A biochemical pregnancy (also called a chemical pregnancy) is a very early pregnancy loss that occurs shortly after implantation. It is detected by a positive pregnancy test (because the body produces hCG) but ends before an ultrasound can show a gestational sac, usually before 5 weeks of pregnancy.
What happens?
A fertilized egg implants in the uterus.
hCG levels rise enough to produce a positive pregnancy test.
The pregnancy stops developing very early.
hCG levels then fall, and bleeding occurs, often around the time of an expected or slightly delayed period.
Common signs
Positive pregnancy test followed by a negative test a few days later.
Light to heavy vaginal bleeding.
Menstrual-like cramping.
hCG levels that rise slowly or begin to decline.
Causes
Most biochemical pregnancies are thought to result from:
Chromosomal abnormalities in the embryo.
Problems with implantation.
Less commonly, uterine abnormalities, hormonal issues, or other medical conditions.
Does it affect future fertility?
Usually no. Many people who experience a biochemical pregnancy go on to have healthy pregnancies. In fact, a biochemical pregnancy confirms that fertilization and implantation occurred.
