Typically, the placenta position in the uterus does not lead to any concerns or problems. The first thing your ultrasound tech will tell you about your placenta is whether it is anterior or posterior.
Anterior placentas are on the front of your uterus. They can make it more difficult to feel kicks and movements in early pregnancy and more challenging for your baby to be heard on a Doppler or baby monitor. There is nothing wrong with an anterior placenta, but many individuals report different experiences regarding how early and intense their baby moves.
Posterior placentas are on the back of your uterus and are not much bother when feeling a baby’s movements or listening to their heart tones. Your placenta has a 50/50 chance of being either posterior or anterior, and there is not usually a rhyme or reason why it inserts where it does.
The next thing that your ultrasound tech will talk about is where your placenta is in relation to your cervical opening or the opening that your baby will eventually come out of if they are born vaginally. Most placentas are more than 2cm away from the cervical opening.
Low-lying placentas only stay that low and cause issues in about 1-2% of all births. If you have a low-lying placenta at your 20-week anatomy scan, you will likely be rescheduled for another third-trimester ultrasound to ensure it has moved up and out of the way. The biggest concern for a low-lying placenta is that during birth, when the cervix begins to dilate, it could dilate where the placenta is attached, leading to high amounts of blood loss and parental and fetal death.
What Is Placenta Previa?
If your ultrasound shows that you have what is called placenta previa, then your placenta is not just low-lying. It is covering the opening of your cervix. Placenta previa is rare, only occurring in about 1 in 200 pregnancies. As with low-lying placentas, typically, you will be rescheduled for a third-trimester ultrasound to see if your placenta has moved off of your cervical opening.
About 90% of placenta previas resolve on their own, but if your placenta does not move, then a cesarean section is the safest route to bringing your baby earthside. The placenta has the same risk factors as low-lying placentas, but the excess bleeding has a higher rate of occurring, and the mortality rates are between 4-8%.
Altering Your Birth Plan
Placenta previa is an automatic high risk during pregnancy. If you have been planning an out-of-hospital birth or vaginal birth, you will need to change gears. Chances are that your care provider will have you being more frequently monitored with ultrasound technology, encourage you to do some version of pelvic and/or bed rest, and will want you to be getting induced at the safest possible time for both you and the baby. If at all possible, most care providers will want you to be around 36 weeks gestation, but there are some cases where a premature birth gives better outcomes than continuing forward in pregnancy. This is one of the pregnancy situations where having a care provider you trust is crucial. If that means getting a second opinion or changing providers, I recommend doing so.
Who Might Be Susceptible?
Although there are some risk factors for placenta previa, nothing you did or didn’t do could change the situation. With that being said, here are a few of the things that could put you at higher risk for placenta previa:
- Having had a baby
- Uterine scars from previous surgery
- History of placenta previa with a previous baby
- The use of assisted reproductive technology to get pregnant
- Carrying multiples
- Being older than 35 years of age
- Smoking
- Use of cocaine or other hard drugs
Even with these risk factors, remember that there is nothing that you could have done differently to prevent this situation. Sometimes, life hands us a pregnancy and birth scenario that we wouldn’t have picked for ourselves, but trusting the process and trusting your body and baby that they know the best way to deliver is crucial. As with all things birth, listen to your gut; you know who the best care provider will be for you and your baby as you continue forward on this path that your pregnancy has taken. Birth can be beautiful, whether it is vaginal or belly-born, and making informed decisions and being an active participant are two great ways to make that happen.
