GUIDE
4 Months Pregnant
Published on ·Updated on
Month 4 covers weeks 14 through 17 — the second trimester brings renewed energy and your baby starts hearing.
Being 4 months pregnant is when pregnancy often starts to feel enjoyable. First-trimester symptoms have faded for most people, energy is returning, and your baby is developing rapidly — growing bones, forming facial expressions, and possibly even sucking a thumb. If this is not your first pregnancy, you may feel the first flutters of movement this month.
Be prepared from day one
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What Happens During Month 4
Month 4 of pregnancy (weeks 14-17) is the start of the second trimester, and for many people, it feels like a fresh start. The fog of first-trimester symptoms lifts, energy returns, and your baby enters a period of rapid growth and development.
At week 14, your baby can squint, frown, and grimace — practicing the facial expressions they will use after birth. By week 15, the skeleton is hardening from cartilage to bone, and some babies are already sucking their thumbs.
Week 16 is a sensory milestone — your baby can hear sounds, including your voice and heartbeat. The tiny bones of the inner ear have hardened enough to transmit sound. By week 17, fat stores are beginning to form under the skin, and sweat glands are developing.
| Week | Baby Size | What Is Happening |
|---|---|---|
| Week 14 | Lemon | Second trimester begins — baby can squint and make facial expressions |
| Week 15 | Apple | Bones hardening throughout the body — baby may suck thumb |
| Week 16 | Avocado | Baby can hear sounds — skeletal system developing rapidly |
| Week 17 | Pear | Fat stores beginning to form — sweat glands developing |
Your Body at 4 Months Pregnant
The energy boost is the defining feature of month 4. After weeks of exhaustion and nausea, many people feel like themselves again. This is a great time to tackle projects, exercise, and enjoy pregnancy.
Your bump is starting to show. The uterus has risen above the pelvic bone and is growing rapidly. You may need to start transitioning to maternity clothing or using belly bands to extend the life of your regular pants. Round ligament pain — sharp, stabbing twinges in the lower abdomen or groin — is common as the ligaments that support the uterus stretch to accommodate its growth.
Heartburn often makes its first appearance during month 4. Progesterone relaxes the lower esophageal sphincter, allowing stomach acid to reflux. Eating smaller, more frequent meals and avoiding lying down after eating can help manage it.
Common Symptoms at Month 4
- Renewed energy — the second-trimester boost is real
- Growing bump becoming noticeable
- Round ligament pain — sharp twinges in the lower abdomen or groin
- Heartburn beginning or worsening
- Nasal congestion from increased blood flow to mucous membranes
- Increased appetite as nausea fades
- Skin changes — melasma, linea nigra, or early stretch marks
- Possible first flutters of fetal movement (especially in subsequent pregnancies)
Month 4 is often the most comfortable period of pregnancy. Enjoy the energy boost while it lasts.
When to Call Your Doctor
- Vaginal bleeding
- Severe abdominal pain or persistent cramping
- Painful or burning urination
- Severe headaches with visual changes
- Fever above 100.4 degrees Fahrenheit
Second-trimester symptoms are generally milder, but always report anything that concerns you.
Looking Ahead
At month 5 (weeks 18-22), you will reach the halfway point and have the anatomy scan — the most detailed ultrasound of your pregnancy. Most people feel definite fetal movement during month 5. For a complete overview of the second trimester, see our second trimester guide.
Related Guides
Sources
- American College of Obstetricians and Gynecologists (ACOG) — How your fetus grows during pregnancy
- Mayo Clinic — Fetal development: trimester by trimester
- March of Dimes — Pregnancy month by month
This guide is for informational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider with any questions about your pregnancy.
Frequently asked questions
- Can I feel the baby move at 4 months?
- Possibly, especially if this is not your first pregnancy. People who have been pregnant before sometimes feel quickening (the first fetal movements) as early as weeks 15-16. First-time mothers usually feel movement between weeks 18 and 22. Early movements feel like flutters, bubbles, or a light tapping that can be hard to distinguish from gas.
- Will I have a baby bump at 4 months?
- Many people begin to show around month 4, though it varies widely. Your uterus is now rising above the pelvic bone and growing rapidly. First-time mothers tend to show later than those in subsequent pregnancies. By the end of month 4, most people need to transition to maternity clothing or looser waistbands.
- Why do I suddenly have so much energy at 4 months?
- The energy boost in the second trimester is largely driven by the placenta taking over hormone production. In the first trimester, rapidly rising hCG and progesterone caused fatigue and nausea. By month 4, hormone levels have stabilized, the placenta is fully functional, and your body has adapted to the increased blood volume.
- Is heartburn normal at 4 months pregnant?
- Yes. Heartburn typically begins or worsens in the second trimester as progesterone relaxes the valve between the stomach and esophagus, allowing stomach acid to flow upward. As your uterus grows, it also pushes the stomach upward, compounding the problem. Eating smaller meals, avoiding spicy or acidic foods, and not lying down after eating can help.
