Chemical Pregnancy

A chemical pregnancy occurs when an embryo implants and begins producing hCG — enough to trigger a positive test — but stops developing within the first few weeks, usually before 5 weeks gestation. It is called "chemical" because it is only detectable biochemically, not yet on ultrasound.

Chemical pregnancies are relatively common and account for up to 50–75% of all miscarriages. They are often caused by chromosomal abnormalities in the embryo. A single chemical pregnancy is generally not cause for alarm, but recurrent chemical pregnancies may prompt evaluation for implantation issues, thrombophilias, or embryo quality problems.