The second trimester, often called the “golden period” of pregnancy, spans weeks 13 through 27. For many expectant parents, this phase brings welcome relief from early pregnancy symptoms and the exciting first flutters of fetal movement. This comprehensive guide details what to expect as your body changes and your baby grows, providing evidence-based information on symptoms, development, self-care, and crucial warning signs.
Quick Reference: Second Trimester at a Glance
| Aspect | What to Expect & Key Information |
|---|---|
| Timeline | Weeks 13 to 27 (Months 4, 5, and 6). |
| Common Symptoms | Reduced nausea, increased energy, visible bump, fetal movements (“quickening”), round ligament pain, nasal congestion, heartburn, skin changes. |
| Baby’s Key Developments | All major organs formed and maturing. Development of hearing, taste buds, fingerprints, and eyelashes. Practice breathing movements begin. |
| Essential Care Focus | Balanced nutrition with increased caloric needs, safe exercise, prenatal screening tests (anatomy scan), establishing comfortable sleep positions. |
| Critical Warning Signs | Severe abdominal pain, vaginal bleeding or fluid leakage, severe headaches with vision changes, sudden swelling, decreased fetal movement after 24 weeks. |
Baby’s Development: A Week-by-Week Journey
The second trimester is a period of remarkable growth and refinement for your baby, transitioning from a fetus to a recognizable infant.
- Weeks 13-16 (Month 4): The baby’s bones begin to harden, and the kidneys start producing urine. Fine hair (lanugo) covers the body, and facial features become more distinct. By week 16, the baby may begin making sucking motions.
- Weeks 17-20 (Month 5): This is often when you’ll feel the first flutters of movement, known as “quickening.” The baby’s nervous system is developing rapidly. A protective coating called vernix caseosa begins to form on the skin. The mid-pregnancy anatomy ultrasound, typically done around weeks 18-20, can check for physical development and often reveal the baby’s sex.
- Weeks 21-27 (Month 6): The baby’s senses are awakening; they can hear sounds from the outside world. Eyelashes and eyebrows appear, and the lungs are developing crucial surfactant to help them breathe after birth. By the end of the second trimester, the baby is viable, meaning there is a chance of survival outside the womb with intensive medical care.
Navigating Common Second Trimester Symptoms
While often more comfortable than the first trimester, new physical changes arise as your body accommodates your growing baby.
- Growing Belly & Round Ligament Pain: As your uterus expands, it stretches the round ligaments that support it, often causing sharp, brief pains on one or both sides of your lower abdomen, especially when changing positions. This is typically normal but should be discussed with your provider.
- Increased Energy & Libido: With hormone levels stabilizing and nausea often subsiding, many people experience a surge in energy and an increased sex drive. Enjoy this boost while practicing safe, comfortable positions.
- Physical Discomforts: Common issues include nasal congestion and nosebleeds (increased blood flow), heartburn and indigestion (relaxed digestive muscles), mild swelling in ankles and feet, and skin changes like the “mask of pregnancy” (melasma) or a linea nigra (dark line on the abdomen).
- Fetal Movement: Feeling your baby move is a reassuring milestone. Early movements may feel like gentle flutters or bubbles. By weeks 24-28, movements become more pronounced and regular. Your provider may ask you to do “kick counts” later in pregnancy.
Your Care Guide: Nutrition, Exercise, and Appointments
- Nutrition: You need about 340 extra calories per day during the second trimester. Focus on:
- Protein & Iron: For baby’s growth and your increased blood volume. Sources: lean meat, beans, lentils, fortified cereals.
- Calcium & Vitamin D: For baby’s bone development. Sources: dairy, leafy greens, fortified foods.
- Hydration: Drink plenty of water to support increased blood volume and reduce swelling and constipation.
- Prenatal Vitamin: Continue taking a daily prenatal vitamin containing folic acid and DHA.
- Safe Exercise: Regular activity improves mood, sleep, and reduces aches. Aim for 150 minutes of moderate exercise per week (e.g., brisk walking, swimming, prenatal yoga). Avoid contact sports, hot yoga, and activities with a high risk of falling.
- Prenatal Appointments & Tests: You’ll see your provider every 4 weeks. Key screenings include:
- Anatomy Scan (18-22 weeks): A detailed ultrasound to check fetal anatomy.
- Glucose Screening Test (24-28 weeks): Checks for gestational diabetes.
- Blood Tests: To check for anemia.
- Sleep & Comfort: Sleeping on your left side is recommended to optimize blood flow to the placenta and kidneys. Use pillows between your knees and under your belly for support.
Red Flags: When to Contact Your Healthcare Provider Immediately
While the second trimester is generally lower risk, contact your provider immediately if you experience:
- Vaginal bleeding or fluid leaking.
- Severe or persistent abdominal pain or cramping.
- Severe headaches, visual disturbances (blurring, spots), or sudden swelling in your face/hands (potential signs of preeclampsia).
- Painful or burning urination.
- A marked decrease or cessation in fetal movement once it’s well-established (after 24-28 weeks).
- Chills or a fever over 100.4°F (38°C).
Trust your instincts. You know your body best—if something feels wrong, seek medical advice.
To learn what happens in the final stretch and how to prepare for birth, read the next guide in our series: Third Trimester Pregnancy Guide (Weeks 28–40): Symptoms, Baby Growth & Birth Preparation.
Authoritative Resources for Further Reading
For more detailed information, consult these trusted sources:
- American College of Obstetricians and Gynecologists (ACOG): Pregnancy Resources
- The Mayo Clinic: Second Trimester Pregnancy Guide
- March of Dimes: Second Trimester Overview
Disclaimer: This guide provides general educational information and is not a substitute for professional medical advice. Always consult your healthcare provider with any questions or concerns about your specific pregnancy.