Why do doctors prescribe multivitamins and iron supplements when you are pregnant?

Well, Iron is the core element of red blood cells, and since additional blood has to be created for the spawn, more iron may be required. Same for vitamins. But that is just me guessing.
Though it would probably be better to adjust the diet. More meat, more fruit. Some delicious blood sausage, maybe.

Mostly to help prevent birth defects (Folic Acid) and to assure that the mother and child get the correct amount of oxygen carried through the blood (Iron) and to make sure that the mother does not lose bone density due to (Calcium) loss.

You can read more about it in the WebMD article

Because pregnant women need folate to prevent birth defects and iron to treat acquired iron deficiency.

On top of what everyone else said, the modern industrial diet is really just lacking in a lot of vitamins. Got to be healthy for baby!

I agree with @incendiary_dan, most people’s diet is terrible and modern day stress levels deplete vitamins from the system.

I understand the concept, but according to the answers to the other question, multivitamins are largely unnecessary. The doctors do not even question what your current diet is or check to find out if you have iron deficiency. They are just prescribed as part of the routine. (I could not stand the iron because it played hell with my digestive system. I just ate more iron rich food.)

Babies are like parasites… they’re going to get what they need, even if they have to take it from your body. The vitamins and supplements are more for YOU than they are for the baby.

@CaptainHarley Such a nice way to put that. Now a good question is, when do they stop being,,,,those, what you said?

LMAO! They aren’t actually parasites, but they do function the same way when they’re in the womb. As soon as they are born, they become these sweet, cuddly lil bundles of joy that we all know and love! : D

@CaptainHarley Are you really sure they don’t stay parasites? ‘cause if they are 30 and still living with me, I just might extend that.

Besides the folic acid others mentioned (which I believe prevents a specific problem with neural development), I think the supplements are more for the mother’s benefit. A woman’s body is pretty much made for having babies. If something in the mother’s diet is lacking, the baby won’t suffer but the mom might. The baby gets all the good first and mom comes second. That doesn’t chance once the baby is born, by the way.

I’m feeling too lazy to look this up, but I think I read somewhere that a pregnant woman who isn’t getting enough calcium to support the baby’s growth is at risk for osteoporosis because her body will basically “steal” calcium from her bones to give to the baby. There are women all over the world who don’t have access to prenatal vitamins but still have pretty healthy babies I would imagine. In some cases the baby might not develop quite right, but in others the mom’s health would be affected, especially after multiple pregnancies. Sorry for the lack of effort in documentation here. I’m running off to bed now!

Lurve for the parasite references. I’ve had that thought many times over the past 12 years.

Edited to say: Crap, I just read my answer above, but in a more concise phrasing. Sorry for the repeat!

The folic acid is to prevent neural tube defects. The neural tube eventually becomes the brain, spine and all the neurons. I believe the most common neural tube defect is spina bifid
Ideally, you take them before you get pregnant because the important time for that development is in the first 8 weeks. If your pregnancy was a surprise, it’s almost out of the window for the folic acid to work best for the embryo.

After that, the pills are for the mother. Like many others have said, the baby get what’s they need, You will get low hemoglobin and iron deficiencies without the vitamins You also need the pills when you’re nursing for the same reasons..

The growing child inside you will take many of the vitamins it needs from you. You need to get extra vitamins for you, so that you can stay healthy and provide for a healthy baby.
Dude, take the fucking vitamins.

@filmfann Dude, I am not pregnant.

@optimisticpessimist

That’s why God gave me a size 12 foot! : D

@CaptainHarley I might have to borrow yours. I only have a size 5.

LOL! I’ll start my own business: “Grown children a problem? Contact The Shoe!” : D

Ask the doctor.

Ever seen women with a lot of children and very few teeth? The theory is that the parasitic effect that kids have on the calcium in the teeth and the bone of the jaw that keeps them in there (combined with poor oral hygiene, of course) contributes to tooth loss. This is in addition to all the other things, like the prevention of neural tube defects (mainly spina bifida), that people have mentioned previously.