Week 14
Your baby is the size of a lemon
Week 14 brings a milestone that sounds small but isn't. Your baby's spleen just fired up red blood cell production. The neck is now defined. Sex is correctly identified on ultrasound about 90% of the time at this gestational age, per a Royal Free Hospital study. Your baby is lemon-sized and increasingly recognizable. You're in the second trimester, and most people feel more like themselves this week than they have in months.
Key takeaways
- Your baby's spleen has taken over red blood cell production this week, according to Mayo Clinic's fetal development data.
- Sex can be identified on ultrasound with roughly 90% accuracy at 14 weeks, though most providers wait until the anatomy scan, performed between 18 and 22 weeks per ACOG, with 18 to 20 weeks generally considered the best window for clear imaging.
- Melasma affects 36 to 75% of pregnant people, and daily broad-spectrum sunscreen can prevent it. Start now if you haven't already.
- Sleep position still isn't a concern at this stage. Back, side, or stomach (if it's still comfortable) are all fine through about 30 weeks.
What your baby can do at 14 weeks
Your baby measures about 3.5 inches from crown to rump and weighs 1.5 ounces this week.
Lemon-sized.
Red blood cell production just moved to the spleen. The yolk sac handled it early on, then the liver took a shift, and now the spleen is running the line. It's a quiet handoff but a big developmental step. Your baby's circulatory system is getting closer to the way it'll work for the rest of their life.
The neck is now distinctly defined. For weeks, your baby's head sat tucked against the chest in a C-shape. Now there's real separation. The head can lift slightly, the chin can tilt, and on ultrasound your baby starts to look less like a curled bean and more like a tiny person with actual posture.
External genitalia are more developed too. Sex determination on ultrasound hits about 90% accuracy at 14 weeks, per a study at the Royal Free Hospital in London. Most providers still wait until the anatomy scan, performed between 18 and 22 weeks per ACOG, with 18 to 20 weeks generally considered the best window for clear imaging. But if you have an early ultrasound on the books, ask. Some sonographers will make a call now.
Other quiet progress this week: skin is starting to thicken, the roof of the mouth is forming, and facial muscles are developed enough to reflexively squint and grimace.
You'd recognize a tiny person if you could see them.
Here's something to hold onto. Your baby's body from this point on is mostly about growing and refining, not building from scratch. The architecture is in place.
How your body is changing
Here's a skin change that surprises a lot of people: brown patches appearing on your forehead, cheeks, or upper lip. That's melasma, also called chloasma gravidarum or the 'mask of pregnancy.'
A 2024 review in Clinical, Cosmetic and Investigational Dermatology found it affects 36 to 75% of pregnant people, depending on skin type and geography.
The cause is hormones plus sun exposure. Pregnancy ramps up melanin production, and any UV light amplifies it.
Good news: the same review found that wearing broad-spectrum sunscreen daily from the first trimester reduces the incidence by more than 90%. A hat helps too. If melasma is going to show up, the second trimester is when it typically starts.
Your bump is probably becoming visible this week, especially in fitted clothes. First-time parents often show later because abdominal muscles haven't been stretched before. A small or absent bump at 14 weeks says nothing about your baby's health.
Breasts are likely larger, veins more visible, and areolas darker. Those small bumps on the areolas are Montgomery tubercles, oil glands that will help with breastfeeding later.
All normal.
The second prenatal visit is probably happening this week or next. Blood pressure, weight, urine check, fundal height, and a chance to ask whatever's been building up. Write your questions down beforehand. You'll forget them otherwise. And if you haven't scheduled the anatomy scan (performed between 18 and 22 weeks per ACOG, with 18 to 20 weeks generally considered the best window for clear imaging), ask your provider about scheduling it.
For dads
Here's your move:
The anatomy scan around week 20 is the next big appointment, and for most couples it's the most detailed look at your baby yet. Book the day off work. Seriously. The scan usually runs 30 to 60 minutes, and you don't want to be checking Slack halfway through. This one matters. Also: if you and your partner haven't settled whether you want to know the sex, have that conversation this week. Sometimes one partner wants to know and the other wants a surprise. Work it out before you're sitting on the exam table asking the sonographer to stop mid-scan.
Real talk:
Your partner may be feeling better, more energy and less nausea, and that shift can make you exhale a little. But here's what I want you to watch for: the mental load doesn't go away just because she's eating cereal again. She's still tracking prenatal appointments, researching pediatricians, worrying about screening results, and thinking about what happens when leave ends. Ask her what's taking up space in her head this week. Then take one concrete thing off her plate. Research car seats. Schedule the dental cleaning she's been putting off. Don't ask what you can help with. Pick something and do it.
Common concerns
Can the ultrasound really tell us the sex at 14 weeks?+
Usually, yes. About 90% of the time in experienced hands, per a Royal Free Hospital study. Most providers still wait until the anatomy scan (performed between 18 and 22 weeks per ACOG, with 18 to 20 weeks the best window for clear imaging) for higher accuracy, but if you have an early ultrasound scheduled, ask. Keep in mind: ultrasound sex determination reads genital anatomy, which can occasionally be misread. NIPT blood work is more definitive if that matters to you.
I've heard other moms talk about 'pregnancy brain.' Is that real?+
Mostly, yes. Many pregnant people report trouble concentrating and short-term memory lapses, especially in the second and third trimesters. Research is mixed on whether cognitive performance actually dips or whether it just feels worse. Either way, the forgetfulness is common and temporary. Keep a list app handy and lower the bar on remembering non-essentials.
My energy is back but my skin looks worse than ever. Is that normal?+
Very. Between oil production changes, melasma, and increased blood flow, many people see breakouts, darkening, or blotchiness in the second trimester. Most of this fades after delivery. Stick to gentle cleansers, daily broad-spectrum sunscreen, and hold off on strong retinoids or hydroquinone unless your provider specifically clears them.
When should I worry about abdominal pain this week?+
Mild, brief twinges from stretching ligaments are normal. Call your provider immediately for severe pain, pain concentrated on one side, pain with bleeding, pain with fever, or pain that doesn't improve with rest. When in doubt, call. Providers strongly prefer hearing from you over having you worry alone.
Product picks for week 14
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Blue Lizard Sensitive Mineral SPF 50 Sunscreen Lotion
100% mineral, fragrance-free lotion with zinc oxide that qualifies as broad-spectrum. This is the daily-use profile the 2024 melasma review identified as reducing incidence by more than 90%.
Simplicity UPF 50+ Wide Brim Straw Sun Hat
Roll-up wide-brim straw hat with UPF 50+ protection. Direct match for the 'a hat helps too' recommendation in the melasma section.
Bearsland Maternity Side Ruched T-Shirt (3-Pack)
Three-pack of side-ruched cotton maternity tees. Rotating basics for the stretch when your regular shirts stop fitting but your bump isn't huge yet.
Sources
- Mayo Clinic, Fetal development: The 2nd trimester (2025) - https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/fetal-development/art-20046151
- Whitlow BJ et al., The sonographic identification of fetal gender from 11 to 14 weeks of gestation, Ultrasound in Obstetrics and Gynecology (1999) - https://pubmed.ncbi.nlm.nih.gov/10380291/
- Shi W et al., Prevention of Melasma During Pregnancy: Risk Factors and Photoprotection-Focused Strategies, Clinical Cosmetic and Investigational Dermatology (2024) - https://pmc.ncbi.nlm.nih.gov/articles/PMC11490249/
- ACOG, How much weight should I gain during pregnancy? (2024) - https://www.acog.org/womens-health/experts-and-stories/ask-acog/how-much-weight-should-i-gain-during-pregnancy
- ACOG, How Your Fetus Grows During Pregnancy (2024) - https://www.acog.org/womens-health/faqs/how-your-fetus-grows-during-pregnancy
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. 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 how we create our content.