Causes of Light Bleeding During the First Month of Pregnancy

Light bleeding in early pregnancy can actually be quite normal, but it may be startling to an expectant mother. Some women may not realize they are even pregnant in the first month. The American Pregnancy Association recommends wearing a pad or pantyliner to assist in monitoring the amount of blood that is shed. Let your health care provider know if you experience bleeding and any other symptoms, including cramping or pain. A general guideline is that a woman who loses enough blood to fill a pad or liner, may have something more serious affecting her.


Miscarriages typically occur within the first 12 weeks of pregnancy, according to the American Pregnancy Association. Besides bleeding, a woman may notice cramping that is slightly stronger than menstrual cramps, passing of tissue in addition to blood, and sometimes a sharp pain in the abdomen. The University of Maryland Medical Center points out that most women will experience bleeding with a miscarriage. A miscarriage can't be prevented, and it can be an emotional time for the expectant parent.

Ectopic Pregnancy

Woman suffering from menstruation pain

Reasons for Spotting When Pregnant

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Ectopic pregnancy occurs less often than miscarriages. It occurs when the fertilized egg attaches somewhere outside the uterus. In most cases, the egg attaches to the fallopian tube tissues. This type of pregnancy is unstable and can end in spontaneous abortion or a medical procedure to safely end the pregnancy without harming the mother. Symptoms of an ectopic pregnancy, in addition to bleeding, include cramping low in the stomach, sharp pain in the abdomen and lower levels of the pregnancy hormone hCG. hCG stands for human chorionic gonadotropin, a hormone that increases in a woman's body around 11 days after conception. This hormone is measured in urine and blood pregnancy tests. When an ectopic pregnancy occurs, the hCG levels will decrease rather than increase.

Molar Pregnancy

A molar pregnancy is extremely rare. It occurs when a "mole" develops instead of an actual human embryo. The mole is a mass of abnormal tissues in the uterus, where an embryo would normally be. In addition to vaginal bleeding, a woman may have an unusually high level of hCG when tested. During a prenatal exam, the fetal heartbeat will be absent, because the mass is not truly an embryo. There may also be grape-like clusters throughout the uterus that are visible in ultrasound.

Implantation Bleeding

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Is bleeding or a period normal in pregnancy?

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Implantation bleeding is completely normal, and occurs in about 20 to 30 percent of pregnancies, says the University of Maryland Medical Center. This type of bleeding occurs somewhere between six and 12 days after the suspected date of conception. It occurs because the fertilized egg attaches to the uterine lining. Some women may notice mild cramping with the bleeding. The bleeding may be moderate for a few hours, or it may be light spotting for several days.

Other Causes

An infection of the pelvic tissues or the urinary tract can cause some vaginal spotting. Sexual intercourse during pregnancy, including during the first month, may cause some mild bleeding. This is perfectly normal as the cervix is more sensitive. If bleeding after intercourse is very heavy and persistent, contact your health care provider right away. You may be put on pelvic rest--asked to stop using tampons and douches and to abstain from sex for a specific period of time-- if some cervical abnormality is discovered.