Because that's when the vital organs are shaped, heart, brain etc.
the organs grow larger
3rd trimester
The time period during which irreversible damage to the fetus may occur from specific events such as malnutrition or exposure to toxins is referred to as the "critical period." This phase is particularly crucial during the first trimester of pregnancy when the foundations for major organs and systems are being established. During this time, the fetus is highly sensitive to external factors that can disrupt normal development.
Fingers and toes develop during the first trimester of pregnancy in a human fetus.
the first trimester
blood flow from the mother to the fetus
At the third trimester.
in the first trimester
It grows in size
they are passed to the fetus and cause imbalanced compounds that effect DNA
in the first trimester/3 MONTHS
The central nervous system develops in a fetus during the first trimester of pregnancy.