Embryology

Events of pregnancy
Day 0- fertilisatn
Day 4- morula
Day 5- blastocyst
Day 6- implantn starts
Day 8- bHCG start synth
Day 11- implantn completd
Day 11- uteroplacentl circulatn
Day 13- primary villi forms
Day 14- haematopoisis starts in yolk sac
Week 2 - bilaminar disc
Week 3 - gastrulatn, trilaminar disc
Day 21- fetoplacentl cirultn
Day 25- anterior neuropore closes
Day 27- posterior neuropore closes
Week 4-5 gestatnl sac
Week 5- 44 somites formd
Week 6- fetal cardiac activity by TVS
Week 7- embryonic movmnt
Week 3to8- embryo
Week 8 to 14- max risk of radiatn
Week 9- early detectn of anencephaly
Week 10- physiolog umb hernia
Week 11- thyroxine productn starts, breathing movmt begins
Week 12- urine productn starts, ADH functns
Week 10 to 12- chorionic V Samp done
Week 11 to 13- nuchal translucency checkd
Week 12 to 18- amniocentesis done
Week 18 & above- cordocentesis
Week 18- anamoly scan
Week 16- quickening starts(multi), W18(primi)
Week 20- meconium forms, keratinstn of fetal skin
Abve W20- no abortn performd
Week 20- external balotment
Week 24to 28- GDM screening
Less than week 28- extremly premature
W28 to W32- very premature
W30 to 32- maternal blood volume reach max
Week 38- lightening of pressure symptm
Above Week 42- postmature