LENGTH OF PREGNANCY

• 267-280 days or 40 weeks or 10 lunar months or 9 calendar months or 3 trimesters.
• First trimester is the period of organogenesis; teratogens (alcohol, drugs, virus, radiation) highly damaging.
• Second trimester is most comfortable for mother with continued fetal growth.
• The third trimester is the period of rapid fetal growth because of rapid deposition of fats, iron and calcium.