4th Month Of Pregnancy - All You Need To Know

Entering the 4th month of pregnancy marks the beginning of the second trimester, a phase often referred to as the most comfortable stage of pregnancy. By now, many early pregnancy symptoms start to ease, and you may begin to notice exciting changes, including increased energy, a growing baby bump, and the first signs of baby movement.   

At 4 months pregnant, your baby is developing rapidly, and an ultrasound at this stage can reveal crucial growth milestones. While 4 months pregnant, symptoms may include mild discomforts like round ligament pain and increased appetite. This is also a time to enjoy the progress of your pregnancy.   

In this guide, we’ll discuss 4 months pregnant baby movement, common symptoms, ultrasound expectations, and essential care tips to help you navigate this exciting phase with confidence! 

4 Months Pregnant: Common Pregnancy Symptoms

While you might not experience all of them, these 4 months pregnant symptoms are common during the 4th month of pregnancy: 

• Weight gain

• Itchy skin around your growing tummy and breasts

• Appearance of stretch marks

• Nasal problems

• Increased energy

• Varicose veins

• Spider veins

• Changes in skin pigmentation.

At 4 months pregnant, there are relatively few nagging symptoms. That’s why this time is referred to as the ‘honeymoon’ period of pregnancy — when many mums-to-be take on decorating, shopping, travelling, and any other preparations that require more energy.

4-Months Pregnant Ultrasound Test  

What Does the Doctor Look for During the 4-Month Pregnancy Ultrasound? 

• Baby’s Growth and Measurements – The doctor will check the measurements of the head, abdomen, and limbs to ensure your baby is growing at a healthy rate. 

• Baby’s Movements – The scan helps observe your baby’s activity, movement, and muscle development inside the womb. 

• Heartbeat and Organs – The scan checks for a strong heartbeat and examines major organs such as the brain, heart, stomach, kidneys, and bladder. 

• Placenta Position – The doctor will assess if the placenta is in a safe position, ensuring it’s not blocking the cervix (a condition called placenta previa). 

• Amniotic Fluid Levels – The scan will check if the amniotic fluid levels are within the normal range, as this fluid protects and nourishes the baby. 

• Umbilical Cord & Blood Flow – This ensures that nutrients and oxygen are reaching the baby properly. 

• Detecting Any Anomalies – The doctor will screen for any physical abnormalities or developmental concerns at this stage. 

The 4-month pregnancy ultrasound is a painless and exciting experience, allowing you to get a clearer look at your baby’s development. Many parents also hear their baby’s heartbeat and may even catch a glimpse of their little one moving or sucking their thumb! 

Four Months Pregnant: Baby Development & Bodily Changes 

At 4 months pregnant, the second trimester is well underway, bringing noticeable changes to both the developing foetus and the pregnant person's body. This stage often comes with increased energy, a growing belly, and exciting milestones in fetal development. 

Foetal Development at Four Months

By the 4^th month of pregnancy, the foetus has grown significantly and is developing more defined features and functions: 

• Size and Growth: The foetus is approximately the size of an avocado, measuring around 4-5 inches (10-12 cm) in length and weighing about 3-5 ounces (85-140 grams). 

• Facial Features: The facial structure becomes more developed, with eyebrows, eyelashes, and even some hair starting to grow. 

• Movement: The foetus begins making more pronounced movements, though they may not be strong enough to be felt yet. These include stretching, yawning, and even sucking their thumb. 

• Organ Development: The liver and spleen are actively producing blood cells, while the kidneys start producing urine, which is excreted into the amniotic fluid. 

• Sensory Development: The ears are forming more fully, and while hearing is still developing, the foetus may start responding to sounds from outside the womb. 

• Skin Changes: A thin layer of fine hair called lanugo starts covering the body, helping to regulate temperature in the womb. 

Bodily Changes at Four Months Pregnant 

The second trimester often brings relief from early pregnancy symptoms, but new changes occur as the body continues to adapt: 

• Visible Baby Bump: The uterus has expanded, and for many, the baby bump becomes more noticeable. Maternity clothes might start feeling more comfortable. 

• Increased Energy: Many experience a boost in energy as early pregnancy fatigue fades. 

• Digestive Changes: The growing uterus can put pressure on the stomach, leading to occasional heartburn, bloating, or constipation. Eating smaller meals and staying hydrated can help. 

• Skin and Hair Differences: Some may notice a pregnancy "glow" due to increased blood circulation, while others experience skin changes such as darkening of the nipples or the appearance of the linea nigra (a dark line running down the belly). 

• Round Ligament Pain: As the uterus stretches, some may feel sharp or dull aches in the lower abdomen or sides, known as round ligament pain. 

• Changes in Appetite: Cravings and increased appetite can become more noticeable, but balanced nutrition remains important. 

• Breast Growth: Breasts may continue to grow and feel fuller as they prepare for milk production. 

What to Expect Next 

As pregnancy progresses, fetal movements will become stronger, and the body will continue adapting. Regular prenatal check-ups help monitor growth and address any concerns. Staying active, eating nutritious foods, and listening to the body’s needs can make this stage of pregnancy smoother. 

Fourth Month of Pregnancy Check List 

The fourth month of pregnancy marks a significant shift, as early symptoms may ease, energy levels rise, and the baby bump starts to become more noticeable. This is a great time to focus on key preparations, prenatal care, and self-care. Below is a helpful guide to keep everything on track. 

• Prepare for the 20-week anatomy scan – This detailed ultrasound checks fetal development and overall health. It's also a great time to learn about upcoming pregnancy symptoms and care tips. 

• Announce the pregnancy – If you haven't already, consider sharing the news with friends, family, or coworkers in a fun and memorable way. 

• Start browsing maternity wear – Your clothes may start feeling snug, so explore comfortable maternity options for the coming months. 

• Manage hunger with healthy eating – Your appetite increases but it’s important to focus on nutrient-rich foods instead of "eating for two." Follow healthcare provider recommendations for a balanced diet. 

• Consider a getaway – The second trimester brings more energy, making it a great time for a relaxing trip before the baby arrives. 

• Research birthing locations – Explore hospitals or birthing centers and check insurance coverage for the best options. 

• Start or update a baby registry – Planning early allows time to research and add must-have items before baby shower invitations go out. 

• Look into baby names – Use a name generator or make a list of favorites to make the decision easier later on. 

• Plan maternity leave – If working, discuss leave options with your employer and plan for a smooth transition. 

• Stay active and comfortable – Light exercise like walking or yoga can help with posture and energy levels, while supportive shoes and seating add comfort. 

What Does a Foetus Look Like at 4 Months? 

At four months pregnant (weeks 14 to 17), the foetus is rapidly growing and developing more distinct features. Here’s what to expect in each week of this stage: 

Week 14 

• The foetus is about the size of a peach (around 3.5-4 inches long). 

• The facial features become more defined, with the ears and eyes moving into their final positions. 

• Fine hair, called lanugo, starts covering the body for warmth. 

• The arms and legs are more proportional, and the foetus may begin making small movements. 

Week 15 

• The foetus measures about 4 inches in length and weighs around 2.5 ounces. 

• The skeletal system is strengthening, and joints are becoming more flexible. 

• The eyelids remain closed, but the foetus can sense light through the thin skin. 

• Taste buds are developing, and the foetus may begin swallowing small amounts of amniotic fluid. 

Week 16 

• The foetus has grown to about 4.5 inches long and weighs around 3.5-4 ounces. 

• Facial muscles are developing, allowing slight expressions like frowning or squinting. 

• The nervous system is becoming more advanced, helping with better coordination of movements. 

• Tiny toenails start forming, and the umbilical cord continues thickening to support nutrient flow. 

Week 17 

• The foetus is now about the size of an avocado (approximately 5 inches long and weighing around 5 ounces). 

• The heart is fully developed and pumping blood efficiently. 

• Fat begins forming under the skin to help with insulation. 

• The foetus may start exhibiting stronger movements, though they might not yet be felt by the pregnant person. 

How Big Is Your Baby When You’re 4 Months Pregnant? 

At four months pregnant, the foetus measures approximately 3.5 to 5 inches in length and weighs between 1.5 to 5 ounces. Around week 14, the foetus is about the size of a peach, growing to an apple by week 15, an avocado by week 16, and a pear by week 17. During this stage, the baby experiences rapid growth, with developing bones, distinct facial features, and increased movement. While these measurements provide a general guideline, individual growth may vary. 

How Far Along Are You at 4 Months Pregnant? 

Pregnancy timelines can be broken down in different ways, but at 4 months pregnant, you are typically between week 13 or 14 and week 16 or 17, depending on how the weeks are grouped into months. This stage marks the beginning of the second trimester, which usually lasts until month seven of pregnancy. During this time, early pregnancy symptoms may start to ease, energy levels may improve, and the baby continues to grow rapidly, developing more distinct features and movements. 

Baby Movements at 4 Months Pregnant 

At 4 months pregnant, the baby is becoming more active, with movements becoming more coordinated. These early movements, called quickening, may feel like fluttering, light taps, or tiny bubbles in the lower abdomen. Some may start noticing these sensations around weeks 16 to 18, while others—especially first-time parents might not feel them until a few weeks later. 

Even though the baby is moving frequently, their small size and the amount of amniotic fluid can make these early kicks and stretches harder to detect. As the baby continues growing, movements will become stronger and more regular, with noticeable kicks, rolls, and stretches in the coming weeks. Regular movement tracking is not yet necessary at this stage, but paying attention to these first signs of activity can be an exciting milestone in pregnancy!