The second trimester, weeks 13 through 27, is often the most comfortable stretch of pregnancy. Nausea typically fades, energy returns, and there’s a window of time to tackle important health screenings, stay active, and prepare for the months ahead. Here’s what actually matters during these weeks.
Key Screenings and Tests
Two major medical milestones happen in the second trimester, and both are worth understanding before you walk in the door.
The anatomy scan, usually scheduled between 18 and 22 weeks, is the most detailed ultrasound of your entire pregnancy. A sonographer takes pictures and measurements of the baby’s heart, brain, spine, kidneys, lungs, stomach, intestines, limbs, and even individual fingers and toes. They also record the heart rate, check blood flow through the umbilical cord, measure amniotic fluid levels, note the position of your placenta, and look at your cervix. This is the appointment where many parents learn the baby’s sex, but its real purpose is confirming that organs and structures are developing normally.
Between 24 and 28 weeks, you’ll have a glucose screening test for gestational diabetes. You’ll drink a sugary liquid and have your blood drawn about an hour later. If your blood sugar comes back high, you’ll be asked to return for a longer follow-up test where you drink a solution containing 100 grams of glucose, then have blood drawn at multiple intervals over three hours. Gestational diabetes is manageable when caught early, so this screening is routine for nearly all pregnant people regardless of risk factors.
Nutrition and Weight Gain
You need roughly 300 extra calories per day during the second trimester, bringing the daily total to about 2,200 calories for most people. That’s less than you might expect. A banana with peanut butter, a handful of nuts, or an extra snack covers it. The goal is steady, gradual weight gain rather than a sudden jump.
Total pregnancy weight gain depends on your pre-pregnancy BMI. For someone who started at a normal weight (BMI 18.5 to 24.9), the CDC recommends 25 to 35 pounds over the full pregnancy. For those who were overweight before pregnancy (BMI 25 to 29.9), the target is 15 to 25 pounds. For those with obesity (BMI 30 to 39.9), 11 to 20 pounds. And for those who were underweight, 28 to 40 pounds. Most of this gain happens in the second and third trimesters, so a steady pace of about a pound per week is typical during this stretch.
Exercise That’s Safe and Worth Doing
The current recommendation is at least 150 minutes of moderate-intensity aerobic activity per week throughout pregnancy. Walking, stationary cycling, swimming, water aerobics, dancing, and resistance training with weights or elastic bands have all been studied extensively in pregnancy and found to be safe and beneficial. If you were doing vigorous exercise before pregnancy, you can generally continue it.
Three specific exercises are particularly useful to start now because they prepare your body for labor and reduce postpartum problems:
- Pelvic floor squeezes: Sit or lie down with your knees bent. Tighten the muscles you’d use to stop yourself from peeing, hold for up to 10 seconds, then release. Aim for 3 sets of 8 squeezes per day. Doing a set at each meal makes it easier to remember. Practice tightening these muscles before and during coughing or sneezing, too.
- Pelvic tilts: Stand with your shoulders and bottom against a wall, knees slightly bent. Pull your belly button toward your spine so your lower back flattens against the wall. Hold for 4 seconds, release, and repeat up to 10 times.
- Cat stretches: Start on all fours with hands under shoulders and knees under hips. Pull in your stomach muscles and round your back toward the ceiling, letting your head drop gently. Hold for a few seconds, then return to a flat back. Repeat 10 times, moving slowly.
Travel and Activity Planning
If you’re planning a trip, the second trimester is the best window. The safest time to fly is between 14 and 28 weeks, when the risk of common pregnancy complications is lowest and you’re likely feeling your best. Long-distance travel lasting more than four hours carries a small increased risk of blood clots. On flights or car trips, get up and walk around regularly, flex and rotate your feet, and wiggle your toes to keep blood circulating through your legs. Staying hydrated also helps.
Dental Care Matters More Than You Think
Pregnancy hormones increase blood flow to your gums, making them more prone to swelling and bleeding. This pregnancy-related gingivitis is most common in the first and second trimesters. It’s not just a comfort issue. Periodontal disease during pregnancy has been linked to preterm birth, preeclampsia, and delivering a baby that’s small for gestational age. Schedule a dental cleaning during the second trimester if you haven’t had one recently, and keep brushing and flossing consistently.
Sleep Position Changes
You don’t need to panic about sleep position in the second trimester, but it’s a good time to start getting comfortable on your side. As your uterus grows, lying flat on your back can compress a large vein called the inferior vena cava, which runs slightly to the right of your spine and carries blood from your lower body back to your heart. Sleeping on your left side takes pressure off this vessel and improves circulation to the placenta. By the third trimester, side sleeping is the recommended position and has been shown to reduce the risk of stillbirth. A pillow between your knees or behind your back can make the transition easier.
Vaccinations
The Tdap vaccine, which protects against whooping cough, is recommended during every pregnancy regardless of when you last received it. The optimal window is 27 to 36 weeks, preferably on the earlier end. Getting vaccinated during this period allows your body to produce antibodies and transfer them to the baby before birth, providing protection during the newborn’s most vulnerable first weeks of life.
Warning Signs to Recognize
Preeclampsia can develop after the 20th week of pregnancy, placing it squarely in second-trimester territory. A blood pressure reading of 140/90 or higher is the primary flag. Other symptoms include a headache that won’t go away, blurred vision or seeing spots, swelling in your face and hands (not just feet, which swell normally in pregnancy), pain in your upper right abdomen, and trouble breathing. Preeclampsia can progress to more dangerous conditions involving seizures, liver problems, and abnormal bleeding. These symptoms aren’t subtle once they appear, but some, like gradually rising blood pressure, only show up at prenatal visits. This is one of the reasons consistent prenatal appointments matter so much during the second trimester.