By moms. For moms.

The Second Trimester of Pregnancy

The Second Trimester of Pregnancy

What to know about the second trimester

all about the second trimester

Dates: The Beginning of Week 13 – The End of Week 26

You’ve made it through the first trimester of your pregnancy (check out these survival tips!), which can be rife with discomfort, nausea, and a lot of physical changes. Now that you’re in the second trimester, there is a lot to look forward to!

Indeed, the second trimester is often referred to as the “Honeymoon Phase” of pregnancy because for many (not all!) women those difficult pregnancy symptoms (especially morning sickness) tend to ease up, and pregnancy may even start to feel enjoyable.

At the same time, you may begin to feel as though the pregnancy is more real. Your bump will begin to show, you’ll feel your baby’s first movements, and you may even learn your baby’s gender if you wish! We’re here to help you navigate the busy “Honeymoon Phase,” whether it feels like a honeymoon or not.

Second Trimester Baby Development

second trimester baby development, how does your baby change during the second trimester

During the second trimester, your baby will quickly grow from a small, partially developed fetus (about the size of a peach) to a moving baby half the length of a newborn (about the size of an eggplant)! Here’s what’s happening with your growing baby week by week from week 13 to week 26:

Week 13: Believe it or not, your baby is just starting to get the chubby cheeks and the adorable, cherub-like face everyone will love. Your baby’s body is beginning to take form—the ears are now in place, and the eyes have their birth color. Arms lengthen and become proportional to the rest of the body at this point, though your baby’s legs will still be comparatively small. Wrists and ankles become mobile now, so your baby can begin to wiggle around a bit.

By now, all the essential organs and systems have formed. The digestive system allows your baby to taste the foods you eat through the amniotic fluid. Waste systems are working hard, with urination taking place about every 40 minutes. Between 13 and 15 weeks, all four lobes of the cerebral cortex are developed. Tooth development begins. Cilia line the airway to defend against foreign materials and infection. Ultrasounds sometimes even reveal babies sucking their thumbs at this stage – although you still have some time before you get to hold those adorable fingers and toes.

Week 14: The theme of this week is movement. Your little one’s arms and legs can now flex, which will allow them to practice moving hands to mouth – an important skill that will be needed for the rest of your baby’s life. The sense of smell and taste will develop this week too. Your baby’s genitals are fully developed by this time, but it may still be too early to learn the gender via ultrasound at this point (though there are some blood tests that can reveal the gender as early as seven weeks).

Week 15: This week, your baby will have a rapid growth spurt. Don’t be surprised if you think your little one is making faces at you; ultrasounds show frowning, squinting, grimacing, and wincing, as fetuses this age flex and strengthen their facial muscles.

Stem cells arrive and multiply in the bone marrow, causing the bones to harden, though they’ll remain somewhat flexible to enable your baby’s passage through the birth canal. The bronchial tree is nearly complete, so the airways are prepared for life outside the womb. Ultrafine hair called lanugo now covers your baby’s head, back, shoulders, ears, and forehead, helping to retain body heat until fat reserves build; this hair typically falls off prior to birth.

Week 16: This week is all about the eyes. Your baby’s eyes will begin to move from side to side and will be sensitive to light, even though the eyelids will still be closed. Because the backbone and the tiny muscles in the back are developing, your little one will be able to stretch out their neck and head just a little bit more. You might be able to detect some movement this week, though it’s possible you won’t notice it. On the other hand, it can be easy to mistake gas or a muscle twitch for that first movement.

Week 17: Over the last two weeks, your baby will have doubled in size as their legs and trunk have now caught up with the size of their head. Fingernails, toenails, and even eyelashes will begin to form. Vital organs begin to operate in new ways this week too. Your baby’s heart will become directed by the brain, rather than beating spontaneously, and the lungs exhale amniotic fluid. Your baby is becoming more fully developed by the day.

Week 18: This week, your baby will begin to hear. The ear bones and nerves are developed enough for your baby to hear you – your blood coursing through the umbilical cord, your stomach rumblings, your heartbeat, and your voice. Sudden, loud noises can startle an 18-week-old fetus, and the soothing sounds of a parent’s voice or gentle music can produce a calming effect.

The fingers have prints making your baby one-of-a-kind, the taste buds are starting to distinguish between sweet and bitter, and the retinas display light sensitivity if a bright light is shined on your abdomen. Rapid Eye Movement, seen during the dreaming stage of sleep, begins between 18 and 21 weeks. Your baby can yawn, hiccup, and swallow, and ultrasounds reveal the sort of vocal box movements made while speaking.

Week 19: This week your baby’s body will be covered with a waxy, cheese-like film called vernix caseosa. A cheese-like substance all over your baby’s body may not sound like the most appealing thing in the world, but this is an important development because it protects your baby’s skin from amniotic fluid, which means they won’t have incredibly wrinkled skin at birth.

Week 20: This week signifies the halfway point of your pregnancy! Your baby may seem to be as happy as a clam at this point. The legs curl, flex, and kick; the torso twists, turns, and wiggles. Don’t worry if you can’t feel any of that movement yet; all babies and moms are different.

Also, your baby is now sleeping and waking regularly. By 20 weeks, the cochlea of the inner ear reaches adult size, allowing the fetus to respond to a medley of sounds. The digestive system will begin to produce a greenish-black substance called meconium, something you’ll see in the first few diapers you change. Your little one may even start "talking" to you through Braxton Hicks contractions at week 20!

This week, maternal fetal medicine doctors, obstetricians and gynecologists may perform an anatomy scan. 

Week 21: Most of your baby’s nourishment still comes from the placenta, but the stomach’s ability to absorb nutrients from the amniotic fluid swallowed accounts for a growth spurt during this period. Your baby may gain an extra four inches in length and two ounces in weight since last week. For the first time, your baby will be bigger than the placenta. Your little one may really begin moving around, and you may feel jabs and kicks more frequently. You may notice routine periods of activity and rest.

Week 22: This week, your baby will begin to look like a tiny version of a newborn baby. Maturing brain cells and nerve endings enable your baby to explore the world of touch with their hands as they become more responsive to external stimuli. In fact, you may be able to see your baby’s response to light and sound while having an ultrasound. At this stage, your baby’s eyelids are still closed, but the eyes themselves move.

Week 23: At this point in your pregnancy, billions of brain cells directing life-long functions, like breathing and movement, develop. The lungs advance their ability to fully inflate and expand in preparation for breathing air. Over the next month, your baby will more than double in weight.

Week 24: Amazing brain development this week consumes more than 50 percent of the total energy used by the fetus, with brain weight increases of 400 to 500 percent! Your baby’s brain communicates with their eyelids to facilitate the blinking response when startled. The balance control center in the inner ear lets your baby know whether they are right side up or upside down.

The brain connections that enable the sensation of pain are wired. Babies in this stage of development respond to pressure, movement, pain, hot, cold, taste, and light. In fact, with the ability to react and respond to some stimuli, your baby might also begin to respond to your voice and stroking motions on your bump!

Week 25: This week, your baby will have a BIG growth spurt and will become over a foot long (13 inches or so) and weigh more than a pound and a half. Your baby’s skin will begin to look pinker as capillaries (small blood vessels) form under the skin, which will eventually facilitate blood circulation throughout your little one’s body. In fact, later this week, blood vessels will develop in your baby’s lungs preparing them for life outside the womb. 

Week 26: During the last week of the second trimester, your baby will be much closer to full maturity after experiencing so much rapid growth throughout the last several weeks. At this point, your baby’s brain waves are similar to full-term newborns, and their breathing rate slows and deepens. The ability to hear will strengthen now, and your baby may be able to hear you as well as other people around you or even the TV or music. Also, your baby’s eyes will open this week. Sure, the view may not be all that exciting, but your baby will be able to see what’s going on now.

Your Physical Changes in the Second Trimester

how does your body change during the second trimester?

Clearly, this is a very busy time for your baby as they continue to grow in the comfort of your uterus. But what about you? It’s true that many women report feeling a lot of relief during the second trimester of pregnancy, but that doesn’t mean that changes aren’t happening for you. Here are some things that you can expect as you continue along your journey through pregnancy:

Growing belly and breasts: For many moms, the pregnancy may begin to feel more real as the belly grows and begins to show. Most moms start showing between 12 and 16 weeks, but the uterus reaches the height of the belly button by the 20th week of pregnancy, causing a more noticeable baby bump. Maternal weight gain continues at 1-2 pounds per week. Your breasts may no longer feel achy like during the first trimester, but they also may grow anywhere from 4-6 inches or 1-3 cup sizes in the second trimester.

Backache: It’s possible that because of the rapid growth and belly development, you may begin to feel pressure in your back. There are ways to ease this pressure, such as sitting in chairs that provide good back support and sleeping on your side with a pillow tucked between your legs. Watch out for middle-of-the-night leg cramps too! This is a good time to ask for some support from your partner, family, and friends – and that support may come in the form of a good back rub!

Bleeding gums: Some women will find that during the second trimester, their gums begin to bleed. This is caused by hormonal changes taking place within your body, but it should go back to normal once your baby is born. With so much to think about, you may not realize that dental hygiene is as critical as it is. However, it’s incredibly important because gum disease has been shown to increase the potential for premature labor

Digestive changes: Two-thirds of pregnant women will experience some heartburn by the time the second trimester rolls around, although it may rear its ugly head right away. The combination of a growing uterus increasing pressure on the stomach and pregnancy hormones may lead to dyspepsia, acid reflux, and heartburn.

These same hormones slow down bowel movements, potentially causing constipation, gas, and abdominal pain. Use your prenatal visits to bring up any discomfort you're experiencing, and don't hesitate to reach out to your doctor between OB appointments.

Discharge: You may notice a thick, milky, white vaginal discharge; this is normal. If you feel uncomfortable, using a thin pad or panty liner may help. Even better? Our Leakproof Panties!

Frequent urination: The urge to go will likely become more frequent during the second trimester because the growing uterus places more pressure on your bladder. Urinary tract infections are more common if the baby puts too much pressure on the uterus, causing a blockage.

Skin changes: Moms may undergo some or no pregnancy skin changes. Some common changes are silvery stretch marks, darkening skin on the forehead and cheeks (melasma), and a dark line from the navel down the abdomen (linea nigra or pregnancy line). Your skin may be more sensitive to the sun, so be sure to slather on the SPF before going outside. Your abdomen may feel dry and itchy as your skin stretches, so use a good moisturizer to ease any sensitivity that might develop.

Hormone changes: In addition to all the other things they impact, hormone fluctuations can also increase perspiration and feelings of apprehension or irritability (ever seen a pregnancy mood swing in a sitcom?!). 

Circulatory changes: Slower blood circulation and increasing fluid production can cause the ankles, hands, and face to swell. These changes, along with increased blood flow to the body’s mucous membranes, sometimes cause dizziness, nasal congestion, and snoring. Varicose veins can start appearing in the second trimester too. 

Second Trimester To-Do List

things to do in the second trimester

Now that you know what to expect for you and your baby during the second trimester, here are some things you may want to do in preparation for the last stage of pregnancy:

1. Shop for official “maternity” clothes. This could be a great time to call on your friends and family to ask if they have any maternity clothes they are no longer wearing. But with all the energy you may be feeling now, it could be a fun time for a shopping spree just for you. Some new clothing can make you feel great as your body changes shape.

2. Slather your belly with moisturizing cream. That belly is growing! It can be itchy and dry, and, yes, you may develop stretch marks. This belly balm will soothe your growing belly.

3. If you want one, start searching for a doula. A doula is a trained professional who provides support for you as you go through pregnancy’s ups and downs. Having a doctor or midwife you trust will get you through the technical aspects of pregnancy and childbirth, but a doula is there just for you. It is by no means necessary, but those who use a doula often feel comforted by having someone at their side who is solely concerned about them and their body.

4. Tell your boss or team about your pregnancy and determine your leave. In the United States, there is no federally mandated parental leave, so you’ll need to know what your state and workplace will provide for you. Encourage your partner to inquire about parental leave as well. Some employers provide time off for partners of new mothers, and if that’s the case for your family, it could be great to have time together after childbirth to nest with your new little one.

And it isn’t too soon to start considering your plan for breastfeeding, especially if you will be working after having your baby. Take a look at our guide to breastfeeding rights for lots of great information about how to navigate the transition back to work.

5. Start exploring childcare options if you’ll need it after your maternity leave. It can be quite a shock to learn how expensive good childcare can be. To get you started, here is an article that reveals the cost of childcare state-by-state. Don’t put off financial planning for childcare before your baby arrives.

6. Decide if you want to know the gender of your baby and how you’ll reveal it to family and friends. This is a deeply personal decision, and each family must consider whether or not they want to know the gender of their baby before they arrive. Some of you may want to know, and you may even want to have a gender reveal party to announce the news.

Others may not want to know or may even choose to raise their children without gender. This part of pregnancy may inadvertently become stressful as others may feel differently about the decision you make. But whatever you decide, stay true to yourself.

7. Start sleeping on your side if you’re not already. Most doctors recommend that pregnant women sleep on the left side because, in that position, your baby won’t compress your inferior vena cava, a large vein that runs up and down your right spine and is responsible for returning blood from the bottom half of your body to your heart. It isn’t clear that there is a big distinction between sleeping on the left or the right side, but you should consult your doctor.

It could be very helpful to borrow or purchase a pregnancy pillow that will help you maintain your spinal alignment as you sleep, especially if you are not accustomed to sleeping on your side. Pamper yourself with a cozy pillow that will cradle you and your baby while you sleep.

8. Consider a baby registry and baby shower. Be clear about what you want in a baby shower or if you want one at all. Get creative and have fun with the theme. Be sure to choose foods you love and gather your friends and family to help you prepare for your new arrival.

9. Consider taking a “babymoon” trip. You’ve heard of a honeymoon, but a babymoon can help you reconnect with your partner before your lives become forever changed. Most pregnant women can travel safely during this trimester, so take advantage of it!

10. Work on any home-improvement projects. Once your baby comes, you will not have much time to tackle home-improvement projects and baby nursery renovations. The second trimester can be a great time to get that to-do list taken care of.

What KB Moms Remember about the Second Trimester

what to know about the second trimester

You can’t really know how you will experience the second trimester until you’ve gone through it yourself. Remember, just as we are all different people, we all have different responses to this monumental time in our lives. No matter what, it can be comforting to hear from others who have already gone through what you are just now experiencing. And always remember to be kind to yourself as you navigate the ever-changing stages of pregnancy.

“It is so easy to feel like the nausea/exhaustion of the first trimester will be that way the entire pregnancy. Unfortunately, for some it is, but for the majority, the second trimester is a breeze. I had so much more energy, and the nausea was pretty much completely gone. I was able to catch back up on housework and dishes, play with my kids more, and have the TV on less. We planned a vacation (I am hesitant to call it a babymoon since the kids came!) for late in the second trimester so we could have some quality family time before the new baby came.” 


“The first time around, my second trimester was awesome! The second time around, I had migraines, the glucose test made me violently ill, I had a cold I couldn’t shake, and I peed every time I coughed. I was healthy but miserable.” 


“I had a ton of energy compared to the first trimester! My nausea was pretty much gone, and I started to nest. The second trimester was the best!” 


“People kept telling me that, typically, it gets better/easier in the second trimester...but it didn’t.” 


“I had more energy, but naps were still a must. I was nauseous up until week 20 with my second baby but never had any nausea with my first. In my second trimester with my first, I had the energy of a toddler and could go-go-go. The typical nerves of the anatomy scan and excitement of finding out the gender stick out the most about my second pregnancy.” 


Congratulations on navigating this beautiful journey. We know that this is an exciting time that can also feel a bit overwhelming. We hope that your second trimester feels like a honeymoon. No matter what you’re feeling now, just remember that you’re doing great.

Also, remember to keep doing what’s best and right for you; take care of your body and mind (keep that blood pressure down!), and consult your medical team if you have any questions or concerns.

You’ve just got one more trimester to go before you get to meet your new little love. Be you. Be brave! Here's to a healthy pregnancy!

Disclaimer: This content is not intended to be a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your health care provider. The American College of Obstetricians and Gynecologists (ACOG) is a great starting point for finding care.

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