-
Start of Period of Zygote
First 2 weeks of pregnancy -
Start of First Trimester
week 1-12 -
End of the Period of Zygote
-
Start of the Period of Embryo
3-8 Weeks -
End of the Period of Embryo
-
Start of the Period of Fetus
9-40 weeks -
Start of Second Trimester
week13-27 -
week of sex detection
18-20 weeks -
week of viable birth
23 weeks -
Start of Third Trimester
week 28-birth -
End of Period of Fetus
-
full term pregnancy
40 weeks
