Third trimester comprises of 27th week of pregnancy till delivery. Total duration of pregnancy is 280 days/ 40 weeks from your last normal menstrual period. So from 27th week starts the last few months of your pregnancy and eagerness increases week by week.Many changes happen in the baby from 27- 40 weeks.
Some interesting facts are:
• As the pregnancy advances baby gains weight, becoming chubby and storing fat all over the body. On an average a healthy baby is 1- 1.2 kg at 28 weeks and reaches 3-3.2 kg by 40 weeks. With deposition of fat beneath the baby’s skin, wrinkles start disappearing.
• Baby’s length (head till buttocks, CRL) increases from 25 cm at 28 weeks to 45-50 cm at 40 weeks.
• Bones are fully developed at 28 weeks but they are pliable and soft, and strengthening of bones, calcium deposition and its growth continues till delivery and afterwards.
• Baby develops a regular sleep wake cycle from 28 weeks onwards.
• Head hair develops by 30th week and baby looks much like as it will look at birth.
• Soft hair covering the baby’s body called lanugo start falling from 32 weeks.
• Throughout the third trimester the brain develops at a fast rate. The baby practices reflexes like grasping, sucking and develops senses.
• Baby’s eye lashes start forming at 28 weeks and baby opens eyes partially at 28 weeks to fully by 30th week.
• Hearing starts at 28-29 weeks, so now you can enjoy talking to your baby. Research has shown that baby develops music preferences by 31 weeks . Hearing matures by 35 weeks.
• Baby starts practicing breathing from 32 weeks onwards but lung maturation continues till the day of delivery.
• Nails appear at 32 weeks and fingers by 38 weeks.
• Baby’s organs are ready to function on their own from 36-37 weeks of pregnancy and by 38 week baby is fit and mature to make appearance into outer world.
• In the last 2 weeks, baby drops into maternal pelvis, this is called lightening; placenta (afterbirth) supplies antibodies to fight against infection and testes continue to descend into scrotum.
• EDD is an estimate and only 5 % actually deliver on the due date.