Pregnancy Stages of Pregnancy Week by Week Pregnancy Week 13 You're entering your second trimester this week! Learn what is happening with your baby's development and how to read food labels to make smart nutritional choices. By Parents Editors Updated on May 17, 2022 Share Tweet Pin Email How Big is Baby? Your beautiful baby is the size of a Meyer lemon this week—and his vocal cords are beginning to develop. Baby's Length: 2.91in.Baby's Weight: 0.81oz. Mom's Changing Body From tripping to dropping dishes, you might be feeling clumsier these days. Relaxin, another hormone that messes with you during pregnancy, loosens up your ligaments and joints in preparation for birth. Even though you need the extra give only in your pelvis, the hormone works on your entire body, which means your hands and feet are affected, too. Baby's Development Your baby is constantly getting bigger and cuter, and his face is looking more human-like every day. His ears have moved up from his neck into place and his eyes—which are looking more and more like your baby blues (or browns, or greens)—have moved from the sides of the head to the front of the face. Up until now, his head has been outpacing his body, but now his body is growing faster. His legs still need to grow longer, but this week his arms will lengthen to be proportionate with his body, and he'll be able to stick his thumb in his mouth. Also by now, all of your baby's essential organs and systems have formed. Read More Weekly Tip Don't forget to keep up with your regular dental checkups. According to the Mayo Clinic, about 80 percent of expectant mamas suffer from gum softening or bleeding. American Institute of Ultrasound in Medicine - AIUM.org Week 13 Ultrasound In this profile shot, notice that the baby-to-be is lying with her bottom on the left-hand side of the image and her head to the right. (Even though the fetus is referred to as "she" here, the sonographer may or may not be able to identify the baby's gender at this point.) Her legs are clearly visible raised up, knees bent. The line across the middle of the profile is the sonographer's measurement of baby's crown-rump length (CRL). With this measurement, the sonographer is able to determine your baby's age. Read More What Week 13 of Your Pregnancy Is Really Like Pregnancy Confidential Podcast Who Says We Can't Eat for Two? It's Week 13 and, for many of you, the fog of the first trimester is finally lifting: You're probably starting to feel like your old self again, minus the constant nausea and irksome food aversions. But out with the old and in with the new: With the start of the second trimester often comes extreme hunger. It sometimes feels like your body is making up for everything it missed out on in the last three months and wants to eat everything in its path (minus those food aversions—those tend to stick around). Good thing you're eating for two... But are you? It seems science always wants to burst your happy bubble. Subscribe on iTunes This Week's To-Do List Begin thinking about baby names.Read More Start sleeping on your side.Read More Research pediatricians.Read More Eat smaller meals more frequently to stave off heartburn.Read More Consider borrowing previously worn maternity clothing from friends or family.Read More This Week's FAQs Must-Reads What to Expect in the Second Trimester Second Trimester Ultrasound Pictures Pregnancy Symptoms in Men Are Real—and They Have a Name Loss of Balance and Pregnancy: What to Expect Every Trimester Find the Most Popular Gender-Neutral Baby Name in Your State Was this page helpful? Thanks for your feedback! Tell us why! Other Submit