Welcome to the second trimester. Your baby is now the size of a lemon, and this week brings a developmental milestone: vocal cords are forming, preparing for that first cry (and years of subsequent on...
The Quick Brief
Welcome to the second trimester. Your baby is now the size of a lemon, and this week brings a developmental milestone: vocal cords are forming, preparing for that first cry (and years of subsequent ones). For your partner, this often marks the turning point—the mythical "pregnancy glow" may appear as blood volume increases and nausea recedes. This week is about preparing for the coming months: researching registries, planning for maternity clothes, and handling the practical tasks that are easier now than they will be later.
What's Happening with Baby
At week 13, your baby measures about 3 inches long—approximately the size of a lemon. Weight is around 0.7-1 ounce. The transition from first to second trimester marks a shift in developmental focus: from forming organs to growing and maturing them.
Key developments this week: vocal cords are forming in the larynx. These won't be used until birth, but the architecture is being established now. The intestines, which developed partly in the umbilical cord due to space constraints, are migrating into the abdomen. Fingerprints are beginning to form—your baby is developing unique identifiers. The head is becoming more proportional to the body; it no longer accounts for half the body length. On ultrasound, it may appear as though the baby is practicing breathing—rhythmic movements of the chest and diaphragm in amniotic fluid.
Movement increases, though you won't feel it yet. The fetus can now turn its head, curl its toes, and bring its hands to its face. These aren't random twitches—they're early coordination practice.
What's Happening with Mom
The second trimester is often called the "honeymoon phase" of pregnancy, and there's truth to that for many women. Nausea typically fades or disappears entirely. Energy returns as hormone levels stabilize. The constant exhaustion of the first trimester often lifts.
New developments this trimester:
The "glow": This isn't folklore. Increased blood volume (up 50% by delivery) means more blood flow to the skin, creating a flushed appearance. Oil glands also increase production, adding a subtle sheen. Some women love this; others just feel oily. Both reactions are valid.
Increased appetite: After weeks of food aversions and nausea, eating normally again feels like a revelation. Appetite often increases as the body shifts into growth mode.
Libido changes: For many women, second trimester brings increased libido. Nausea is gone, energy has returned, and blood flow to the pelvic area increases sensitivity. Others experience the opposite. Both are normal.
Visible bump: The uterus rises above the pubic bone and the baby bump becomes visible to others. Many women transition to maternity clothes during the second trimester.
What Dad Should Do This Week
1. Research baby registries
You're not ready to register yet, but you should understand the landscape:
Where to register: Target, Amazon, and Buy Buy Baby are the major players. Amazon offers completion discounts; Target has good return policies. Some couples register at multiple places.
What you actually need: Most registry "must-have" lists are marketing. Essential categories: car seat, safe sleep space (crib or bassinet), feeding supplies, diapers, basic clothing. Everything else is optional.
Research first, register later: Spend time in the second trimester researching gear—read reviews from actual parents, not sponsored content. By week 20-22, you'll be ready to build a registry.
Tip: Talk to parents with kids under 2 years old. Ask what they actually used versus what collected dust. Real-world experience beats marketing copy.
2. Plan for maternity clothes shopping
Your partner will need new clothes. Second trimester is typically when regular clothes stop fitting comfortably. Here's how to help:
Budget appropriately: Maternity clothes don't need to be expensive, but they're not free. Target, Old Navy, and ThredUp (secondhand) offer reasonable options. Budget $200-500 depending on workplace dress code needs.
Offer to accompany or give space: Some women want help shopping; others want to figure out their changing body privately. Ask which she prefers.
Practical support: She may need specific items for work (professional maternity wear is harder to find and more expensive) versus casual weekends. Identify what's needed for her actual life.
3. Schedule dental appointments
If you didn't do this last week, make it happen now. The second trimester is the ideal time for dental work. After about week 28, lying flat becomes uncomfortable, making dental procedures more challenging. Both of you should get cleanings and address any pending dental issues now.
4. Update beneficiaries and documents
Life admin that nobody wants to do but everyone should:
Life insurance: If you haven't gotten coverage, do it now. Term life insurance is affordable and straightforward.
Beneficiaries: Review 401(k), life insurance, and bank account beneficiaries. Are they current?
Wills: If you don't have wills, start the process. Online options (like Trust & Will or Willing) are simpler and cheaper than attorneys for straightforward situations.
Nobody wants to think about this, but becoming a parent means being responsible for someone who depends entirely on you. Handle the paperwork.
Research your parental leave now. FMLA gives 12 weeks unpaid. One first-time dad discovered his company's notification deadline was 30 days prior — he nearly missed it because nobody told him — your company may offer paid leave on top of that. There are notification deadlines that most dads miss. Ask HR this week, not when you’re packing the hospital bag.
The Relationship Check-In
The second trimester often feels like a reset. The crisis mode of first trimester—the nausea, exhaustion, anxiety about miscarriage—starts to fade. This is a good time to reconnect as a couple, not just as expectant parents.
Plan something just for the two of you: dinner out, a weekend away, a movie night without baby planning discussions. Your relationship is the foundation for your growing family. Nurturing it now isn't indulgent—it's strategic. The third trimester will bring new physical limitations, and then the baby arrives. Invest in your partnership while you can.
What's Coming Up
The anatomy scan (level 2 ultrasound) typically happens around weeks 18-20. This detailed scan checks all major organs and body systems and can reveal the baby's sex if you want to know. Before that appointment, decide together whether you want to find out. Other second trimester milestones: feeling fetal movement (usually weeks 18-22 for first pregnancies), glucose screening test around week 24-28, and visible belly growth that makes the pregnancy undeniably apparent.
Enjoy the second trimester. Many couples find it the most enjoyable phase—symptoms improve, energy returns, and the finish line starts to feel real without being immediately imminent.
Quick Reference Box
Baby size: Lemon (~3 inches)
Key milestone: Vocal cords forming, entering second trimester
Dad priority: Research registries and plan maternity wardrobe logistics
Source: Cleveland Clinic Fetal Development, March of Dimes Week-by-Week
Sources:
Cleveland Clinic: Fetal Development Stages of Growth
March of Dimes: Pregnancy Week by Week
American College of Obstetricians and Gynecologists (ACOG)