The second trimester runs from week 14 through week 27 and is often called the most comfortable stretch of pregnancy. First-trimester nausea typically fades, energy returns, and the baby undergoes rapid growth, going from about three inches long to nearly 15 inches by the end of this period. Here’s what’s actually happening, week by week and symptom by symptom.
How Your Baby Develops
The second trimester is when your baby transitions from a tiny, fragile form into something that looks and moves like a newborn. Around week 13, bones in the skull and limbs begin to harden. By week 15, a scalp hair pattern is forming. The eyes start shifting slowly at week 16, and ears move toward their final position on the head.
Week 18 marks a major milestone: the ears begin to stand out from the head, and your baby may start hearing sounds for the first time. The digestive system kicks into gear around the same time. By week 19, your baby is releasing urine that makes up most of the amniotic fluid, and the skin is coated in a greasy, cheese-like substance called vernix that protects it from the fluid.
By week 21, fine downy hair covers the entire body, and the sucking reflex is developing, meaning your baby may already be sucking a thumb. Eyebrows and hair become visible around week 22. In the weeks that follow, fingerprint and footprint patterns form on the palms and soles, the lungs begin producing a substance that will help them inflate after birth, and the eyes develop fully, though they won’t open until closer to week 28.
Near the end of the trimester, around week 25, your baby may move in response to familiar sounds like your voice. By week 27, the nervous system is maturing and fat is accumulating under the skin, giving it a smoother appearance.
When You’ll Feel Movement
Most women feel their baby’s first movements, called quickening, between weeks 16 and 20. If you’ve been pregnant before, you may notice it as early as 16 weeks because you recognize the sensation. First-time mothers often don’t feel movement until closer to 20 weeks, and some not until 24 weeks.
Early movements feel like flutters, gas bubbles, or light tapping. They’re easy to miss. If your placenta is positioned at the front of your uterus (anterior placenta), it acts like a cushion between the baby and your belly wall, which can delay how soon you notice kicks. This is normal and doesn’t mean anything is wrong.
Body Changes You’ll Notice
Your body is doing significant work during these weeks, and the signs show up in some unexpected ways.
Rising hormone levels increase your blood volume substantially, which can cause the lining of your nose to swell. That means stuffiness and nosebleeds are common, even if you’ve never had sinus issues before. The same hormonal shift increases melanin production in your skin. You may notice brown, tan, or gray patches on your face (a pattern sometimes called the “mask of pregnancy”) or a dark vertical line running down the center of your belly. Stretch marks, small visible veins on the face and legs, and overall skin changes are all typical.
Round ligament pain is another hallmark of the second trimester. As your uterus expands, the ligaments supporting it stretch, which can cause sharp, quick pains in your lower abdomen or groin, especially when you change positions. It’s uncomfortable but harmless.
Braxton Hicks Contractions
Some women start feeling practice contractions during the second trimester. These are irregular tightening sensations across the belly that don’t follow a pattern and often stop if you walk, rest, or change positions. They’re your uterus rehearsing for labor.
The key differences from real labor contractions: Braxton Hicks don’t come at regular intervals, don’t get closer together over time, and tend to be felt only in the front of the abdomen. Real contractions follow a pattern, intensify, and continue regardless of what you do. If rest and hydration make them go away, they’re practice contractions.
Key Medical Appointments
The Anatomy Scan
The 20-week ultrasound is the most detailed imaging appointment of your pregnancy. A technician takes pictures and measurements of your baby’s heart, brain, spine, kidneys, bladder, limbs, hands, feet, face, chest, lungs, stomach, and intestines. They also record the heart rate, check blood flow through the umbilical cord, evaluate the placenta’s position, measure amniotic fluid levels, and examine your cervix. This is often when you can learn the baby’s sex, if you want to know.
Glucose Screening
Between weeks 24 and 28, you’ll have a glucose screening test for gestational diabetes. The standard version involves drinking a sweet liquid containing 50 to 75 grams of glucose, then having your blood drawn to check how your body processes the sugar. If results are elevated, a longer follow-up test using 100 grams of glucose confirms the diagnosis. Gestational diabetes is manageable but needs to be caught early, which is why this screening is routine.
Weight Gain and Nutrition
Most of your pregnancy weight gain happens during the second and third trimesters. Total recommended gain for the entire pregnancy depends on your pre-pregnancy BMI: 25 to 35 pounds for a normal-weight starting point, 15 to 25 pounds if you started overweight, and 11 to 20 pounds if you started obese. For those who were underweight before pregnancy, the range is 28 to 40 pounds.
Your calorie needs increase only modestly in the second trimester, roughly 300 to 350 extra calories per day. What matters more than quantity is getting specific nutrients. You need 27 milligrams of iron daily to support the increased blood volume and your baby’s development. Calcium needs are 1,000 milligrams per day for adults (1,300 for teens). Iron-rich foods include lean red meat, spinach, beans, and fortified cereals. Dairy, fortified plant milks, and leafy greens cover calcium.
Sleep Gets Complicated
During the second trimester, sleeping on your back starts to become uncomfortable for a reason: the growing uterus can press on the large blood vessels that carry blood to and from your lower body. Research suggests this compression isn’t a significant concern before 30 weeks, but many women find side sleeping more comfortable well before that point simply because of the belly’s size. A pillow between the knees or under the belly can make a noticeable difference.
Leg cramps, vivid dreams, and more frequent bathroom trips also start disrupting sleep during this period. These are driven by the same hormonal and circulatory changes happening throughout your body.
What Actually Feels Better
For many women, the second trimester brings genuine relief. The nausea and exhaustion of the first trimester typically ease by week 14 or 15. Energy levels rebound. The risk of miscarriage drops significantly. Many women describe this stretch as the period where pregnancy starts to feel exciting rather than just difficult, especially once those first kicks show up and the anatomy scan confirms the baby is developing on track.