Skip Navigation

Little One Pregnancy Place  

Pregnancy Snapshot

The first week

(*Ages are referenced from time of conception or fertilization,
not from the beginning of your last menstrual period. One month equals 4 weeks.)
 
Next
 
Movie clip from The Biology of Prenatal Development. Buy Now!
 

Pregnancy Pictures

 
See Labels [Fertilization]

Development begins with a single-cell embryo at conception!!! (Age: 0-1 day old) Play Movie [Fertilization]
See Labels [Two-Cell Human Embryo]

One cell becomes two. (30 to 36 hours old) Play Movie [Cell Division]
See Labels [The Human Morula]

With 12 to 16 cells, the embryo is shaped like a tiny bunch of grapes. (3 days old) Play Movie [With 12 to 16 cells, the embryo is shaped like a tiny bunch of grapes.]
See Labels [Blastocyst with Inner Cell Mass]

The site of the future back and chest can be seen. (4 days old)
See Labels []

The embryo begins to implant in the womb. (6 days) Play Movie [Implantation]


*All prenatal ages are referenced from the time of fertilization (or conception).
One month is defined as exactly four weeks.