Possible Clues:

• Describing an unborn baby of late development
• Like first position reversed, bit by bit, of late
• When cold, people often sleep in such a position
• Concerning embryos in the later stages of pregnancy
• Relating to an unborn in the later stages of development
• Young horse with alien wasn't born yesterday, today or tomorrow
• Embryonic challenger to chess champion
• Relating to the baby in the womb
• Relating to the unborn