The placenta is an amazing organ and does an incredible job keeping your baby supplied with nutrients and oxygen.
However, many pregnant women don’t know much about it.
If you find out you have a posterior placenta, you’ll probably wonder what that means.
You might even be a little concerned about it and worry it’ll affect your baby’s health.
Keep reading as we explore the term ‘posterior placenta’ and what it means for you and your baby.
What is a placenta?
The placenta is the organ responsible for keeping your growing baby nourished while in the uterus.
It supplies all vital components, such as oxygen and nutrients, to ensure your baby gets everything that’s needed for growth and development.
The umbilical cord attaches to the placenta and is basically your baby’s lifeline. Its blood vessels supply your baby with oxygen and essential nutrients.
What is the placental location?
In the very early weeks of pregnancy, your baby (known at this stage as a blastocyst), travels down the fallopian tubes and into your uterus.
Here it burrows its way into the uterine wall and attaches itself. This is called implantation, and you can read more about it here.
The fertilized egg can position itself anywhere on the wall of the uterus. As the pregnancy progresses, the spot where it attaches is known as the placental location.
The position of the placenta can be anterior, posterior or low lying.
Ideally, the best place for your placenta to implant itself in the uterus at the start of pregnancy is either posterior or anterior.
Keep reading to find out what these positions mean.
What is a posterior placenta?
Posterior placenta means your baby has implanted right at the back wall of the uterus (the side closest to your spine).
Ideally, a posterior placenta at the back of the uterus is the best type of positioning when considering placental location and pregnancy.
A mother with a placenta in the posterior position might feel her baby kicking earlier than a mother with anterior position placenta.
Posterior placenta gender
Interestingly, one study showed having a posterior placenta could be associated with having a baby boy.
Don’t get too excited though! Even this study’s content suggests more research needs to be done.
Posterior low lying placenta
Having an ultrasound can be a very exciting time for any new parents-to-be.
It’s the first time they’ll get to see their growing baby and it’s fascinating.
The ultrasound done at about 20 weeks of pregnancy is the most important scan. Among other things, it checks the position of the placenta, as placenta location and pregnancy outcome are linked.
It’s important for the placenta to be clear of the opening of the uterus, otherwise known as the cervix.
A low lying placenta (known as placenta previa) can have a big impact on a mother’s chance of having a normal vaginal birth.
When a placenta is low lying it means the baby has implanted itself low in the wall of the uterus.
A low lying posterior placenta is when the placenta is embedded low into the back wall of the uterus.
If the placenta is too close to the birth canal it can put both the mother and baby at risk of heavy bleeding.
There are varying degrees of low lying placental positions, some with greater risks than others.
Placenta previa presentation on an ultrasound scan needs further follow-up and close care of a mother and her baby.
Read more here in our article Low Lying Placenta – What Does It Mean?
Anterior vs posterior placenta
Anterior placenta means your baby has implanted itself in the front wall of the lining of the uterus.
A placenta location at the front can sometimes make it harder for a woman to feel her baby’s movements.
Anterior placental positioning can also affect your doctor or midwife’s ability to locate the baby’s heartbeat during pregnancy.
This study suggests anterior placenta position in pregnancy can bring an increased risk of pregnancy-induced hypertension, placental abruption, gestational diabetes and intrauterine growth restriction.
The same study shows a possible increased risk of pre-term labor associated with a posterior placenta position.
Another interesting comparison in this study is that women who have an A-positive blood group are more likely to have a posterior placenta; in those having an O-positive blood group, the anterior placenta is more common.
Can a posterior placenta cause back pain?
If you’re suffering back pain during pregnancy you might be wondering whether the location of the placenta can be the cause.
As your body adjusts to the shifting weight as your baby grows, and with the softening of the ligaments due to your changing hormones, it’s common to have all sorts of aches and pains.
There’s some evidence to suggest the positioning of the placenta can be related to an increase in back pain for some women.
This study showed an increase in backache for women who had the placenta positioned posteriorly rather than the anterior placenta.
There’s not really a lot you can do about where your placenta positions itself, but you can certainly treat any symptoms of back pain.
Read our article Is Tiger Balm Safe To Use During Pregnancy? for some suggestions about how to manage your back pain safely.
Does a posterior placenta affect labor?
As we mentioned earlier, having a posterior placenta increases the chances of having pre-term birth, but it’s less likely to cause any further trouble with birth.
Having an anterior placenta puts you at a higher risk of having posterior labour. Posterior labour tends to take longer and can give a woman more back pain.
To learn more about posterior labour, read our article 8 Signs Your Baby’s Position Is Affecting Labour.
Although you can’t change the position your placenta has implanted, there are ways you can help your little one into an ideal position for birth if you have a posterior baby.
Overall, having either a posterior or anterior placenta position is completely normal and doesn’t cause major concerns.
In most cases, mothers go on to have completely normal vaginal births.