Nuchal scan accurate dating

All these medical advances in obstetrics were a lever for the introduction of men into an arena previously managed and run by women—midwifery.

The 18th century marked the beginning of many advances in European midwifery.These advances in knowledge were mainly regarding the physiology of pregnancy and labour.In the 18th century medical men began to train in area of childbirth and believed with their advanced knowledge in anatomy that childbirth could be improved.In France these male-midwives were referred to as "accoucheurs".This title was later on lent to male-midwives all over Europe.

The founding of lying-hospitals also contributed to the medicalization and male-dominance of obstetrics.

Despite this, increasing numbers of women are choosing to have additional scans for no medical purpose, such as gender scans, 3D and 4D scans.

A normal gestation would reveal a gestational sac, yolk sac, and fetal pole.

X-rays and computerized tomography (CT) are not used, especially in the first trimester, due to the ionizing radiation, which has teratogenic effects on the foetus.

No effects of magnetic resonance imaging (MRI) on the foetus have been demonstrated, but this technique is too expensive for routine observation.

These lying-hospitals were establishments where women would come to have their babies delivered, which had prior been unheard of since the midwife normally came to home of the pregnant woman.