How Do Pregnancy Hormones Affect Your Hair?

Understanding how hair grows helps clarify the ways pregnancy affects it. In most cases, about 90 percent of a person's total hair is growing at any one time.

The hair on your head grows for several years. Arm, leg, and facial hair only grow for about 100 days, which is why the hair on your head grows longer than your eyebrows or eyelashes. After the growth phase, over about two to four weeks, the root separates, and the hair eventually falls out. The hair follicle forms a new hair, and the process starts again.

There are three phases of hair growth; the rise in estrogen during pregnancy and return to normal estrogen levels after childbirth affect them all.

Active hair growth is the anagen phase. The catagen phase is when active growth stops and the hair follicles shrink, and the telogen phase is a resting phase before the hair falls out of the follicle.

New hair continues to grow during pregnancy, but if it seems like your hair is thicker than usual, that is likely because of how pregnancy hormones affect the telogen phase. Everyone sheds hair on a daily bases, but the hormonal shifts during pregnancy actually prevent hair from falling out at the same rate.

In other words, it's not that your hair is getting thicker; you're just not losing as much.

Telogen efflivium is a condition in which a change or shock to the body, such as having a baby, causes more hairs to enter the telogen or resting phase. Usually, only about 10 percent of your hair is in the resting phase. With telogen effluvium, this increases to about 30 percent.

On average, people lose about 100 hairs a day. Someone with telogen effluvium may lose as many as 300.

At the end of pregnancy, the follicles that experience an extended growth or anagen phase rapidly enter the catagen and telogen phases, which is why people lose so much hair in the postpartum period.

This hair loss typically affects the hair on the front and sides of the head, but it can be more generalized.

Postpartum hair loss usually lasts about 16 weeks because a larger number of hairs are triggered to rest and fall out, and it takes some time for all of the hairs to shed.

You may notice a few more hairs coming out after you wash or brush your hair, or you may lose it in clumps.

Although postpartum hair loss is frustrating and can be emotional, your hair should return to normal within six months. Some people see their hair loss spontaneously resolve in as little as three months. On rare occasions, it can continue for up to a year.

Although it may seem like your hair went from voluminous to thin overnight, it is important to remember that both the apparent "thickening" and "thinning" processes are natural and temporary.

There is no way to prevent post-pregnancy hair loss. The best thing you can do is ensure you eat a healthy diet and get enough iron and protein.

Being prepared for postpartum hair loss can also help you cope. Knowing that it is normal and natural may help you feel less frustrated.

There is no treatment for postpartum hairloss, but there are some things you can do to prevent further damage and help your hair look and feel its best.

Try volumizing shampoos and conditioners and treat your hair with care. Use low heat settings on hairdryers and other styling tools, and avoid tight braids and ponytails that could tug your hair and cause additional hair loss. Shorter hair also looks fuller, so you might consider a new style that is also easier to care for during your upcoming months of minimal sleep.

If your postpartum shedding seems excessive or you continue to lose your hair for longer than six months after giving birth, you may want to check with your doctor.

Other conditions, like iron-deficient anemia or postpartum thyroiditis, can also lead to hair loss after giving birth.