Common Causes for Bleeding in the First Trimester

Updated on May 2, 2014

Perhaps you've noticed a little blood in your undies, or felt a gush and looked down only to see your bed covered in blood. Immediately you are full of fear and with good reason. Bleeding in pregnancy is most commonly associated with miscarriage so it is natural to assume the worst.

Before you lose all hope, know that 50% of women who experience bleeding in the first trimester go on to have healthy pregnancies and healthy babies. This article will cover the different causes of bleeding in the first trimester and what you should do about it.

If you are suffering or have suffered a miscarriage, I am so sorry.  I understand the depths of your pain.
If you are suffering or have suffered a miscarriage, I am so sorry. I understand the depths of your pain. | Source


Lets get the scariest cause for 1st trimester bleeding out of the way first. Approximately half of all 1st trimester bleeding is caused by an impending miscarriage.

What is it?

A miscarriage happens when the body expels the embryo or fetus from the uterus prior to 20 weeks gestation. Miscarriages are usually related to a chromosomal or genetic defect in the embryo or fetus, problems with the placenta or umbilical cord,hormonal issues and other factors. Unfortunately, the cause of miscarriage often cannot be identified.

Once a miscarriage is in progress, there is nothing that can be done to stop it.

How Common is Miscarriage?

Doctors estimate that about 20% of all known pregnancies end in miscarriage and up to 80% of all miscarriages occur in the first trimester (What to Expect When Your Expecting). About half of all cases of bleeding in the 1st trimester are attributed to miscarriage

Symptoms of Miscarriage

  • heavy, bright red vaginal bleeding similar to a period, possibly with clots and tissue
  • Cramping or pain in the back or lower abdomen, which may become severe
  • Pronounced decrease in pregnancy symptoms
  • Once bleeding becomes heavy, it continues for several days, (it usually doesn't die down within a couple hours, for example)

How to Diagnose Miscarriage as the Cause of Bleeding

Severe and persistent cramping and/or passing large clots suggests miscarriage (but could be from other causes as well), however, passing tissue, which often looks gray or beige in color is most likely the baby and is a definite sign that you have miscarried. Descending HCG levels also indicate an impending miscarriage. An ultrasound may show no heartbeat or no fetus (indicating that the miscarriage is complete). As terrible as this sounds, you may also see heart tones that are much slower than normal, and/or that the baby is measuring smaller than it should be. This can imply an impending miscarriage.

Implantation Bleeding

What is Implantation Bleeding?

Implantation bleeding is (usually) light spotting or bleeding that occurs between 6 and 12 days after conception, as the blastocyst (week old baby) implants into the uterine wall. It is often one of the first signs of conception, but can also occur after pregnancy is confirmed, causing alarm; however, implantation bleeding is harmless.

How Common is it?

Implantation bleeding occurs in approximately 20-30% of all pregnancies.

Symptoms of Implantation Bleeding

Implantation bleeding is usually pinkish or darker in color and occurs between 6-12 days after conception. Implantation bleeding can occur for up to a few days, resembling a light period or be as little as a light streak of blood seen once. It may also be associated with light, period-like cramping from the blastocyst burying into the uterine lining.

How is implantation bleeding diagnosed?

simply by the description above. A positive pregnancy test and/or rising HCG levels can also confirm that the bleeding is nothing serious.

Cervicitis and Cervical Polyps

What is Cervicitis?

Cervicitis is when the cervix becomes irritated and bleeds. Causes include the hormonal changes in pregnancy, intercourse, ph imbalance and infection, most commonly yeast or STDs.

Signs and Symptoms of Cerviticis

Cervicitis can cause light spotting after intercourse, (which may be painful) or be accompanied by gray or yellowish discharge that may be foul smelling.

What are Cervical Polyps?

Cervical Polyps are the harmless overgrowth of tissue around the cervix, usually caused by hormonal changes during the reproductive years.

Signs and Symptoms of Cervical Polyps

Cervial Polyps usually doesn't cause anything more than spotting, but it can cause heavier bleeding as well. A practitioner can identify polyps during a vaginal exam.


Subchorionic Bleed

What is a Subchorionic Bleed?

A subchorionic bleed, or subchorionic hemotoma occurs when blood collects between the uterine lining and the outer fetal membrane or under the placenta, often from the yolk sac or placenta tearing away slightly from the uterine wall. This can cause bleeding ranging from just noticeable spotting to heavy bleeding or gushing blood, depending on the size of the hematoma. A subchorionic bleed is not necessarily dangerous to mom or baby but it should be monitored to ensure that no complications arise. Mom should relax and rest, refrain from heavy lifting, and intercourse until 48-72 hours after bleeding has stopped to give the bleed time to heal.

How Common is a Subchorionic Bleed?

20% of first trimester bleeding is caused by a subchorionic hematoma.

Signs and Symptoms of a Subchorionic Bleed

  • Spotting or Bleeding, that may be brownish (old blood) or even bright red (fresh blood).
  • May or may not experience cramping
  • Bleeding and cramping may come and go or die down after some time
  • Bleeding may be accompanied by clots of blood, but not tissue

How to Diagnose Subchorionic Bleed

Bleeding, not accompanied by tissue, that goes away, and hearing a strong heartbeat despite this bleeding suggests that this may be the culprit. To be sure, an ultrasound should be performed and will show blood in the uterus and a healthy fetus.

Second but empty sac on the right side indicating a twin that didn't make it past the embryonic stage. See the blood in the lower half that that sac.
Second but empty sac on the right side indicating a twin that didn't make it past the embryonic stage. See the blood in the lower half that that sac.

Vanishing Twin Syndrome

What is Vanishing Twin Syndrome?

Vanishing Twin Syndrome is a phenomena where multiple eggs are fertilized (usually two) but one of the embyros/fetuses fails to progress. Often, the deceased embryo/fetus gets absorbed by the placenta, the mother or the other baby. VTS occurring in the 1st trimester of pregnancy is usually not harmful to mom or the surviving twin.

What Causes VTS?

VTS is a miscarriage of one baby in a set of twins, usually caused by chromosomal abnormalities in the developing baby that are incompatible with life or when the yolk sac or placenta does not implant correctly.

How Common is Vanishing Twin Syndrome?

Vanishing twin syndrome is more common than you might think. It is estimated that vanishing twin syndrome occurs in up to 20% of all twin pregnancies, which means it occurs in 6 out of every 1000 pregnancies overall.

What are the symptoms of Vanishing Twin Syndrome?

Symptoms of Vanishing Twin Syndrome vary widely. Some women have no symptoms at all and may only find out if they knew they were having twins before the second twin died. On the other end of the spectrum you could have spotting and mild cramping or even strong cramping, bleeding and pain, much like if you were having a miscarriage of a singleton.

How is Vanishing Twin Syndrome Diagnosed?

An ultrasound is the only way to diagnose VTS during the 1st trimester. The ultrasound will show a second sac where a second baby should be. Instead of a fetus, the ultrasound may show fluid, or blood in the sac and or the remains of the second baby.

Decidual Bleeding

What is Decidual Bleeding

Decidual bleeding is hormonally related bleeding, occurring when some of the uterine lining is sloughed off, causing spotting or menstrual-like bleeding. The passage of this tissue may be confused with miscarriage or menstrual blood.

How Common is Decidual Bleeding?

Decidual bleeding is responsible for about 10% of 1st trimester bleeding.

Symptoms of Decidual Bleeding

Spotting or bleeding ranging from brown spotting to menstrual-like bleeding that may or may or may not be accompanied by cramping. Blood clots may be passed, but fetal material will not be.

Diagnosing Decidual Bleeding

Dicidual bleeding is diagnosed by ruling out other causes for bleeding.

  • Get off your feet and relax, preferably lying down or feet up
  • Take a warm bath and/or Tylenol to help with cramping
  • Drink plenty of water
  • Watch for blood clots and tissue
  • Call your Doctor and let them know what is happening

When is 1st Trimester Bleeding a Medical Emergency?

If you are soaking through overnight pads in under an hour, or start to feel dizzy or lightheaded, staying at home is no longer appropriate. You should go to the emergency room to ensure you are not hemorrhaging.

What to Do if You Experience 1st Trimester Bleeding

If you become one the of 30% of women who will experience 1st trimester bleeding, stay calm and remember that no matter how heavily you are bleeding, there are several possible explanations besides miscarriage.

Let your doctor or midwife know what you are experiencing. Your doctor may tell you to go to the emergency room or labor and delivery to be checked out. Understand that a 1st trimester miscarriage in progress cannot be stopped and going to either place will be very costly for you. The main benefit to going in right away is that you will hopefully find out immediately what is going on.

Know, however, that you do have the option of staying at home until normal office hours, or to miscarry naturally in an environment in which you will be more comfortable. A D&C is not usually necessary unless the remains have not passed within a week or so or if the bleeding becomes too heavy that it becomes dangerous for mom.

If you experience 1st trimester bleeding, get off your feet and drink plenty of water. Tylenol and/or a warm bath can help relieve any cramping. If you are not miscarrying, lying down may reduce the amount of blood flow. If it does, take it easy and stay off your feet as much as possible until the bleeding completely subsides. It is especially important to stay off your feet until a subchorionic hematoma under the placenta can be ruled out.

Wear super absorbent or overnight pads and make note of how often you are soaking through them. Collect any large clots you pass in a plastic bag or container. If you are miscarrying the baby you will then have the option to bury or cremate the remains if you so choose.

First trimester bleeding is indeed very scary, as you have read is not always related to miscarriage. It is not usually necessary to go to the emergency room when you experience bleeding, although many doctors currently advise this. As long as you are comfortable at home and are not bleeding excessively, you are safe staying home until you feel physically and mentally ready to go to a hospital or office to find out what is going on with your baby.

© 2014 Sarah


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      kekee 8 weeks ago

      hi Lydia I am going through the same thing as you. I have been bleeding since 11/01 and now its 11/24. The doctors said they don't know whats wrong. I got an ultrasound at 7 weeks 4 days and saw a heartbeat.

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      LYDIA 2 months ago

      I've bled with clots for over 4 weeks now, the can showed a sac with no embryo but with closed cervix, i was put on duphustone for 2 weeks but nothing has changed, yesterday i had something in my panty and when i checked it was a small piece greyish in colour with some mucus -like mixed with red. am supposed to go back to the doctor for another scan today but the bleeding has always been on and off and little but with some small clots. am scared, anyone with similar issues plese share with me

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      Naylaa 3 months ago

      I started with a brown spotting that turns into light pink and heavy red blood with small clot. Yesterday night there’s something came out of me like a flesh with blood on it and when I woke up today one more flesh came out from me. It’s like a minced fat. (Sorry for the word) is there anyone experienced same? I’m worry abt my 6weeks baby.

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      10 weeks, spotting, article helped 9 months ago

      I'm about 10 weeks prefix, have had mild cramping the past 3 days, and started spotting this eve. In my previous pregnancy I had a bit of spotting around this same time of pregnancy, and baby was fine.. I'm praying for the same this time. I've been very busy the past week and on my feet a lot, so I am hoping possibly it's just something mild, and not to worry.. Guess we shall see... God willing, Life willing, my little one will live...