▁where ▁the ▁fet us ▁has ▁not ▁achieved ▁independent ▁existence , ▁an ▁act ▁causing ▁harm ▁to ▁an ▁un born ▁child ▁may ▁be ▁treated ▁leg ally ▁as ▁harm ▁to ▁the ▁mother ▁herself . ▁For ▁example , ▁in ▁the ▁case ▁St ▁George ' s ▁Health care ▁N HS ▁Trust ▁v ▁S ; ▁R ▁v ▁Collins ▁& ▁Or s , ▁ex ▁parte ▁S ▁it ▁was ▁held ▁a ▁tres pass ▁to ▁the ▁person ▁when ▁a ▁hospital ▁terminated ▁a ▁pre gn ancy ▁invol unt arily ▁because ▁the ▁mother ▁was ▁diagn osed ▁with ▁severe ▁pre - ec lam ps ia . ▁The ▁court ▁held ▁that ▁an ▁un born ▁child ' s ▁need ▁for ▁medical ▁assistance ▁does ▁not ▁prev ail ▁over ▁the ▁mother ' s ▁aut onomy ▁and ▁she ▁is ▁entitled ▁to ▁refuse ▁consent ▁to ▁treatment , ▁whether ▁her ▁own ▁life ▁or ▁that ▁of ▁her ▁un born ▁child ▁depends ▁on ▁it . ▁▁ ▁United ▁States ▁▁ ▁As ▁of ▁ 2 0 0 2 , ▁ 2 3 ▁states ▁in ▁the ▁United ▁States ▁still ▁employed ▁the ▁rule , ▁to ▁less er ▁or ▁greater ▁extent . ▁The ▁abol ition ▁of ▁the ▁rule ▁has ▁proceeded ▁pie c eme al , ▁from ▁case ▁to ▁case ▁and ▁from ▁stat ute ▁to ▁stat ute , ▁rather ▁than ▁wh oles ale . ▁One ▁such ▁land mark ▁case ▁with ▁respect ▁to ▁the ▁rule ▁was ▁Commonwealth ▁vs . ▁Cass , ▁in ▁the ▁Commonwealth ▁of ▁Massachusetts , ▁where ▁the ▁court ▁held ▁that ▁the ▁still b irth ▁of ▁an ▁eight - month - old ▁fet us , ▁whose ▁mother ▁had ▁been ▁injured