This site is like KidSpiration, but it is free and easy to use. elements story, create-your-own-topic. Source: Liz Phillips. After a teacher types in the story starter, students log in to write. read, the class decides which direction the story should take. class agrees the story is finished.
Fetal development - month 1. First trimester. At the end of four weeks: Baby is 1/4 inch long. Heart, digestive system, backbone and spinal cord begin to form. Placenta (sometimes called afterbirth) begins to develop. The single fertilized egg is now 10,000 times larger than it was at conception.
The mathematic formula for estimating the gestational age from measurements of the gestational sac is: Gestational age = 4 weeks plus (mean sac diameter in mm x days). For example, a gestational sac measuring 8 mm would be approximately 5 weeks and 1 day gestational age.(8mm equals 8 days; 4 weeks plus 8 days = 5 weeks and 1 day).eave this field blank. Keyword Tags: ultrasound sonogram gestational sac fetus early pregnancy. The gestational sac is the structure surrounding the fetus early in pregnancy and its shape early in pregnancy (usually before 8-10 weeks) is important.