Week 13: Beginning of the Second Trimester
Week thirteen marks the start of the second trimester. The "golden period" of pregnancy begins!
Baby size: Peach (35-40 mm)
Baby development
Unique fingerprints and preparation for the first cry
Your baby is becoming more and more like a newborn. Its head now makes up only a third of the total body size, making it more proportionate.
What’s happening this week:
- Fingerprints: A unique pattern has formed on the pads of the tiny fingers, which will stay with them for life.
- Vocal cords: They continue to develop — this is the foundation for the first cry and future speech.
- Bones: The skeleton is actively hardening. The little bones of the arms, legs, and spine become stronger.
- Intestines: They have fully moved into the abdominal cavity.
If you’re having a girl, her ovaries already contain over 2 million egg cells. It’s incredible, but she already carries the potential for the next generation.
Changes for mom
Energy surge and growing belly
With the start of the second trimester you’ll likely feel like a new person. It’s a great time to return to your favorite activities.
What you may notice:
- Increased libido: Many women note a return or even an increase in sexual desire. This is linked to hormone stabilization and improved well‑being.
- Appearance of a "real" belly: Your uterus rises above the pelvic floor, and the belly becomes more noticeable.
- Breast discharge (colostrum): In some women, the first drop of colostrum may appear at this stage. This is completely normal.
- Ligament pain: With sudden movements you may still feel a pulling pain on the sides of the abdomen — the round ligaments continue to stretch.
The resurgence of sexual desire is a great opportunity to strengthen the relationship with your partner. Learn more in the article "Relationships and Sex During Pregnancy".
Overview
Week 13: Welcome to the "golden" trimester!
Week thirteen officially kicks off the second trimester — a period that many women consider the most comfortable and pleasant of the entire pregnancy. The most exhausting symptoms, such as nausea and fatigue, subside, and energy returns.
Your baby is now the size of a peach or a lemon. It already has unique fingerprints! Although you may not feel its movements yet, it is actively exercising inside you.
For you, this is a time when the pregnancy becomes more noticeable. The belly starts to round out, and you may feel the need for looser clothing. It’s a wonderful period to enjoy your condition and resume social activity.
Enjoy this time! The second trimester is the "honeymoon" of pregnancy. You feel better, and there is still plenty of time ahead to prepare for meeting your baby.
Learn more about all the benefits and features of this stage in our detailed overview of the second trimester.
Tips for mom
Put your energy to good use
Now that you have more energy, you can focus on pleasant and beneficial aspects of preparing for motherhood.
Ideas for this week:
- Start safe workouts. If your doctor approves, now is an ideal time for prenatal yoga, swimming, or Pilates. This will help keep muscles toned and prepare for delivery.
- Focus on balanced nutrition. Enjoy a varied diet rich in vegetables, fruits, protein, and healthy fats.
- Announce the news at work. If you haven’t done so yet, now is the right moment to inform management and colleagues.
- Start moisturizing your belly skin. While stretch marks are largely genetic, regular moisturizing can help reduce itching and discomfort.
To know which foods are most beneficial for you and your baby, check out our guide on balanced nutrition.
Tips for partner
Time for shared adventures and planning
Your partner feels better, and this is a great opportunity for shared activities and future planning.
How to spend this time together:
- Plan a "babymoon". The second trimester is an ideal time for a short romantic trip. It’s your chance to unwind together before the baby arrives.
- Be her companion in sports. Go for walks or to the pool together. Shared activity motivates.
- Dream together about the nursery. Start gathering ideas, browsing photos, discussing style and colors.
- Enjoy closeness. Use this period to strengthen emotional and physical connection.
Work and career during pregnancy also require discussion. Learn more about this aspect in the article "Work and Career During Pregnancy".
Checklist
Your action plan for week 13
We’re entering the second trimester with enthusiasm!
- ✅ Announce the pregnancy at work.
- 🧘♀️ Sign up for prenatal yoga or another safe form of exercise.
- 🧴 Buy oil or cream for stretch‑mark prevention.
- ✈️ Start planning a "babymoon" or simply a shared weekend.
- 👶 Start making a baby shopping list. This will help avoid stress later.
- 📚 Get inspired for preparation by reading the article on preparing the home and nursery.