The petrous portion of the temporal bone can be demonstrated by transvaginal ultrasound at 14-16 weeks of gestation.
Odeh
M
M
Ophir
E
E
Bornstein
J
J
D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D006801:Humans; D011247:Pregnancy; D013701:Temporal Bone / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000196:embryology*; D016216:Ultrasonography, Prenatal