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 13 of 36 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 13 Week 17: Mascara Your baby is a long way from the size of an eyelash and has now graduated to about the length of a mascara tube, 5.12 inches. Previous Next Start Slideshow Pregnancy