Here's what rhymes with blastocyst.

Consider these alternatives

embryo / no implantation / operation oocyte / might embryos / those pupal / pupil embryonic / chronic preimplantation / operation astrocytes / rights cryopreservation / information adipocytes / rights epithelium / helium ovum / chosen amniotic / subamniotic ascites / needs implanting / understanding oocytes / rights neutrophils / years notochord / called maturation / operation gastrulation / relation glia / idea