Patient: I had an IVF cycle. After one week of egg transfer i was given a 500 iu hcg injection and one week after that is the beta hcg test. i just wanted to know will the 500 iu be out of my system by then. In how much time it is ouf of the system…will i get false positive. 4 days after the injection am getting positive in hpt. am i pregnant or not
Doctor: Hello,Thanks for the query to ATD for an opinion,It is normal protocol to give an hcg shot of at least 5000 IU aft er the egg transfer , but i am surprised at the 500 IU dosing schedule being used. Nevertheless as far as your query is concerned, the half life of hcg is 28 hrs which means that your hCG levels should decrease by half every 28 hours. There are three injection amounts; 10 000 IU, 5000 IU, and 2500 IU. If you have had the 10 000 IU shot, you’ll need to wait for at least 14 days after the shot to take the pregnancy test; the 5000 IU test will have you waiting 10 days, and a week’s wait for the 2500 IU shot. So now as you have been give 500 Iu it should wear off by 4 days. So, a week’s wait would be ideal for doing a blood based serum beta hcg test rather than the urine pregnancy test which would be definitive. Also important would be doubling of hcg levels in 48 hrs ( serial beta hcg monitoring) if the embryo has been taken up and the pregnancy is progressing which is a healthy sign.So please wait for the complete 7 days to avoid any false positive as the test after 4 days may be a false positive.I hope i have answered your query in detail,Wishing you successful conception.Regards
Comments / Follow Ups
Patient: thank you so much for the reply.. I did a beta after 4 days of the hcg 500 iu and it came as 235 ..may i please know how to interpret that…I understand and will do on the scheduled 7 days also but as of now too curious to know…can i be hopeful?
Doctor: It is difficult to make a comment before the complete hcg from the injection is termed to have been metabolised in order confirm that the fresh hcg is from the pregnancy. However serial beta hcg is more reliable than single hcg value. So wait for 3 more days and then you may get it done.Please be patient.