( ( `` ( ( Most '' ) women ) ) ( ( ( feel ( ( ( fetal movement ) ( -LRB- ( quickening -RRB- ) ) ) ( at ( 18 weeks ) ) ) ) ( if ( it ( ( is ( your ( first baby ) ) ) ( -LRB- ( ( ( i.e. ( ( 18 weeks ) ( from ( your ( last ( menstrual period ) ) ) ) ) ) ( - LMP ) ) -RRB- ) ) ) ) ) ) . ) )
(ROOT (S (NP (`` ``) (NP (JJS Most)) ('' '') (VP (VBN women))) (VP (VBP feel) (NP (NP (NP (JJ fetal) (NN movement)) (PRN (-LRB- -LRB-) (NP (NN quickening)) (-RRB- -RRB-))) (PP (IN at) (NP (CD 18) (NNS weeks)))) (SBAR (IN if) (S (NP (PRP it)) (VP (VBZ is) (NP (PRP$ your) (JJ first) (NN baby)) (PRN (-LRB- -LRB-) (FRAG (X (X (SYM i.e.)) (NP (NP (CD 18) (NNS weeks)) (PP (IN from) (NP (PRP$ your) (JJ last) (JJ menstrual) (NN period))))) (: -) (NP (NNP LMP))) (-RRB- -RRB-)))))) (. .)))
"Most" women feel fetal movement (quickening) at 18 weeks if it is your first baby (i.e. 18 weeks from your last menstrual period - LMP).
(ROOT (S (NP (DT The) (JJ fetal) (NN period)) (VP (VBZ lasts) (NP (NP (QP (RB approximately) (CD 30)) (NNS weeks)) (NP (NNS weeks)))) (. .)))