What Is Placenta Previa?

In easy terms (as I like to keep things!) Placenta previa is when your placenta lies really low in your uterus, blocking some or all of your cervix. The placenta normally attaches itself near to the top of the uterus, but sometimes it will attach lower down.

Placenta previa isn't normally too bad during the early pregnancy stage, but it can cause bleeding in late pregnancy. This could mean that you may have to deliver your baby early, and this will normally be done by caesarean section

Placenta previa symptoms

Placenta praevia (as it is also known) is not a common complaint in pregnancy, and normally only affects around 0.5% of women worldwide.

There aren't really any symptoms apart from vaginal bleeding. This is normal pain free, and bright red blood. An ultrasound is the most likey way that you will discover that you have a previa.

There are 4 different types of previa:

Low lying previa is where the placenta lies very close to the cervix, but not covering it. Marginal previa is where the placenta touches the cervix, but does not cover it. Partial previa is where the placenta partially covers the cervix.Total or complete previa is where the placenta covers the whole of the cervix.

What will happen when you're diagnosed with this condition?

As with most things in your pregnancy, consultants will look at a number of factors. If you are still in your second trimester, there is a chance that the placenta will move (it doesn't actually move but with your uterus expanding the placenta ends up further away)and no longer cover your cervix.

In later pregnancy if previa is found, consultants will keep an eye on things by ultrasound, and you will be asked to watch for any bleeding. You will be told not to have sex, and there will be no internal examinations. Taking it easy is the best idea in these circumstances.

If you do start to bleed, it may be because your cervix is thinning and disrupting blood vessels. With bleeding or early contractions you will be advised to stay in hospital. You will then be carefully monitored. If there is any distress to the baby, or if the bleeding doesn't stop or is severe, then your baby will be delivered by c-section, even if he is premature.

If the bleeding does stop and your baby is doing well, then you may be given drugs to help your baby's lungs to mature (just in case he has to be delivered early) Otherwise you may be sent home. If things go well from there on you will normally be given a c-section around the 37th week of pregnancy. Your baby is classed as full term after 37 weeks.A normal delivery isn't possible with complete or partial placenta previa as the placenta blocks the baby's delivery path. If you start with contractions and your cervix starts to dilate this can cause extremely severe bleeding.

Placenta previa and other complications

After your baby has been delivered by c-section, the consultant will also remove the placenta and then give the mother a drug which will cause the uterus to contract. This is done to help stop the bleeding from where the placenta was attached to the uterus. Because placenta previa means that the placenta was attached to the bottom of the uterine wall, the bottom part doesn't contract as well as the top, and so makes bleeding harder to control.

Sometimes with placenta previa the placenta implants too deeply into the uterus, this means that after your baby has been born, your placenta may not separate away from the uterus properly, this can cause severe bleeding to the extent that blood transfusion and hysterectomy may be needed.

Who is at risk?

There are certain factors that will put some women more at risk than others. These are

If you have had c-sections before. The more c-sections you've had, the higher the chances that will experience previa.
If you've had fibroid removal or D&C in the past.
If you have had placenta previa in previous pregnancies.
The older you are, the more risk involved.
There is more chance of previa with the more babies you have had.
If you are having a multiple pregnancy.
You smoke during pregnancy.
If take cocaine during pregnancy.

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