Low Lying Placenta

Worried about your ultrasound? Told you have a low lying placenta?

So many women are told this at their early ultrasounds and then asked to check back at about 32 weeks.

They spend the next 10 weeks of pregnancy worrying and panicking, thinking they may need a caesarean or that there is something “wrong”. Only to be told at the next ultrasounds that “its okay” , “its moved up”.

Congratulations on finding and reading this blog! You will be able to understand the situation now and see that the chances of your placenta being any problem for birth is extremely low – it is most likely that all is very normal and very well 🙂

What IS happening?

Following conception, the placenta implants itself somewhere in your uterus, in no specific position. It may implant low, high, posterior (back) or anterior (front).

In your first and second trimesters, the uterus still has much growing to do, so an ultrasound late in your third trimester (after the uterus has finished growing) will give you and your doctor or midwife a better picture of what’s really going on.

An ultrasound may show that a placenta is near the cervix in early pregnancy. But, only a few women will develop true placenta previa. It is common for the placenta to move away from the cervix as the uterus grows. Only two to five percent of placentas that are “low lying” end up grade three or grade four previas by full term.

If the placenta does remain near or over the bottom of the uterus neck at the cervix, then there can be signs or symptoms to look out for:

Sudden, painless, bright red vaginal loss, usually in the later half of the pregnancy
Painless vaginal bleeding after sex
Uterine cramping with bleeding
Bleeding during labour

How Close To The Cervix Can My Placenta Be?

Doctors have different limits for how low they are happy for the placenta to be before they will tell you that you shouldn’t have a vaginal birth. It can be useful to get second/third opinions on a low placenta if you would like to avoid a caesarean section. Some doctors will be happy with the placenta to be above 2cms (20mm) from the os (cervix) and some prefer 3cms (30mm).

Get informed, find out what distance the placenta is from the cervix and ask your doctor or midwife if they would be willing to support your wishes for a vaginal birth (should it not move, as well as what measurement they want it to be).

What else you can do?

Insist on a tansvaginal scan to get a thoroughly accurate picture of what’s happening.

Transvaginal ultrasound scan is more accurate to assess placenta previa, trans abdominal scan usually over diagnosis it in up to one-fourth of the cases.

MRI: Can clearly outline the location of a placenta previa, but it is much more expensive and less readily available.