From the Guidelines
Chemical abortion, also known as spontaneous abortion or miscarriage, can be caused by various factors including chromosomal abnormalities in the embryo, maternal health conditions, hormonal imbalances, uterine abnormalities, or immunological factors, and a low human chorionic gonadotropin (hCG) level that is still doubling within a week may indicate a viable pregnancy, but at an earlier stage than expected, or it could signal a potential problem with the pregnancy, such as an ectopic pregnancy or impending miscarriage, as suggested by studies 1.
Causes of Chemical Abortion
The causes of chemical abortion can be multifactorial, including:
- Chromosomal abnormalities in the embryo
- Maternal health conditions
- Hormonal imbalances
- Uterine abnormalities
- Immunological factors A low hCG level that is still doubling within a week may indicate a viable pregnancy, but at an earlier stage than expected, or it could signal a potential problem with the pregnancy, such as an ectopic pregnancy or impending miscarriage, as suggested by studies 1.
Importance of Proper Evaluation
It is essential to consult with a healthcare provider immediately for proper evaluation, which may include additional hCG measurements, ultrasound examination, and possibly progesterone level testing, as recommended by studies 1. The normal doubling time for hCG is approximately every 48-72 hours in early pregnancy, and if the hCG levels are rising but not doubling at the expected rate, this could indicate a potential issue, such as an ectopic pregnancy or impending miscarriage, as suggested by studies 1.
Monitoring and Testing
The doctor may recommend close monitoring with serial hCG measurements and early ultrasound to determine the viability of the pregnancy, as recommended by studies 1. It's essential to understand that about 10-20% of known pregnancies end in miscarriage, often due to factors beyond control, and medical intervention is necessary to determine the specific cause in each case, as suggested by studies 1.
From the Research
Causes of Chemical Abortion
- A chemical abortion, also known as a medical abortion, can occur due to various factors, including the use of medications such as mifepristone and misoprostol 2, 3, 4, 5.
- In cases where the human chorionic gonadotropin (hCG) levels are low, it may indicate a potential issue with the pregnancy, such as a miscarriage or an ectopic pregnancy 6, 3, 5.
- A low count of hCG that is doubling in one week may still be a concern, as a single low value for hCG at admission can be followed by abortion, regardless of gestational age 6.
hCG Levels and Abortion
- Studies have shown that measuring serum hCG before treatment and at follow-up is more effective than ultrasound to confirm a successful medically induced abortion in early pregnancy 2, 3, 4.
- A decline in hCG level of ≥80% within seven days can effectively confirm complete abortion and rule out ectopic and ongoing pregnancies in early medication abortion 3.
- A serum hCG level ≤253 IU/l is sufficient to affirm the efficacy of medical abortion, but ultrasound should be reserved for women with high hCG levels 4.
Detection of Ectopic Pregnancy
- Very early medical abortion (VEMA) protocols can increase early diagnosis and treatment of asymptomatic ectopic pregnancies (EP) 5.
- Serum β-hCG levels can be correlated to ultrasound findings, and a decline in β-hCG after successful VEMA can help identify complete abortion 5.
- However, the rate of ectopic pregnancies is very low, and VEMA may be of particular clinical benefit for women, offering a possibility to start an abortion without delay and detect EP at an early gestational age 5.