The first sign of development of the baby is not evident until the fourth week since the last missed period. During the fourth week, the vital organs such as the brain, spinal cord, heart and other organs starts developing in the primitive baby or the embryo. The blood circulation and heart beat begin during the fifth week of the pregnancy. The heart beat is evident in an ultrasound examination. The fingers and toes of the baby begin to develop during the eight week while the sex of the child is apparent by the end of the eleventh week.

First trimester is considered as the most important phase of pregnancy, as the vital organs required for the normal functioning of the body are being formed during this phase. All three trimesters are equally important and proper care helps both the mother and the baby to remain healthy.¹     

Next page: Second trimester

Written by: Healthplus24 team
Date last updated: April 04, 2012