/* Hoffman weight for gestational age criteria, by gender and race from: " Analysis of Birth Weight, Gestational Age, and Fetal Viability, U.S. Births, 1968" H. J. Hoffman, C.R. Stark, F. E. Lundin, and J.D. Ashbrook, Obstetrical and Gynecological Survey, Vol 29, No. 9, pp 651-681 , 1974 SAS program offered by Karen Norberg, MD; e-mail norberg@nber.org issues to keep in mind: The current version of this program is available from: http://www.nber.org/~norberg/nstat.html 1) In spite of the large sample on which this table is based, the 10th percentiles at extreme gestational ages are based on small numbers in this data; some nonlinearities probably reflect random variation. 2) These weights are based on single live births, based on 50% sample of births from 36 reporting states and the district of Columbia in 1968, the first year of a revised US standard birth certificate that included report of date of last menstrual period. Data based on live births may result in "anomalous" distributions at very early or late gestational ages. 3) There is controversy about whether racial differences in birthweight in the U.S. are the result of economic or social factors, or reflect biological variations (such as mean height and weight) between different ethnic populations. You may wish to use the black/white distinction, or not, depending on the purposes of the study. However, differences in birthweight by gender are well established and clearly have a biological basis; on average, girls are smaller than boys at birth. 4) There are other weight standards available; this table is chosen because it reflects a nationally representative sample, not selected for the presence or absence of prenatal illness or congenital malformations, and is the largest published sample. Other standards may be more appropriate for particular purposes . Hoffman criteria, by gestational age, gender and race, over gestational age range = 22 - 52 weeks note: 1 gram = .035 oz; 1 oz = 28.349 grams conventional cutoffs for gestational age are: less than 37 or 38 weeks = premature; more than 41 weeks = postmature; Variable definitions: sex 1 = male 2 = female black 0 = other 1 = black hs10 1 = equal to or below tenth percentile of weight for gestational age 0 = above tenth percentile hs25 1 = equal to or below 25th percentile of weight for gestational age 0 = above 25th percentile */ data nstat; label gwt = "birth weight in grams "; label gestage = "gestational age in completed weeks"; label hs10 = "weight 10th percentile or less"; label hs25 = "weight 25th percentile or less"; if gwt = . then hs10 = .; else if black=0 and sex=1 and gestage=22 and gwt le 191 then hs10= 1 ; else if black=1 and sex=1 and gestage=22 and gwt le 165 then hs10= 1 ; else if black=0 and sex=1 and gestage=23 and gwt le 414 then hs10= 1; else if black=1 and sex=1 and gestage=23 and gwt le 465 then hs10= 1; else if black=0 and sex=1 and gestage=24 and gwt le 521 then hs10= 1; else if black=1 and sex=1 and gestage=24 and gwt le 530 then hs10= 1; else if black=0 and sex=1 and gestage=25 and gwt le 547 then hs10= 1; else if black=1 and sex=1 and gestage=25 and gwt le 560 then hs10= 1; else if black=0 and sex=1 and gestage=26 and gwt le 582 then hs10= 1; else if black=1 and sex=1 and gestage=26 and gwt le 637 then hs10= 1; else if black=0 and sex=1 and gestage=27 and gwt le 655 then hs10= 1; else if black=1 and sex=1 and gestage=27 and gwt le 642 then hs10= 1; else if black=0 and sex=1 and gestage=28 and gwt le 843 then hs10= 1; else if black=1 and sex=1 and gestage=28 and gwt le 907 then hs10= 1; else if black=0 and sex=1 and gestage=29 and gwt le 1046 then hs10= 1; else if black=1 and sex=1 and gestage=29 and gwt le 1019 then hs10= 1; else if black=0 and sex=1 and gestage=30 and gwt le 1161 then hs10= 1; else if black=1 and sex=1 and gestage=30 and gwt le 1219 then hs10= 1; else if black=0 and sex=1 and gestage=31 and gwt le 1310 then hs10= 1; else if black=1 and sex=1 and gestage=31 and gwt le 1405 then hs10= 1; else if black=0 and sex=1 and gestage=32 and gwt le 1548 then hs10= 1; else if black=1 and sex=1 and gestage=32 and gwt le 1577 then hs10= 1; else if black=0 and sex=1 and gestage=33 and gwt le 1709 then hs10= 1; else if black=1 and sex=1 and gestage=33 and gwt le 1696 then hs10= 1; else if black=0 and sex=1 and gestage=34 and gwt le 2009 then hs10= 1; else if black=1 and sex=1 and gestage=34 and gwt le 2012 then hs10= 1; else if black=0 and sex=1 and gestage=35 and gwt le 2119 then hs10= 1; else if black=1 and sex=1 and gestage=35 and gwt le 2143 then hs10= 1; else if black=0 and sex=1 and gestage=36 and gwt le 2250 then hs10= 1; else if black=1 and sex=1 and gestage=36 and gwt le 2225 then hs10= 1; else if black=0 and sex=1 and gestage=37 and gwt le 2513 then hs10= 1; else if black=1 and sex=1 and gestage=37 and gwt le 2391 then hs10= 1; else if black=0 and sex=1 and gestage=38 and gwt le 2621 then hs10= 1; else if black=1 and sex=1 and gestage=38 and gwt le 2544 then hs10= 1; else if black=0 and sex=1 and gestage=39 and gwt le 2743 then hs10= 1; else if black=1 and sex=1 and gestage=39 and gwt le 2608 then hs10= 1; else if black=0 and sex=1 and gestage=40 and gwt le 2890 then hs10= 1; else if black=1 and sex=1 and gestage=40 and gwt le 2676 then hs10= 1; else if black=0 and sex=1 and gestage=41 and gwt le 3006 then hs10= 1; else if black=1 and sex=1 and gestage=41 and gwt le 2689 then hs10= 1; else if black=0 and sex=1 and gestage=42 and gwt le 3010 then hs10= 1; else if black=1 and sex=1 and gestage=42 and gwt le 2660 then hs10= 1; else if black=0 and sex=1 and gestage=43 and gwt le 2972 then hs10= 1; else if black=1 and sex=1 and gestage=43 and gwt le 2633 then hs10= 1; else if black=0 and sex=1 and gestage=44 and gwt le 2957 then hs10= 1; else if black=1 and sex=1 and gestage=44 and gwt le 2629 then hs10= 1; else if black=0 and sex=1 and gestage=45 and gwt le 2935 then hs10= 1; else if black=1 and sex=1 and gestage=45 and gwt le 2636 then hs10= 1; else if black=0 and sex=1 and gestage=46 and gwt le 2921 then hs10= 1; else if black=1 and sex=1 and gestage=46 and gwt le 2694 then hs10= 1; else if black=0 and sex=1 and gestage=47 and gwt le 2838 then hs10= 1; else if black=1 and sex=1 and gestage=47 and gwt le 2660 then hs10= 1; else if black=0 and sex=1 and gestage=48 and gwt le 2825 then hs10= 1; else if black=1 and sex=1 and gestage=48 and gwt le 2548 then hs10= 1; else if black=0 and sex=1 and gestage=49 and gwt le 2813 then hs10= 1; else if black=1 and sex=1 and gestage=49 and gwt le 2691 then hs10= 1; else if black=0 and sex=1 and gestage=50 and gwt le 2820 then hs10= 1; else if black=1 and sex=1 and gestage=50 and gwt le 2630 then hs10= 1; else if black=0 and sex=1 and gestage=51 and gwt le 2841 then hs10= 1; else if black=1 and sex=1 and gestage=51 and gwt le 2574 then hs10= 1; else if black=0 and sex=1 and gestage=52 and gwt le 2823 then hs10= 1; else if black=1 and sex=1 and gestage=52 and gwt le 2524 then hs10= 1; else if black=0 and sex=2 and gestage=22 and gwt le 150 then hs10= 1 ; else if black=1 and sex=2 and gestage=22 and gwt le 251 then hs10= 1 ; /* ( the above number has been interpolated ) */ else if black=0 and sex=2 and gestage=23 and gwt le 240 then hs10= 1 ; else if black=1 and sex=2 and gestage=23 and gwt le 354 then hs10= 1 ; else if black=0 and sex=2 and gestage=24 and gwt le 527 then hs10= 1 ; else if black=1 and sex=2 and gestage=24 and gwt le 512 then hs10= 1 ; else if black=0 and sex=2 and gestage=25 and gwt le 537 then hs10= 1 ; else if black=1 and sex=2 and gestage=25 and gwt le 563 then hs10= 1 ; else if black=0 and sex=2 and gestage=26 and gwt le 566 then hs10=1; else if black=1 and sex=2 and gestage=26 and gwt le 626 then hs10= 1; else if black=0 and sex=2 and gestage=27 and gwt le 628 then hs10= 1; else if black=1 and sex=2 and gestage=27 and gwt le 692 then hs10= 1; else if black=0 and sex=2 and gestage=28 and gwt le 758 then hs10= 1; else if black=1 and sex=2 and gestage=28 and gwt le 788 then hs10= 1; else if black=0 and sex=2 and gestage=29 and gwt le 1006 then hs10= 1; else if black=1 and sex=2 and gestage=29 and gwt le 1083 then hs10= 1; else if black=0 and sex=2 and gestage=30 and gwt le 1124 then hs10= 1; else if black=1 and sex=2 and gestage=30 and gwt le 1133 then hs10= 1; else if black=0 and sex=2 and gestage=31 and gwt le 1275 then hs10= 1; else if black=1 and sex=2 and gestage=31 and gwt le 1299 then hs10= 1; else if black=0 and sex=2 and gestage=32 and gwt le 1527 then hs10= 1; else if black=1 and sex=2 and gestage=32 and gwt le 1564 then hs10= 1; else if black=0 and sex=2 and gestage=33 and gwt le 1611 then hs10= 1; else if black=1 and sex=2 and gestage=33 and gwt le 1695 then hs10= 1; else if black=0 and sex=2 and gestage=34 and gwt le 1858 then hs10= 1; else if black=1 and sex=2 and gestage=34 and gwt le 1872 then hs10= 1; else if black=0 and sex=2 and gestage=35 and gwt le 2068 then hs10= 1; else if black=1 and sex=2 and gestage=35 and gwt le 2053 then hs10= 1; else if black=0 and sex=2 and gestage=36 and gwt le 2176 then hs10= 1; else if black=1 and sex=2 and gestage=36 and gwt le 2181 then hs10= 1; else if black=0 and sex=2 and gestage=37 and gwt le 2350 then hs10= 1; else if black=1 and sex=2 and gestage=37 and gwt le 2266 then hs10= 1; else if black=0 and sex=2 and gestage=38 and gwt le 2545 then hs10= 1; else if black=1 and sex=2 and gestage=38 and gwt le 2446 then hs10= 1; else if black=0 and sex=2 and gestage=39 and gwt le 2629 then hs10= 1; else if black=1 and sex=2 and gestage=39 and gwt le 2544 then hs10= 1; else if black=0 and sex=2 and gestage=40 and gwt le 2713 then hs10= 1; else if black=1 and sex=2 and gestage=40 and gwt le 2592 then hs10= 1; else if black=0 and sex=2 and gestage=41 and gwt le 2786 then hs10= 1; else if black=1 and sex=2 and gestage=41 and gwt le 2601 then hs10= 1; else if black=0 and sex=2 and gestage=42 and gwt le 2802 then hs10= 1; else if black=1 and sex=2 and gestage=42 and gwt le 2603 then hs10= 1; else if black=0 and sex=2 and gestage=43 and gwt le 2762 then hs10= 1; else if black=1 and sex=2 and gestage=43 and gwt le 2611 then hs10= 1; else if black=0 and sex=2 and gestage=44 and gwt le 2747 then hs10= 1; else if black=1 and sex=2 and gestage=44 and gwt le 2568 then hs10= 1; else if black=0 and sex=2 and gestage=45 and gwt le 2738 then hs10= 1; else if black=1 and sex=2 and gestage=45 and gwt le 2573 then hs10= 1; else if black=0 and sex=2 and gestage=46 and gwt le 2722 then hs10= 1; else if black=1 and sex=2 and gestage=46 and gwt le 2558 then hs10= 1; else if black=0 and sex=2 and gestage=47 and gwt le 2677 then hs10= 1; else if black=1 and sex=2 and gestage=47 and gwt le 2548 then hs10= 1; else if black=0 and sex=2 and gestage=48 and gwt le 2651 then hs10= 1; else if black=1 and sex=2 and gestage=48 and gwt le 2513 then hs10= 1; else if black=0 and sex=2 and gestage=49 and gwt le 2728 then hs10= 1; else if black=1 and sex=2 and gestage=49 and gwt le 2389 then hs10= 1; else if black=0 and sex=2 and gestage=50 and gwt le 2646 then hs10= 1; else if black=1 and sex=2 and gestage=50 and gwt le 2301 then hs10= 1; else if black=0 and sex=2 and gestage=51 and gwt le 2639 then hs10= 1; else if black=1 and sex=2 and gestage=51 and gwt le 2516 then hs10= 1; else if black=0 and sex=2 and gestage=52 and gwt le 2605 then hs10= 1; else if black=1 and sex=2 and gestage=52 and gwt le 2351 then hs10= 1; else if gestage > 21 and gwt > . then hs10 = 0; if gwt = . then hs25 = .; else if black=0 and sex=1 and gestage=22 and gwt le 477 then hs25=1; else if black=1 and sex=1 and gestage=22 and gwt le 412 then hs25= 1; else if black=0 and sex=1 and gestage=23 and gwt le 613 then hs25= 1; else if black=1 and sex=1 and gestage=23 and gwt le 652 then hs25= 1; else if black=0 and sex=1 and gestage=24 and gwt le 633 then hs25= 1; else if black=1 and sex=1 and gestage=24 and gwt le 683 then hs25= 1; else if black=0 and sex=1 and gestage=25 and gwt le 672 then hs25= 1; else if black=1 and sex=1 and gestage=25 and gwt le 720 then hs25= 1; else if black=0 and sex=1 and gestage=26 and gwt le 742 then hs25=1; else if black=1 and sex=1 and gestage=26 and gwt le 841 then hs25= 1; else if black=0 and sex=1 and gestage=27 and gwt le 903 then hs25= 1; else if black=1 and sex=1 and gestage=27 and gwt le 957 then hs25= 1; else if black=0 and sex=1 and gestage=28 and gwt le 1118 then hs25= 1; else if black=1 and sex=1 and gestage=28 and gwt le 1117 then hs25= 1; else if black=0 and sex=1 and gestage=29 and gwt le 1230 then hs25= 1; else if black=1 and sex=1 and gestage=29 and gwt le 1285 then hs25= 1; else if black=0 and sex=1 and gestage=30 and gwt le 1482 then hs25= 1; else if black=1 and sex=1 and gestage=30 and gwt le 1626 then hs25= 1; else if black=0 and sex=1 and gestage=31 and gwt le 1635 then hs25= 1; else if black=1 and sex=1 and gestage=31 and gwt le 1729 then hs25= 1; else if black=0 and sex=1 and gestage=32 and gwt le 1791 then hs25= 1; else if black=1 and sex=1 and gestage=32 and gwt le 1892 then hs25= 1; else if black=0 and sex=1 and gestage=33 and gwt le 2064 then hs25= 1; else if black=1 and sex=1 and gestage=33 and gwt le 2124 then hs25= 1; else if black=0 and sex=1 and gestage=34 and gwt le 2254 then hs25= 1; else if black=1 and sex=1 and gestage=34 and gwt le 2337 then hs25= 1; else if black=0 and sex=1 and gestage=35 and gwt le 2449 then hs25= 1; else if black=1 and sex=1 and gestage=35 and gwt le 2509 then hs25= 1; else if black=0 and sex=1 and gestage=36 and gwt le 2473 then hs25= 1; else if black=1 and sex=1 and gestage=36 and gwt le 2594 then hs25= 1; else if black=0 and sex=1 and gestage=37 and gwt le 2751 then hs25= 1; else if black=1 and sex=1 and gestage=37 and gwt le 2683 then hs25= 1; else if black=0 and sex=1 and gestage=38 and gwt le 2943 then hs25= 1; else if black=1 and sex=1 and gestage=38 and gwt le 2791 then hs25= 1; else if black=0 and sex=1 and gestage=39 and gwt le 3080 then hs25= 1; else if black=1 and sex=1 and gestage=39 and gwt le 2930 then hs25= 1; else if black=0 and sex=1 and gestage=40 and gwt le 3163 then hs25= 1; else if black=1 and sex=1 and gestage=40 and gwt le 3030 then hs25= 1; else if black=0 and sex=1 and gestage=41 and gwt le 3225 then hs25= 1; else if black=1 and sex=1 and gestage=41 and gwt le 3051 then hs25= 1; else if black=0 and sex=1 and gestage=42 and gwt le 3248 then hs25= 1; else if black=1 and sex=1 and gestage=42 and gwt le 3034 then hs25= 1; else if black=0 and sex=1 and gestage=43 and gwt le 3228 then hs25= 1; else if black=1 and sex=1 and gestage=43 and gwt le 3013 then hs25= 1; else if black=0 and sex=1 and gestage=44 and gwt le 3210 then hs25= 1; else if black=1 and sex=1 and gestage=44 and gwt le 3013 then hs25= 1; else if black=0 and sex=1 and gestage=45 and gwt le 3212 then hs25= 1; else if black=1 and sex=1 and gestage=45 and gwt le 3034 then hs25= 1; else if black=0 and sex=1 and gestage=46 and gwt le 3206 then hs25= 1; else if black=1 and sex=1 and gestage=46 and gwt le 3077 then hs25= 1; else if black=0 and sex=1 and gestage=47 and gwt le 3177 then hs25= 1; else if black=1 and sex=1 and gestage=47 and gwt le 3055 then hs25= 1; else if black=0 and sex=1 and gestage=48 and gwt le 3163 then hs25= 1; else if black=1 and sex=1 and gestage=48 and gwt le 2935 then hs25= 1; else if black=0 and sex=1 and gestage=49 and gwt le 3154 then hs25= 1; else if black=1 and sex=1 and gestage=49 and gwt le 3096 then hs25= 1; else if black=0 and sex=1 and gestage=50 and gwt le 3144 then hs25= 1; else if black=1 and sex=1 and gestage=50 and gwt le 2876 then hs25= 1; else if black=0 and sex=1 and gestage=51 and gwt le 3166 then hs25= 1; else if black=1 and sex=1 and gestage=51 and gwt le 2819 then hs25= 1; else if black=0 and sex=1 and gestage=52 and gwt le 3147 then hs25= 1; else if black=1 and sex=1 and gestage=52 and gwt le 2761 then hs25= 1; else if black=0 and sex=2 and gestage=22 and gwt le 373 then hs25=1; else if black=1 and sex=2 and gestage=22 and gwt le 653 then hs25= 1; else if black=0 and sex=2 and gestage=23 and gwt le 541 then hs25= 1; else if black=1 and sex=2 and gestage=23 and gwt le 629 then hs25= 1; else if black=0 and sex=2 and gestage=24 and gwt le 653 then hs25= 1; else if black=1 and sex=2 and gestage=24 and gwt le 672 then hs25= 1; else if black=0 and sex=2 and gestage=25 and gwt le 655 then hs25= 1; else if black=1 and sex=2 and gestage=25 and gwt le 767 then hs25= 1; else if black=0 and sex=2 and gestage=26 and gwt le 706 then hs25=1; else if black=1 and sex=2 and gestage=26 and gwt le 851 then hs25= 1; else if black=0 and sex=2 and gestage=27 and gwt le 841 then hs25= 1; else if black=1 and sex=2 and gestage=27 and gwt le 993 then hs25= 1; else if black=0 and sex=2 and gestage=28 and gwt le 1085 then hs25= 1; else if black=1 and sex=2 and gestage=28 and gwt le 1145 then hs25= 1; else if black=0 and sex=2 and gestage=29 and gwt le 1198 then hs25= 1; else if black=1 and sex=2 and gestage=29 and gwt le 1292 then hs25= 1; else if black=0 and sex=2 and gestage=30 and gwt le 1395 then hs25= 1; else if black=1 and sex=2 and gestage=30 and gwt le 1454 then hs25= 1; else if black=0 and sex=2 and gestage=31 and gwt le 1636 then hs25= 1; else if black=1 and sex=2 and gestage=31 and gwt le 1722 then hs25= 1; else if black=0 and sex=2 and gestage=32 and gwt le 1759 then hs25= 1; else if black=1 and sex=2 and gestage=32 and gwt le 1881 then hs25= 1; else if black=0 and sex=2 and gestage=33 and gwt le 1939 then hs25= 1; else if black=1 and sex=2 and gestage=33 and gwt le 2104 then hs25= 1; else if black=0 and sex=2 and gestage=34 and gwt le 2194 then hs25= 1; else if black=1 and sex=2 and gestage=34 and gwt le 2270 then hs25= 1; else if black=0 and sex=2 and gestage=35 and gwt le 2368 then hs25= 1; else if black=1 and sex=2 and gestage=35 and gwt le 2382 then hs25 =1; else if black=0 and sex=2 and gestage=36 and gwt le 2534 then hs25= 1; else if black=1 and sex=2 and gestage=36 and gwt le 2543 then hs25= 1; else if black=0 and sex=2 and gestage=37 and gwt le 2651 then hs25= 1; else if black=1 and sex=2 and gestage=37 and gwt le 2604 then hs25= 1; else if black=0 and sex=2 and gestage=38 and gwt le 2782 then hs25= 1; else if black=1 and sex=2 and gestage=38 and gwt le 2683 then hs25= 1; else if black=0 and sex=2 and gestage=39 and gwt le 2947 then hs25= 1; else if black=1 and sex=2 and gestage=39 and gwt le 2773 then hs25= 1; else if black=0 and sex=2 and gestage=40 and gwt le 3055 then hs25= 1; else if black=1 and sex=2 and gestage=40 and gwt le 2873 then hs25= 1; else if black=0 and sex=2 and gestage=41 and gwt le 3107 then hs25= 1; else if black=1 and sex=2 and gestage=41 and gwt le 2917 then hs25= 1; else if black=0 and sex=2 and gestage=42 and gwt le 3124 then hs25= 1; else if black=1 and sex=2 and gestage=42 and gwt le 2898 then hs25= 1; else if black=0 and sex=2 and gestage=43 and gwt le 3105 then hs25= 1; else if black=1 and sex=2 and gestage=43 and gwt le 2910 then hs25= 1; else if black=0 and sex=2 and gestage=44 and gwt le 3093 then hs25= 1; else if black=1 and sex=2 and gestage=44 and gwt le 2872 then hs25= 1; else if black=0 and sex=2 and gestage=45 and gwt le 3091 then hs25= 1; else if black=1 and sex=2 and gestage=45 and gwt le 2866 then hs25= 1; else if black=0 and sex=2 and gestage=46 and gwt le 3080 then hs25= 1; else if black=1 and sex=2 and gestage=46 and gwt le 2851 then hs25= 1; else if black=0 and sex=2 and gestage=47 and gwt le 3036 then hs25= 1; else if black=1 and sex=2 and gestage=47 and gwt le 2827 then hs25= 1; else if black=0 and sex=2 and gestage=48 and gwt le 3024 then hs25= 1; else if black=1 and sex=2 and gestage=48 and gwt le 2730 then hs25= 1; else if black=0 and sex=2 and gestage=49 and gwt le 3078 then hs25= 1; else if black=1 and sex=2 and gestage=49 and gwt le 2818 then hs25= 1; else if black=0 and sex=2 and gestage=50 and gwt le 2999 then hs25= 1; else if black=1 and sex=2 and gestage=50 and gwt le 2834 then hs25= 1; else if black=0 and sex=2 and gestage=51 and gwt le 3014 then hs25= 1; else if black=1 and sex=2 and gestage=51 and gwt le 2764 then hs25= 1; else if black=0 and sex=2 and gestage=52 and gwt le 2953 then hs25= 1; else if black=1 and sex=2 and gestage=52 and gwt le 2761 then hs25= 1; else if gwt > . and gestage > 21 then hs25 = 0;