If the penis is small, testosterone or human chorionic gonadotropin (hCG) injections may be given to enlarge it before surgery.

Until about the end of the second month of pregnancy, the villi cover the entire chorion, and are almost uniform in size but, after this, they develop unequally.

Parts The part of the chorion that is in contact with the decidua capsularis undergoes atrophy, so that by the fourth month scarcely a trace of the villi is left.