For many women, everything tends to work in favor of hair health during their pregnancy. The increased levels of estrogen may lead to up to 95% of hair entering the anagen or growth phase (the normal amount is about 85%). This can result in some of the thickest and most luxuriant hair you will ever have on your head.

The extra estrogen during pregnancy can increase your metabolism to the degree that more nutrients than normal are available for your whole body, including your hair. This hormonal increase tends to jolt hair follicles into more production than normal. Consequently the greater percentage of hairs that are in the growth phase means that the normal 100 to 150 hairs a day are not shed.

And many women are especially scrupulous about personal health during this time - making sure they get all of the nutrients they need; taking all the supplements they think are important; and getting plenty of rest as well. All of these factors can contribute to providing the healthiest bodily environment for all of its systems to thrive, including the hair.

Of course, there are those women who experience something rather different while pregnant. Their hair can change its very structure and become a lifeless and limp mop. Again, hormones are the culprits as they affect the entire hair fiber, changing it from one type to another: from curly to limp or in some cases, from limp or straight to curly.

One can sometimes examine one's hair to determine if the body is getting all of the nutrients needed during pregnancy. Hair that appears to be damaged, or that is starting to shed, may be a signal of some kind of deficiency that should be brought to the attention of your doctor.

But all those of women who find that pregnancy has a very positive effect on their hair, may eventually experience the opposite effect at some point after pregnancy. As the body reduces the previously elevated hormone levels, all of the wonderful new growth may be lost. Just as there was a higher than normal percentage in the growth phase before pregnancy ended, there can be higher than normal hair loss during an extended rest, or telogen phase. As much as 35% of the head's hair can be in the resting phase following pregnancy. There can be an anxiety-producing amount of shedding while this happens, and it can go on for quite some time. In some cases it can last as long as a year.

Though this is a perfectly normal part of the pregnancy experience, it can prove stressful for some mothers, even though they know this. Unfortunately, high levels of stress can also contribute to hair loss. While it may take a while (up to a few years) for the hair to completely return to its normal level, it will almost certainly return to it.

There are other conditions associated with reproduction that can contribute to abnormal hair growth/loss occurrences. Any termination of a pregnancy has the potential to cause excess hair loss, as the body corrects previously high hormone levels. It's just an indication of a change in the amount of estrogen, and your body's response to this change.

To do all that you can, be sure to take the necessary precautions for the health of your hair, and for overall health - both during and after pregnancy. Make sure your doctor monitors your hormone levels. Eat the foods that are in the best interest of your overall health, and take vitamin and mineral supplements to be sure you're getting enough. Be gentle in the handling of your hair. And avoid hairstyles that pull the hair or that are too tight.

And don't be overly concerned about the unusual effects that pregnancy has on your hair. Your body knows what its doing and it will almost always correct itself.