BIRTHSTOOL (אָבְנָ֑יִם, bearing stool). The birthstool is referred to in Exodus 1:16 when Heb. women were having babies in Egypt and was a type of stool on which women sat while giving birth. The Heb. name for it, “double stones,” implies that it was a pair of stones one supporting each thigh with a gap between them to allow the midwife to effect the delivery. Giving birth in this position is really more logical than the modern positions of back or left-side as gravity will add to the natural powers effecting the birth. The same word is tr. “potter’s wheel” (Jer 18:3), since basically it means “disk.”

International Standard Bible Encyclopedia (1915)

burth’-stool: Found only in Ex 1:16, in connection with Hebrew women in Egypt when oppressed by Pharaoh. The Hebrew (’obhnayim) here rendered "birth-stool" is used in Jer 18:3, and is there rendered "potter’s wheel." The word is used in both places in the dual form, which points, no doubt, to the fact that the potter’s wheel was composed of two discs, and suggests that the birth-stool was similarly double.

See Stool.