4 months pregnant: Development and what to expect

By month 4 of pregnancy, you’ve officially entered your 2nd trimester. You might have started to feel like you’ve finally got a grip on some of the changes you’ve noticed. You may have crossed your 1st-trimester scan and blood tests off your list of milestones, and your early pregnancy symptoms may finally be easing up. 

As you enter this next phase of pregnancy, it’s really important to remember that every pregnancy is different. Your symptoms might disappear as you move into week 14, or you might notice some new ones. You may also be curious about what’s going on inside your 4-months-pregnant belly and how your baby is developing. To get the lowdown, Flo expert Dr. Renita White, obstetrician and gynecologist, Georgia Obstetrics and Gynecology, Georgia, US, shares everything you need to know about being 4 months pregnant. 

And don’t forget to try a pregnancy-tracking app like Flo for more information and tips on how your pregnancy is developing week by week. 

Key takeaways

• Your baby does a lot of growing this month of pregnancy, expanding from the size of a peach to a pomegranate. They’ll also gain little details like eyelashes, toenails, and fingerprints. 
• You may feel your baby move for the first time this month, although this is still considered to be pretty early. Everyone is different, but many people don’t experience this until 20 weeks pregnant. 
• You might not feel nauseous, tired, or have tender boobs anymore. However, there’s a whole new host of symptoms that are often linked to the 2nd trimester. Hello, round ligament pain. 

Fetal development between weeks 14 and 17 of pregnancy

Fourteen weeks pregnant marks a milestone for you as well as your baby, who now has all their organs and systems. “Right now, the organs continue to develop and move into their permanent positions,” says Dr. White. “The fetus also continues to grow in length and weight.”

Your baby will also become more active this month of pregnancy as their central nervous system matures. You might even feel your first baby kicks, especially if this isn’t your first pregnancy. However, many people don’t feel this until around week 20. A lot is going on, so let’s look at what’s happening with your pregnancy week by week in more detail. 

Week 14

At 14 weeks pregnant, your baby is starting to form nails. Their skin is also starting to thicken, and fingerprints are beginning to form, too.  

It’s also the week they start forming fetal red blood cells in their spleen. These cells have important jobs: transporting oxygen around the body (which converts to energy) and carrying carbon dioxide to your lungs for you to exhale. By the 3rd trimester, your baby’s red blood cells will start developing in their bone marrow instead.  

This week, your baby’s genitals are fully developed, meaning their sex will be more obviously apparent. It’s a few weeks before your next pregnancy scan, though, which happens around 20 weeks. So, if you don’t know the sex of your baby already and want to find out, the countdown starts now.

Week 15

Thanks to their developing hearing, it’s likely your baby can hear your voice around now at 15 weeks pregnant. This might feel like a meaningful moment, but don’t worry if talking to your belly feels strange at first. Alongside your voice, they’ll hear your heartbeat and your tummy gurgles. 

Your baby’s scalp hair pattern is starting to form this week, and they are also sprouting eyelashes. Meanwhile, the small movements they’ve been making since the 1st trimester are starting to become more purposeful. 

Week 16

This week, your baby is starting to move the muscles in their face and make their very first facial expressions. They’re not in control of their frowns and smiles at the moment but will be practicing these expressions by 37 weeks pregnant. 

At 16 weeks pregnant, your baby’s limb movements are also becoming more coordinated. The muscles in the limbs are able to flex thanks to their developing nervous system. 

You might see their punches and kicks during a scan. Some people may even be able to feel them, as Dr. White explains: “It is possible to feel early flutters by 16 weeks. People who have been pregnant before are more likely to feel movement because it is a feeling they may recognize.” 

The sensations will feel different for everyone, but some people describe them as bubbles popping, tiny pulses, or flutterings like a butterfly. Most people will feel their baby move by the time they are 20 weeks pregnant. 

Week 17

Although they could still fit in the palm of your hand, your baby is growing quickly and is now around the size of a pomegranate. At the beginning of this month of pregnancy, they were just the size of a peach — that’s a whole lot of growing.

They are also continuing to get more active in their amniotic fluid at 17 weeks pregnant and may even react to sensations around them, like loud music or belly rubs. Their moves are becoming more advanced, and they may now be rolling or flipping inside you. 

They might sound dramatic, but it’s perfectly normal if you can’t feel these movements just yet. If you’re feeling impatient for that first kick, hold tight and try not to worry. 

Symptoms you might experience when 4 months pregnant

If you’ve felt nauseous or tired during your 1st trimester, you might start to feel better around the start of month 4. “Right now, you may feel more energy and less bothersome symptoms,” says Dr. White. 

“However, round ligament pain is most common around this time,” says Dr. White. “This is a cramping, aching, or pulling sensation that occurs in the lower abdomen as the uterus grows and puts tension on the ligaments. It is also possible to feel headaches, episodes of dizziness, and muscle cramps.”

Here’s more on the symptoms you may experience during the 4th month of pregnancy: 

An increased appetite

While the idea that you’re “feeding for two” is a myth, you will need up to 340 extra calories a day during the 2nd trimester.

Round ligament pain

You can feel this type of pain in both the lower pelvis or on either or both sides. Along with round ligament pain, you may find the skin on your belly itching as it stretches and grows. 

Bleeding gums

This surprising symptom is due to the increase in hormones affecting the mucous membranes in the mouth. 

Nosebleeds and nasal congestion

The increased hormones and blood flow in pregnancy can also affect the mucous membranes and blood vessels in the nose. 

Hemorrhoids

Thanks to increased pressure on the veins in your anus, increased blood volume, and greater chances of constipation, hemorrhoids during pregnancy are unfortunately common. 

Varicose veins

Due to the increased hormones and pressure of the baby on your blood vessels, pregnancy can make you more susceptible to varicose veins. These are lumpy rope-like veins that are visible under your skin, often on the legs, ankles, and vulva.

Skin changes

You may notice a line down the middle of your belly forming this month called the linea nigra. Your areolas (the skin around your nipple) may also get darker, along with other breast changes during pregnancy, like stretch marks. 

Heartburn

Pregnancy hormones can relax the valve between your stomach and esophagus, causing stomach acid to leak through and result in heartburn during pregnancy.  

Constipation

The increase in hormones can slow down your digestive system and lead to constipation. 

Dizziness

Pregnancy causes changes in your circulation, which can leave some people feeling dizzy. If you have dizziness with a mild headache or blurry vision, you should get in touch with a health care professional. If the headache or blurred vision is severe, or if the dizziness is accompanied by any other worrying symptoms (like vaginal bleeding), you should ​​contact your hospital or emergency department.

Remember, if in doubt about any body changes, it’s always a good idea to speak to your doctor. It’s also important to remember that every pregnancy is different, and not everyone experiences the 2nd-trimester pregnancy in the same way. If you’re still rushing to the bathroom with nausea several times a day or fighting fatigue, you’re not alone. Hang in there — you may start to feel better soon. And don’t forget to speak to your doctor about your pregnancy symptoms in case they can help. 

Take care of yourself in the 2nd trimester and beyond

You might be feeling more energetic during the 4th month of pregnancy and excited for the changes yet to come. But even if you’re feeling better than ever, it’s super important to keep looking after yourself. “Continue your prenatal care visits and take care of your body by getting rest, drinking water, and exercising,” says Dr. White. In addition to all the information you need on fetal development, Flo’s pregnancy tracker can give you tips on how to take care of yourself as your pregnancy progresses.