Bleeding when pregnant sounds scary, and it certainly can be. However, about 20% of women experience some bleeding during their first trimester of pregnancy. Some causes of bleeding during pregnancy are normal and not necessarily a sign that something is wrong, but you should be aware of what bleeding when pregnant means and when you should see your doctor.
Benign Causes of Bleeding When Pregnant
Within the first six to twelve days post-conception, you may experience some spotting as the fertilized egg implants in the lining of the uterus. This is often mistaken as a period by women who don’t yet realize they are pregnant. This type of bleeding when pregnant is usually very light, lasting from a few hours to a few days.
Pregnancy causes extra blood to flow to the cervix. As a result, intercourse or pelvic exams can cause light bleeding. This is normal and no cause for concern.
A harmless growth on the cervix, cervical polyps are more likely to bleed during pregnancy as a result of increased estrogen levels and the increased number of blood vessels in the tissue around the cervix.
Abnormal Causes of Bleeding During the First Half of Pregnancy
Unfortunately, 15% to 20% of pregnancies end in miscarriage within the first twelve weeks of pregnancy. While we don’t always know why a pregnancy has ended in misacarriage, the majority of early losses are related to chromosomal issues limited to that specific pregnancy, and are not related to maternal factors. If you are experiencing continued bleeding, or cramping combined with bleeding, you should reach out to your care team.
An ectopic pregnancy occurs when the egg implants itself somewhere outside the uterus, most often in the fallopian tubes. Ectopic pregnancies happen in 1 out of 50 pregnancies. Along with bleeding, you may experience strong abdominal cramping low in the stomach, sharp pain in the abdominal area, and low HCG levels.
A rare cause of early bleeding, molar pregnancies involve the growth of abnormal tissue instead of the embryo. Along with bleeding, tests may reveal high HCG levels, absent fetal heart tones, and grape-like clusters seen in the uterus by ultrasound.
Some vaginal and uterine infections can also cause bleeding. When assessing vaginal bleeding in pregnancy, your midwife or doctor will often screen for common infections.
Abnormal Causes of Bleeding During the Second Half of Pregnancy
This case is extremely rare, occurring in only 1% of pregnant women, and more likely during their last twelve weeks of pregnancy. Placental abruption occurs when the placenta detaches from the uterine wall before or during labor. Along with bleeding, you may have stomach pain.
You are at a higher risk for placental abruption if you:
- Have already had children
- Are over 35
- Have a history of abruption
- Have hypertension
- Have sickle cell anemia
- Have had trauma or injury to your stomach
- Use cocaine
This very serious condition occurs when the placenta lies low in the uterus either partly or completely covering the cervix. It requires immediate medical attention. Occurring in 1 out of 200 pregnancies, the bleeding is not usually accompanied by pain.
You are at a higher risk for placenta previa if you:
- Have already had children
- Had a previous cesarean birth
- Had other surgery on the uterus
- Are carrying twins or triplets
The mucus plug sometimes passes up to a few weeks before labor begins, it is made up of mucus and blood. If it occurs any earlier, you may be entering preterm labor. Other signs include:
- Watery mucus or bloody discharge
- Pelvic or lower abdominal pressure
- Low, dull ache in back
- Stomach cramps
What Should You Do If You’re Bleeding When Pregnant?
While there is often no cause for alarm, bleeding when pregnant can be a sign that something is wrong, so you should always consult with your midwife or doctor. They will be able to determine whether your bleeding is normal or cause for concern.
It’s a good idea to use pads or a panty liner to keep track of the amount of blood flow to report to your care team. You should avoid the use of tampons.
Together, you and your healthcare provider can discuss and take the appropriate next steps for the health and safety of yourself and your baby.