GUIDE
4 Months Pregnant
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
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.
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.
