There are few things more worrying in pregnancy than seeing blood. However, there’s no need to panic. There are many reasons why a woman may bleed during pregnancy, not all of them related to the pregnancy itself. According to the American Pregnancy Association, about 20 to 30 percent of women experience some kind of bleeding during early pregnancy. Fifty percent of these women go on to have healthy pregnancies.
Some women spot pink or brown blood when the fertilized egg implants into the uterine lining–usually this occurs about six to 12 days after conception. This is called implantation bleeding. Implantation bleeding occurs because when the egg burrows into the uterus, it can break the mother’s blood vessels causing small amounts of blood to be released. When it occurs, implantation bleeding can last anywhere from a few hours to a few days.
During pregnancy, the blood supply to your cervix increases, making it more sensitive and prone to bleeding. You may notice spotting due to an irritated cervix after a Pap smear, an internal vaginal exam or after intercourse. Bleeding due to an irritated cervix is not usually something to be concerned about as long as it is light and not accompanied by cramping.
Subchorionic bleeding and hematoma
Sometimes during early pregnancy, blood or blood clots accumulate in the outer fetal membrane (“chorion”), just next to the developing placenta. This can result in bleeding, sometimes quite heavy bleeding. Usually, the blood or clots harmlessly reabsorb. However, if the bleeding or clots get large enough they can cause the placenta to break from the uterine wall, which will cause a miscarriage. There is no consistent treatment for subchorionic hematomas: some doctors advise the mother to rest and abstain from sex; some prescribe blood thinners, such as Lovenox or Heparin. According to Justmommies.com, 97 to 99 percent of women with a subchorionic bleed go on to have healthy pregnancies, although at greater risk for placental abruption later in the pregnancy.
Bleeding can also be a sign of impending miscarriage, particularly during early pregnancy. If a woman is bleeding bright red blood and experiencing cramps or passing tissue, there is a good chance she is having or about to have a miscarriage. The American Pregnancy Association reports that 15 to 20 percent of all pregnancies end in miscarriage, and most occur in the first 12 weeks. Most miscarriages occur because there was a problem with the developing fetus, not because of any act of the mother.
Occasionally, a fertilized egg will implant somewhere other than in the uterus, most frequently in the fallopian tube. When this happens, bleeding can occur, along with cramping and severe abdominal pain. Unfortunately, if an ectopic pregnancy is diagnosed, there is no other option but to end the pregnancy.
Bleeding during the second and third trimesters is often caused by placental problems such as placental abruption or placenta previa. Placental abruption occurs when the placental detaches from the uterine wall. The symptoms are bleeding and stomach pain. This problem affects only 1 percent of pregnant women and usually occurs during the last 12 weeks of pregnancy. A more common placental problem, placenta previa, occurs when the placenta covers the cervix either partially or entirely. This is a serious condition that can put your pregnancy at risk, if bleeding does occur. If you have been diagnosed with placenta previa and you are bleeding, you should consult your doctor immediately.