Medically reviewed by
Dr. Gary Emerson
McLeod OB/GYN Associates

Approximately one in four pregnant women may experience some bleeding during the different phases of her pregnancy. McLeod OB/GYN Dr. Gary Emerson provides an overview of possible causes for this occurrence.

FIRST TRIMESTER

“Bleeding is especially common during the first 3 months (trimester) of pregnancy,” says McLeod OB/GYN Dr. Gary Emerson. “In many cases, the woman experiences only spotting, a small amount of blood from pink to dark brown. Spotting is different from bleeding, which would require a pad or tampon to stop the blood.”

Early in a woman’s pregnancy, vaginal mucosa becomes congested and turn red or purple, called Chadwick’s Sign.

During the first trimester, the bleeding most likely can be caused by:

• Implantation, a sign that the embryo is implanting in the wall of the uterus.
• Miscarriage. Other symptoms might include back pain, weight loss, cramping, and mucous or clot-type material coming out of the vagina. With a miscarriage, little can be done to maintain the pregnancy.
• Ectopic pregnancy, where the embryo implants outside of the uterus rather than inside. The woman may experience weakness, dizziness or pelvic pain.
• Infection or simply changes to your cervix during pregnancy.

SECOND TRIMESTER

During the second trimester (months 4 through 6 of the pregnancy), a cervical exam or intercourse may cause irritation that leads to bleeding. Another common cause could be non-cancerous growths, such as cervical polyps, which usually don’t cause serious problems.

Minor bleeding during your second trimester is not unusual, but you should be checked by your OB/GYN.

THIRD TRIMESTER

In the final 3 months of pregnancy, the expectant mother may again experience light bleeding after a cervical exam or intercourse.

Heavy bleeding will require emergency medical care. The bleeding may signal several serious issues:

• When part or all of the placenta invades the wall of the uterus (placenta accreta), not only can bleeding during pregnancy result, but it may also cause severe bleeding during delivery.
• The placenta may cover the cervix, which is called a placenta previa. Your doctor should tell you at your 20-week ultrasound about the placenta. This can resolve as the baby grows and will likely be followed during the pregnancy.
• The placenta can detach from the uterus wall before or during birth (abruption). If this complication is not resolved, the pregnant woman may experience severe bleeding and the baby may not receive enough oxygen.

ACTION YOU CAN TAKE

If you have any doubts about bleeding during pregnancy, contact your OB/GYN to discuss.

Find an OB/GYN near you.