At 14 weeks, your baby measures about 3.4 inches (8.7 cm) from crown to rump and weighs roughly 1.5 ounces (43 grams). That’s about the size of a lemon. You’re right at the start of the second trimester, and your baby is shifting from building basic structures to refining them.
Size and Weight at 14 Weeks
The 3.4-inch measurement is taken from the top of the head to the bottom of the buttocks, not including the legs. This “crown-to-rump” measurement is the standard way babies are measured through ultrasound during this stage because their legs are often curled up tight. If you stretched your baby out from head to heel, the total length would be closer to 6 inches.
At just over an ounce and a half, your baby weighs less than a standard AA battery. But growth is accelerating now. Over the next few weeks, your baby will roughly double in weight as the body starts catching up to the head, which has been disproportionately large throughout the first trimester.
What Your Baby Is Doing Right Now
Your baby is actively moving at 14 weeks, stretching, kicking, and flexing new joints. This movement isn’t random. It plays a direct role in developing muscles, bones, and joints, essentially preparing the body for life outside the womb. The kidneys have also started producing urine, which gets released into the surrounding amniotic fluid. This is a normal and important part of how amniotic fluid volume is maintained throughout pregnancy.
Facial features are becoming more defined. Your baby can squint, frown, and grimace as the facial muscles gain function. Some babies may even begin sucking their thumb around this time, practicing the reflex they’ll need for feeding after birth.
Can You Feel Movement Yet?
Probably not. Even though your baby started moving around 12 weeks, the movements are still too small for most people to detect. If this is your first pregnancy, you likely won’t feel anything until around 20 weeks. If you’ve been pregnant before, you may notice those first flutters (called quickening) a bit sooner, sometimes around 16 weeks. The difference comes down to experience: once you know what fetal movement feels like, you’re more likely to recognize the subtle sensations earlier.
Skin and Body Changes for Your Baby
Your baby’s skin is still translucent and extremely thin at 14 weeks. The fine, downy hair called lanugo hasn’t appeared yet. That typically develops between 16 and 20 weeks. When it does show up, it serves a surprisingly important purpose: lanugo helps a waxy coating called vernix stick to the skin. Vernix acts as a waterproof barrier, protecting your baby’s delicate skin from constant exposure to amniotic fluid. Without it, the fluid could irritate or damage the skin over months of submersion.
Lanugo also helps regulate your baby’s body temperature until enough body fat builds up to do that job. And the tiny hairs may even contribute to growth. When lanugo moves, it sends vibrations to sensory receptors in the skin, which stimulate development.
What’s Changing in Your Body
At 14 weeks, the top of your uterus is sitting just above your pubic bone. For many people, this is when a visible bump starts to emerge, though it varies widely depending on your body type, core muscle tone, and whether this is a first pregnancy. You may notice your pants fitting tighter even if the bump isn’t obvious to anyone else yet.
The second trimester often brings a noticeable shift in how you feel. The nausea and fatigue that dominated the first trimester tend to ease up around this point as hormone levels stabilize. Many people describe the next several weeks as the most comfortable stretch of pregnancy, with more energy and fewer symptoms before the physical demands of the third trimester set in.
How Growth Is Measured Going Forward
Up to this point, your baby’s size has been tracked primarily through crown-to-rump length on ultrasound. As the second trimester progresses, measurements shift to include head circumference, abdominal circumference, and femur (thigh bone) length. These combined measurements give a more accurate picture of overall growth and help estimate fetal weight as your baby gets bigger. Your provider will also begin measuring your fundal height (the distance from your pubic bone to the top of the uterus) with a tape measure at prenatal visits, typically starting around 20 weeks, as a simple way to track growth between ultrasounds.