Birth height and birth weight has little input on actual adult height. Birth measurements are based on intra-uterine nutrition and placental functioning.
As others have noted, you can get a better idea as a child grows, and settles into their "curve" on the growth charts. Even those aren't always accurate in predicting adult height though--a early or late bloomer will throw the prediction off.
Lala (2004), and Big Sis 2 (1992)
Grammy to Mr. Boss (2011), Mr. Helper (2012), and Mr. Attached-to-Grammy's-Hip (2014)
All living snuggly together
Big Sis 1 (1991) visiting often!