When a woman gets a positive pregnancy test result, even if it’s faint, and then has a period a few days later, she may experience a chemical pregnancy.
This is an early miscarriage that happens when a sperm or egg gets too many or not enough chromosomes, and the embryo can’t develop. It’s common and typically not your fault.
Causes of chemical pregnancies
In most chemical pregnancies, an embryo forms and even embeds in the uterus (implantation) but then stops developing, leading to early miscarriage. The loss often happens before the five-week mark, and many women don’t realize they have had a miscarriage until their period arrives a few days or a week after they were expecting to get one.
The reason the implantation isn’t progressing normally is because there is an abnormal genetic change in the fertilized egg, Dr. Purdie explains. The embryo has the wrong number of chromosomes, and it can’t grow or develop properly.
Because of the abnormal chromosomes, the embryo isn’t able to grow and cause the levels of pregnancy hormone hCG (human chorionic gonadotropin) to rise high enough for the pregnancy to be detected on a home pregnancy test or at the doctor’s office. Eventually, the level of hCG goes down and the pregnancy is lost, says Dr. Rodgers.
Because the symptoms of a chemical pregnancy closely mirror those of a regular menstrual cycle, many women experience feelings of confusion and guilt. They may believe they’ve somehow caused the loss, even though it is usually a chromosomal abnormality that’s at fault. Bleeding from a chemical pregnancy usually begins around the time of—or slightly after—an expected period and can range from light to heavy. A few days or a week later, the uterus then sheds the embryo and lining.
Symptoms of chemical pregnancies
Bleeding in the early stages of pregnancy can feel very similar to a period, but it isn’t necessarily a sign of miscarriage. Sometimes, it is implantation bleeding as the embryo embeds in the wall of the uterus. Other times, it is a symptom of a chemical pregnancy or an infection.
When a woman has a chemical pregnancy (also known as biochemical pregnancy), her body produces human chorionic gonadotrophic hormone, or hCG. This is what gives a home pregnancy test or a urine test at a fertility specialist a positive result. Typically, the embryo doesn’t develop past the fifth week of gestation, and hCG levels drop quickly. This is why many women don’t realize they have had a chemical pregnancy. They might just think they have a late period that’s heavier than usual.
A miscarriage can be a devastating experience, especially if it took long to conceive or you have had fertility treatment. It can feel like a loss of hope, particularly if you’ve worked hard to get pregnant or if you had planned your family.
However, it is important to understand that a chemical pregnancy isn’t your fault and doesn’t prevent you from getting pregnant again or having a healthy pregnancy in the future. In fact, some people who have had a chemical pregnancy go on to have a successful live birth later on.
Treatment of chemical pregnancies
A chemical pregnancy occurs when an egg is fertilized but does not implant and the embryo stops growing extremely early in a pregnancy. It is also referred to as an early miscarriage. It accounts for 50-75% of all miscarriages. It usually happens before the fifth week of gestation and often is a surprise to women who have gotten a positive pregnancy test or missed their period. At this point in a pregnancy the fetus is too small to see on an ultrasound and hCG levels drop quickly.
Bleeding from a chemical pregnancy can look very similar to a regular period and may begin as spotting or get heavier over time. It can last a few days to a week or longer. It is important to contact your doctor if you are experiencing spotting or light bleeding that does not subside.
A doctor can diagnose a chemical pregnancy in the same way as they would a regular miscarriage (blood or urine test showing a rise in hCG, followed by a negative test or no evidence of a fetus on an ultrasound). There is no physical treatment needed for this type of pregnancy, but it is important to have a follow-up appointment with your OB-GYN to ensure that an ectopic pregnancy does not occur, which requires urgent medical attention.
Recovery after chemical pregnancies
A chemical pregnancy can be very upsetting and confusing. But it’s important to remember that you did nothing wrong and that it is completely normal to experience grief following a loss like this. It can also be helpful to speak with a mental health professional if you are feeling overwhelmed and in need of help.
Chemical pregnancies occur when a fetus is implanted in the uterus but doesn’t grow, usually after about five weeks of pregnancy, explains Dr. Lauren Averbuch of OB-GYN Westside in New York City. They are very common and account for 30% to 50% of miscarriages. “We think they happen because of chromosomal problems, which are errors in the DNA that give your child their characteristics,” she says.
Symptoms of a chemical pregnancy often mimic those of a period, which is why they are so hard to detect. Those symptoms include bleeding, which can be lighter or heavier than usual, and menstrual cramps. Often, the bleeding happens right before or after a positive pregnancy test and can last up to a week.
Most of the time, a woman doesn’t need any treatment for a chemical pregnancy. This is because the miscarriage happens so early, before a fetus has had a chance to grow. But if the bleeding does not stop or it is heavier than usual, it’s a good idea to visit your doctor.
