Pregnant women have a positive nitrogen balance. Why is that so?

So my thinking is there's a fetus developing and therefore they need the nitrogen to increase protein production in order for proper fetal development. So I guess the increase in protein is due to the needs of the infant rather than the mother herself. I'm actually pretty confused. If it is because of the fetus, could someone explain the mechanisms involved. Like how the protein is actually used and how an inadequate intake would harm the mother and/or fetus.

Thanks

Originally Posted by ginaj

Pregnant women have a positive nitrogen balance. Why is that so?

So my thinking is there's a fetus developing and therefore they need the nitrogen to increase protein production in order for proper fetal development. So I guess the increase in protein is due to the needs of the infant rather than the mother herself. I'm actually pretty confused. If it is because of the fetus, could someone explain the mechanisms involved. Like how the protein is actually used and how an inadequate intake would harm the mother and/or fetus.

Thanks

If this is for an assignment I suggest you look at some research articles and studies (of which there are many...I just googled it myself).

If not, then from what I can tell through a quick google search, you are correct - there is a positive nitrogen balance in pregnancy, children, and those recovering from illness and this is because they require increased protein synthesis. I think that the increased protein would be for the mother herself to sustain a normal pregnancy, but again I don't know so you should def read some articles..

Simply for protein production.

Why do pregnant women need more nitrogen to produce protein than non-pregnant women? I know that they require a lot more energy (kcal) in a day but how does that relate to protein? I know protein can be broken down and used as energy but aren't carbs the way to go? The pregnant woman wouldn't use protein unless she wasn't getting enough energy from carbs, correct?

Protein is broken down into amino acids which are the monomers used for building functional proteins. Very little protein is used for energy except when other forms are in short supply. Your body has no protein reserve just functional proteins.

Wait so protein is typically not used as a fuel source. Then what is it mainly used for? When I think protein I think building muscles, repairing tissues ect. Is it safe to say that since pregnant women are going through so many hormonal and developmental changes during their pregnancy, they need an increased about of protein for things such as tissue repair?

Originally Posted by ginaj

Wait so protein is typically not used as a fuel source. Then what is it mainly used for? When I think protein I think building muscles, repairing tissues ect. Is it safe to say that since pregnant women are going through so many hormonal and developmental changes during their pregnancy, they need an increased about of protein for things such as tissue repair?

Yes. Pretty much the simplest way to put it.

Originally Posted by ginaj

Why do pregnant women need more nitrogen to produce protein than non-pregnant women? I know that they require a lot more energy (kcal) in a day but how does that relate to protein? I know protein can be broken down and used as energy but aren't carbs the way to go? The pregnant woman wouldn't use protein unless she wasn't getting enough energy from carbs, correct?

PRODUCING protein is very very VERY different from breaking them down. One of the reasons pregnant women require more energy is because both they and the fetus need to synthesize lots of proteins.

Originally Posted by ginaj

Wait so protein is typically not used as a fuel source. Then what is it mainly used for? When I think protein I think building muscles, repairing tissues ect. Is it safe to say that since pregnant women are going through so many hormonal and developmental changes during their pregnancy, they need an increased about of protein for things such as tissue repair?

Proteins are a hugely integral part of every single bodily system you can think of. Creating a whole new human being with a whole new set of body systems, that is continually growing, will require a lot of protein to be produced. Tissue repair is probably not a large part of the need for increased protein.

The fetus gets all its nutrients from the mother through the umbilical cord and placenta. The mother must then take in enough nutrients to support herself + the fetus.

Proteins are used by cells for basically EVERYTHING. Nitrogen is needed to synthesize new proteins. The body can synthesize about 16 of the 22 proteogenic amino acids. The other 6 need to be obtained through digestion of food.

Pregnant women have a positive nitrogen balance because they must take in way more than they need in order to supply the fetus with enough nutrients to grow. In order to grow a full human being, you need to create all the new cells, each containing enormous amounts of proteins. These proteins require nitrogen to be synthesized.

Pregnant women do NOT take in more nitrogen to create proteins to be broken down for energy. That makes no sense. Why would you build something just to break it down again? And if you consider the second law of thermodynamics, you would in fact lose energy if you did that because it would take more energy to synthesize the proteins then the amount of energy you would get out of decomposing them for energy.