( ( ( Pregnancy , ) ( Birth ( , ( Infancy ( Index 8.1 ) ) ) ) ) . )
(ROOT (NP (NP (NNP Pregnancy)) (, ,) (NP (NNP Birth) (, ,) (NNP Infancy) (NNP Index) (CD 8.1)) (. .)))
Pregnancy, Birth, Infancy Index 8.1.
(ROOT (S (NP (NP (DT The) (JJ first) (NN year)) (PP (IN after) (NP (NN birth)))) (VP (VBZ is) (VP (VBN called) (NP (NN infancy)))) (. .)))