Bleeding During Early Pregnancy (First Trimester)

  • Medical Author: Wayne Blocker, MD
  • Medical Editor: Melissa Conrad Stöppler, MD
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Quick GuideFetal Development Stages: Month by Month Embryo Pictures

Fetal Development Stages: Month by Month Embryo Pictures

Ectopic pregnancy

  • Mild vaginal bleeding and increasing abdominal pain may indicate the presence of an ectopic pregnancy.
  • An ectopic pregnancy occurs in approximately 1 out of 60 pregnancies.
  • An ectopic pregnancy occurs when the fertilized egg implants outside of the uterus, where the blood supply is inadequate to sustain the growth of a normal pregnancy.
  • In the majority of cases of ectopic pregnancy, the embryo is located within one of the Fallopian tubes; this sometimes is referred to as a tubal pregnancy. As the pregnancy grows and the tube distends, abdominal pain becomes increasingly severe.
  • Sometimes these pregnancies can actually rupture the Fallopian tube, leading to significant blood loss.
  • In some cases, a blood transfusion and emergency surgery are needed for prompt resolution of this potentially life-threatening condition.

Threatened miscarriage

  • If a woman is bleeding during the first trimester of pregnancy, the possibility of a miscarriage must be ruled out.
  • Symptoms of a threatened miscarriage are bleeding and mild cramping, but the cervix stays closed and the fetus is still viable.
  • In many women the bleeding stops and the pregnancy continues. For others, the bleeding continues, and they eventually have a miscarriage (i.e. spontaneous pregnancy loss).
  • Despite many articles in the lay press, there is no evidence that restriction of physical activity will aid in preventing a pregnancy loss.

Subchorionic hemorrhage

  • In this condition blood collects between the gestational sac and the wall of the uterus.
  • At times the intrauterine clot can be seen on ultrasound examination.
  • These blood clots are frequently reabsorbed by the body, but, on occasion there may be passage of old dark blood or even small clots from the vagina.

When should you call your doctor about bleeding during the first trimester?

Any time you notice bleeding during any stage of pregnancy, it is appropriate to call your doctor. It is particularly important to seek medical attention if the bleeding is heavy (like a menstrual period) or accompanied by pain or cramping.

How is the cause of bleeding during the first trimester of pregnancy diagnosed?

If the bleeding is more than just light spotting due to an obvious reason, your health-care professional will try to determine the cause by performing pelvic and ultrasound examinations. Specific blood tests also may be ordered.

What about bleeding during the second and third trimesters of pregnancy?

Bleeding or spotting later in pregnancy can be due to a number of causes. Sometimes, having sex or even having an internal (pelvic) examination by a healthcare provider can cause light bleeding. Problems with the cervix, including cervical insufficiency (when the cervix opens too early in pregnancy) or infection of the cervix, can lead to bleeding. More serious causes of bleeding in later pregnancy include placenta previa, preterm labor, uterine rupture, or placental abruption.


Norwitz, E.R., et al. "Overview of the etiology and evaluation of vaginal bleeding in pregnant women." Updated Jul, 17, 2015.

Medically Reviewed by a Doctor on 11/30/2016

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