The best replacement for yolk sac is gestational sac.

The best alternatives to yolk sac are rated as following:
★★★★★  gestational sac
★★★★★  fetal pole
★★★★  placenta
★★★★  twins
★  embryo
★  fetal pole just gestational sac
★  amniotic sac
★  fetus pole
  secondary yolk sac

Your alternative for yolk sac is not listed? Suggest!
Speaking about yolk sac, one probably shouldn't forget about no fetal pole.

Other search terms related to yolk sac and their ratings are:
★★★★★ no fetal pole
★★★ fetal pole
★★★ blighted ovum
★★ fetus
★★ heartbeat
★ embryo
★ no heartbeat
★ molar pregnancy
★ an embryo
yolk
gestational sac
fetal
pole
You have in mind a companion for yolk sac and it is not yet here? Propose!



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yolk sac
gestational sac
fetal pole