A chemical pregnancy happens when a fertilized egg does not attach itself to the uterine wall. This is also known as a very early miscarriage. According to ACOG, the American College of Obstetricians and Gynecologists, chemical pregnancies account for 50-75% of all miscarriages. Unlike miscarriages, which typically occur before the 20th week of gestation, chemical pregnancies occur just after implantation. In cases where the woman is not expecting to become pregnant, she may not realize she was since menstruation bleeding usually occurs around the same time. If she is expecting and takes a test, it could lead to false positive pregnancy test results.
In the past, sensitive pregnancy tests were administered by doctors via blood tests. Nowadays, there are several over-the-counter products that are able to detect pregnancies almost a week before menstruation is due. This could be why so many women are realizing they are pregnant, only to learn the pregnancy resulted in a chemical pregnancy or early miscarriage. Research has shown up to 70% of all conceptions end in miscarriage. Health care providers do not clinically confirm a pregnancy until it is detected on an ultrasound. First ultrasounds are typically given between the 4th and 6th weeks of gestation.
Signs and Symptoms of a Chemical Pregnancy
In most cases, women have no symptoms of a chemical pregnancy. In actuality, most women do not know they were ever pregnant. Some women report mild abdominal cramping and mild spotting a week before their period is due, but there are usually no pregnancy symptoms such as fatigue or nausea, since the fertilized egg did not implant itself to the uterine wall. Vaginal bleeding will occur after a positive pregnancy test and blood tests may reveal low hCG levels that decrease instead of increase. Menstruation cycles are typically on time or a couple days late.
What Causes a Chemical Pregnancy?
Experts have no conclusive evidence stating what causes a chemical pregnancy. However, most experts believe it happens for the same reasons why other miscarriages happen- abnormal chromosomes in the developing embryo. Abnormal chromosomes can be the result of many factors such as poor quality of the sperm or egg, genetic abnormalities of the mother or father, or an abnormal cell division of the fetus. Experts believe half of all chemical pregnancies are due to some form of chromosomal abnormality. Additional potential causes may include the following:
- Infections such as toxoplasmosis, chlamydia, genital herpes, or syphilis
- Systemic illnesses such as untreated thyroid disease
- Uterine abnormalities (congenital and acquired)
- Abnormal hormone levels
- Luteal phase defect
- Inadequate uterine lining
Treating and Preventing Chemical Pregnancies
Unfortunately, chemical pregnancies can not be prevented, nor is there a specific type of treatment method. Women who experience a chemical pregnancy are encouraged to follow-up with tests to ensure their hCG levels return to normal. There is no evidence suggesting chemical pregnancies will affect future pregnancies, as many women go on to have healthy pregnancies, labors and deliveries. For some couples, treatment may involve treating the emotional side of a chemical pregnancy, especially for those who are hopeful to conceive. Seeking counseling can help you cope with the pregnancy loss. Treatment for recurrent chemical pregnancies may include the following:
- Progesterone cream
- Vitamin B6 (minimum 50mg per day)
- Baby aspirin
- Antibiotics may be prescribed if an infection is present
- Genetic counseling for those who experience several early miscarriages
If you are anxious to ‘try again,’ it is recommended that you wait at least one regular menstrual cycle. Talk with your doctor or midwife about an appropriate treatment plan for you.