What is a chemical pregnancy?
Chemical pregnancy is an early miscarriage that occurs soon after the embryo implants in the uterus, usually within the first five weeks of pregnancy. "It is usually detected by a pregnancy test but can be mistaken for a late period," says obstetrician-gynecologist Dr Kavitha Kovi, Aster Whitefield Hospital, India.
Many women may not even realize they are pregnant because miscarriages happen so early. The Journal of Clinical Medical Research reports that 50 to 60 percent of first pregnancies end in miscarriage, with 25 percent of those occurring when the woman does not know she is pregnant.
Symptoms of chemical pregnancy
Symptoms of a chemical pregnancy can include a positive pregnancy test followed by a negative one, light bleeding or spotting, mild abdominal pain, and the absence of other early pregnancy symptoms like nausea, says Dr. Kovi. These symptoms are often similar to those of a regular period, making them easy to miss.
Causes of chemical pregnancy
Chromosomal abnormalities
Embryos with the wrong number of chromosomes often lead to early miscarriage, which is the body's way of preventing embryos from developing properly. A study published in Maedica found that chromosomal abnormalities are responsible for at least 50% of first-trimester miscarriages.
Hormonal imbalance
Progesterone is one of the hormones needed to maintain pregnancy and insufficient levels of the hormone can cause miscarriage in the early stages, according to research published in Revista de Chime.
Abnormalities of the uterus
Structural problems such as fibroids or scar tissue can interfere with implantation and growth of the embryo. These conditions can often be diagnosed with imaging tests and treated with medication or surgery. Women who have had miscarriages have a 3.2 to 6.9 percent chance of having a uterine malformation, according to research published in the journal Seminars in Reproductive Medicine.
Infection
According to a study published in Human Reproductive Update, 15 percent of early miscarriages are caused by preventable infections. Another study, published in the journal Diagnostics, found that the human papillomavirus (HPV) can infect the placenta, leading to infection during the first trimester of pregnancy.
Immune system problems
When the immune response becomes excessive, it can attack the embryo, causing a chemical pregnancy; there are now specialized therapies and medications that can help control this disorder.
