Subchorionic Hematoma: What It Means for Your Pregnancy

You're in early pregnancy, maybe just saw the heartbeat last week. Then you notice bleeding - sometimes just spotting, sometimes heavier flow that sends you to the ER in a panic. An ultrasound reveals a subchorionic hematoma. Your doctor says to rest and monitor, but you're left wondering: what is this? Will my baby be okay?

What Is a Subchorionic Hematoma?

A subchorionic hematoma (also called subchorionic hemorrhage or SCH) is a collection of blood that forms between the uterine wall and the chorion (the outer fetal membrane surrounding the embryo) or under the placenta. Think of it like a bruise between the gestational sac and the uterus.

When the fertilized egg implants, blood vessels can tear slightly, causing bleeding that pools in this space instead of being absorbed or expelled. The blood clot can range from tiny (a few millimeters) to large (several centimeters).

How Common Are Subchorionic Hematomas?

Subchorionic hematomas occur in about 1-3% of all pregnancies, though they're detected more frequently now with early ultrasounds. Many small hematomas go unnoticed because they don't cause bleeding and resolve on their own.

They're most commonly diagnosed between 6-9 weeks of pregnancy, though they can appear anytime in the first trimester and occasionally into the second trimester.

Symptoms of Subchorionic Hematoma

The main symptom is vaginal bleeding, though about 20% of hematomas are found incidentally on routine ultrasound without any bleeding at all.

Bleeding Patterns

• Light spotting: Pink or brown discharge on toilet paper or underwear
• Moderate bleeding: Bright red blood requiring a pad
• Heavy bleeding: Soaking through a pad, sometimes with clots
• Bleeding that comes and goes: Stops for days or weeks, then starts again

The bleeding occurs as the hematoma drains or breaks down. Older blood appears brown, while fresh bleeding is bright red.

Cramping

Some women experience mild cramping or pelvic pressure along with bleeding. Severe, intense cramping is less common with SCH and might indicate something else.

No Symptoms

Many small hematomas cause no symptoms whatsoever and are only discovered during routine ultrasound. These are often the ones with the best outcomes.

What Causes Subchorionic Hematomas?

The exact cause isn't fully understood, but several factors may contribute:

Implantation Abnormalities

When the embryo burrows into the uterine lining, it disrupts blood vessels. Sometimes this process isn't perfectly smooth, causing bleeding that pools between membranes.

Placenta Formation

As the placenta develops and blood supply increases in early pregnancy, small bleeding episodes can occur. The blood may collect rather than being reabsorbed.

Risk Factors

Certain factors increase risk, though many women with SCH have none of these:

• IVF or fertility treatments
• Advanced maternal age (over 35)
• Multiple pregnancy (twins, triplets)
• Previous miscarriage or placental problems
• Uterine abnormalities
• Hypertension

How Is It Diagnosed?

Subchorionic hematomas are diagnosed via ultrasound, usually when investigating first trimester bleeding:

Ultrasound Findings

On ultrasound, the hematoma appears as a dark (hypoechoic) crescent-shaped area between the gestational sac and uterine wall. Your doctor will measure:

• Size: Length, width, depth in millimeters or centimeters
• Location: Where it sits relative to the placenta and cervix
• Percentage of sac separation: What proportion of the gestational sac is affected

Size Matters: Small vs Large Hematomas

Small hematomas (under 2cm) have excellent outcomes. Large hematomas affecting more than 25% of the gestational sac carry higher risks but many still result in healthy pregnancies.

Risks and Complications

The good news: most subchorionic hematomas resolve completely without affecting the pregnancy. However, there are some risks to be aware of:

Miscarriage Risk

The risk depends on hematoma size and when it's detected:

• Small hematomas: 2-5% miscarriage risk (similar to general population)
• Moderate hematomas: 10-20% miscarriage risk
• Large hematomas (over 50% of sac): Up to 40% miscarriage risk

Most losses occur in the first trimester. If you make it past 12 weeks with a resolving or stable hematoma, outcomes are much better.

Pregnancy Complications

Large or persistent hematomas into the second trimester may increase risk of:

• Placental abruption (placenta separating prematurely)
• Preterm labor
• Intrauterine growth restriction
• Preterm premature rupture of membranes

However, most small to moderate hematomas that resolve in the first trimester don't increase these risks.

Treatment and Management

There's no specific treatment to make a hematoma go away faster, but your doctor will likely recommend:

Pelvic Rest

This means:

• No sexual intercourse
• No vaginal exams (except necessary medical ones)
• No douching
• No tampons or menstrual cups
• No strenuous exercise

The goal is to avoid anything that might dislodge the clot or increase bleeding.

Modified Bed Rest or Activity Restriction

Your doctor might recommend reducing activity, especially if the hematoma is large. This doesn't mean strict bed rest (which has its own risks), but rather:

• Avoid heavy lifting over 10-15 pounds
• No running, jumping, or intense workouts
• Reduce standing for long periods
• Take it easy, but light walking is usually okay

Hydration

Staying well-hydrated may help the body reabsorb the hematoma more efficiently. Aim for 8-10 glasses of water daily.

Follow-up Ultrasounds

Your doctor will schedule repeat ultrasounds every 1-3 weeks to monitor:

• Whether the hematoma is shrinking, stable, or growing
• Fetal growth and heart rate
• Location of the hematoma relative to the placenta

Progesterone Supplementation

Some doctors prescribe progesterone supplements (pills or vaginal suppositories) to support the pregnancy, though research on its effectiveness for SCH is mixed.

What to Expect: Timeline of Resolution

Weeks 1-2 After Diagnosis

You may have continued bleeding or spotting as the hematoma drains. Brown discharge is old blood being expelled - this is actually a good sign that the clot is resolving.

Weeks 2-4

Bleeding often tapers off. Small hematomas typically resolve within 2-4 weeks. Larger ones may take 6-8 weeks or longer.

Second Trimester

Most hematomas resolve by 12-14 weeks as the placenta matures and blood flow patterns change. If a hematoma persists into the second trimester, your doctor will monitor more closely.

When to Call Your Doctor Immediately

Contact your healthcare provider right away if you experience:

• Heavy bleeding (soaking through a pad in an hour)
• Passing large clots (bigger than a golf ball)
• Severe cramping or abdominal pain
• Fever above 100.4°F
• Dizziness or fainting
• Sudden increase in bleeding after it had slowed

Can You Prevent Subchorionic Hematomas?

Unfortunately, there's no proven way to prevent subchorionic hematomas since the cause isn't fully understood. They often occur spontaneously with no clear trigger.

General pregnancy health measures may help:

• Avoid smoking and alcohol
• Manage blood pressure
• Take prenatal vitamins
• Avoid excessive physical strain in early pregnancy

Success Stories and Realistic Outcomes

Here's what the data shows about outcomes:

Overall Success Rate

About 80-90% of women diagnosed with subchorionic hematoma in the first trimester go on to have healthy pregnancies and babies. The key factors for good outcomes:

• Strong fetal heartbeat at diagnosis
• Small to moderate hematoma size
• Hematoma detected before 9 weeks
• Bleeding decreases over time
• Follow-up ultrasounds show shrinking hematoma

What Improves Your Chances

• Seeing a heartbeat: If the baby has a strong heartbeat when the hematoma is found, prognosis is excellent
• Early gestational age: Hematomas found at 6-8 weeks generally do better than those found later
• Small size: Under 2cm has very low complication rates
• No continued heavy bleeding: Light spotting or decreasing bleeding is reassuring

Life with a Subchorionic Hematoma

Emotional Impact

Living with SCH is stressful. Every trip to the bathroom brings anxiety about bleeding. Every ultrasound feels critical. This is completely normal. Consider:

• Joining online support groups for women with SCH
• Talking to a therapist about pregnancy anxiety
• Asking your doctor all your questions - no question is too small
• Focusing on one day at a time rather than the full pregnancy

Work and Daily Life

Depending on hematoma size and your job, you might need:

• Modified work duties (no heavy lifting, more breaks)
• Work from home if possible
• Short-term leave if the hematoma is large
• More frequent bathroom breaks (to monitor bleeding)

Questions to Ask Your Doctor

• How large is the hematoma and where is it located?
• What percentage of the gestational sac is affected?
• When will we do the next ultrasound?
• What level of activity is safe for me?
• What type of bleeding should I expect?
• At what point should I go to the ER?
• Should I take progesterone?
• Can I continue working?

The Bottom Line

Subchorionic hematomas are frightening, especially when they cause bleeding in early pregnancy. But the majority resolve on their own without harming the pregnancy. Small hematomas have excellent outcomes, and even moderate to large ones often result in healthy babies with proper monitoring.

If you're diagnosed with SCH, follow your doctor's recommendations for rest and activity restriction, stay hydrated, and attend all follow-up appointments. Most importantly, remember that bleeding doesn't automatically mean miscarriage - many women with subchorionic hematomas go on to deliver perfectly healthy babies.

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