( ( If pregnant ) ( , ( ( avoid ( toxic ( chemical exposure ) ) ) . ) ) )
(ROOT (S (PP (IN If) (ADJP (JJ pregnant))) (, ,) (VP (VB avoid) (NP (JJ toxic) (NN chemical) (NN exposure))) (. .)))
If pregnant, avoid toxic chemical exposure.
(ROOT (S (NP (DT A) (JJ pregnant) (NN woman)) (VP (MD should) (VP (VB avoid) (NP (JJ toxic) (NNS substances)) (SBAR (IN while) (FRAG (ADJP (JJ pregnant)))))) (. .)))