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Trimester 2

16 Weeks Pregnant

At week 16, your baby is focusing on growth and refining their movements. They are starting to hear the sounds of your heartbeat and voice, and their tiny muscles are getting stronger as they practice kicking and rolling in the womb.

8 min read Medically Reviewed Updated 2024-05-01
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Your baby is the size of a Avocado
12 cm
Length
100 g
Weight
Week 1Week 13 - End of Trimester 1Week 27Week 42

Baby's Development This Week

At week 16, your baby is focusing on growth and refining their movements. They are starting to hear the sounds of your heartbeat and voice, and their tiny muscles are getting stronger as they practice kicking and rolling in the womb.

  • The musculoskeletal system is maturing — movements become more coordinated.
  • Toenails begin growing.
  • The circulatory system is fully functional.
  • The fetus can grasp with its hands.
  • Eyes are moving slowly under closed lids.
  • About 11.6cm — the size of an avocado.

Your Symptoms at Week 16

Week 16 is part of the 'honeymoon phase' of pregnancy. You likely have more energy now and your bump is starting to show. You might notice changes in your hair and skin, and you're probably starting to feel the wonderful sensation of your baby moving.

Back pain
Use a support pillow; prenatal yoga helps. (moderate)
Constipation
Eat 25-30g fiber daily; prune juice helps. (moderate)
Pregnancy brain (forgetfulness)
Use lists, reminders, and a planner. (mild)
Increased vaginal discharge
Wear breathable cotton underwear. (mild)

When to Call Your Doctor

  • Severe back pain that doesn't improve with rest
  • Painful contractions or regular cramping
  • Vaginal bleeding or unusual discharge
  • Decreased fetal movement if you've been feeling it

Week 16 Checklist

  • Schedule your mid-pregnancy anatomy ultrasound (18-22 weeks) (essential)
  • Begin sleeping with a pregnancy pillow (recommended)
  • Start looking into childbirth education classes (recommended)
  • Research cord blood banking if interested (optional)

Nutrition in the Second Trimester

Many people find their appetite returns and nausea eases up during the second trimester, which makes this a good window to focus more deliberately on nutrient-dense eating. Energy needs increase modestly during this stage, and it’s a common point for providers to check in more specifically about iron, calcium, and protein intake as the baby’s growth accelerates.

  • Iron needs increase in the second trimester — pair iron-rich foods (lean meat, beans, leafy greens) with vitamin C sources to help absorption.
  • Calcium and vitamin D support your baby’s developing bones — dairy, fortified plant milks, and leafy greens are common sources.
  • Protein needs increase somewhat; spreading protein across meals (eggs, beans, meat, dairy, tofu) rather than concentrating it in one meal can help you meet your daily needs.
  • Fiber-rich foods (whole grains, fruits, vegetables) can help with digestive symptoms like constipation, which often become more noticeable in the second trimester.
  • Continue to avoid alcohol, raw/undercooked proteins, unpasteurized dairy, and high-mercury fish.
  • If heartburn starts appearing, smaller and more frequent meals, plus avoiding lying down right after eating, can help.

Staying Active in the Second Trimester

For many people, the second trimester is when energy returns and exercise becomes more comfortable again, though your center of gravity is starting to shift as your belly grows, which is worth factoring into your choice of activities. This is generally a good stage to continue or start prenatal-appropriate strength training, walking, swimming, or prenatal yoga classes, while avoiding activities with a high fall risk or direct abdominal impact. As always, if your provider has flagged any pregnancy-specific concerns, follow their individual guidance over general recommendations.

For Partners: Supporting the Second Trimester

As energy often returns during the second trimester, this can be a good window for partners to get more involved in shared activities — attending appointments together, going to childbirth or prenatal classes, or simply being present for the visible physical changes that tend to become noticeable during this stage. It’s also a practical time to start conversations about logistics further down the line: parental leave planning, nursery preparation, and how responsibilities will be divided after the baby arrives.

Frequently Asked Questions

Medical Disclaimer: This content is for informational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider for personalized guidance about your pregnancy.