( ( This problem ) ( ( started ( in ( immediate ( postpartum period ) ) ) ) . ) )
(ROOT (S (NP (DT This) (NN problem)) (VP (VBD started) (PP (IN in) (NP (JJ immediate) (NN postpartum) (NN period)))) (. .)))
This problem started in immediate postpartum period.
(ROOT (S (S (NP (DT The) (NN postpartum) (NN period)) (VP (VBZ starts) (SBAR (IN after) (S (NP (DT the) (NN baby)) (VP (VBZ is) (VP (VBN born))))))) (, ,) (CC and) (S (NP (DT the) (NN placenta)) (VP (VBZ is) (VP (VBN expelled) (PP (IN from) (NP (DT the) (NN body)))))) (. .)))