Your placenta is working around the clock to nourish and protect your baby, yet most of us know surprisingly little about it until something prompts concern. Whether you've read something unsettling online, heard a new term at your last appointment, or simply want to understand what's happening inside your body, knowing the basics of placenta health in pregnancy can help you speak up, ask better questions, and feel more confident as your pregnancy progresses.

What the Placenta Actually Does (and Why It Matters)

Your Baby's Lifeline

The placenta is the only organ your body grows temporarily, and it performs several critical jobs at once. It delivers oxygen from your bloodstream to your baby and carries carbon dioxide away. It transfers nutrients—glucose, amino acids, vitamins—that fuel growth and development. It produces hormones like progesterone and human chorionic gonadotropin (hCG) that sustain the pregnancy. And it filters waste products your baby can't yet process on their own.

A Protective Barrier—With Limits

The placenta acts as a selective barrier. Many beneficial substances cross easily: antibodies that help protect your baby from infection, for example. But it's not a perfect filter. Alcohol, nicotine, some medications, and certain infections can cross the placenta and affect your baby. That's why your provider will ask about medications, supplements, and lifestyle choices throughout your pregnancy.

When It Forms and How It Changes

The placenta begins forming at implantation, but it is a microscopic structure in the earliest weeks, only becoming a fully functional organ capable of supporting your baby by the end of the first trimester. It continues to grow throughout pregnancy, typically weighing about one to two pounds at term. Development in those early weeks sets the stage for how well the placenta will support your baby later, which is why early prenatal care matters.

Common Concerns About Placenta Health in Pregnancy

Placenta Position (Placenta Previa, Low-Lying Placenta)

During your anatomy scan, your sonographer will note where the placenta is attached. A low-lying placenta sits close to the cervix; placenta previa means it partially or completely covers the cervical opening. Hearing a term like "low-lying placenta" during an anatomy scan can be unsettling. It's normal to feel worried, but it's helpful to remember that for the majority of cases, this is a routine observation that requires nothing more than a follow-up scan.

The good news: many low-lying placentas move up as the uterus grows. Your provider will schedule a follow-up scan, typically around 32 weeks, to check whether it has shifted. If placenta previa persists into the third trimester, you'll need a cesarean delivery to avoid bleeding during labor.

Placental Abruption

Placental abruption happens when the placenta separates from the uterine wall before delivery. It's uncommon but serious, requiring immediate medical attention. Risk factors include high blood pressure, smoking, trauma to the abdomen, and a prior abruption. Warning signs include vaginal bleeding, persistent abdominal or back pain, and frequent contractions. If you experience these symptoms, call your provider or go to the hospital right away.

Placenta Accreta Spectrum

Sometimes the placenta attaches too deeply into the uterine wall. This is called placenta accreta (or increta or percreta, depending on the depth). It's more common in people who've had prior cesarean deliveries or have placenta previa. Your care team may monitor for it with ultrasound if you have risk factors. Delivery planning is essential, often involving a scheduled cesarean with a specialized surgical team.

Placental Insufficiency

Placental insufficiency means the placenta isn't delivering enough oxygen or nutrients to support your baby's growth. It can be linked to high blood pressure, preeclampsia, diabetes, or other conditions that affect blood flow. It's often detected through ultrasound measurements showing slower-than-expected fetal growth, or Doppler studies that assess blood flow through the umbilical cord. If diagnosed, your provider will monitor you closely and may recommend early delivery if your baby would be safer outside the womb.

A patient whose 20-week scan shows a low-lying placenta will typically have a repeat ultrasound at 32 weeks. In most cases, the placenta has moved and vaginal delivery remains an option. Someone with gestational hypertension might have extra growth scans to ensure the placenta is functioning well enough to support the baby through term.

How Chronic Conditions Affect the Placenta

High Blood Pressure and Preeclampsia

High blood pressure, whether chronic or pregnancy-induced, can reduce blood flow to the placenta. Preeclampsia—a condition marked by high blood pressure and signs of organ stress—can impair placental function and increase the risk of abruption or growth restriction. Close monitoring, medication, and sometimes early delivery become necessary to protect both you and your baby.

Smoking, Substance Use, and Environmental Exposures

Smoking narrows blood vessels and reduces oxygen delivery to the placenta. It's associated with lower birth weight, placental abruption, and preterm birth. Quitting at any point in pregnancy offers benefits. Substance use—including alcohol, marijuana, and opioids—can also affect placental development and function. If you're struggling to quit, talk to your provider about support options. They're there to help, not judge.

Inflammation and Infection

Certain infections during pregnancy, such as untreated urinary tract infections or specific viral infections, can affect the placenta. Scientists continue to study the broader role inflammation may play in placental health and long-term outcomes, but this research is still unfolding. What's clear now: treating infections promptly and attending routine prenatal visits help keep problems at bay.

Diabetes, Thyroid Disease, and Autoimmune Conditions

Conditions like diabetes, thyroid disease, clotting disorders, and autoimmune diseases can all influence how well the placenta works. Managing these with your provider—through medication, monitoring, or lifestyle adjustments—supports healthier placental function and better outcomes for your baby.

A patient with chronic hypertension might start having growth ultrasounds earlier and more frequently than someone without risk factors. Someone who smoked early in pregnancy and quits at 14 weeks still gives their placenta and baby a better environment for the remainder of gestation.

Warning Signs to Watch For (and When to Call)

Many placenta issues are detected on routine scans before you'd notice anything yourself, which is one reason keeping appointments matters. Still, some symptoms warrant an immediate call to your provider or a trip to the hospital:

  • Vaginal bleeding, especially in the second or third trimester
  • Severe, persistent abdominal or back pain
  • A sudden decrease in fetal movement
  • Signs of preeclampsia: severe headache that doesn't respond to medication, vision changes (spots, flashing lights, blurriness), upper abdominal pain, or sudden swelling of your face or hands

If something feels wrong, always call. Your provider would rather reassure you than have you wait through something serious.

Questions to Ask at Your Appointments

You don't need to be a medical expert to advocate for yourself. Asking specific questions helps you understand what's happening and what to watch for. Save this list for your next prenatal appointment:

At your anatomy scan (18–22 weeks):

  • "Where is my placenta positioned?"
  • "Is there anything about the placenta that needs monitoring?"

If you have risk factors (prior cesarean, high blood pressure, diabetes, etc.):

  • "How does this condition affect my placenta?"
  • "Will I need extra scans or tests?"

If fetal growth is measuring behind:

  • "How is my placenta functioning?"
  • "What tests can check blood flow to the baby?"

If you're diagnosed with a placenta condition:

  • "What does this mean for my delivery?"
  • "What symptoms should I watch for at home?"
  • "How often will you check it?"

At any appointment:

  • "Is there anything about my placenta's position or function that I should know?"

A patient with a low-lying placenta at 20 weeks might ask when the follow-up scan is scheduled and what happens if it hasn't moved. Someone whose baby is measuring smaller than expected can ask whether a Doppler study would be useful to assess placental blood flow.

What Happens to the Placenta After Birth

Delivery of the Placenta (Third Stage of Labor)

After your baby is born, your uterus continues contracting to expel the placenta. This usually takes five to thirty minutes. Your provider may gently pull on the umbilical cord or massage your abdomen to help it along. You might be asked to push lightly. Many people barely notice this stage after the intensity of delivering the baby.

Why It's Checked

Your provider will examine the placenta to make sure it's complete. Retained placental tissue can cause heavy bleeding or infection, so confirming everything came out is an important safety check. They'll also look at its size, shape, and condition, which can provide information about your pregnancy and your baby's health.

Placenta Encapsulation and Lotus Birth

Some people choose to explore options like placenta encapsulation or lotus birth (leaving the umbilical cord attached until it separates naturally). It's important to note that these practices lack scientific support for health benefits and may carry risks of infection. Your OB-GYN is your best resource for discussing the safety of these choices if you're considering them.

Frequently Asked Questions

Can I do anything to keep my placenta healthy?

General prenatal care supports placenta health: eating a balanced diet, managing chronic conditions with your provider, avoiding smoking and substance use, and attending all your appointments. Despite online claims, there's no special supplement or food that specifically targets the placenta. Focus on the basics that support your overall health, and your placenta will benefit too.

How do doctors check placenta health?

Ultrasound is the main tool. It shows the placenta's position, appearance, and—when Doppler is used—blood flow through the umbilical cord and placental vessels. Your provider also tracks your baby's growth by measuring your abdomen and monitoring fetal movement. Blood pressure checks are important too, since high blood pressure can affect placental function. If concerns arise, additional tests might be ordered.

Will I know if something is wrong with my placenta?

Some conditions cause noticeable symptoms: bleeding, pain, or a decrease in fetal movement. But many placenta issues are detected on routine scans before you'd feel anything different. That's why keeping your prenatal appointments is so important. Regular monitoring catches problems early, often while they're still manageable.

Does placenta position affect delivery?

It can. If the placenta covers your cervix (placenta previa) at term, you'll need a cesarean delivery because vaginal birth would cause dangerous bleeding. Most other placenta positions don't affect your ability to labor. An anterior placenta (attached to the front of your uterus) might make it harder to feel early fetal movements, but it doesn't change your delivery options.

What does new research about the placenta mean for my pregnancy?

Scientists are continually learning more about how the placenta works, what can affect it, and how it influences long-term health. Your provider will apply evidence-based guidelines to your care—not preliminary findings from early-stage research. If you read something that worries you, bring it to your next appointment. Your provider can put it in context and explain whether it changes anything about your specific situation.

Understanding the basics of placenta health in pregnancy helps you feel more prepared and more confident speaking up when something doesn't feel right. The placenta is working behind the scenes every day, and your prenatal care is designed to make sure it keeps doing its job well. When you know what to watch for and which questions to ask, you're better equipped to partner with your care team and focus on what matters most: a healthy pregnancy and a healthy baby.