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You’re 12 weeks pregnant and at the end of your first trimester, Mom! Read on for why this week is such a big marker in your pregnancy journey.
How Big is Baby?
Growing so fast, but still so tiny! Baby is a little over 1 ½ inches this week.
What’s New with Baby?
Your little one has grown so much this first trimester! By now, baby’s head has developed into a rounded shape. Many of their organs are in working order—the kidneys are making urine and the pancreas is making insulin. And baby’s limbs, hands and feet are taking shape too—the cartilage is forming but it won’t harden into bones for a few more weeks, according to the American College of Obstetricians and Gynecologists.
What’s New with Mom?
This week is big milestone in your pregnancy: After this point, the risk for spontaneous miscarriage decreases significantly, explains Dr. Leen Al-Hafez, a maternal-fetal medicine specialist at UT Southwestern Medical Center. Lots of moms-to-be choose this time to share the news that they’re pregnant. Not ready yet? No rush, Mom.
Leen Al-Hafez, M.D., is an assistant professor in the Department of Obstetrics and Gynecology at UT Southwestern Medical Center. She specializes in diagnostic genetic procedures and fetal anomalies.
Heather Fisher, M.S., is a certified genetic counselor in the Department of Obstetrics and Gynecology’s Division of Maternal-Fetal Medicine at UT Southwestern Medical Center. She specializes in prenatal and preconception genetic counseling.
Common symptoms this week include nausea, vomiting, fatigue, dizziness, constipation, and increased urination.
Fun Fact
Fingernails are now beginning to grow on those little hands! Baby’s nails, just like yours, grow slowly from the nailbed. They won’t reach the tip of their fingertips until you’re well into your third trimester.
What to Know About Genetic Testing in Pregnancy
Your healthcare provider may offer a variety of screenings and tests in your pregnancy to help determine your baby’s risk for—or even diagnose—certain genetic disorders before birth. These tests are offered for all pregnancies but are always optional, so factor your personal beliefs and values into the decision.
“A woman might consider genetic testing to provide more information on whether the baby is affected by a chromosomal abnormality, such as Down Syndrome,” explains Al-Hafez. “The different options include genetic screening or diagnostic testing. A genetic screening test is a simple blood draw from the mother that is used to assess whether the baby is at high risk or low risk for a chromosome problem. A diagnostic test involves having to sample some cells from the placenta (chorionic villus sampling or CVS) or taking a sample of the fluid around the baby (amniocentesis) in order to definitively determine whether the baby is affected with a chromosome problem.”
One genetic screening test you may consider is called non-invasive pregnancy testing, or NIPT. Typically done after 10 weeks, this involves a simple blood draw “to assess whether the baby is at high risk or low risk for Trisomy 21 (Down Syndrome), Trisomy 13 (Patau syndrome), Trisomy 18 (Edward syndrome), and sex chromosome abnormalities (such as Turner or Klinefelter syndrome),” says Al-Hafez. The NIPT is a screening only—it is not diagnostic, and it does not test for all genetic conditions. And it does not test for physical birth defects, for which an ultrasound is used.
If you have an abnormal genetic screening result, abnormalities noted on ultrasound or a family history of a chromosome or genetic disorder, your doctor may advise CVS testing. This is typically done between weeks 11 and 13 and can definitively test for the same chromosomal abnormalities as NIPT, as well as other chromosomal and genetic syndromes.
Amniocentesis is the second way to perform diagnostic genetic testing in pregnancy. Performed after 16 weeks, it involves taking a sample of the amniotic fluid from around the baby.
If you have questions or want to discuss genetic testing further, ask about genetic counseling. “Genetic counselors are available and very helpful with explaining a patient’s genetic testing options, helping them understand their genetic testing results, and guiding them through the genetic screening/testing process,” says Heather Fisher, a certified genetic counselor in the Department of Obstetrics and Gynecology at UT Southwestern Medical Center. “All genetic testing is optional during pregnancy. Genetic counselors help patients make decisions about what genetic information they are interested in testing for or not, and how having that information might inform the rest of their pregnancy or reproductive decisions in the future.”
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This blog is provided for educational and informational purposes only and does not constitute the provision of medical advice or professional services. This blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
The above article was written by DFWChild editor Amanda Collins Bernier with information provided by UT Southwestern Medical Center as part of their sponsored content.
