Week 6 – Gestational Age / Week 4 – Fetal Age
** Gestational age is the age of the pregnancy from the last normal menstrual period (LMP) and fetal age is the actual age of the growing baby.
The formation of the lungs, jaw, nose and palate begin now. The hand and feet buds have webbed looking structures that will become the fingers and toes. The brain is continuing to form into its complex parts. A vaginal ultrasound could detect an audible heartbeat at this time. The embryo is about a ½ inch in length.
Source: American Pregnancy Association