15 Weeks Pregnant: What to Expect & Important Prenatal Screening Tests
- July 21, 2020
- Michael Allibone
- Posted in Resources

You've made it to the 15-week mark. How are you feeling? Your energy may be up and your morning sickness has likely eased. You're probably curious to know how big your baby is doing. Is she healthy and developing well?
The 15-week mark is a good time to start thinking about second-trimester prenatal screening tests so you and your OB can check in on your baby's development.
At 15 weeks, your baby is developing fast. Your body is growing to accommodate her needs. It may even be time to consider maternity clothing. Increased hormones cause many changes, from sore gums to a stuffy nose. But rest assured, these symptoms are perfectly normal.
Let's take a look at what you can expect for you and your baby at 15 weeks. We'll also cover the prenatal screening tests that are available at this point in your pregnancy.
Pregnancy Symptoms at 15 Weeks
What can you expect during week 15 of your pregnancy? Everyone is different, but many women are finally sporting baby bumps by now. The miserable early pregnancy symptoms like nausea and fatigue have often disappeared by week 15. This is thanks to your placenta taking over the production of key hormones for your baby.
Do your gums bleed when brushing your teeth? It may be alarming, but don't worry. Bleeding gums are an unfortunate — but common — side effect of the hormone surge in your body during pregnancy. An increase in progesterone and estrogen causes more blood to be pumped through your mucus membranes, causing bleeding when you brush.
The second trimester is a great time to schedule a cleaning with your dentist. This reduces your risk of gingivitis and tooth decay. Just make sure to ask your OB which dental procedures are safe.
You may also have a stuffy nose that just doesn't go away. Like swollen, bloody gums, nose troubles can be attributed to your hormones and increased blood supply. It makes the tiny blood vessels in your nose swell, causing congestion (and sometimes nose bleeds). Saline spray is a safe way to help alleviate a stuffy nose.
Your first trimester may have been spent avoiding food or eating very little, but now is the time to gain weight! Talk with your OB about your weight gain goals, but in general, you should plan to gain around one pound a week.
Your Baby's Development at 15 Weeks
The next time you're at the grocery store, pick up a pear. At around 4 inches long and just a few ounces, this is roughly the size of your baby at 15 weeks! Because your baby is so small, you probably can't feel her yet, but she is moving around constantly.
Around 15 weeks, your baby's ears have moved into their proper positions, and she's starting to hear sounds. Her eyes are also moving from the side of her head to the front of her face. At this time, your baby's eyes are still closed, but she is beginning to sense light.
Your baby's skeleton is also ossifying, which means it's turning to bone and hardening. Blood vessels are forming beneath her transparent skin, and soft hair — called lanugo — is growing on her head. Your baby will also begin sucking her thumb around 15 weeks.
Prenatal Screening Tests at 15 Weeks
Prenatal screening tests during the second trimester are an important opportunity to make sure your baby is developing in a healthy, normal way. NTD Eurofins offers several screening options at this point in your pregnancy.
The Sequential Screen, Part 2
The Sequential Screen is a two-part prenatal screening test that determines your baby's risk of trisomy conditions such as Down syndrome and trisomy 18. It also checks for open neural tube defects (ONTDs). The first part of the test is done around 9 weeks. The second is done around 15 weeks.
An ONTD is an abnormality that affects a baby's brain, spine, or spinal cord. Spina bifida is the most common type of ONTD. It occurs when the spine does not close properly, leaving the spinal cord exposed. Babies born with spina bifida may have mild to severe physical and intellectual disabilities.
The Sequential Screen looks at four pregnancy hormones: free beta hCG (fbhCG), alpha-fetoprotein (AFP), inhibin-A, and unconjugated estriol. A nurse will take a small blood sample and send it off to the lab for analysis.
Abnormally high or low levels of these hormones may indicate a trisomy disorder. They may also be a sign of an ONTD such as spina bifida or anencephaly, a defect in which part of the skull and brain don't form.
The Quad Screen
The Quad Screen is a stand-alone test that can be performed during the second trimester, anytime between 15 and 21 weeks, 6 days. It's an option for those who didn't have the first part of the Sequential Screen performed. The Quad Screen looks at the same four hormones as the second part of the Sequential Screen., and tests for your baby's risk of Down syndrome, trisomy 18, and ONTDs.
The AFP Test
The Alpha-Fetoprotein (AFP) Test primarily looks for your risk of having a baby with an ONTD. You can take this prenatal screening test beginning at week 15 of your pregnancy. A nurse will take a small sample of your blood, which is then analyzed by a lab. The test looks at your levels of AFP, and a genetic counselor will help you understand the results.
The AFP Test also looks for other risks during your pregnancy including chromosomal disorders, low birth weight, preeclampsia, ventral wall defects, fetal loss, and stillbirth. These are frightening terms, but remember, the test just analyzes your risk and doesn't make a diagnosis.
Remember, your OB is there to discuss any questions or concerns you may have at every point in your pregnancy, not just the 15-week mark. Talking with your physician will help you understand your test results and your baby's development and will go a long way in easing your mind.
To learn more about prenatal screening tests and other pregnancy-related issues, please visit our website. At NTD Eurofins, we're here to help!
—
References
- Felman, A. (2018). Your Pregnancy at 15 Weeks. Medical News Today. https://www.medicalnewstoday.com/articles/300465
- Lewis, R. (2020). What to Know About Bleeding Gums During Pregnancy. Healthline Parenthood. https://www.healthline.com/health/pregnancy/bleeding-gums-pregnancy
- Miller, S. G. (2016). Morning Sickness Really Is a Good Thing. LiveScience. https://www.livescience.com/56255-morning-sickness-miscarriage.html
- NTD Eurofins. (n.d.). AFP Test (for ONTDs). NTD Eurofins. https://www.ntd-eurofins.com/patients/screening-options/prenatal-screening/afp-test-for-ontds/
- NTD Eurofins. (n.d.). Prenatal Timeline Tool. NTD Eurofins. https://www.ntd-eurofins.com/patients/screening-options/testing-timeline/?week=15
- NTD Eurofins. (n.d.). Quad Screen | Fß. NTD Eurofins. https://www.ntd-eurofins.com/healthcare-providers/screening-options-overview/prenatal-screening/quad-screen-fs/
- NTD Eurofins. (n.d.). The Sequential Screen | Fß. NTD Eurofins. https://www.ntd-eurofins.com/healthcare-providers/screening-options-overview/prenatal-screening/sequential-screen-fs/
- University of Rochester Medical Center. (n.d.) Open Neural Tube Defects (ONTDs) in Children. University of Rochester Medical Center. https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=160&contentid=90
- WebMD. (2018). Gain Weight Safely During Your Pregnancy. WebMD. https://www.webmd.com/baby/guide/healthy-weight-gain#1
- What to Expect. (2019). 15 Weeks Pregnant. What to Expect. https://www.whattoexpect.com/pregnancy/week-by-week/week-15.aspx
The information provided represents the general opinions of NTD Eurofins and is not intended to be used as specific advice for any one individual. Individuals should always consult with a physician to obtain specific advice and to receive answers to any and all questions or concerns related to health, wellness, pregnancy, and birth.
Pursuant to applicable federal and/or state laboratory requirements, Eurofins NTD, LLC has established and verified the accuracy and precision of its testing services. Tests are developed and performance characteristics determined by Eurofins NTD, LLC. The methods and performance characteristics have been reviewed and approved by the New York State Department of Health.
We use cookies to understand how you use our site and to improve your experience. Please refer to our Terms and Conditions and Privacy Policy for more information about cookies we use and how we protect your privacy.