This post is part of The Ultimate Month by Month Pregnancy Guide. If you are interested in a step by step breakdown, view the roadmap here. The Ultimate Month-by-Month Pregnancy Guide: What To Expect
The fourth month of pregnancy is a major milestone for both the parents and the developing baby. It’s around this time that a lot of early worries start to fade, and the baby begins to look and act more like a newborn inutero. I remember finding it super helpful to understand what to expect at this stage, especially with all the body changes and symptoms popping up. Here’s everything you might want to know about baby development in the fourth month, the changes your body may experience, and some practical tips for staying well and feeling good!
The Growing Baby: Size and Development in Month 4
Your baby takes some pretty big steps in development during the fourth month. Right at the start of this month, the fetus is usually about 3.5 to 4 inches long (roughly the size of an avocado) and weighs close to 1.5 ounces. By the end of the month, length can reach about 6 inches and weight can jump up to 4 to 5 ounces. That’s a lot of growth in just a few weeks!
This rapid pace means a lot of exciting changes. The baby’s facial features become more defined. Picture a defined nose and chin, and even some expressions. Eyebrows, eyelashes, and hair start to grow, and the ears move closer to their final position. Most parents are surprised to learn, that by this time, the baby can yawn, stretch, and even suck his/her thumb. Muscles and bones are also growing stronger, and your baby’s heart, which has already been beating for weeks, keeps getting more efficient at pumping blood.
The nervous system starts to function better, making movements more coordinated, although you probably won’t feel those first flutters (sometimes called “quickening”) until a bit later in the month or the fifth month. Your baby’s skin is still thin and translucent but is developing more layers every day. Fingerprints also begin to form on those tiny fingers, and the baby may even start moving his/her hands to his/her mouth, showing early reflexes that will be more obvious later in pregnancy.
Pregnancy Symptoms in the Fourth Month
By the fourth month, some early pregnancy symptoms like nausea and morning sickness tend to improve for many women, but new symptoms can appear. Here’s what you might notice:
- More energy: Feeling less tired than in the first 3 months, but still needing extra rest now and then.
- Appetite increases: Your hunger might amp up because your baby is growing quickly, but don’t feel pressured to “eat for two.” Staying mindful of nutritious eating is what matters the most.
- Round ligament pain: Aching or a sharp pain as your uterus grows. This unexpected pain can catch you off guard at odd moments.
- Constipation: Hormone shifts can slow digestion, so bathroom trips might be less frequent for bowel movements, but urination will still happen frequently.
- Visible veins: Your blood supply is increasing, and sometimes new veins show up, especially on the legs and chest.
- Skin changes: Some women get the “pregnancy glow,” (I did!) but others may spot darkening skin patches (melasma), (my sister) especially on the cheeks and forehead.
- Nasal congestion and nosebleeds: Stuffy nose or mild nosebleeds are common due to extra blood flow to mucous membranes.
- Breast growth and tenderness: Breasts continue to grow and can begin to feel full and heavy, preparing for future milk production.
Easy Ways to Manage Fourth Month Pregnancy Symptoms
Everybody’s experience is unique, and symptoms come and go. These solutions can help make things a bit more comfortable and keep you feeling your best:
- Tiredness: Snag short naps and take breaks when you need to, even if you’re feeling more energetic. Prioritizing rest is always a wise move.
- Constipation: Add more fiber rich foods (fruits, beans, whole grains), drink water throughout the day, and stay active with gentle movement like walking or yoga. Prune juice or warm fluids in the morning may also help get things moving.
- Round ligament pain: Changing positions slowly, wearing supportive undergarments, and using pillows for extra support can ease aches, especially when lying down.
- Skin changes: A gentle moisturizer and sunscreen with at least SPF 30 can ease dryness and prevent skin darkening from getting worse. Try to avoid excessive sun exposure.
- Heartburn: Eating smaller meals, avoiding spicy or greasy foods, and not lying down right after eating can make a big difference. Elevating your upper body during rest can also help.
- Nasal congestion: Use a cool mist humidifier and saline nasal sprays to soothe stuffiness. Be gentle if you need to blow your nose to help avoid nosebleeds.
- Breast tenderness: Supportive bras and cotton fabric may make you more comfortable as your breasts increase in size. Cotton fabric is gentle on your breasts when they are tender and sore.
Vitamins and Nutrition: What To Eat (and What To Skip)
The fourth month is a great time to refresh your approach to food and supplements. Your baby needs a steady supply of nutrients, and so do you. Here’s what doctors and dietitians commonly recommend:
- Pre-natal vitamins: Keep taking them daily. Look for ones that include folic acid, iron, vitamin D, calcium, iodine, and DHA (an omega3 fatty acid).
- Folate and iron: Folate (or folic acid) is essential for your baby’s neural growth, while iron helps prevent the common pregnancy symptom of anemia by supporting your increased blood supply.
- Calcium: Growing bones call for extra calcium, so try lowfat dairy, almonds, or fortified non-dairy milk. Dark leafy greens and broccoli are also solid picks.
- Protein: Lean meats, beans, tofu, and eggs help your baby’s muscles and organs expand. Peanut butter and other nuts or seeds work for quick protein boosts, too.
- Fruits and veggies: Colorful produce delivers fiber, vitamins, and antioxidants. Berries, oranges, spinach, and carrots are all great options to rotate into your meals.
- Whole grains: Adding whole wheat bread, brown rice, oatmeal, and other grains helps fuel your rising energy needs and supports digestion.
Some foods and drinks are better to skip entirely:
- Alcohol: No safe level has been found, so it’s recommended to steer clear of all alcohol during pregnancy.
- Excess caffeine: Most experts suggest sticking to less than 200 mg a day (about one mug of coffee).
- Raw or under cooked meat and eggs: These can carry bacteria and parasites that are risky for you and your baby.
- Unwashed produce & unpasteurized dairy: Both can harbor germs that may pose a threat to your health or your baby’s development.
- Deli meats and high mercury fish: Heat deli meats until steaming, and pick fish like salmon, sardines, or trout for safe, nutritious protein.
- Certain herbal teas and supplements: Some herbs have not been studied during pregnancy. Check with your provider before adding anything new.
Activities and Precautions: Staying Safe in the Fourth Month
Keeping active is encouraged, but certain activities are safer than others at this stage of pregnancy. Gentle exercise like walking, swimming, or maternity yoga can give a boost to your energy and strengthen your body for what’s ahead. If you were active before pregnancy, you can usually keep doing what you were doing; just remember to check with your doctor or midwife first.
When it comes to sex, it’s generally safe during pregnancy unless you have complications such as placenta previa or a history of pre-term labor. If you notice bleeding, pain, or anything unexpected, mention it to your healthcare provider for peace of mind.
Here are a few activities worth skipping or being extra careful about:
- Contact sports or activities with a risk of falling, like skiing, ice skating, or horseback riding.
- Hot tubs, steam rooms, and saunas. These can heat up your body too much and can cause issues especially in early pregnancy.
- Heavy lifting or straining your core muscles. Ask for help with tasks involving lifting or climbing.
- High intensity workouts unless cleared by your health provider.
Safe daily routines, such as stretching, keeping hydrated, wearing supportive shoes, balancing physical activity with relaxation, and taking breaks, all help offset aches or fatigue so you feel steadier throughout the month.
Risks of Miscarriage and Causes in Month 4
The risk of miscarriage drops quite a bit once you reach the second trimester, which begins at week 13. In the fourth month, the risk is generally below 1-3%, according to The American College of Obstetricians and Gynecologists or ACOG. Most pregnancy losses at this stage result from issues in fetal chromosome development, sometimes called “chromosomal abnormalities.” These are usually beyond your control and not caused by anything you’ve done or left undone.
Sometimes, underlying health conditions such as poorly controlled diabetes, infection, or thyroid disorders play a role in pregnancy loss as well. Smoking, heavy alcohol or drug use, and physical trauma all raise the risk, so quitting smoking and steering clear of risky substances and risky behavior is really important for both you and your baby. Watch for symptoms such as heavy bleeding, severe abdominal pain, or a sudden loss of appetite and contact your doctor or midwife right away if anything seems off.
Other Pregnancy Complications: Preeclampsia, Gestational Diabetes, and More
The fourth month is sometimes when complications start popping up, though most pregnancies go smoothly. Preeclampsia, which involves high blood pressure and protein in the urine, can start after 20 weeks, but it’s smart to keep an eye out for warning signs early. Understanding Preeclampsia Swelling in your face or hands, headaches, sudden weight gain, or changes in vision should be reported to your care team. Regular checkups help your provider keep tabs on your blood pressure and protein levels.
Gestational diabetes is generally screened for between weeks 24 to 28, but it’s worth keeping in mind. Managing your diet, staying active, and following your provider’s guidance can lower your risk. Other issues, such as incompetent cervix or early labor, rarely show up in the second trimester. Your provider will take a closer look for risk factors if there are signs or a personal/family history of complications. If you’re worried about personal or family risk, don’t hesitate to ask questions at every appointment. Being proactive helps you stay in the know and spot problems early.
Other rare complications can include urinary tract infections and anemia. Both can often be managed effectively with prompt attention and treatment, so staying alert to discomfort or more frequent urination is always worthwhile. Eating iron-rich foods and staying hydrated adds a layer of protection against these hiccups.
FAQ: Common Questions About Baby Development in the Fourth Month
Can I find out the baby’s sex in month 4?
Usually, yes! The external sexual organs are well developed now, so many women/couples get their first glimpse during an ultrasound this month. Be sure to let your ultrasound technician know if you’re hoping to find out. If you don’t want to know, be sure to tell them in advance of the ultrasound.
Should I “feel” the baby move yet?
Some women notice faint flutters near the end of the month; for others, it starts a bit later. Both experiences are totally normal.
How much weight should I have gained by now?
Most women gain between 4 and 8 lbs. by month four, but there’s a lot of variation. What matters most is steady progress at your own pace, and eating healthy. Your doctor or healthcare provider will check your weight at each pre-natal visit.
Is travel safe in the fourth month?
For most women, short trips (by car, train, or even plane) are okay, but it’s smart to check in with your doctor/healthcare provider about any travel plans just to be sure. Bring healthy snacks, water to stay hydrated and take breaks to stretch on long rides.
Takeaways for a Healthy Fourth Month
The fourth month of pregnancy brings growth, relief of many symptoms, and a lot of changes for the mom and the baby. Eating well, managing discomfort, checking in regularly with your doctor, healthcare provider or midwife, and staying active all help this month feel more manageable. Staying informed makes the whole experience less stressful and a lot more exciting as your pregnancy moves forward. If you want to learn more from a trustworthy resource for all things related to pregnancy and baby health, check out the March of Dimes.