What is the placenta?
The placenta is an organ attached to the lining of your womb during pregnancy and is the only transient organ in the human body. This means that it grows and stays temporarily, and is expelled when it’s fulfilled its purpose.
It keeps your unborn baby’s blood supply separate from your own blood supply, as well as providing a link between the two. This connection allows the placenta to carry out functions that your unborn baby can’t perform for itself.
Attached to your baby by the umbilical cord, it releases hormones such as progesterone, oestrogen and human chorionic gonadotrophin (HCG) which help your baby to grow, while also supplying them with nutrients and oxygen. The placenta is also responsible for carrying waste products from the baby, such as carbon dioxide, back to your bloodstream to be excreted. The placenta also gives some protection against infection for your baby while it’s in the womb, protecting it against most bacteria. However, it doesn’t protect your baby against viruses.
Alcohol, nicotine, and other drugs can also cross the placenta and can cause damage to your unborn baby.
Towards the end of your pregnancy, the placenta passes antibodies from you to your baby, giving them immunity for about 3 months after birth. However, it only passes on antibodies that you already have.
What does it mean to have an anterior placenta?
The placenta develops wherever the fertilised egg embeds into your uterus, and can attach virtually anywhere in the uterus, but usually it is positioned at the top or the side.
If the placenta attaches to the back of the uterus, towards the spine, it is known as a posterior placenta.
An anterior placenta simply means that your placenta is attached to the front wall of your uterus, between the baby and Mum’s tummy.
The sonographer will check the position of your placenta during your 20-week scan, to ensure its position won’t affect your pregnancy.
An anterior-sited placenta is completely normal and a good place for it to implant and develop. It isn’t connected to having a low-lying placenta or placenta praevia and it shouldn’t cause you problems.
The biggest impact it can have on your pregnancy is taking longer to feel your baby kick. For the same reason, it might be harder to find your baby’s heartbeat during a Doppler ultrasound with your midwife or make invasive prenatal tests such as amniocentesis more challenging.
What difference does it make to my baby’s movements?
Most women first feel their baby move somewhere between 16 and 24 weeks of pregnancy.
If you have a posterior placenta, you are more likely to feel first movements much earlier than those with an anterior placenta, as the anterior placenta cushions any subtle wriggling because there is an extra layer between you and the baby.
When you have an anterior placenta, it can be harder to feel your baby kick, punch or move around because the placenta acts as a buffer. It is common to not feel kicks until after 20 weeks of pregnancy. This is because before 20 weeks your baby’s movements may not be strong enough to feel through the placenta. You partner may not be able to feel any kicking until a few weeks later when baby is bigger and movements more powerful.
Regardless of placental position, if you reach the 24th week of pregnancy without feeling movement, you should inform your midwife.
As your pregnancy progresses, it is very important to become familiar with your baby’s normal pattern of movement. If you have an anterior placenta, you’re more likely to feel movement at the sides and lower down towards your bladder. These movements will be subtle at first, like gentle bubbles or wind, but will gradually get stronger as the baby gets bigger.
Although feeling movement can be more difficult if your placenta is at the front, there should be a regular pattern to the kicks that you feel, and these movements are a sign of fetal wellbeing. If you feel as though your baby’s movements have slowed down or stopped or that there is a change, it’s important not to assume your placenta is the reason for the reduced movements. Call your midwife or Day Assessment Unit straight away if you have any concerns.