Once you reach month four of your pregnancy, you’re able to see a little of the light that awaits you at the end of the pregnancy tunnel—welcome to your second trimester.

Many women hear about the big changes that occur during the beginning and end of their pregnancies, but what about the middle? Whether it’s understanding what to expect in the first trimester or the second, it is important for a woman to know what she will experience from early pregnancy until giving birth. To get a better idea of this period of pregnancy, keep reading our inclusive guide on what to expect in the second trimester.

What is the Second Trimester?

Between conception and birth, medical professionals divide your pregnancy into three equal sections—the first, second, and third trimesters.¹

The second trimester is seen as the “golden hour” of pregnancy. From weeks 13 to 26, you can expect less painful pregnancy symptoms and negative side effects. (Morning sickness, be gone!)

However, you’ll probably still experience a few physical and emotional symptoms, which we’ll dive into below.

How Will I Change During the Second Trimester?

Every pregnant woman will experience different changes whether it's with pregnancy hormones changes or physical and emotional change. When rounding the second trimester lap, you might feel a sudden shift in your pregnancy symptoms. Everything from your sleep cycle to your gums can change, all thanks to pregnancy’s natural magic.

To smooth this transition, here’s a breakdown of the changes you might experience during your second trimester.

Hormonal Changes

Compared to the first trimester, the second trimester has fewer new hormonal shifts (which can mean fewer mood swings—phew). Instead, the same hormones continue rising, alongside a few additions to the roster.

These hormones support both mom and baby through the second trimester:²

• Progesterone – Protects the placenta and increases blood flow to baby
• Estrogen – Prepares mammary glands and regulates other hormones
• Human placental lactogen (hPL) – Breaks down nutrients for fetal growth
• ​​Human chorionic gonadotropin (hCG) – Supports pregnancy hormone production
• Relaxin – Relaxes uterine and pelvic muscles for easier delivery
• Cortisol – Regulates metabolism and blood sugar

Physical and Emotional Changes

Your body has one goal for the second trimester—to continue to support your growing baby. Fortunately, as first trimester morning sickness and mood swings fade, you’re left with fewer and subtler symptoms.

However, your body is still changing, growing, and working hard to sustain your baby during this time. Prioritize down time during these changes and relax in our pregnancy robes. Some of the most common physical and emotional changes you can experience in the second trimester include:³

• Weight gain and growing belly – The biggest second trimester shift is your size. This is a crucial period of growth for you and your baby. To help deliver all the nourishment you both need, your body will rev up the appetite engine. Expect to gain about one pound per week, totaling 14 to 15 pounds.

• Braxton Hicks Contractions – If you feel a little contraction in your lower abs, don’t freak out—the baby’s not coming yet. During the second trimester, Braxton Hicks contractions can happen after physical activity or at random, but they’re completely safe. ⁴If these contractions start to occur more frequently, seek advice from your advice.

• Nasal problems – Thanks to estrogen and progesterone, you can experience increased blood flow which helps to support your baby. However, this can also lead to nasal congestion and even snoring or nosebleeds. Drinking extra fluids and using saline drops can help alleviate these symptoms.

You might also experience some of the following symptoms during the second trimester:

• Dizziness
• Gestational diabetes
• Dental issues (such as bleeding gums or gum sensitivity)
• Skin browning or development of colored patches
• Skin changes (such as varicose veins or stretch marks)
• Leg cramps
• Swollen feet, ankles, and hands
• Urinary tract infections

Baby Development During the Second Trimester

Throughout pregnancy, every mom-to-be has one question on her mind—how is my baby doing? Thanks to modern science, we can estimate your baby’s growth and development during the second trimester so you can have a bit more clarity on your baby’s journey from embryo to tiny human.

Here’s a typical mid-pregnancy timeline of your little one’s growth.⁵

Weeks 13 to 17

Just a few inches long, your baby might actually resemble a tiny human on the ultrasound by this point. Typical developments include:

• Active urinary system
• Hardening bones
• Defined sex organs
• Eye and limb movements
• Growth in size (total weight of about 4 ounces)

Weeks 18 to 22

Now, not only is your baby beginning to look like a human, but they’re also beginning to act like a human. Developments around mid-second trimester include:

• Hearing abilities
• Thumb sucking
• Sleep cycles
• Active digestive system
• Vernix caseosa (a protective coating on fetal skin)
• Increased movement
• Lanugo (soft hair coating)
• Visible head hair

Weeks 23 to 26

At the end of the second trimester, more details settle in. Tiny changes like feet shape and parting eyelids begin to take place, alongside other functional growths, such as:⁶

• REM (rapid eye movement)
• Lung development
• Fingerprint formation
• Skin thickening
• Final second trimester growth (about 12 inches in length and 2 pounds in weight)

Prepare for Your New Life with Monica + Andy

The second trimester marks the midpoint of your pregnancy journey, which means your little one’s arrival is even closer than before! This is when you notice your baby move and grow while experiencing changes like pregnancy hormones and physical changes. So, while you’re picking out nursery paint colors, adding items to your baby shower gift registry, and deciding on a name, take some time to join the Monica + Andy parent community. We offer virtual and in-person classes that cover all things pregnancy, baby, and parenting—from feeding schedules to your own post natal healthcare.

Whether you’ve traveled down the pregnancy path before or are new to the pregnancy journey, Monica + Andy has everything you need to prepare you for your newest family member.

Sources:

1. University of California-San Francisco. Pregnancy: The Three Trimesters. https://www.ucsfhealth.org/conditions/pregnancy/trimesters
2. Today’s Parents. How pregnancy hormones affect your body in each trimester. https://www.todaysparent.com/pregnancy/pregnancy-health/how-pregnancy-hormones-affect-your-body-in-each-trimester
3. What to Expect. Your Guide to the Second Trimester of Pregnancy. https://www.whattoexpect.com/second-trimester-of-pregnancy.aspx
4. Mayo Clinic. 2nd trimester pregnancy: What to expect. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy/art-20047732
5. Mayo Clinic. Fetal development: The 2nd trimester. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/fetal-development/art-20046151
6. American Pregnancy Association. ​​Baby Development Month By Month. https://americanpregnancy.org/healthy-pregnancy/week-by-week/baby-development-month-by-month/