Biochemical pregnancy is a miscarriage that happens before the pregnancy can be seen with an ultrasound.
A biochemical pregnancy is a pregnancy that stops growing and resolves before it becomes large enough to see it with ultrasound. Not long after fertilization and implantation, the pregnancy stops developing – usually due to a severe chromosomal abnormality within the pregnancy. “Biochemical” means that the only evidence that the pregnancy existed was the positive pregnancy test itself. Repeated early miscarriage can indicate fertility issues.
A normal pregnancy cannot typically be seen with ultrasound until around 5 1/2 weeks of gestation or about 1 ½ weeks after a missed period. At that time, the hCG level measures approximately 1500 units. In a biochemical pregnancy, the pregnancy is typically lost prior to 5 1/2 weeks, before the hCG level rises high enough for the pregnancy to be visualized.
What causes biochemical pregnancy?
The vast majority of miscarriages are due to one or more chromosomal abnormalities within the very early embryo. This may occur when an abnormal egg is fertilized by a normal sperm, when an abnormal sperm fertilizes a normal egg, or when there is a mistake made during cell division following normal fertilization. These mistakes typically result in embryos that do not have the normal number of 46 chromosomes.
Embryos that do not have a normal number of chromosomes almost always miscarry spontaneously. There are a few exceptions (like Down’s Syndrome), in which embryos can have an abnormal number of chromosomes yet still survive. Typically, these babies have developmental defects that can range from mild to life threatening. Most chromosomal abnormalities cause the baby to have a limited ability to grow and develop. When that limit is reached, development stops and a miscarriage occurs.
Miscarriages are common but having more than two means you need a professional evaluation
Biochemical pregnancies are common. However, if you have had two or more miscarriages, you should have an evaluation. There are many treatable conditions that can cause miscarriages such as a chromosomal abnormality in one member of the couple, abnormalities of the uterus, infection, blood clotting disorders, thyroid disease, and low ovarian reserve.
Our physicians at Texas Fertility Center would love to help. They will discuss with you all the possible causes of miscarriages and perform a comprehensive evaluation. They will then recommend treatment that can significantly increase your chances for a healthy pregnancy.