From week 11 until the time your baby is full term, he or she is officially described as a fetus. With all organ systems in place, growth becomes more rapid. From week 11 until week 20 of pregnancy - the halfway mark - your baby will increase his or her weight thirtyfold and will about triple in length. To accommodate all this growth, blood vessels in your placenta are growing larger and more numerous to keep up the supply of nutrients to your baby. His or her ears are moving up and to the side of the head this week, and his or her reproductive organs are developing
quickly, too. What was a tiny tissue bud of external genitalia has begun to develop into either a penis or a clitoris and labia majora, which will soon be recognizable.
Any sickness should start to fade and you will begin to feel less tired. You should start to think seriously about ante-natal classes because private ones can get booked up quickly. Contact your hospital or the National Childbirth Trust, or ask at your doctor's surgery about local classes.
When 11 weeks pregnant, most of the major organs are formed, so the most vulnerable time will be over by the end of this week. The baby is now relatively safe from any congenital abnormalities and infections, excepting rubella. The external genitals have formed, along with either ovaries or testicles. The heart is now pumping blood to all the major organs of the body. The baby weighs around 0.25 ounce (7 gram) and is now about 1.6 inch (4.1 cm) long.