Implantation bleeding during early pregnancy: What is it and why does it happen?

Implantation bleeding is a normal part of being pregnant. Implantation bleeding is usually light, stops spontaneously, and doesn’t need treatment. If you have concerns about any type of vaginal bleeding during pregnancy, visit a health care provider.

What does implantation bleeding look like?

Implantation bleeding looks like light spotting that appears when you wipe. It may also look like a consistent, light flow of blood that needs a light pad or panty liner. The blood may look orange, pink, or brown. There are usually no clots in implantation bleeding in the early stages of pregnancy. It may last from a few hours up to several days.

Implantation bleeding may occur in combination with the other signs of early pregnancy:

• Mood swings
• Breast tenderness
• Fatigue
• Abdominal bloating
• Faint or light cramping (less severe than cramps during normal periods)

Make sure to note the consistency, color, and frequency of any bleeding during early pregnancy, as well as any implantation bleeding signs and symptoms. It may be useful to share these details with a health care provider for a diagnosis.

How heavy can implantation bleeding be?

Implantation bleeding in early pregnancy is generally only a light spotting of blood that appears when you wipe or that needs a light pad or panty liner. It may also look like a light flow of blood, but it is different from the typical flow of normal periods. Typical implantation bleeding in the early stages of pregnancy is pink- or brown-colored discharge.

When does implantation bleeding happen?

Implantation bleeding usually occurs 10 to 14 days after conception. It is an early symptom of pregnancy and generally happens when you are expecting your period. It can be easy to mistake light bleeding during early pregnancy for a regular period.

Causes of implantation bleeding

During conception, a sperm fertilizes an egg to form an embryo. The embryo then travels through the uterine tubes and enters the uterine cavity. Once in the uterus, the embryo implants itself into the uterine wall. This implantation may break some blood vessels in the uterine wall and cause light bleeding in the early stages of pregnancy. This bleeding doesn’t result in any kind of problems for the fetus.

Other possible causes of bleeding in early pregnancy

Bleeding during early pregnancy can be due to reasons other than implantation. If you are having heavy bleeding during early pregnancy with or without cramping or pain, be sure to visit a health care provider.

Some other causes of bleeding in early pregnancy include the following:

• Sex is one of the possible causes of bleeding in early pregnancy because the cervix is very tender and sensitive at this time.
• Ectopic pregnancy may be one of the causes of bleeding in the early stages of pregnancy. This is a condition where the embryo implants and develops somewhere outside the uterus, such as the uterine tubes, abdominal cavity, ovaries, or cervix (the lower part of the uterus that connects to the vagina). An ectopic pregnancy can also cause vaginal bleeding along with pelvic pain or cramps (particularly one-sided cramps), dizziness, nausea, and vomiting. It’s a life-threatening condition and requires emergency medical aid. 
• Threatened abortion may be one of the causes of bleeding in early pregnancy. In this condition, the embryo is still inside the uterus, but the pregnancy may be in danger. A threatened abortion can occur due to an infection, certain medicines, or physical trauma. 
• Complete miscarriage can also cause bleeding in early pregnancy. According to estimates, miscarriages occur in about 10 percent of all clinically recognized pregnancies. Apart from vaginal bleeding, other symptoms of miscarriage include cramping or pain in the lower back or abdomen and the passage of bloody tissue or fluid from the vagina. Visit a health care provider if you are pregnant and experience these symptoms. 
• Molar pregnancy is a rare pregnancy complication that occurs when an abnormal mass of cells — rather than a fetus — develops inside the uterine cavity. It may be one of the causes of bleeding during early pregnancy. Apart from bright red to dark brown vaginal bleeding, it may cause symptoms of severe vomiting and nausea, a passage of cysts (grapelike) from the vagina, and pelvic pain or pressure. If you suspect that any of your symptoms are due to a molar pregnancy, visit a health care provider as soon as possible. 
• Cervical problems, including inflammation of the cervix, abnormal growths, or cervical infection, may also cause bleeding in the early stages of pregnancy. 
• Infections of any kind in the vagina or cervix, including sexually transmitted infections such as herpes, chlamydia, or gonorrhea, may cause bleeding during early pregnancy.

Can you take a pregnancy test during implantation bleeding?

It’s best to wait until after the first day of a missed period to take a pregnancy test, as the results may be more accurate by then. If the home pregnancy test result is positive, you should visit a health care provider to confirm the results with a blood test.

Risks of bleeding in early pregnancy for mother and baby

The effects and risks of bleeding in early pregnancy depend on the cause and whether it can be treated. 

• Ectopic pregnancy — If the cause of bleeding during early pregnancy is an ectopic pregnancy, it is highly unlikely for the fetus to survive. The risk of another ectopic pregnancy in the future may also be increased. With appropriate treatment, the prognosis after an ectopic pregnancy for the mother is good. 
• Threatened abortion — If the cause of bleeding during early pregnancy is a threatened abortion, there is still a chance to have a healthy pregnancy and delivery. Miscarriage is also a possible outcome. It is critical to visit a health care provider as soon as possible.
• Complete miscarriage — The pregnancy is terminated during a complete miscarriage. There may be no risks to the mother associated with complete miscarriage. 
• Molar pregnancy — In this type of pregnancy, no fetus has formed and, therefore, cannot be harmed. A molar pregnancy may have serious complications for the mother, including cancer.

When to see a health care provider

It is important to see a health care provider whenever you have abnormal bleeding or spotting, whether you are pregnant or not. Although period-like bleeding during early pregnancy may be nothing to worry about, it’s important to visit your health care provider to be sure. 

Furthermore, if the result of a home pregnancy test is positive, make sure to see a health care provider to confirm the results of the test. 

Also, see a health care provider if you experience heavy bleeding in early pregnancy, as it may indicate something more serious than implantation bleeding.