A chemical pregnancy is an early pregnancy loss that occurs shortly after implantation. Many women might not even realize they’ve had one unless they’re actively trying to conceive and performing early pregnancy tests. These pregnancies account for 50-75 percent of all miscarriages, making them a common, although often silent, experience among many women.
While a chemical pregnancy can be emotionally challenging, especially for those eagerly expecting, it’s important to know that having one doesn’t typically impact a woman’s fertility.
What is Considered a Chemical Pregnancy?
Medically, a chemical (or biochemical) pregnancy is considered a very early miscarriage. It happens before the sixth week of gestation and often just after the fertilized egg attaches to the uterine lining.
The term “chemical” refers to the detection of pregnancy by means of biochemical markers, specifically the presence of human chorionic gonadotropin (hCG) hormone. hCG levels can start to increase as soon as pregnancy occurs, but before one can be seen on an ultrasound.
Some women experience no symptoms at all after a chemical pregnancy, while others have mild symptoms such as light spotting or abdominal cramps. A heavier-than-normal period might also occur after the chemical pregnancy.
How Do You Test for a Chemical Pregnancy?
Detection of a chemical pregnancy generally occurs through a pregnancy test that is sensitive enough to detect hCG before a woman misses her period.
“Early response” pregnancy tests can identify elevated levels of hCG in the urine or blood about three days before a missed period. hCG levels might initially rise and then quickly decrease, leading to bleeding that resembles a menstrual period.
What’s the Difference Between a Chemical Pregnancy and a Miscarriage?
While a chemical pregnancy is a form of miscarriage, it differs from more commonly recognized miscarriages that occur later in the first trimester or beyond.
Chemical pregnancies are characterized by a positive pregnancy test that quickly turns negative due to the pregnancy ending before any fetal development can be visually detected through ultrasound. While a chemical pregnancy cannot be seen on an ultrasound, a confirmed or “clinical pregnancy” can, meaning the gestational sac can be seen on an ultrasound, and the fetal heartbeat can also be heard.
Most often, chemical pregnancies occur before the fifth or sixth week of pregnancy, while miscarriages (loss of a clinical pregnancy) occur after the sixth week, most often before the 14th week in the first trimester.
What Causes a Chemical Pregnancy?
The exact cause of a chemical pregnancy isn’t always known, but it’s thought that it often happens for the same reasons as a miscarriage. Potential factors contributing to a chemical pregnancy can include:
- Chromosomal abnormalities in the embryo that prevent it from developing.
- Hormonal imbalances that might not support pregnancy.
- Inadequate uterine lining, which makes it difficult for the embryo to implant and grow.
- Underlying medical conditions, such as thyroid disorders or clotting disorders.
When to Seek Help For Reoccurring Chemical Pregnancies
Chemical pregnancies are thought to be common, and most don’t usually require medical intervention or treatment.
In most cases, it’s possible to conceive again soon after a chemical pregnancy. Consulting with an OBGYN can still provide you with support and medical attention while you’re trying to conceive, including if you’ve had one or more chemical pregnancies or miscarriages. For example, in some cases, when a chemical pregnancy is suspected, a doctor might recommend blood tests to monitor hCG levels and ensure they return to non-pregnant levels.
If you’re having trouble getting pregnant, particularly if you’ve been trying for more than six to 12 months, seeking help is recommended to rule out potential causes and discuss any necessary follow-up care to support fertility planning.
At Stony Brook Gynecology and Obstetrics, we prioritize patient care and strive to provide a comforting environment where all questions and concerns can be addressed. Our team is dedicated to supporting women of all ages and through all stages of their reproductive health, whether they are just entering puberty, trying to become pregnant, expecting a baby, or transitioning through menopause.
