A: Based upon your history, you have three possible reasons for having a type of hair loss called telogen effluvium; thyroid disease, medication induced (Prozac) and pregnancy.

Telogen effluvium is diagnosed by a hair pull test and observing club hairs under the microscope. It is generally a reversible condition, regardless of the cause. Telogen effluvium most often occurs 2-3 months after the inducing event, so your pregnancy is the most likely cause.

Prozac would less likely be the problem since you have only been on it for a short time. Besides causing Telogen effluvium, thyroid disease can also alter your hair characteristics, which can make your hair appear thinner.

Other causes of hair loss, such as genetic female pattern hair alopecia, must be ruled out.

Please see Hair Loss in Women page on the Bernstein Medical – Center for Hair Restoration website for more information.

A: The Telogen phase of the hair cycle is about 3 months long and about 12% of follicles are in this phase at any one time. It is speculated that the follicles may be empty for perhaps 1/2 that time (this number may vary significantly between people). Therefore, approximately 6% of the hair follicles may be in telogen at any one time.

On average about 15% of the follicular units are 1-hair units (but this also may very greatly between patients). If 6% of all follicles are “empty” telogen follicles, then there should be .15 x .06 = .009 or about 1% of the patient’s 1-hair follicular units in the empty telogen phase that can’t be identified and will be missed on dissection.

The 1% isn’t very large. However, also consider that the remaining 5% of the empty follicles are associated with larger follicular units (i.e. those with 2-4 hairs). If these follicular unit grafts are closely trimmed, as is the practice with very dense packing, a much more significant number of follicles are at risk of being lost. With chubby follicular unit grafts (i.e., where the microscopic dissection leaves a protective sheath of tissue around the follicles) the risk should be closer to the 1%.

The lesson for hair transplantation is that over-trimming of grafts, for the sake of very dense packing, may waste telogen hairs as well as place the grafts at an unnecessary risk of mechanical trauma, drying and warming.