# causes of small placenta?



## caedmyn (Jan 13, 2006)

When my last baby was born (2 years ago), the placenta was noticeably smaller than it had been with my others. It was sort of a UC, with a friend who was a L&D nurse and in the early stages of studying to be a midwife there. She noticed that the placenta was small but I didn't ask questions of her like I would have if an actual midwife had been there. We froze the placenta and I weighed it later and IIRC it weighed about 10 oz.

What could have caused the placenta to be so small? I have eaten a whole foods (non-vegetarian) diet for years and continued that during the pregnancy. Didn't have any pregnancy complications other than a bit of borderline high blood pressure at the end which was stress-related I am sure. Didn't have any birth or postpartum complications either. Baby was the same size as 2 out of 3 of his siblings and born at the same gestational age as 2 out of the 3 of them as well.

I did have some thyroid and adrenal problems at the time (undiagnosed) and my health really tanked when he was a few months old...could those have caused the placenta to be small? Oh and I was anemic too (untreated, undiagnosed...long story) but in hindsight had also been anemic for the previous two babies.

I'd maybe like to have another baby someday but am concerned that the small placenta would happen again and maybe another baby wouldn't be lucky enough to not have any problems from it.


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## cyclamen (Jul 10, 2005)

Hypertension can cause small placentas. There are some other causes of small placentas which are also pretty concerning and a threat to health of mom and baby, so it's smart of you to be asking these questions.

It might or might not happen again. This is a good pre-conception question to ask your midwife or OB. Prenatal care can help you manage, mitigate, or avoid some of these issues.


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## caedmyn (Jan 13, 2006)

I only had the borderline high blood pressure the last couple of weeks, so I don't see that being the cause. The rest of the time my blood pressure was fine.

I'm not entirely certain if placental insufficiency is the same thing as a small placenta, but googling "cause of small placenta" comes up with a bunch of links for placental insufficiency and one of the causes of that is anemia, so that seems like a likely cause, as I was severely anemic at 10 month PP with no excessive bleeding to have caused it so I am sure I was anemic during the pregnancy, and it was never diagnosed or treated because I always had good hemoglobin levels so my midwife said I wasn't anemic (in spite of extreme fatigue 2nd & 3rd trimesters).


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## Metasequoia (Jun 7, 2005)

I've read that a large placenta is a sign of compensation by the body to provide for the baby - so a "small placenta" might not be a negative thing. Like, the placenta isn't getting enough nutrition or oxygen or whatever to baby so it increases in size to ensure baby's needs are met - make sense? 

I've had pretty severe adrenal insufficiency during my pregnancies and my midwives have never said my placentas were small or in any way abnormal. I've always had great iron levels though...


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## cyclamen (Jul 10, 2005)

Very large or very small placentas are both abnormal and warrant further investigation. I believe large placentas are often associated with diabetes. Anything that causes decreased perfusion (blood flow and oxygenation) to the placenta is going to affect its function, and may affect its size. If you have concerns about this, please seek information from a professional who knows more about placentas. Anemia can potentially cause problems with perfusion to the placenta. Hypertension causes microscopic damage to organs and vessels which may be one reason why gestational hypertension is associated with smaller placentas. (On the other hand, abnormal placentation is thought to potentially be a cause of hypertension and pre-eclampsia. It's a complicated topic.) edit: placentas should continue to grow throughout the pregnancy and keep apace with the fetus. If they don't, that suggests some alteration in perfusion.

The good news is that even with a placenta that isn't working as well as it should be, there are many things that can be done to protect mom and baby from ill effects, and good prenatal care includes all that.


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## cyclamen (Jul 10, 2005)

Also, 10 oz seems small to me, but there is a wide variation in what's normal for placentas. The average size at term is about 16 oz and around 9-10" across and about 1-1 3/4 in (2.5-4cm) thick. Major concerns are signs of clotting, damage, and calcification, a too thick placenta or a too thin one. Again, I bet the best person to evaluate this would be an OB professional.


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## Metasequoia (Jun 7, 2005)

@cyclamen, what do lobes mean? Anything?


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## cyclamen (Jul 10, 2005)

My understanding is that normally developed placentas have one lobe, which is divided up into "lobules" or "cotyledons." The placenta has a dinner plate shape and is made up of several distinct but fully connected pieces of tissue. 

A placenta with extra lobes may have what looks like a big round lobe and a little round lobe connected by some vessels and thin tissue. This is called a succenturiate placenta. Bi-lobed placentas are two equally sized placental lobes narrowly joined at the edges. There are also tri-lobed placentas. These are all abnormal and are more susceptible to rupture. They are also more likely to have tissue retained at delivery, which can cause post-partum hemorrhage.

A placenta with "all its lobes" could be an intact 1-lobed placenta, or a 2-lobed placenta that has both lobes. 

Placentas are cool.


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