From the Guidelines
Yes, a chemical pregnancy is considered a type of very early miscarriage. It occurs when a pregnancy is lost shortly after implantation, typically before the fifth week of gestation. In a chemical pregnancy, a pregnancy test may detect the pregnancy hormone hCG (human chorionic gonadotropin), but the embryo stops developing before it can be seen on an ultrasound. According to the most recent study by the Society of Radiologists in Ultrasound consensus conference recommendations 1, the term "Early Pregnancy Loss (EPL)" is a general term endorsed by OB-Gyn communities and societies to describe a pregnancy that may or will not progress, which includes chemical pregnancies.
The main characteristics of a chemical pregnancy include:
- A pregnancy test detecting hCG, but the embryo stopping development before being visible on ultrasound
- Typically occurring before the fifth week of gestation
- Often experienced as a slightly late period that may be heavier or more painful than usual
- Affecting up to 25% of all pregnancies, with many women not even realizing they were pregnant
- Usually caused by chromosomal abnormalities in the embryo that prevent proper development
As stated in the study published in the American Journal of Obstetrics and Gynecology 1, no medical treatment is usually required for a chemical pregnancy, as the body naturally expels the tissue. While emotionally difficult, having a chemical pregnancy doesn't generally indicate fertility problems, and most women go on to have successful pregnancies afterward. The study also highlights the importance of using clear and consistent terminology when describing sonographic findings in the first trimester, including the use of terms such as "Early Pregnancy Loss" and "cardiac activity" to avoid confusion and ensure accurate communication with patients.
From the Research
Definition of Chemical Pregnancy and Miscarriage
- A chemical pregnancy is a type of early pregnancy loss that occurs when a fertilized egg implants in the uterus but fails to develop, often before a woman even knows she is pregnant 2.
- Miscarriage, also known as spontaneous abortion, is the loss of a pregnancy before the 20th week 3.
Relationship Between Chemical Pregnancy and Miscarriage
- A chemical pregnancy can be considered a type of miscarriage, as it is a failure of the pregnancy to progress 2.
- However, the term "miscarriage" often refers to a later pregnancy loss, whereas a chemical pregnancy occurs very early in pregnancy 3.
Key Differences
- The main difference between a chemical pregnancy and a miscarriage is the stage at which the pregnancy loss occurs 2.
- Chemical pregnancies are often characterized by a positive pregnancy test followed by a negative test, whereas miscarriages may involve more noticeable symptoms such as bleeding and cramping 3.
Studies on Chemical Pregnancy and Miscarriage
- One study found that women experiencing chemical pregnancies had a higher frequency of antiphospholipid antibodies (APA) than women with implantation failure associated with a negative pregnancy test 2.
- Another study found that the treatment of early miscarriage with medication, such as misoprostol, is effective and has few side effects 4.
- Ultrasound and beta-hCG testing can be used to verify the effectiveness of medical abortion and diagnose pregnancy loss 5, 6.