By the end of the 12th week, the fetal will have fingernails. (Joy, Donald M., PhD.Bonding. p 90. TX: Word Books, 1985.)

Fetus is able to yawn. (Imrdkl, A Smiling Fetus is a Happy Fetus.)

Ovaries begin developing in female fetus. (Blum, Deborah. Sex on the Brain. p 28-30. NY: Penguin Books, 1997.)

Androgens produced by the testes of a male fetus cause Wolffian structures to grow (and the Mullerian structures degenerate). (Arnold, Caroline. Sex Hormones. p 60-61. NY: William Morrow & Company, 1981.)

Swallows amniotic fluid regularly. (Ludington-Hoe, Susan, PhD, with Susan K. Golant, MA. How to Have a Smarter Baby. p 16. NY: Bantam Books, 1985.)

The female system (if the fetus is to be female) begins to produce the ovarian hormones estrogen and progesterone. (Stump, Jane Barr, PhD. What’s the Difference? p 79. NY: William Morrow and Company, Inc., 1985.)