The placenta stops working?

[minkajane]

I hear this a LOT. Women saying that they had to be induced or sectioned because their placenta stopped working, doctors insisting that the placenta stops working or deteriorates after 40 weeks, etc. It just doesn't make sense to me. It's not like your lungs or your heart or your finger or whatever just randomly stops working or stops at a certain age or whatever. So why would a placenta just stop working?

Is there some kind of medical justification for this theory? Or is this along the same lines as "Episiotomies prevent tearing" and "A scarred uterus is a ticking time bomb"?

[lovemybubus]

I too have heard this. My mw said it basically expires. I don't have any scientific evidence other then what my mw said. Maybe it's case by case?

[GoBecGo]

It does have a "shelf life", yes, though it begins to deteriorate AFTER 42 weeks, not at 40, and plenty of babies are born at 43+ weeks with a normal placenta. Unlike a liver or a heart or a finger which are all designed to grow and last a lifetime the placenta is designed to support a certain stage of development of a human baby and with age, when the baby's needs have begun to surpass what the placenta can deliver, they begin to break down. This translates into their membranes being not so effective, so they are less effective at waste removal and oxygen and nutrition provision. Some think this breakdown actually contributes to the start of labour, the theory being that the baby's body reaches a stage when it knows it needs to move to by-mouth sustenance in order to continue and maintain it's rate of growth.

In terms of being sectioned at 40weeks it's generally rubbish. Only babies with IUGR have placentas which aren't working properly and they are generally delivered a long time before 40weeks. For the majoirty of women induced or section before 42 weeks the statement "the placenta will stop working" from the ob is synonymous with "my buddies are waiting for me on the golf course this weekend and i don't want your labour ruining my round".

[MsBlack]

Women gestate for varying lengths of time--40 weeks strictly represents an average and nothing more. 40 wks takes into account that most normally healthy women, with normally functioning placentas, give birth normally to sufficiently developed-and-ready babies, most often between 38-42 wks...which mathematically is a 40wk average (stating this very simplistically). Now, there are occasionally underlying physical or physiological issues for mom and/or baby which prevent labor from starting in that time frame--but most pregnancies that go to 42 weeks or even a week or more beyond that, are still normal. Placenta still functioning and all!

"Placenta failure" is just another 'dead baby card' that is pulled by HCPs who do not fully trust or understand birth, and who prefer to control birth as much as possible (whether out of fear, or out of convenience or both). And of course, it is far easier to control moms who fear for their baby's life, than those who feel that they and their baby are perfectly fine.

Placentas are amazingly complex and highly ABLE organs that perform a multitude of tasks. Even a placenta that has indeed 'begun to expire' can fully support a healthy baby for awhile. Even a placenta that is partially abrupted can fully support a healthy baby for some time.

There is even some thought that it is a normal element of the complex processes which initiate normal labor, for the placenta to start 'failing' That is, that the initial stages of a placenta's 'expiration' sends chemical signals to mom and baby both; this is part of an intricate hormonal/biochemical dance between mom and baby, a cascade of biochemical events that leads to labor and birth, bonding and lactation, etc. And in most cases, a placenta that has 'reduced functioning' in late pregnancy is still functioning plenty well enough. Which only makes sense since pregnancy and birth are so very well designed, and most often work so very very well.

It can truthfully be stated that a placenta has 'an expiration date'--but it is not truthful to say that that date is at 40wks for any/all women. A baby who is growing well and is still adequately vigorous inside a mom who is still normally healthy no matter how many weeks gestation, still has a fully-enough functioning placenta. The very most usual 'full expiration date' of a placenta turns out to be the day of birth, whether earlier or later than that 'average'.

[jennyfah]

Originally Posted by MsBlack

There is even some thought that it is a normal element of the complex processes which initiate normal labor, for the placenta to start 'failing' That is, that the initial stages of a placenta's 'expiration' sends chemical signals to mom and baby both; this is part of an intricate hormonal/biochemical dance between mom and baby, a cascade of biochemical events that leads to labor and birth, bonding and lactation, etc. And in most cases, a placenta that has 'reduced functioning' in late pregnancy is still functioning plenty well enough.

:

That is what I was going to say.