What Is an Anterior Placenta?

If you're expecting, you already know that the placenta is a vital part of your pregnancy. This temporary organ has lots of functions, including providing oxygen and nourishment to your growing baby through the umbilical cord, and taking waste away from them.

The placenta can attach to uterine wall in many different locations. If it's in front of the uterus, close to the abdomen, it's known as an anterior placenta. Anterior placentas are common, occurring in about half of all pregnancies, and they don't pose increased risk to the pregnant person or baby — though the placenta position might make harder to detect your baby's kicks and heartbeat.

An anterior placenta won't change the shape of your pregnant belly, and it won't make your bump bigger. "An anterior placenta will usually cause no pregnancy or health complications, says Monte Swarup, M.D., FACOG, board-certified in OB-GYN in Chandler, Arizona and founder of HPD Rx.

So how do you know if you have an anterior placenta, and what can you expect during pregnancy, labor, and delivery? Keep reading for answers to these questions and more.

How Common Is an Anterior Placenta?

The placenta will typically develop wherever the fertilized egg implants on the uterine wall. About half of all placentas are in the anterior position, making it one of the most common locations. Note that the position of your placenta might also change as your uterus expands during pregnancy, which isn't a cause for concern.

Finding Out If You Have an Anterior Placenta

Wondering if you have an anterior placenta? As it turns out, you can't tell your placenta's location just by looking at your belly. The only way to determine placenta positioning is through an ultrasound.

Most pregnant people find out they have an anterior placenta during their anatomy scan around 18 to 21 weeks. In this case, your practitioner will see that the placenta is located in front of your baby.

Anterior Placenta vs. Posterior Placenta: What's the Difference?

Placentas can actually take a multiple different positions aside from anterior. These include posterior, lateral, fundal, and low-lying.

• Posterior: The placenta is at the back of your uterus, near the spine
• Lateral: The placenta is on the side of your uterus (either left or right)
• Fundal: The placenta is at the top of your uterus
• Low-lying: The placenta is toward the bottom of your uterus, where it might cover your cervix
  

Note that the placenta can safely attach to the top, sides, front, and back of your uterus. The riskiest position is low-lying, as it can cause placenta previa, which happens when the placenta lies near or over the cervix . This condition can also occur with anterior or posterior placentas, though it's more rare, says Dr. Staci Tanouye, a private practice OB-GYN in Jacksonville, Florida. Placenta previa makes your pregnancy higher risk, and it often necessitates a C-section because the risk of bleeding excessively is too high.

How an Anterior Placenta May Affect Your Pregnancy

For most of your pregnancy, you're unlikely to notice the placenta, and its location is unlikely to make a difference. However, there are a few factors that might be different if you have an anterior placenta.

Feeling Fetal Movements

Fetal movements may be harder to feel with an anterior placenta. The first fetal movements are usually detected between around weeks 18 to 24, but this may be slightly delayed with an anterior placenta. That's because the placenta forms a cushion between your unborn baby and your belly, which can dampen the force of these kicks. But you shouldn't think an anterior placenta is causing fewer kicks. It's a good idea to note your unborn baby's typical movements and seek medical attention if they appear reduced.

Hearing Your Baby's Heartbeat

If you have an anterior placenta, fetal heartbeats may be harder to detect with Doppler machines because the placenta blocks the sound waves. But again, this isn't usually a cause for concern, and your technician will have experience navigating the situation.

Getting Diagnostic Tests

Some pregnant people get an amniocentesis; the diagnostic test involves taking a sample of your amniotic fluid with a needle for further testing. Having an anterior placenta can make amniocentesis difficult, though your care team can use ultrasound to make sure your placenta isn't harmed.

Possible Increased Risk of Certain Complications

Having an anterior placenta isn't cause for concern, and most pregnancies progress without any complications. That said, some studies have linked the positioning to an increased risk of certain pregnancy complications, including the following:

• C-section
• Induced labor
• Back labor — Often because the baby is be in the occiput posterior position (head down but facing your stomach instead of your back)
• Gestational diabetes
• Placental abruption
• Placenta previa
• Intrauterine growth retardation
• Pregnancy-induced hypertension

Does Anterior Placenta Affect Delivery?

In most cases, an anterior placenta doesn't have a huge impact on your delivery. Your contractions won't feel any different, and your birthing experience isn't likely to be affected. Both vaginal and C-sections are considered safe; if you have a C-section, your doctor will use ultrasound to find the best incision location. Delivery problems might only arise if your placenta is partly or fully covering the cervix in a low-lying position.

When to Seek Medical Care

An anterior placenta isn't' cause for concern during your pregnancy. If you experience any of these symptoms, it's a good idea to seek immediate medical care.

• Fewer fetal movements or none at all
• Pain in your abdomen
• Vaginal bleeding
• Constant or fast contractions
• Severe back pain
• Firmness or rigidity of your abdomen