A positive pregnancy test is a joyous occasion, but is the pregnancy normal? How do we know that things are ok? This is a common question patients have once the news has sunk in. The best way to follow an early pregnancy in via blood levels of the pregnancy hormone HCG. A gestational sac is not visible until about 5 weeks gestation or when the HCG is over 1500 miu/ml. Typically the HCG rises by 66% every 48 hrs during early pregnancy. This is why here at Texas Fertility Center we repeat the HCG 48hrs after the initial positive test. If the rise is appropriate then that is a good sign and we can wait for a week before rechecking and follow the trend. The rise in HCG may be inadequate in cases of abnormal pregnancies such as a biochemical pregnancy or an ectopic (tubal) pregnancy. These abnormal pregnancies need closer monitoring initially to delineate which of the two we are dealing with. Often in a biochemical pregnancy the HCG will rise initially and then starting dropping on its own. No further treatment is required in these cases and the HCG is simply followed down to <5 Miu/ml. In the case of an ectopic pregnancy, the HCG continues to have a slow rise and sonogram shows no gestational sac in the uterus. It is important to recognize and treat an ectopic pregnancy early to prevent tubal rupture which constitutes a medical emergency. If diagnosed early, most ectopics can be treated with a medication called Methotrexate. In more advanced cases or in the event of tubal rupture, surgery becomes necessary. Early diagnosis of an ectopic if extremely important. So, if patients are wondering why their HCG levels are being checked frequently, it is to be sure the pregnancy is following a normal trend and recognize abnormal pregnancies early.