What Are the Causes of Bleeding in the 4th Month of Pregnancy?

By Erica Loop
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The fourth month of pregnancy marks the beginning of your second trimester. While some of the unpleasant parts of pregnancy, such as morning sickness and a constant case of fatigue, may have passed, you can still have worries. If you suddenly experience vaginal bleeding, it’s crucial to get examined by a medical professional as soon as possible. Even though it's often a minor issue that resolves on its own with no harm to you or the baby, only a doctor can diagnose the source of the bleeding.

Placenta Previa

Placenta problems may appear at the end of the fourth month of pregnancy. In placenta previa, the placenta covers, or partially covers, the cervix. This is a potentially serious condition and may cause maternal hemorrhaging, preterm birth, birth defects, slowed fetal growth or infection following delivery, according to the Children's Hospital of Wisconsin.

Several issues can cause this condition, such as uterine scarring from previous pregnancies, fibroids, a maternal age older than 35, smoking cigarettes or having placenta previa before, according to the Children’s Hospital of Wisconsin.

Bright red bleeding without abdominal pain is the most common sign of placenta previa, although some women have no bleeding with this condition. If you suspect placenta previa, talk with your doctor immediately. The doctor needs to do a physical exam and ultrasound to reach a diagnosis.

The course of treatment depends on factors such as your overall medical history and the extent of the condition. Your doctor also factors in gestational age, fetal health and how much you're bleeding. Depending on where the placenta is, your doctor may need to perform an emergency C-section, or he may decide to just continue to monitor the condition. If you are hemorrhaging heavily, you may also need a blood transfusion.

Placental Abruption

Placental abruption is another possible cause of bleeding. During a placental abruption, the placenta separates from the uterus wall. The placenta may not completely separate from the uterus. The amount of bleeding typically reflects how much of the placenta has pulled away from the uterine wall.

Other symptoms of this condition include abdominal pain, contractions, nausea, faintness and decreased fetal movements. Your doctor uses an ultrasound and exam to determine if you have a placental abruption along with the extent of the damage.

Possible factors that put you at risk for a placental abruption include having the condition in a previous pregnancy, high blood pressure, a multiple pregnancy or cigarette smoking.

There is no cure or reversal of placental abruption. Your doctor determines the severity of the abruption, amount of bleeding and your baby’s gestational age before creating a course of action. A placental abruption often requires a C-section. Like with placenta previa, heavy hemorrhaging may require a blood transfusion.

Bleeding from a Miscarriage

A miscarriage is a common, although heartbreaking, cause for bleeding in pregnancy. The term miscarriage refers to the loss of a pregnancy in the first 20 weeks. Signs include bleeding, passing clots and cramping, according to the American College of Obstetricians and Gynecologists. While it’s common to worry that you’re having a miscarriage if you’re bleeding in the fourth month, only your doctor can give you a diagnosis.

It is essential to get prompt medical care if you are experiencing the signs of miscarriage. Aside from a diagnosis, the doctor needs to determine whether the fetal and placental tissue is completely expelled. If it isn't, the doctor needs to prescribe a medication or use a surgical procedure to remove it.

Other Common Causes

Bleeding during the fourth month of pregnancy doesn’t always mean that there’s a complication. Some causes of bleeding are minor and often resolve quickly on their own. These include hormonal changes, irritation from an internal vaginal exam or agitation from sex. For example, a cervical check may cause minor bleeding directly after an obstetric exam. Like any other potential cause, you should always consult a medical professional if you have unexplained bleeding.

About the Author

Based in Pittsburgh, Erica Loop has been writing education, child development and parenting articles since 2009. Her articles have appeared in "Pittsburgh Parent Magazine" and the website PBS Parents. She has a Master of Science in applied developmental psychology from the University of Pittsburgh's School of Education.