New facial or body hair during pregnancy: what's normal

By trimester

Weeks 1–13

1st trimester

Early pregnancy is usually too soon to notice much change in hair growth or thickness; the anagen-extending effect of pregnancy hormones tends to become more apparent later.

Weeks 14–27

2nd trimester

General hair thickening is commonly noticed by this point, and in one documented case, new facial hirsutism specifically began around 20 weeks, making the second trimester a reasonable point to start paying attention to whether any new growth looks like ordinary thickening or something more localized and coarse.

Weeks 28–birth

3rd trimester

Any hair changes tend to be at their most noticeable by now. This is a reasonable point to bring up new or unusual hair growth at a prenatal visit if you haven't already, particularly if it's appeared alongside acne, voice changes, or other new symptoms.

What does the evidence show for facial and body hair growth?

• High circulatory estrogen levels during pregnancy are understood to prolong the anagen, or active growth, phase of hair follicles, meaning more hairs stay in active growth at once; this reverses after delivery as estrogen drops, shifting more follicles into the resting telogen phase, a pattern known as telogen gravidarum that produces postpartum shedding. 1
• One review of hair follicle changes in women describes increased hair growth during pregnancy as a rare finding associated with signs of virilization such as a deepening voice, acne, and clitoral enlargement, framing new coarse hair growth, as opposed to general thickening of existing hair, as something that points toward an underlying hormonal cause rather than an expected pregnancy change. 2
• Pregnancy luteoma, a rare, typically harmless ovarian growth that resolves on its own after delivery, has been reported to cause androgen-excess features including acne, a deepening voice, facial or abdominal hirsutism, and clitoral enlargement; these features generally begin during pregnancy and ease after delivery, though hirsutism specifically was noted to sometimes persist postpartum in a documented case. 3
• A published case described facial hirsutism beginning at 20 weeks and persisting after delivery, without a deepened voice or other virilization signs. An ovarian pregnancy luteoma was nevertheless found during cesarean delivery. This single case shows why absent voice changes cannot rule out an underlying cause of new coarse facial hair. 3
• Outside of pregnancy specifically, hirsutism, coarse, dark hair growth in a male-pattern distribution, is most commonly caused by polycystic ovary syndrome, with thyroid disorders, adrenal or ovarian tumors, Cushing syndrome, congenital adrenal hyperplasia, and certain medications as other named causes; a provider should be contacted if hair grows rapidly or if other masculinizing changes appear. 4

When should I call my provider about facial and body hair growth?

New hair growth that appears alongside a deepening voice, clitoral enlargement, significant new or worsening acne, or noticeable increases in muscle bulk points toward an androgen-related cause rather than ordinary pregnancy hormone changes and should be evaluated by your provider. Rapidly progressing hair growth, rather than a gradual change over weeks, is also named as a reason to seek care rather than waiting for a routine visit. General, gradual thickening of hair you already had is not itself a warning sign. If you are ever unsure which side of the line you are on, make the call. Obstetric teams handle these check-ins as routine, not as overreacting.