Pregnancy Stages of Pregnancy Week by Week Pregnancy Week 16 You've reached the end of your fourth month! Find out how your baby is developing in week 16 as well as how to deal with stretch marks, changes in your feet, and more. By Parents Editors Parents Editors The Parents Editors byline means there is an experienced group of editors and journalists behind the scenes of the article. Learn more about the Parents team, our core values, and editorial guidelines. our editorial guidelines Updated on May 17, 2022 Share Tweet Pin Email How Big is Baby? Your baby is now the size of an avocado—and she can make a fist and even suck her thumb. Baby's Length: 4.57in.Baby's Weight: 3.53oz. Mom's Changing Body Got butterflies in your belly? It could very well be your baby kicking! Most moms-to-be experience this major pregnancy milestone between their 16th and 20th weeks, but don't expect any big karate chops just yet. The first kicks, called quickening or flutters, are so subtle that they're often mistaken for stomach rumblings or indigestion—and many first-timers may have a hard time detecting them initially. Baby's Development Your baby's delicate skeleton continues to harden from rubbery cartilage to bone. Even so, his bones will remain somewhat flexible for an easier trip through the birth canal. The umbilical cord has fully matured with one vein and two arteries that are protected by Wharton's jelly (a thick substance that makes the cord slippery so it can move freely around your baby). By the way, if you're having a girl, hundreds of thousands of eggs are forming in her ovaries this week—your future grandchildren! Read More Weekly Tip Even if you didn't experience constipation in the first trimester, you could experience it now as the hormone progesterone relaxes smooth muscle tissue throughout your body including your gastrointestinal tract which slows down digestion and also leads to gas, bloating, and burping. In fact, constipation affects about half of all pregnant women. Laxative pills or mineral oils aren't a good idea during pregnancy, but lots of fluids and fiber can help. To help remedy your stomach woes, it's a good idea to cut back on foods that make gas worse, such as beans, cabbage, and dairy products. American Institute of Ultrasound in Medicine - AIUM.org Week 16 Ultrasound In this closeup view of Baby's profile, you can see how his facial features are becoming more defined. Notice that the sonographer has measured the length of his nasal bone. This specialized measurement may be useful in screening for some genetic abnormalities. Read More What Week 16 of Your Pregnancy Is Really Like Pregnancy Confidential Podcast Home, Hospital or Birthing Center? You Decide. Decisions, decisions, decisions: pregnancy can feel a little full of them at times. But at Week 16 you're at the best part of your pregnancy, some say—the bit where the first trimester ickiness is in the rearview mirror and your barely-there bump is far from holding you back. If you're feeling full of energy and ready to organize the world, now might be a great time to consider your birthing options. While some of your options may be dictated by your type of provider, it's never too late to change your mind, or get educated on your choice of where you deliver. Subscribe on iTunes This Week's To-Do List Be sure to get plenty of calcium now, from low-fat dairy foods or supplements.Read More Tour local birth centers.Read More Start your baby registry.Read More Ask your mother or grandmother about their birthing experiences.Read More This Week's FAQs What happens if I develop a fever during my second trimester? Must-Reads Baby Must-Haves (and Don't-Needs) for Your Registry 7 Amazing Benefits of Prenatal Yoga 11 Pregnancy Symptoms You Shouldn't Ignore How to Get a Good Night's Sleep While Pregnant Should You Choose an OB-GYN or a Midwife? Was this page helpful? Thanks for your feedback! Tell us why! Other Submit