Bleeding in the second or third trimester of pregnancy

By trimester

Weeks 1–13

1st trimester

First-trimester spotting is common and usually has a different, often benign, explanation than bleeding later in pregnancy. This page focuses on the second and third trimester, when bleeding is less common and more often points to a specific cause.

Weeks 14–27

2nd trimester

Bleeding that starts in the second trimester is worth a same-day call. Placenta previa is often first spotted on a routine anatomy-scan ultrasound before any bleeding happens, which is one reason that scan matters even without symptoms.

Weeks 28–birth

3rd trimester

Both placental abruption and placenta previa are more likely to become symptomatic in the third trimester. If previa is still present near your due date, a cesarean delivery is typically planned around 36 to 37 weeks rather than waiting for labor to start.

What does the evidence show for vaginal bleeding in the second or third trimester?

• In a hospital-based study of antepartum hemorrhage, placental abruption and placenta previa together accounted for roughly 95% of cases, and about half of the women affected experienced an adverse maternal outcome such as postpartum hemorrhage or anemia. 1
• Placental abruption, the premature separation of the placenta from the uterine wall, affects about 0.4% to 1.0% of pregnancies and classically causes vaginal bleeding with acute abdominal pain and uterine tenderness, though the absence of visible bleeding does not rule it out. 2
• Placenta previa, when the placenta covers the cervix, affects about 0.3% to 2% of pregnancies in the third trimester and classically presents as painless vaginal bleeding, which is the main feature that distinguishes it from abruption. 3
• When placenta previa is suspected, a digital cervical exam should be avoided because it can trigger severe hemorrhage; delivery is generally planned by cesarean around 36 to 37 weeks, or sooner if bleeding does not stop. 3
• Vaginal bleeding is listed among the pregnancy danger signs that call for immediate transport to a health facility, since bleeding, especially in a woman who is anemic, can become life-threatening within hours. 4

When should I call my provider about vaginal bleeding in the second or third trimester?

Heavy bleeding, bleeding with strong or constant abdominal pain, uterine tenderness, contractions, dizziness, or a sudden change in fetal movement are signs of possible placental abruption, a premature separation of the placenta that is an obstetric emergency; the absence of visible bleeding does not rule it out. Painless bleeding that soaks through a pad, even without any pain at all, is the classic pattern of placenta previa and still needs same-day evaluation. Because exam findings alone cannot always confirm or exclude these causes, any second- or third-trimester bleeding calls for prompt hands-on assessment rather than a wait-and-see approach. Whatever the pattern, any symptom that feels beyond your usual range is a reason to call: obstetric teams expect these questions and would rather hear early than late.