5 reasons for spotting during pregnancy and how to tell when it's serious

• Spotting, or light bleeding, during pregnancy, can be due to normal changes in your cervix.
• However, if you're experiencing other symptoms like fever or abdominal pain, seek medical aid.
• Complications like miscarriage or ectopic pregnancy are more likely to cause heavy bleeding.

Light bleeding, also known as spotting, is most common during the first trimester of pregnancy. However, you may experience some light bleeding at any point.

In fact, 25% to 40% of pregnant women experience some bleeding between conception and delivery.

Spotting might look like a few drops of blood, but not enough to fill a panty liner. Light spotting isn't usually a cause for concern. But if you're experiencing a couple of days of spotting or a heavier or longer flow of blood, reaching out to your healthcare provider can give you the clarity you need.

Keeping track of how long your spotting lasts and its timing can help you determine what's causing your bleeding. For example, implantation bleeding might result in a couple days of spotting, while an infection might cause hours to days of heavier bleeding.

Here are five common causes of spotting during pregnancy and when to reach out to your health provider.

1. Implantation bleeding

Implantation bleeding is a common sign of pregnancy that starts 10 to 14 days after conception. Since it's often around the time your period would start, it's easy to confuse implantation bleeding with your period.

However, this type of vaginal bleeding is typically lighter than your usual period and lasts for a shorter time, up to two days.

Symptoms may include:

• Brown or pink blood
• Mild to no cramping
• One to two days of light bleeding

Implantation bleeding can be a normal and even expected part of pregnancy. If you think you may be experiencing this condition, an evaluation with your doctor can help to rule out any potential concerns and give you greater peace of mind.

2. Sexual intercourse

Sexual intercourse may cause spotting due to changes in your cervix that occur during pregnancy. This is more likely to cause light bleeding in your second or third trimester.

Symptoms include:

• Light spotting or bleeding for up to several hours after sex
• Tenderness or sensitivity in the lower abdomen

If you experience bleeding after intercourse, you should wait to have intercourse again until after you've seen your provider to prevent further irritation. Your doctor may advise different types of sex or refraining until after delivery.

If you experience heavy bleeding, frequent contractions, or your abdomen feels painful or stiff, seek evaluation immediately as this could be a sign of pregnancy complications.

3. Cervical issues

During pregnancy, your cervix shortens and softens in preparation for delivery. Blood flow also increases to the cervix. All of these changes make it easier to irritate the cervix, which can cause spotting.

"Bleeding from cervical issues can happen from something physical like intercourse, exercise, or even straining with a bowel movement," says Lisa Holloway, WHNP-BCC and founder of Sweet Pea Childbirth Prep.

Here are a few other cervical issues that can cause spotting:

• Cervical polyps affect 2% to 5% of women and generally don't produce symptoms. While typically small and asymptomatic, your doctor may recommend removing any polyps that cause bleeding or discharge. Some doctors believe cervical polyps are more likely to bleed during pregnancy due to increased estrogen levels and blood vessels in the tissue around the cervix.
• Cervical ectropion (cervical ectopy) is often asymptomatic and only requires treatment if you're struggling with issues like spotting. However, treatment is usually delayed until after pregnancy. This condition causes bleeding after intercourse in 5% to 25% of women, making it one of the most common causes of vaginal bleeding in the third trimester.
• Cervicitis is an infection or irritation of the cervix often caused by sexually transmitted infections like chlamydia. While only 5% to 30% of women experience symptoms, you may experience vaginal discharge, abdominal or pelvic pain, bleeding, or changes in urination.

Let your health care provider know about any new bleeding you experience - they will likely recommend an evaluation to look for its cause. "If the bleeding is coming from inside of the uterus, the baby may be affected," Holloway says.

4. Infections

Pregnancy alters your immune system, leaving you more vulnerable to infections that can inflame the cervix and may cause spotting.

"Women are at an increased risk of urinary tract, yeast, and bacterial infections during pregnancy, leading to raw, irritated surfaces that can cause bleeding," says Brian Levine, MD and practice director at CCRM Fertility. Other infections include STIs like gonorrhea and chlamydia.

If you have an infection, in addition to bleeding, you might experience the following:

• Discharge
• Burning while urinating
• Pain during intercourse
• Fever

It's important to see your doctor if you think you may have an infection since, in the case of STIs, they can be transmitted from mothers to infants during childbirth or create significant risks for your pregnancy.

According to one 2021 study of over 14 million mother-infant pairs in the United States, sexually transmitted infections also increase a woman's risk of preterm birth. The rates were 9.9% in women with chlamydia, 12.2% in women with gonorrhea, and 13.3% in women with syphilis.

5. Pregnancy complications

"All of the scary pregnancy complications that can be associated with bleeding like ectopic pregnancies, molar pregnancies, or miscarriages can be identified by blood work, ultrasound, or both," says Levine.

Pregnancy complications can affect you or your fetus's wellbeing, even if you were healthy before getting pregnant.

Common causes of pregnancy complications include:

• Ectopic pregnancy occurs when a fertilized egg implants outside of your uterus and is identifiable in the first trimester. This can cause bleeding and become life-threatening.
• Molar pregnancy occurs when an egg and sperm join incorrectly, and a noncancerous tumor forms instead of a placenta. Since the primary symptom is bleeding within the first three months of your pregnancy, your doctor can spot this in your first trimester.
• Miscarriage is a pregnancy loss resulting from natural causes before 20 weeks. Signs include spotting, bleeding, cramping, or tissue passing from the vagina.

"Each pregnancy complication has its own characteristic patterns of bleeding and presentation," says Levine.

While these conditions are more likely to cause heavy bleeding than spotting, it's safest to share any symptoms with your doctor immediately so they can determine if your bleeding is caused by anything serious.

Insider's takeaway

While spotting during pregnancy is common, you should always seek medical care for any vaginal bleeding.

"As many as one in five women experience spotting or bleeding during any given pregnancy. If you're experiencing bleeding that's more than a pad an hour, or if it's associated with cramping, call your OB-GYN to seek advice and guidance," says Levine.

While you wait for a call back, find a safe place to sit, stay hydrated, and make sure a friend or family member knows what's happening.

"Most importantly, remember that bleeding during pregnancy is very common, and your provider can help," says Levine.