Week 15 of Pregnancy
Learn about your baby's development and what to expect at 15 weeks pregnant.
Baby's Size This Week
Baby Development at Week 15
- ● Your baby is about 10.1 cm long and weighs approximately 70g — roughly the size of an apple.
- ● The skeleton is hardening from cartilage to bone, with the process advancing from the center of each bone outward.
- ● Facial muscles allow for expressions like squinting, frowning, and grimacing as the nervous system matures.
- ● Your baby is practicing swallowing amniotic fluid, which exercises the digestive system and supports lung development.
- ● Fine lanugo hair now covers the entire body, and eyebrows and eyelashes are beginning to develop.
- ● Ultrasound may reveal the sex this week or in coming weeks as external genitalia become more distinguishable.
Your Body at Week 15
- ● Energy continues to improve and many women feel their best during this mid-second trimester period.
- ● Your belly is becoming more noticeable, and a visible baby bump is appearing for most women by now.
- ● Skin changes continue — the linea nigra may darken, and the pregnancy glow from increased circulation is common.
- ● You may begin to feel the first faint flutters of movement (quickening) this week, especially if this is not your first pregnancy.
- ● Backache can begin as the growing uterus shifts your center of gravity and puts strain on the lower back.
- ● Nasal congestion and nosebleeds may continue due to increased blood volume affecting the nasal mucosa.
Week 15 Checklist
- ☐ Schedule your mid-pregnancy anatomy ultrasound for weeks 18-22 if not already booked.
- ☐ Begin wearing a supportive maternity bra and consider a belly support band for back pain relief.
- ☐ Continue prenatal vitamins and focus on DHA-rich foods (fatty fish, fortified eggs) for fetal brain development.
- ☐ Start sleeping on your left side using a pregnancy pillow to improve circulation and comfort.
- ☐ Research and compare childbirth education classes — hospital-based, Lamaze, Bradley, and Hypnobirthing options.
- ☐ Schedule a dental cleaning if you have not had one, as pregnancy gingivitis risk peaks in the second trimester.
Frequently Asked Questions
When will I feel my baby move for the first time?
First-time mothers typically feel movement (called quickening) between weeks 18-22, while women in subsequent pregnancies often notice it earlier, around weeks 14-18. Early movements feel like flutters, bubbles, or gentle taps. At 15 weeks, your baby is moving frequently, but the sensations may be too subtle to distinguish from gas or digestion.
Is back pain normal at 15 weeks?
Yes, back pain affects more than 50% of pregnant women, often starting in the second trimester. The growing uterus shifts your center of gravity forward, increasing strain on the lower back and pelvis. Hormones like relaxin also loosen joints and ligaments. To manage it: maintain good posture, wear supportive shoes, use a pregnancy pillow, and try prenatal yoga or swimming. Contact your provider if pain is severe or radiates down your leg.
What is the quad screen blood test?
The quad screen is a blood test offered between weeks 15-20 that measures four proteins (AFP, hCG, estriol, inhibin A) to screen for Down syndrome, trisomy 18, and neural tube defects. It is a screening test with some false positives, so abnormal results lead to further diagnostic testing. It is often combined with first-trimester NIPT results for better accuracy. Discuss with your provider whether it is right for you.
How much should my baby be moving at 15 weeks?
At 15 weeks, your baby is very active — flipping, kicking, and stretching frequently — but most mothers cannot feel these movements yet because the baby is still small and the movements are not strong enough to reach the uterine wall consistently. You will likely begin feeling distinct movements in the coming weeks, particularly between 18-22 weeks for first-time mothers.
Should I be gaining weight by 15 weeks?
Most women with normal pre-pregnancy BMI have gained about 5-10 pounds by 15 weeks. Weight gain in the first trimester is typically 1-4 pounds total, with gain accelerating in the second trimester to about 1 pound per week. Some women who experienced severe morning sickness may have lost weight and are just beginning to gain. Your provider will track your weight at each prenatal visit and advise if adjustments are needed.
Track Your Exact Pregnancy Week
Use our free Pregnancy Week Tracker to find out exactly how far along you are based on your last menstrual period or due date.
Track My Pregnancy →Sources
- ACOG
- WHO Fetal Growth Charts
- Mayo Clinic
Medical disclaimer: This content is for informational purposes only and is not intended as medical advice. Always consult a qualified healthcare provider for guidance specific to your pregnancy.