Second Trimester: What to Expect in Weeks 13-26

The second trimester runs from week 13 through week 26 and is often called the "honeymoon phase" of pregnancy. For many women, the morning sickness and exhaustion of the first trimester finally fade, energy returns, and the baby bump starts to show. It's also a trimester packed with milestones — the first kicks, the detailed anatomy scan, and rapid fetal growth.

Here's what to expect, week by week, plus the appointments, tests, and comfort tips you'll want to know about.

Milestones at a Glance

• Weeks 13-14: first-trimester symptoms ease and energy starts to return
• Weeks 16-20: first movements (quickening) and the anatomy scan
• Week 24: viability milestone; the glucose screening window begins
• Week 26: baby approaches 2 pounds and the lungs keep maturing

Your Baby's Development in the Second Trimester

Weeks 13-16: Organs in Place

By the start of the second trimester, your baby's major organs are already formed and now begin to mature. The kidneys start producing urine, bones begin to harden, and the baby can make facial expressions. The baby is about 3.5 to 4.5 inches long by week 16 — roughly the size of an avocado.

Weeks 17-20: First Movements

This is when many parents feel the first flutter of movement, called quickening. First-time mothers usually notice it between 18 and 22 weeks, while those who've been pregnant before often feel it sooner. Around week 20, the baby is about 6.5 inches long and weighs around 10 ounces. Hearing is developing, so your baby can start to recognize your voice.

Weeks 21-26: Rapid Growth & Viability

The baby gains weight quickly, and the lungs continue to develop surfactant — the substance that will help them breathe after birth. By week 24, the baby reaches a milestone called viability, meaning there's a meaningful chance of survival outside the womb with intensive medical care. By week 26, the baby is about 14 inches long and weighs nearly 2 pounds.

How Your Body Changes

Symptoms That Usually Ease

• Morning sickness — often fades by weeks 12-14
• Extreme fatigue — energy typically rebounds
• Frequent urination — pressure eases as the uterus rises out of the pelvis

New Symptoms to Expect

• Back pain — your center of gravity shifts as the belly grows
• Round ligament pain — sharp, brief pains on the sides of the belly
• Leg cramps — common at night; gentle stretching can help
• Heartburn and indigestion — hormones relax the digestive tract
• Stretch marks and linea nigra — a dark line down the belly is normal
• Nasal congestion and bleeding gums — increased blood flow to mucous membranes
• Braxton Hicks contractions — irregular "practice" contractions, usually late in the trimester

Prenatal Visits & Screening Tests

During the second trimester, appointments are usually scheduled about every four weeks. Two key tests happen in this window:

The Anatomy Scan (Weeks 18-22)

Also called the level-2 ultrasound, this detailed scan checks the baby's brain, heart, spine, organs, limbs, amniotic fluid, and placenta placement. It's often when you can learn the baby's sex if you'd like to know.

Glucose Screening (Weeks 24-28)

This test screens for gestational diabetes by checking how your body processes sugar. You'll drink a sweet glucose solution and have your blood drawn about an hour later. If the result is high, a follow-up glucose tolerance test is done.

Nutrition & Weight Gain

Your calorie needs increase by roughly 300 extra calories per day in the second trimester. Focus on nutrient-dense foods: lean protein, leafy greens, whole grains, calcium-rich foods, and healthy fats. Most women gain about 1 pound per week during this trimester, though your provider will personalize this based on your pre-pregnancy weight. Keeping up with a quality prenatal vitamin stays important throughout.

Your Second Trimester To-Do List

• Schedule the anatomy scan (weeks 18-22) and glucose screening (weeks 24-28)
• Keep taking prenatal vitamins — iron and DHA become especially important now
• Research childbirth classes and hospital tours; popular ones fill up early
• Start planning maternity leave — review your employer and local leave policies
• Begin a baby registry while you still have energy
• Interview pediatricians and schedule a meet-and-greet if offered
• Book any travel — the second trimester is often the most comfortable time to fly (check airline policies)

Sleep & Comfort Tips

As your belly grows, getting comfortable in bed gets harder. These adjustments can help:

• Sleep on your side — by the second trimester, lying on your left side improves blood flow to the baby and your kidneys
• Use pillows strategically — one between your knees and one under your belly reduces strain
• Elevate your head if heartburn keeps you up at night
• Stretch before bed — gentle calf and back stretches can reduce nighttime leg cramps
• Drink fluids during the day but taper them before bedtime to limit nighttime bathroom trips

Staying Comfortable: Products That Help

As your bump grows, a few simple products can make a big difference in how you feel day to day:

• Pregnancy body pillow — supports your belly, back, and hips for better sleep
• Maternity leggings — comfortable, over-the-bump support for everyday wear
• Maternity belly band — eases lower-back and round ligament pressure
• Stretch mark oil or cream — keeps stretching skin moisturized and may reduce itching

Warning Signs: When to Call Your Doctor

Most second-trimester changes are normal, but contact your provider right away if you notice:

• Heavy vaginal bleeding
• Severe or persistent abdominal pain or cramping
• Fever over 100.4°F (38°C)
• Severe headache, vision changes, or sudden swelling of the hands and face (possible preeclampsia)
• A sudden gush or steady leak of fluid
• A noticeable decrease in fetal movement after 24 weeks

Looking Ahead to the Third Trimester

The third trimester (weeks 27-40) brings more rapid weight gain, increased fatigue, and preparation for birth. You'll feel the baby move more forcefully, and appointments become more frequent — every two weeks from week 28 to 36, then weekly until delivery. It's a good time to finalize your hospital bag and confirm your birth plan with your provider.

Frequently Asked Questions

Is it normal to feel fewer symptoms in the second trimester?

Yes. The nausea and exhaustion that defined your first trimester often lift as your hormones stabilize. If a specific symptom disappears suddenly or you're worried, it's always reasonable to check with your provider.

When will I feel the baby move?

Most first-time mothers feel movement between 18 and 22 weeks, though it can be earlier or later. If you haven't felt movement by 24 weeks, mention it to your healthcare provider.

Is it safe to exercise in the second trimester?

For most healthy pregnancies, moderate exercise is encouraged — walking, swimming, and prenatal yoga are great choices. Avoid contact sports and activities with a high fall risk, and always follow your provider's advice.