Pregnancy week by week brings new development in woman's body. Pregnancy period of 40 weeks can be divided into 3 trimester (which means three months long). First trimester includes the period from week 1 to week 12. Second trimester is from week 13 to week 26 while third trimester commences at week 27 and continues to term (which is the 40th week).

Week 1 to week 12

In this trimester of pregnancy week by week child grows rapidly and forms all organs and body structures, though very tiny. To put things into perspective - the baby is tinier than a grain of rice!!! Week 4 makes the woman realize that she is pregnant. Within a week, heart of the baby starts beating.

Week 13 to Week 26

Thirteenth week onwards, pregnancy enters into the second trimester and there are further developments in pregnancy week by week. Baby further develops and gradually, vocal chords begin to form, the nervous system starts to function and the reproductive organs become fully developed. Baby's hair, eyelids, eyebrows, eyelashes, nails, fingers and toes also get formed. This is a period where one can see on ultrasound whether it is a boy or a girl. By week 20 one can feel the baby moving. Within next 3-4 weeks baby's skin is reddish in color, wrinkled with veins visible through baby's translucent skin. This is also the period when the baby may start responding to sounds.

Week 26 to Week 40

This is the trimester during which pregnancy week by week enters into its culminating stage. During this period the fat starts depositing on the baby. His/Her hearing is fully developed and can move with the rhythm to music. By week 27 babies can even cry. By Week 29 of pregnancy the senses of sound, smell and taste are also developed. Week 32 is the time when baby spends most of its time in sleeping. Lungs are almost fully developed, baby can open and close the eyes and can also grasp firmly. During these weeks the baby position changes to prepare itself for delivery. The baby drops down in the pelvis with its head facing down towards the birth canal.

As one shall realise by now, pregnancy is by far the most sophisticated process in the human body. Pregnancy week by week undergoes marvellous changes - changes which have till date left even the most scientifically equipped human amazed at this intricate accomplishment of nature