There are several important factors involved when producing a 3D/4D ultrasound. One factor is the amount of space remaining in the womb. 2D ultrasound sees through everything but when scanning in 3D, everything becomes solid. Therefore things like the umbilical cord or placenta can act as a barrier if sitting in front of the baby.
The most optimal time to see the baby is between 26 – 30 weeks because there is still room in the womb. The further into the pregnancy you are, the more the remaining space decreases. Another important factor is how much amniotic fluid is present. It is important to stay hydrated throughout the pregnancy. Extra fluid intake a few days prior to coming in for a 3D/4D baby ultrasound scan is known to help with the clarity of the pictures.
The placenta position is another element that affects a ultrasound. An anterior placenta is on the front side of the womb and in front of the baby while a posterior placenta is on the backside of the womb and in back of the baby. With 3D/4D imaging, the posterior is ideal however, it is possible to capture the baby with an anterior.
