Around 15% to 25% of pregnant women experience bleeding during the first trimester. Light bleeding and spotting can be perfectly normal, especially if it occurs around the time you would have had a period. Heavy bleeding or clots could indicate something more serious. You should always let your obstetrician or midwife know if you're bleeding during pregnancy.
What causes blood clots during pregnancy?
There are many different conditions that can cause you to pass clots during pregnancy. Some are minor. Some are not.
Unfortunately, about 10% to 15% of known pregnancies end in miscarriage in the first trimester. About half of all miscarriages are caused by chromosomal abnormalities that aren't genetic. Most women who have a miscarriage can have healthy pregnancies in the future. Symptoms of miscarriage can include:
- Bleeding or spotting from the vagina
- Cramps or abnormal pain
- Back pressure or pain
- Passing small or large clots
An ectopic pregnancy occurs when a fertilized egg implants somewhere other than the uterus. This usually happens in the fallopian tubes. An ectopic pregnancy can be life-threatening if it's not treated. You may not realize you have an ectopic pregnancy because it often has the same early signs and symptoms as a normal pregnancy. Some other symptoms of an ectopic pregnancy can include:
- Pain in the pelvis or abdomen
- Vaginal bleeding
- Dizziness or fainting
- Low blood pressure
- Low back pain
In a normal pregnancy, after an egg is fertilized tissue develops that forms the placenta and fetus. In a molar pregnancy, the tissue that would normally form the placenta develops into a mass of cysts. Fortunately, molar pregnancies only happen in about 1 in 1000 pregnancies. Most women who have molar pregnancies can go on to have a normal pregnancy. Signs of molar pregnancy are:
- Passing grape-sized cysts from your vagina
- Vaginal bleeding
- Severe nausea and vomiting
- High blood pressure
- Pelvic pain or pressure
A threatened miscarriage is when you have all of the signs of a miscarriage but your cervix is still closed. Your symptoms can last for days or weeks. You may go on to have a healthy pregnancy, or you may have a miscarriage. Unfortunately, there's rarely anything that can be done to prevent a miscarriage. Bedrest used to be recommended, but there's no evidence that this helps.
A subchorionic hematoma is bleeding between the wall of your uterus and the fetal amniotic sac, the "bag of fluid" that surrounds your baby. The bleeding happens when the placenta partially tears away from the wall of your uterus. The severity of a subchorionic hematoma depends on its size. Small ones often go away on their own. Larger ones are more likely to cause problems. Subchorionic hematomas are the most common cause of bleeding in women who are 10 to 20 weeks pregnant.blood vessels. It can bleed because of inflammation, irritation, or infection. If you have untreated chlamydia or gonorrhea, it can cause bleeding in early pregnancy.
Treatment for blood clots in early pregnancy
You should let your doctor know immediately if you have any bleeding during pregnancy. The treatment for blood clots will depend on the cause. Your doctor may test to determine the cause and best course of treatment for you. These tests may include a vaginal exam, blood tests, or an ultrasound.
If you are having a miscarriage, you may be able to go home and let it take its course. This can happen over days or weeks. You may be able to take medicine to help speed up the process. If your miscarriage isn't complete, you may need to have a dilatation and curettage (D&C). This is a minor surgery where your doctor opens your cervix and removes any remaining pregnancy tissue.
Can a miscarriage be prevented?
Most early miscarriages can't be prevented because they're caused by chromosomal abnormalities in the baby. These are usually mechanical errors in copying the genetic code that happen during fertilization or early cell division, and are not inherited or anyone's fault. Miscarriages rarely happen because of something you did or didn't do. You shouldn't blame yourself. While there's no definite way to prevent a miscarriage, there are some things you can do to reduce your risk:
- Eat a healthy, well-balanced diet.
- Stay active.
- Limit your caffeine before and during pregnancy.
- Don't drink alcohol during pregnancy.
- Don't use illegal drugs during pregnancy.
- Don't smoke.
- Achieve a healthy weight before pregnancy.
- Try to avoid infections such as rubella (German measles) during pregnancy.
- Keep all of your prenatal appointments.
- Manage any chronic conditions you may have.
What should you do if you're bleeding during early pregnancy?
Although it doesn't always mean you're having a miscarriage, heavy bleeding is worrying. You should let your midwife or doctor know immediately, even if the bleeding stops. You should also:
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Bondick, C.; Das, J.; Fertel, H. Subchorionic Hemorrhage. StatPearls. 2019.
KidsHealth: "Ectopic Pregnancy."
March of Dimes: "BLEEDING AND SPOTTING DURING PREGNANCY," "MOLAR PREGNANCY."
Pregnancy Birth and Baby: "Treatment of miscarriage," "Types of miscarriage."
Reproductive Health Access Project: "PREGNANCY LOSS (MISCARRIAGE)."
Tommy's: "Preventing miscarriage."
UpToDate: "Acute Cervicitis."