Week 17
Your baby is the size of a pear
What's happening this week
Your baby is now the size of a pear — about 5 inches (13cm) from crown to rump and weighing around 5 ounces. A significant shift is happening beneath the skin this week: your baby is starting to develop adipose tissue — body fat. This fat layer will eventually help regulate body temperature after birth and give your baby that adorable, round newborn look.
The skeleton continues its transformation from soft cartilage to hard bone, a process called ossification. If you had an X-ray (which you wouldn't during pregnancy), you'd see the bones becoming increasingly defined. Toenails are now growing, following the fingernails that started weeks ago.
Your baby's sweat glands are developing, and the umbilical cord is getting thicker and stronger to support the increasing demands of a rapidly growing body. The placenta, which is now roughly the same size as your baby, is working overtime — filtering blood, delivering nutrients, and removing waste.
Your baby is an active gymnast at this point: rolling, flipping, stretching, and kicking with increasing strength. The movements are still too subtle for most first-time parents to feel, but they're constant. Your baby also has distinct periods of sleep and wakefulness now, though the sleep cycles are much shorter than yours — about 20 to 40 minutes at a time.
One delightful detail: your baby's unique fingerprints, which started forming a few weeks ago, are now fully established. No one else in the world has the same pattern — not even an identical twin.
Your body this week
The second trimester energy boost is likely in full effect, and many people find week 17 to be one of the more enjoyable stretches of pregnancy. Nausea is typically gone, sleep is better than it was in the first trimester, and the bump is visible without being cumbersome.
Your body is producing more blood than ever — about 50% more than your pre-pregnancy volume. This increased circulation is essential for supporting the placenta and your growing baby, but it comes with some side effects: you might feel warmer than usual, notice visible veins on your breasts and abdomen, and experience the occasional nosebleed.
You may notice that your center of gravity is shifting as your belly grows. This can affect your balance, especially when standing quickly or navigating stairs. It's not dramatic yet, but it's worth being mindful of — swap heels for flats if you haven't already.
Appetite is likely robust now, and your provider may recommend adding about 340 extra calories per day starting in the second trimester. This is roughly the equivalent of a yogurt with granola or a banana with peanut butter — not the 'eating for two' feast some people imagine.
If you haven't felt your baby move yet, don't worry. Quickening — the first perceptible fetal movement — typically happens between weeks 16 and 22, and first-time parents often don't recognize it until the later end of that range. When it does happen, it may feel like bubbles, flutters, or a gentle tapping low in your abdomen.
For dads
The anatomy scan is likely coming up in the next 1-3 weeks, and it's one of the most detailed and informative appointments of the entire pregnancy. This ultrasound checks your baby's organs, brain, spine, heart chambers, limbs, and more. It's also typically when you can find out the sex, if you want to know. Have the conversation with your partner before the appointment: do you both want to find out? Do you want to find out together in the room, or have it sealed in an envelope for a reveal? Getting aligned before you're lying in the exam room avoids an awkward split-second decision.
Your partner's body is changing in ways that are now visible to the world, and that can bring a mix of pride and vulnerability. She may love her bump or feel self-conscious about it — or both, depending on the day. Physical intimacy may look different than it did before pregnancy, and that's normal. If she's feeling good and interested, great — the second trimester often brings a return of desire. If not, respect that without taking it personally. The most important thing: keep talking openly about how you're both feeling. Bodies change, needs change, and navigating that together strengthens the partnership.
Common concerns
Is it normal to feel clumsy during pregnancy?+
Yes — your center of gravity is shifting forward as your belly grows, which can affect your balance and coordination. Additionally, the hormone relaxin, which loosens joints and ligaments to prepare for birth, can make you feel less stable on your feet. Wear supportive, flat shoes, hold handrails on stairs, and be mindful when standing up quickly. The clumsiness is temporary and very common.
How many extra calories do I actually need?+
Despite the 'eating for two' saying, you don't need dramatically more food. Most providers recommend no extra calories during the first trimester, about 340 extra calories per day in the second trimester, and about 450 extra in the third. Focus on nutrient-dense foods rather than just adding calories — think protein, iron, calcium, and healthy fats. Your provider can give you personalized guidance based on your pre-pregnancy weight and activity level.
Can my baby hear me yet?+
Almost — your baby's hearing is developing rapidly and will likely be functional by next week. Right now, the structures of the inner ear are nearly complete. By week 18, your baby will be able to hear sounds, starting with internal noises like your heartbeat and digestive sounds, and gradually including external sounds like your voice and music. So keep talking and singing — your baby will recognize your voice at birth.
When should I be concerned about round ligament pain?+
Round ligament pain — sharp, pulling sensations on one or both sides of your lower abdomen — is a normal part of your uterus growing. It's typically triggered by sudden movements like standing up, sneezing, or rolling over. However, contact your provider if the pain is constant rather than intermittent, is severe and doesn't ease with position changes, or is accompanied by bleeding, fever, or chills. Persistent or severe pain should always be evaluated.
Product picks for week 17
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Pregnancy-safe flat shoes with arch support
Your center of gravity is shifting and your feet may swell — supportive flats are safer and more comfortable than heels now.
Nutrient-dense snack box subscription
Second trimester appetite is real — a curated box of healthy, protein-rich snacks keeps you fueled between meals.
Baby registry starter guide
With the anatomy scan approaching, many parents start their registry — a guide helps you know what you actually need vs. nice-to-have.
A quick note: This content is for informational purposes only and is not a substitute for professional medical advice. Always talk to your healthcare provider about any questions or concerns. Learn how we create our content.
Content based on guidance from the American College of Obstetricians and Gynecologists (ACOG), the American Academy of Pediatrics (AAP), Mayo Clinic, and peer-reviewed medical literature. Learn more about how we create our content.