which is managed medically with methotrexate or by conservative surgerymonitoring is done by estimating β-hCG levels.Following conservative surgery or medical treatment ,estimation of β-hCG should be done weekly till the value becomes 5.0 mIUmlDutta Obs 6e, p 191d. Endodermal sinus tumor-These tumors are yolk sac tumors and their markers are Alpha fetoprotein and antityrypsinso their levels and not betahCG. So hCG levels are not used for monitoring.Shaw 14e, p 380 