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.

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Bleeding during pregnancy facts

  • Vaginal bleeding or spotting during the first trimester of pregnancy is relatively common.
  • Some amount of light bleeding or spotting during pregnancy occurs in about 20% of pregnancies, and most of these women go on to have a healthy pregnancy.
  • In some cases, particularly when there is heavy bleeding and cramping (similar to menstrual bleeding and cramping), bleeding during pregnancy is the sign of a serious problem.
  • Implantation bleeding is bleeding that occurs when the fertilized egg implants in the lining of the uterus. This happens around the time of the expected menstrual period.
  • Implantation bleeding may occur before a woman realizes she is pregnant.
  • Serious causes of vaginal bleeding in the first trimester include

Is bleeding during pregnancy normal?

Vaginal bleeding during the first three months of pregnancy is relatively common and usually is a cause of concern for the mother. Women wonder how much bleeding during early pregnancy is normal. While early bleeding may indicate the presence of a serious problem, this is frequently not the case. In fact, approximately 20% of pregnant women experience light bleeding or spotting during the first trimester of pregnancy. Most go on to have uncomplicated pregnancies and ultimately deliver a healthy baby.

Spotting usually refers to a few drops of blood that would not cover a pad or panty liner. Bleeding refers to blood flow that is heavy enough to require wearing a pad. If bleeding occurs during the first trimester, a panty liner or pad should be worn so that you are able to get an idea of the amount of bleeding that is occurring and can tell the health-care professional. However, you should not use a tampon in the vagina during pregnancy or douche.

What is implantation bleeding during the first trimester?

A common benign cause of bleeding may occur even before a woman realizes that she is pregnant. Many women bleed when the fertilized egg attaches to the lining of the uterus. This is called implantation bleeding. It frequently occurs when the next menstrual period is expected.

What are the signs and symptoms of implantation bleeding?

Implantation bleeding consists of light bleeding or spotting around the time of the expected menstrual period. This does not happen in every pregnancy.

What are other common causes of bleeding during the first trimester?

  • Changes in the cervix: The normal hormone production during pregnancy can cause changes to the cervix, rendering it softer and more prone to bleeding. Also, a cervical polyp (a benign overgrowth of tissue) may form, and this may bleed more easily during pregnancy. In both cases, spotting or light bleeding may be provoked following sexual intercourse or a pelvic examination.
  • Infection: A vaginal infection may cause spontaneous vaginal bleeding. The bleeding may be accompanied by an abnormal vaginal discharge.

What are serious causes of bleeding during the first trimester of pregnancy?

Vaginal bleeding during early pregnancy may sometimes indicate a serious problem. These serious causes of bleeding in pregnancy include:

  • Miscarriage
  • Ectopic pregnancy
  • Molar pregnancy

Serious causes of bleeding during pergnancy are provided in this information.


  • Bleeding, abdominal pain, and back pain are common signs of miscarriage.
  • An exam shows that the cervix is open.
  • Tissue may be extruded through the cervix and vagina.
  • A miscarriage occurs in an estimated 15% to 20% of pregnancies, usually during the first 12 weeks of gestation.
  • A genetic defect confined to the specific embryo in question represents the most common cause of miscarriage.
  • Few circumstances exist wherein a miscarriage in progress can be prevented.

Molar Pregnancy

  • Molar pregnancy, also known as gestational trophoblastic disease or hydatidiform mole, is an abnormality of fertilization that results in the growth of abnormal tissue within the uterus.
  • Molar pregnancy is not a typical pregnancy, but the growth within the uterus leads to the typical symptoms of early pregnancy.
  • In a complete hydatiform mole, there is only abnormal tissue in the uterus (and no fetus).
  • In a so-called partial mole, there is abnormal tissue growth along with the presence of a fetus with severe birth defects.
  • The fetus is typically consumed by the abnormal growth of tissue in the uterus, and a molar pregnancy cannot result in a normal fetus or delivery.
  • Vaginal spotting or bleeding can be a symptom of molar pregnancy.
  • A sonogram yields a typical pattern and is used to diagnose molar pregnancy.

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Ectopic Pregnancy Symptoms

There are three classic signs and symptoms of ectopic pregnancy

  1. abdominal pain,
  2. the absence of menstrual periods , and
  3. spotting (vaginal bleeding or intermittent bleeding).

However, approximately 50% of women with an ectopic pregnancy will not have all three signs.

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.

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Reviewed on 11/30/2016

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

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