Popsugar Parenting Pregnancy How Big Is My Baby? A Week-by-Week Fetus-Size Guide Based on Objects You Actually Know 8 June 2018 by Annie Gabillet View On One Page Photo 17 of 36 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 17 Week 21: a Magazine There won't be much time to read once you welcome your baby, who is 10.51 inches long. Previous Next Start Slideshow Pregnancy