Conditions That Cause Spotting in the Third Trimester

Pregnant woman with nurse

As the end of your pregnancy draws near, you may start to have concerns about spotting in third trimester.

Spotting During Early Pregnancy

Many women experience spotting at some point in their pregnancy, usually in the first trimester. This spotting is often the first sign telling a woman that she could be pregnant. Early pregnancy spotting occurs for several reasons. First, spotting may occur when implantation occurs, usually about 10-14 days after ovulation. Not all women experience this, but those who do may confuse the spotting with the start of a period. Implantation bleeding, however, only lasts a few hours to a day and is light with no definite flow.

Pregnant women also experience spotting during the first few weeks as their body is stretching to accommodate the growing embryo. This spotting is normal, but any heavy bleeding or clots should be reported to a doctor immediately.

Spotting in Third Trimester

Bleeding that occurs during the third trimester, which starts at 27 weeks, can be a sign of a potential complication. Any woman who experiences bleeding or spotting in third trimester should call her doctor's office immediately, since this can be a sign of serious problems for both the mother and the baby.

The conditions that third trimester spotting can indicate include:

  • Placental abruption: This is caused when the placenta becomes unattached to the uterus. Because the placenta is no receiving nutrients through the uterus, this is a dangerous condition for the baby. Stomach pain also occurs with the spotting and is more likely to occur in older moms or women who have an injury to their stomach or suffer from sickle cell anemia or high blood pressure.
  • Placenta previa: This can occur when the placenta attaches low in the uterus or covers the cervix. In a normal pregnancy, the placenta attaches higher in the uterus in an area that is able to stretch and grow with the development of the baby. When the placenta attaches too low, the stretching in late pregnancy can cause bleeding. If left untreated, hemorrhaging and preterm labor may occur. Since placenta previa can start without any discomfort to the mother, it's important that she reports any spotting to her doctor. Bed rest is one of the most common treatments for placenta previa.
  • Preterm labor: Spotting in third trimester may also be an indication of preterm labor. This is usually accompanied by contractions, fluid leakage from the vagina, and back pain. If a woman starts labor before 37 weeks, she needs to get to a hospital or doctors office immediately. In some cases, doctors may be able to stop the labor from progressing to allow the baby more time to develop.

Although the above conditions are all very serious, they only occur in a small number of pregnancies. For most women nearing the 40 week mark, spotting is likely a sign that labor is starting. As labor begins, the mucus plug, which has kept the cervix closed during pregnancy, can fall out, bringing some blood and discharge with it. If this happens, it's time for the mother to put her birth plan to work and start preparing for labor.

Since the cervix and vagina has a greater blood circulation during pregnancy, spotting can also be caused by any kind of vaginal irritation, including intercourse, OB/Gyn exams, and transvaginal ultrasounds. Though any kind of bleeding may alarm a pregnant woman, this type of spotting is generally harmless and should go away after a few hours. Still, it's always a good idea to talk to a doctor about any spotting in third trimester to rule out complications.

Conditions That Cause Spotting in the Third Trimester