Progeria: is there any effect on the unborn fetus if it has progeria?

Not specifically: Although their average birth weight of 6 pounds is a bit smaller than average the infants appear normal at birth.There may be some subtle features dealing with hair growth but few are recognized before a year of age.The rarity of the process and lack of early markers make any study of prenatal appearance unlikely.

Progeria: Features of Progeria will usually become more visible as the baby ages. Newborns look normal. However there are some disorders that are similar to Hutchinson-Gilford progeria syndrome (HGPS) which cause changes in utero: Progeroid syndrome with Ehlers-Danlos features & Wiedemann-Rautenstrauch syndrome (WRS), (AKA neonatal progeroid syndrome)