Beta hCG after an abortion

hCG or human chorionic gonadotropin is a hormone that is produced by the placenta during pregnancy to promote fetal growth. In case the hCG levels decrease during pregnancy, this could also indicate a miscarriage.

For the avoidance of doubt let’s say right away that it is not the quantity of beta hCG that can cause a miscarriage. The measurement of beta hCG is only used as a parameter to find out the progress of the pregnancy.

The hCG levels during a healthy pregnancy

The hCG hormone is produced by placental cells to provide nourishment to the fertilized egg after it attaches to the uterine wall. Measuring the level of hCG in blood or urine is the basis of how clinical and home pregnancy tests work .

Levels of hCG are measured in international milliunits per milliliter (mIU/mL).

Levels of hCG above 5 mIU/mL (million international units per milliliter) usually indicate pregnancy.

In most healthy pregnancies, the hCG count doubles every 48 to 72 hours. The hormone reaches its maximum during 8 to 11 weeks of pregnancy, after which it progressively decreases and reaches a stable phase.

The hCG levels after a miscarriage

As we saw above, in the beginning of a healthy pregnancy the hCG level should stay above a certain value and double every 48-72 hours.

A low quantitative dosage of beta hCG for gestational age or the absence of rising levels could be one of the signs of a miscarriage . However, the diagnosis of a spontaneous abortion requires a more complete clinical analysis and a transvaginal ultrasound which highlights the absence of embryonic cardiac activity when the fetal sacrum length is > 7 mm or, even, disappearance of previously detected embryonic cardiac activity; and the absence of a fetal pole when the mean sac diameter is greater than 2;

If the miscarriage occurred early in the pregnancy, the hCG test after the miscarriage will show a lower count and can easily go back to zero. If the count was high during the miscarriage or if the miscarriage occurred during the last course of the pregnancy, it may take many days or even weeks to get back to zero.

When hCG rises after an abortion

A miscarriage is not always followed by a drop in beta hCG.

The hCG dosage may still be high in the following cases:

  1. Ectopic pregnancy. An ectopic pregnancy occurs when one fetus attaches itself to the uterine wall and another to the outside of the uterus, mostly in the fallopian tube ( ectopic pregnancy ) or sometimes in the ovary or cervix.
  2. Persistent trophoblastic disease. This occurs when some molar tissue is still left in the woman’s uterus even after a molar pregnancy has been surgically removed
  3. Damaged egg. A spoiled egg is a fertilized egg that implants itself in the uterine wall but does not develop.

Ovulation after a miscarriage

The hCG hormone suppresses the normal ovulation process. After the miscarriage, the ovulation cycle will only begin when the hCG hormone levels fall below 5 mIU/mL.

Usually, after miscarriage the beta hCG dosage reaches undetectable levels in 4-6 weeks, and then the cycle begins. When hCG concentrations do not return to undetectable levels, they may indicate the presence of hCG-producing tissue that needs to be removed.

Katherine Johnson, M.D., is a board-certified obstetrician-gynecologist with clinical expertise in general obstetrics and gynecology, family planning, women’s health, and gynecology.

She is affiliated with the Obstetrics and Gynecology division at an undisclosed healthcare institution and the online platform,

Leave a Reply

Your email address will not be published. Required fields are marked *