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What causes bleeding in the first trimester of pregnancy?

Related Topics: Pregnancy, First Trimester

Answers From Experts & Organizations (1)

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About 20% of women have some bleeding during the first 12 weeks of pregnancy. Possible causes of first trimester bleeding include:

Implantation bleeding. You may experience some normal spotting within the first six to 12 days after you conceive as the fertilized egg implants itself in the lining of the uterus. Some women don't realize they are pregnant because they mistake this bleeding for a light period. Usually the bleeding is very light and lasts from a few hours to a few days.

Miscarriage. Because miscarriage is most common during the first 12 weeks of pregnancy, it tends to be one of the biggest concerns with first trimester bleeding. About half of women who bleed in pregnancy eventually miscarry, but that doesn't necessarily mean that if you're bleeding you've lost the baby, especially if you don't have any other symptoms.

Other symptoms of miscarriage are strong cramps in the lower abdomen and tissue passing through the vagina.

Ectopic pregnancy. In an ectopic pregnancy, the fertilized embryo implants outside of the uterus, usually in the fallopian tube. If the embryo keeps growing, it can cause the fallopian tube to burst, which can be life-threatening to the mother. Although ectopic pregnancy is potentially dangerous, it only occurs in about 2% of pregnancies.

Other symptoms of ectopic pregnancy are strong cramps or pain in the lower abdomen, and lightheadedness.

Molar pregnancy (also called gestational trophoblastic disease). This is a very rare condition in which abnormal tissue grows inside the uterus instead of a baby. In rare cases, the tissue is cancerous and can spread to other parts of the body.

Other symptoms of molar pregnancy are severe nausea and vomiting, and rapid enlargement of the uterus.

Additional causes of bleeding in early pregnancy include:

  • Cervical changes. During pregnancy, extra blood flows to the cervix. Intercourse or a Pap test, which cause contact with the cervix, can trigger bleeding. This type of bleeding isn't cause for concern.
  • Infection. Any infection of the cervix, vagina, or a sexually transmitted infection (such as chlamydia, gonorrhea, or herpes) can cause bleeding in the first trimester.

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Archived: March 20, 2014

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Read the Original Article: Bleeding During Pregnancy

Answers from Contributors (2)

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Implantation bleeding can last longer than 12 days. It maybe considered something else after so long, but that is what my Dr. called it. I am not writing this because I think I know more than what WMD gave as an answer. However, as a first time pregnant woman who has experienced light bleeding and cramping intermittently from week 3rd through my current 7th week, I believe there is not enough information available about 1st trimester bleeding. I read so many articles like this that my head was swimming. I knew I wasn't having a miscarriage, but what I was reading (all from credible sources btw) left me feeling like I was either doomed to miscarry, or I would be bed ridden. When I went in for an ultra sound the nurse pointed out a little dark area between the amniotic sac and my uterine wall. she said that is where the blood was coming from. At 7w1d I was still experiencing implantation bleeding- it was still attaching in an area. She said it is common, and everything was fine! I saw my little button wiggle, and we heard a heart beat! Baby measures perfectly. Not every story is going to end quite as uncomplicated, but I want women to have hope. There are a lot of answers- every pregnancy  is different. Talk to your Dr., and never, ever assume the worst. There is hope!

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