Table 1.
Distribution of birth weights for gestational age for babies born to HIV-negative women in Botswana compared with median for babies born to black women in the U.S.
| Gestational Age (weeks) | N | Minimum (grams) | Lower Quartile (grams) | Median (grams) | Upper Quartile (grams) | Maximum (grams) | U.S. median * (grams) | Δ Median (Botswana - U.S.) | p-value† |
|---|---|---|---|---|---|---|---|---|---|
| 26 | 9 | 700 | 880 | 930 | 1230 | 1680 | 857 | 73 | .051 |
| 27 | 20 | 670 | 1013 | 1116 | 1610 | 2310 | 977 | 139 | .004 |
| 28 | 29 | 790 | 1120 | 1260 | 1740 | 2700 | 1120 | 140 | .003 |
| 29 | 54 | 750 | 1200 | 1375 | 1725 | 2950 | 1304 | 71 | .015 |
| 30 | 62 | 860 | 1390 | 1660 | 2180 | 2990 | 1525 | 135 | .002 |
| 31 | 71 | 810 | 1535 | 1815 | 2630 | 3300 | 1804 | 11 | .032 |
| 32 | 119 | 800 | 1680 | 2085 | 2730 | 3440 | 2084 | 0.6 | .099 |
| 33 | 162 | 1170 | 2055 | 2410 | 2790 | 3790 | 2358 | 52 | .370 |
| 34 | 268 | 1380 | 2100 | 2510 | 2928 | 3850 | 2571 | - 61 | .095 |
| 35 | 394 | 1180 | 2320 | 2700 | 3060 | 4200 | 2733 | - 33 | .172 |
| 36 | 687 | 1470 | 2560 | 2850 | 3115 | 4335 | 2870 | - 20 | .164 |
| 37 | 1056 | 1790 | 2690 | 2960 | 3240 | 4680 | 3014 | - 53 | < .001 |
| 38 | 1758 | 1900 | 2820 | 3060 | 3330 | 4550 | 3158 | - 98 | < .001 |
| 39 | 2340 | 1890 | 2890 | 3130 | 3405 | 5150 | 3277 | - 147 | < .001 |
| 40 | 2482 | 1960 | 2970 | 3220 | 3500 | 4920 | 3356 | - 135 | < .001 |
| 41 | 1357 | 1980 | 3000 | 3290 | 3600 | 5000 | 3399 | - 109 | < .001 |
| 42 | 746 | 2000 | 3000 | 3300 | 3610 | 5080 | 3346 | - 45 | .016 |
| 43 | 125 | 2300 | 3000 | 3280 | 3540 | 4405 | 3316 | - 35 | .492 |
| 44 | 14 | 2680 | 3100 | 3345 | 3700 | 4785 | 3328 | 16 | .583 |
* Oken E, Kleinman KP, Rich-Edwards J, Gillman MW. A nearly continuous measure of birth weight for gestational age using a United States national reference. BMC Pediatrics 2003;3:10.
† Wilcoxon signed rank test.