Second Trimester: What to Expect Weeks 13-27

Pregnancy

Second Trimester: What to Expect Weeks 13-27

The second trimester is often called the “golden period” of pregnancy. After navigating the nausea and fatigue of early pregnancy, many people find their energy returning, their bump becoming beautifully visible, and the reality of meeting their baby suddenly feels very real. This guide walks you through what’s happening in your body and your baby’s development week by week.

Quick Answer: The second trimester (weeks 13-27) is when pregnancy feels most energetic and stable. You’ll show noticeably, feel your baby move, get your anatomy scan at week 20, and likely pass your gestational diabetes screening. Common symptoms include round ligament pain, Braxton Hicks contractions, and increased appetite—all normal signs your body is supporting new life.

The Second Trimester Overview: A Shift in Pregnancy

Your second trimester begins at week 13 and continues through week 27, spanning roughly 15 weeks of transformation. This is when pregnancy transitions from something you feel internally to something the world can see—and something you can feel your baby doing.

During this phase, your hormone levels stabilize somewhat after the dramatic shifts of the first trimester. Your placenta is now fully functional, taking over much of the hormone production that made early pregnancy so intense. This hormonal shift is why many people report feeling dramatically better starting around week 13.

Physically, your uterus grows from about the size of a grapefruit to roughly the size of a basketball. Your baby grows from about 3 inches long to roughly 14-15 inches. The second trimester is when development accelerates—your baby’s organs continue refining, their nervous system becomes more complex, and they begin moving with intention.

According to the American College of Obstetricians and Gynecologists (ACOG), most of the significant structural development has happened by the start of the second trimester. What’s happening now is refinement and growth.

Energy Returns: Weeks 13-16

One of the most noticeable changes at the start of your second trimester is the return of energy. If you’ve been living in a fog of exhaustion and nausea, you may suddenly feel like yourself again—or even better than yourself.

This shift isn’t just psychological. Your hormone levels, particularly progesterone and human chorionic gonadotropin (hCG), have stabilized. That hCG hormone, which surges in early pregnancy and can contribute to nausea and fatigue, now plateaus. Your progesterone remains elevated but no longer in flux.

Your appetite likely increases during these weeks. This is your body’s signal that it needs more calories to support your growing baby. You’re not “eating for two” in the sense of doubling your intake, but you’ll need roughly 300 extra calories per day during pregnancy, according to the Mayo Clinic. Focus on nutrient-dense foods: protein, healthy fats, whole grains, fruits, and vegetables.

Your baby during weeks 13-16 is developing rapidly. They now have fingerprints, their heart is beating around 140-150 beats per minute, and they’re beginning to make small movements—though you won’t feel them yet. Their ears are moving into their final position, and gender can usually be confirmed via ultrasound by week 15-16.

Many providers recommend starting or continuing pregnancy-safe exercises during this time. You’ll likely feel more capable of movement after the fatigue of the first trimester, and gentle exercise (walking, prenatal yoga, swimming) supports cardiovascular health and can ease some pregnancy discomforts.

Showing and Quickening: Weeks 17-20

By week 17, most people are noticeably pregnant. You’re past the point where it could be bloating—there’s a genuine bump. Some people love this; others feel self-conscious. Both reactions are valid. Your body is doing something remarkable.

Weeks 19-20 bring a milestone you’ll never forget: quickening, or feeling your baby move. Many parents describe it as “butterflies” or “gas bubbles,” but then it becomes unmistakable. You’re feeling your baby roll, stretch, and kick. There’s nothing quite like that first moment you know, without doubt, that there’s a moving human inside you.

Quickening happens earlier in second and subsequent pregnancies (around week 16-18) because you know what to feel for. First-time parents usually notice around weeks 18-20. Trust your instincts—if you feel movement, you’re feeling movement, regardless of what “average” says.

Week 20 brings your anatomy scan (also called the mid-pregnancy scan or “big ultrasound”). This is typically a longer, more detailed ultrasound than your first-trimester scan. Your provider will measure your baby’s head, femur, and abdomen to confirm dates and growth. They’ll check the placenta’s position, amniotic fluid levels, and confirm that major organ structures are developing typically. Most providers can confirm gender at this scan if you want to know.

This scan is genuinely exciting—you’ll get a much better “look” at your baby. Some of the 3D images can feel shockingly real. Many parents cry. This is normal and beautiful.

Physical Changes and Common Discomforts: Weeks 21-24

As your second trimester progresses, your body’s expansion accelerates. Your belly is definitely pregnant now, not ambiguous. Your rib cage may expand slightly. You might notice your feet spreading—pregnancy hormones can actually permanently increase shoe size in some people.

Round ligament pain is extremely common in the second trimester. Your uterus is suspended by ligaments (the round ligaments, among others), and as your uterus grows, these ligaments stretch and can cause sharp or dull pain, especially on the sides of your lower belly. This pain is harmless but can be uncomfortable. You’ll ease it by changing positions slowly, avoiding sudden movements, applying heat, and doing gentle stretching. If pain is severe or accompanied by other symptoms, contact your provider.

Braxton Hicks contractions often begin in the second trimester, usually around week 20 or after. These are practice contractions—your uterus tightening for 30 seconds to 2 minutes. They’re not painful, just tight. Some people don’t notice them at all. Braxton Hicks are completely normal and don’t indicate labor is starting. Stay hydrated and change positions if they feel uncomfortable.

Your skin may glow—or it may develop dark patches (chloasma or “mask of pregnancy”) because pregnancy hormones trigger melanin production. This fades postpartum. Some stretch marks may appear as your skin stretches. Cocoa butter, vitamin E oil, and hydration help, though genetics play a larger role than any cream.

Nose and gum bleeding can happen due to increased blood volume and hormone effects on your mucous membranes. This is harmless. So is the increased vaginal discharge you might notice—it’s typically clear or milky and has no odor. If discharge changes color, develops odor, or is accompanied by itching or pain, contact your provider.

Weeks 25-27: Entering the Third Trimester Stretch

As you approach week 27, your baby is becoming increasingly viable outside the womb. At week 24, survival rates for premature babies increase significantly with medical support. By week 27, your baby weighs around 2 pounds and is about 14-15 inches long.

Your belly may feel heavy now. Sleeping becomes more complicated. You might notice you can’t bend the way you used to. Finding comfortable positions for eating and sitting becomes intentional. This is when many pregnant people start using pregnancy pillows—they genuinely help.

Gestational diabetes screening typically happens between weeks 24-28. You’ll drink a sweet liquid and have your blood drawn after an hour. This screens for gestational diabetes, a form of diabetes that develops during pregnancy. If your screening is positive, you’ll do a longer glucose tolerance test to confirm. Gestational diabetes is manageable with diet and sometimes medication, and it doesn’t reflect on your diet or health choices—it’s an effect of pregnancy hormones on insulin regulation.

Your baby’s movement becomes more pronounced—less fluttery, more distinct kicks and rolls. You might see your belly move when your baby shifts. This is completely normal and delightful to watch.

If you haven’t already, weeks 25-27 are a great time to take prenatal classes, tour your hospital or birth center, and start thinking about your hospital bag. Many people begin gentle pregnancy exercises to maintain strength for labor and delivery.

Nutrition and Wellness Through the Second Trimester

Your nutritional needs increase during the second trimester. Focus on prenatal vitamins containing folic acid (methylfolate is often better tolerated), iron, and calcium. Iron is particularly important in the second trimester as your blood volume expands—many pregnant people develop mild anemia without adequate iron intake.

Continue avoiding foods that pose listeria, toxoplasmosis, or other risks. This means no unpasteurized dairy, undercooked meats, or high-mercury fish. Learn which foods to avoid to protect your baby.

Stay hydrated. Your blood volume increases by about 50% during pregnancy, and you need extra water to support this. A good guideline is drinking enough that your urine is pale yellow.

Your appetite may be intense during the second trimester. Eat when hungry, but choose foods that nourish you and your baby. Those extra 300 calories should come from nutrient-dense sources—not just empty calories.

Planning for Later: Nursery and Preparations

The second trimester is when pregnancy feels real enough to start practical planning. Many people begin setting up a nursery or preparing space for their baby. Some begin hospital or birth center tours. Others start thinking about feeding choices, childcare, and postpartum support.

This is a good time to review what you learned in the first trimester and plan for the third trimester. Think about your birth preferences—you might not write a formal birth plan yet, but begin considering what kind of birth experience you want.

If you have questions about anything in this trimester—pain, bleeding, movements, or just normal pregnancy concerns—contact your provider. Second trimester is also when you can begin seeing a maternal-fetal medicine specialist (perinatologist) if your pregnancy is considered high-risk.

FAQ: Second Trimester Pregnancy

When will I feel my baby move?

Most first-time pregnant people feel movement between weeks 18-20. Second-time parents often feel it by week 16-17. It starts as subtle flutters and becomes more distinct kicks and rolls as weeks progress. Every pregnancy is different—trust what you feel.

Is round ligament pain dangerous?

Round ligament pain is completely normal and not dangerous. It’s sharp or dull pain on the sides of your lower belly as your uterus grows and ligaments stretch. Change positions slowly, apply heat, and contact your provider if pain is severe or accompanied by bleeding or contractions.

What happens at the anatomy scan?

At week 20, your provider does a detailed ultrasound measuring your baby’s structures, checking organ development, confirming dates, and assessing amniotic fluid and placenta position. Most providers can confirm gender if you want to know. This scan typically takes 20-30 minutes.

Can I continue exercising in the second trimester?

Yes. Most pregnant people can continue or even start gentle exercise in the second trimester. Pregnancy-safe exercises like walking, prenatal yoga, and swimming are excellent. Avoid contact sports and exercises where you could fall. Always check with your provider about your specific situation.

What is gestational diabetes screening and should I worry?

Gestational diabetes screening (usually weeks 24-28) checks if pregnancy hormones have affected your insulin regulation. A positive screening doesn’t mean you have diabetes—a follow-up test confirms. Gestational diabetes is manageable with diet and sometimes medication, and it doesn’t reflect your health choices.

Medical Disclaimer: This article is for educational purposes and should not replace professional medical advice. Every pregnancy is unique. Always consult with your healthcare provider about your specific symptoms, concerns, and pregnancy management. If you experience severe pain, bleeding, decreased fetal movement, or other concerning symptoms, contact your provider immediately or seek emergency care.

Last Updated: March 26, 2026 | Author: iPrego Editorial Team

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