HCG Levels Following Miscarriage

  My wife had her last menstrual period on 8/25. On 9/15 she began heavy bleeding, and was tested in the ER. Urine tests were negative. Blood tests showed HCG levels of 6; she was advised that she was experiencing a miscarriage in the very early stages of pregnancy (10 days or less). She continued to bleed and discharge until 9/21. It's now 10/8, and she suspects she's pregnant; Urine test (HPT) is testing positive now. Do HCG levels continue to increase following miscarriage? Could she have negative pregnancy test results in the ER on 9/15, miscarry, and then have positive results weeks later on 10/8, because the HCG level rose high enough to now show on the Urine test? Or, is this a new pregnancy? Thanks.
Dear JJ:
Some women will experience bleeding around the time of the expected menstrual flow and a pregnancy continues without problem.
hCG levels fall after a complete miscarriage and become undetectable. The menstrual cycle resets and there may be an ovulation that anticipates the next menstrual flow. If a woman conceives from this first ovulation after a miscarriage, she can be pregnant without having an intervening menstrual period.
Women who have an incomplete miscarriage will have irregular bleeding and the pattern of hCG in blood is not predictable. Ectopic pregnancy is another scenario wherein there is bleeding and variable hCG levels.
Serial quantitated hCG levels combined with ultrasound imaging of the pelvis will sort out what is happing.
Following a miscarriage, most physicians recommend barrier contraception (condom, foam, diaphragm) until the next real menstrual flow occurs.
Keywords: hCG, miscarriage
This information is provided for education purposes and is not a medical consultation. If you have specific questions, please contact your physician.