High White Blood Cell Count in Pregnancy: What It Means and When to Worry

Pregnancy is filled with new experiences, questions, and sometimes—lab results that seem confusing or even a little scary! One of those results might be an elevated white blood cell count, or WBC count for short.

So what does a high white blood cell count in pregnancy mean? Is it normal? Is it something to worry about? Let’s break it all down!

What are white blood cells (WBCs)?

White blood cells are part of your immune system. Their main job is to help your body fight off infections and other foreign invaders.

There are several types of WBCs, each with a unique role—like attacking bacteria, fighting viruses, and managing inflammation.

Is it normal for WBC count to be elevated in pregnancy?

Yes—it’s not only normal, it’s expected! In fact, many providers consider a slightly elevated white blood cell (WBC) count during pregnancy to be a standard part of the journey.

Here’s why 👇

During pregnancy, your body is working overtime to support two immune systems—yours and your baby’s! Your immune system adapts in some pretty fascinating ways to protect you both:

• It ramps up certain defenses to help you fight off infections more efficiently
  
  
• It tones down other parts of your immune response so your body doesn’t reject baby as “foreign”
  
  
• And—one big change—your WBC count naturally goes up, especially in the second and third trimesters

This increase is a result of hormonal shifts, increased blood volume, and your body’s way of prepping for the major event of birth. Many pregnant people will have WBC counts that are slightly higher than the “normal” range for non-pregnant adults—and that’s totally fine!

Here's What You Might See on Your Labs:

• Early pregnancy (first trimester): Slight changes or still within typical adult ranges
• Second trimester: A steady increase may begin
• Third trimester: WBCs can rise even more—this is when it’s most common to see elevated numbers
• Labor: Your WBC count may spike again due to physical stress and inflammation during childbirth

💡 Fun fact: A high-normal or mildly elevated WBC count without symptoms is one of the most common lab findings during pregnancy. Your provider sees this all the time, and unless there are other red flags (like fever or pain), it usually doesn’t raise concern.

What does a high WBC count in pregnancy mean?

A high white blood cell (WBC) count during pregnancy can feel a little alarming but in many cases, it’s completely normal! 🙌

White blood cells are your body’s defenders—they help you fight off infection, heal from inflammation, and manage stress responses. So, when your WBC count is elevated, it means your immune system is activated.

But here’s the key: pregnancy itself is a trigger for increased WBC production.

So, what does it really mean?

It depends on two big things:

1. How high is “high”?
2. Are there any symptoms or other abnormal findings?
   

Let’s break it down 👇

Mildly elevated WBC? Usually no big deal!

During pregnancy—especially as you get into the third trimester—it’s super common to see WBC levels that hover above what’s considered “normal” in non-pregnant adults.

For example:

• A non-pregnant adult might have a normal WBC count between 4,500 and 11,000
  
• But in pregnancy, counts between 12,000 and 15,000 (or even higher during labor) are often still within normal limits!

If your WBC count falls into that range and you’re feeling totally fine (no fever, pain, or signs of illness), your provider will likely chalk it up to one of the many normal immune shifts happening in your body right now.

But if it’s very high? Or you’re having symptoms?

That’s when your provider may want to take a closer look.

Here are some things they’ll consider:

• Is your WBC count rising quickly over time?
• Are other labs showing signs of infection or inflammation?
• Are you having symptoms like fever, chills, pain, or discharge?
  

In those cases, a high WBC count could point to:

• A bacterial infection (like a UTI, kidney infection, or respiratory infection)
• Inflammation or injury
• An immune-related condition
• In rare cases, blood disorders (though these are very uncommon in pregnancy)

But here’s the thing: your WBC count is just one piece of the puzzle. Your provider will interpret it alongside your symptoms, physical exam, and other lab results before jumping to any conclusions.

TL;DR:

• A slightly elevated WBC count? Usually nothing to worry about!
  
• A very high count plus other signs of illness? Your provider will investigate and treat as needed

No matter what—you’re not alone and your care team is here to keep you and baby safe 💕

So, what counts as a high WBC count?

In non-pregnant adults, the normal WBC range is usually between 4,500 and 11,000 cells per microliter of blood.

During pregnancy, it’s not uncommon for that number to climb up to 12,000 or even 15,000—especially in the third trimester.

And during labor, it can spike even higher!

Normal WBC ranges in pregnancy

Here's a quick look at what might be considered “normal” in pregnancy:

• First trimester: 5,700–13,600
  
  
• Second trimester: 5,600–14,800
  
  
• Third trimester: 5,900–16,900
  
  
• During labor: Can rise up to 20,000 or more!

These numbers might seem high—but your body is working hard to prepare for birth and protect you both!

Why does WBC count increase in pregnancy?

Let’s talk about your immune system—it’s doing some serious multitasking during pregnancy! 

Your body is growing a whole new human, which means your immune system has to walk a fine line. It needs to protect you from infections while also "tolerating" your baby, who—fun fact—is technically genetically different from you!

And that delicate balancing act? It causes some changes in your bloodwork—including a natural increase in WBC count.

Here’s why your WBCs are on the rise:

• Hormonal shifts

Hormones like estrogen and progesterone aren’t just helping your uterus grow and your placenta thrive—they’re also influencing your immune system. These shifts can trigger a mild increase in inflammation, which boosts your WBC production.

• Increased blood volume 

Did you know your blood volume increases by nearly 50% during pregnancy? 😲 That extra volume means your bone marrow is working overtime to produce more red and white blood cells to support you and your baby’s growing needs.

• Inflammation 

Pregnancy itself is considered a pro-inflammatory state (especially early and late in pregnancy). Inflammation doesn’t always mean infection—sometimes it's your body’s way of adapting to all the changes. Think of it as your immune system staying “on alert.”

• Labor prep

In the third trimester, your immune system starts gearing up for the big event—birth! Researchers believe that elevated WBC levels may help your body respond to labor stress, heal postpartum, and fight off any potential infections during delivery.

• Stress

Physical stress (like growing a human!) and even emotional stress can nudge your WBC count upward. Your body recognizes stress—good or bad—as a trigger to protect and defend.

So, It’s Not Just Normal—It’s Smart!

Your body is amazing. It’s not just growing your baby—it’s also putting systems in place to keep you both safe. A higher white blood cell count is just one of those changes. And in most cases, it’s a totally healthy sign that your immune system is doing its job ✅

When to be concerned

You should talk to your provider if:

• Your WBC count is very high (which hopefully they are already aware of and investigating)
  
  
• You’re experiencing fever, chills, or signs of infection
  
  
• You feel unwell or have other concerning symptoms

In most cases, elevated WBCs during pregnancy are nothing to panic about—but your provider may run additional tests to rule out infection or other issues.

How your provider might interpret an elevated WBC count

So, you got your lab results back and saw your white blood cell (WBC) count is higher than usual. First of all—take a deep breath 💛 In pregnancy, this is super common and often not a red flag 🚩

Still, your provider won’t look at that number in isolation. They’ll look at the whole picture to decide whether your elevated WBCs are just part of normal pregnancy changes—or a signal that something else might be going on.

How high is it, really?

There’s a big difference between a WBC count that’s just slightly elevated and one that’s significantly above the expected range. Your provider will compare your count to pregnancy-adjusted norms (which are higher than for non-pregnant folks!).

For example:

• A WBC of 13,000 in the third trimester? Probably normal!
• A WBC of 20,000+ with no labor or signs of infection? That might raise some eyebrows.

What are your symptoms?

Your provider will ask things like:

• Do you have a fever?
• Are you feeling generally unwell?
• Any localized pain, swelling, burning, or discharge?

If you're feeling great, and your WBC is just a little high? They’ll likely chalk it up to pregnancy itself 👏 But if you’re having other symptoms, they’ll dig deeper.

What do other lab results say?

WBC counts don’t tell the whole story. Your provider may look at:

• Differential count (which type of WBCs are elevated—neutrophils? lymphocytes?)
• CRP (C-reactive protein) or ESR (inflammatory markers)
• Urinalysis (to check for urinary tract infections)
• Blood cultures or swabs (if infection is suspected)

These help pinpoint whether your body is just prepping for birth—or fighting something off.

Where are you in your pregnancy?

Timing matters. As I previously mentioned, a high WBC in late pregnancy or during labor is usually expected—your body is under physical stress and your immune system is on high alert.

But in early pregnancy, a significantly elevated count might warrant more attention and possibly further testing, just to be safe.

What’s the trend?

One high reading might not be a big deal. If your WBC count keeps rising—or if your symptoms change—your provider may want to:

• Monitor your labs again in a few days
• Rule out developing infection
• Adjust care accordingly to keep you and baby safe

Burning questions about WBC counts and pregnancy

You’ve got questions—we’ve got answers! Let’s tackle some of the most common concerns mamas have when they see a high white blood cell count on their labs

1. Can stress or anxiety raise my WBC count?

It sure can!

Your body responds to emotional stress the same way it responds to physical stress—by releasing hormones like cortisol and adrenaline. These stress hormones can temporarily increase your WBC count as part of your body’s “fight or flight” response 🧠⚡

Even if you don’t feel super anxious, things like:

• Sleep deprivation
• Overwhelm or mental load
• Major life changes
• Pregnancy-related anxiety (hello, Google spiraling!)

...can all lead to subtle immune changes—including a bump in white blood cells.

Pro tip: If you’re feeling especially anxious, talk to your provider. They can help screen for prenatal anxiety and connect you with resources like counseling, meditation tools, or support groups ❤️

2. Will high WBCs affect my baby?

In most cases—nope!

If your elevated WBC count is simply due to pregnancy or labor-related changes (which is the case for most people), it poses no risk to your baby. Your immune system is doing what it’s meant to do—protecting you both!

However, if a high WBC is caused by something like an untreated infection, your provider will step in quickly with the right treatment to keep things safe.

That might look like:

• Starting antibiotics (for something like a UTI or respiratory infection)
• Monitoring fetal wellbeing
• Running additional labs to confirm what’s going on

So while high WBCs alone aren’t usually dangerous, they’re a good early alert system that helps your provider keep an extra close eye on things.

3. Does WBC count increase during labor?

Oh yes—it definitely can!

Labor is a major physical stressor, and your body treats it like a super intense workout + potential immune challenge rolled into one 

So it’s totally normal for your WBC count to:

• Rise dramatically during active labor
• Peak shortly after delivery
• Gradually return to your normal postpartum levels within a few days

Your provider expects this, and they won’t be alarmed by high WBCs during or right after birth—unless you’re showing signs of infection or complications.

So if your birth team mentions your WBCs are “elevated,” know that it’s a totally expected part of your labor and recovery process!

The bottom line?

A high WBC count during pregnancy can feel scary when you see it pop up on your lab results—but here’s the truth: in most cases, it’s completely normal and expected.

Your body is doing SO much right now—it’s literally growing a human and preparing for the powerful event of birth! That means your immune system is working around the clock to:

• Protect you and your baby
• Respond to stress and inflammation
• Heal quickly and efficiently when labor kicks in

It’s super common for providers to see slightly elevated WBC counts—especially in the third trimester and during labor—and not bat an eye. Unless there are other concerning symptoms or lab markers, a high WBC is just part of your body’s normal adjustment to pregnancy 💪

But of course, if you’re ever feeling off, don’t hesitate to check in with your provider. They’ll take a full look at everything—your symptoms, physical exam, other labs—and make sure you’re in the clear. That’s what they’re there for!

✨ You’re not expected to interpret this stuff alone. It’s okay to ask questions. It’s okay to need reassurance. And it’s definitely okay to not Google spiral when you’ve got a solid team on your side 💛

So take a deep breath, mama—you’re doing amazing. And your body? It’s doing exactly what it was designed to do.