An Incredible Placenta

At a homebirth earlier this year I had a very good reminder of why we shouldn’t artificially rupture the membranes without very good reason!

Usually the vessels of the cord and the placenta are located over the main body of the placenta, here as you can see the cord inserts right at the edge of the placenta and one of the big blood vessels is located not over the placenta but it travels through the amniotic sac (velementous insertion) – it is therefore possible that if a midwife or doctor uses an amnio hook to ‘break the waters’ the vessel could be torn and the baby bleed out of that vessel. Even on a labour ward with a theatre just down the corridor that’s not a situation anyone wants to imagine!

We never know which way round the placenta sits on the uterine wall. This placenta was located on the anterior wall of the uterus, the vessel through the membranes may well have been sat below the placenta and been close to the cervix. Equally it may not.
Had this woman birthed in hospital she would have been expected to have her waters ruptured on admission in labour as per the local NHS Trust’s VBAC (vaginal birth after cesarean) guideline. Had she accepted an offer to artificially rupture her membranes it could have been disastrous.

I, thankfully, do not believe there is a justification for artificially breaking a woman’s waters just because she has had a previous section and so these waters broke spontaneously a way that did not risk piercing a blood vessel with an amniohook.
Like all interventions, there are times that ARM (artificial rupture of membranes) is valuable and worthy of consideration, but it is NOT a risk free procedure and so should never be taken lightly.