Gestational age Length (US) Weight (US) Length (cm) Mass (g) (crown to rump) (crown to rump) 8 weeks 0.63 inch 0.04 ounce 1.6 cm 1 gram 9 weeks 0.90 inch 0.07 ounce 2.3 cm 2 grams 10 weeks 1.22 inch 0.14 ounce 3.1 cm 4 grams 11 weeks 1.61 inch 0.25 ounce 4.1 cm 7 grams 12 weeks 2.13 inches 0.49 ounce 5.4 cm 14 grams 13 weeks 2.91 inches 0.81 ounce 7.4 cm 23 grams 14 weeks 3.42 inches 1.52 ounce 8.7 cm 43 grams 15 weeks 3.98 inches 2.47 ounces 10.1 cm 70 grams 16 weeks 4.57 inches 3.53 ounces 11.6 cm 100 grams 17 weeks 5.12 inches 4.94 ounces 13 cm 140 grams 18 weeks 5.59 inches 6.70 ounces 14.2 cm 190 grams 19 weeks 6.02 inches 8.47 ounces 15.3 cm 240 grams 20 weeks 6.46 inches 10.58 ounces 16.4 cm 300 grams (crown to heel) (crown to heel) 20 weeks 10.08 inches 10.58 ounces 25.6 cm...