Welcome to week 10. 30 more weeks to go!
Your little grape-sized baby has grown to the size of a kumquat this week. Your baby measures about 1.3 inches (3.2 cm) from crown to rump. They weigh 1.2 ounces (35 grams).
Your baby is looking cuter and more human by the day. Tooth buds are forming underneath the gums. Bones and cartilage are forming. Hair is even starting to sprout. Start talking because your little one can hear you now since the inner workings of their ear are complete. Neurons appear at one end of the spinal cord, and the basic divisions of the brain are present. If your baby is a boy, he is already producing testosterone. In the next three weeks, your baby will double in size.
If you have been able to hide the bun in your oven until now, you may not be able to hide it much longer. Your uterus has increased from about the size of a small pear to the size of a grapefruit. If you are not quite ready for maternity clothes, you can opt for bottoms with forgiving elastic waistbands or go for low-rise waistlines that sit below your belly. Please do not suffer in uncomfortable clothes.
You may also notice more visible veins on your chest and abdomen. These can be especially obvious if you have fair skin. Your network of veins has expanded to carry the increased blood supply needed to nourish your growing baby. As the weeks go on, you may also notice that the veins in your hands and feet also seem larger and more prominent. This is normal, and eventually, they will disappear.
Your doctor or midwife may offer several prenatal tests after week ten. Check out Your Guide to Prenatal Testing for a breakdown of testing options.
The first-trimester screen is a noninvasive test that combines a blood test for the mom with an ultrasound evaluation of your baby. This test is between 10 weeks and 13 weeks, six days, and can identify risk for specific chromosomal abnormalities, including Trisomy-21 (Down syndrome). A study published in the New England Journal of Medicine states that the combined accuracy rate for the screen to detect chromosomal abnormalities is approximately 85%, with a false positive rate of 5%. It is crucial to remember that a positive result on a screening test does not equate to having an abnormality; it indicates that you may want to discuss further testing with your care provider.
Results from a first-trimester screen can also be combined with a quad screen test in the second trimester in an integrated screening test. Combining results from both tests has a higher detection rate for Down syndrome than either of the two tests alone.
You can take a cell-free DNA (cfDNA) test as early as ten weeks. This test uses a blood sample to look for fragments of your baby’s DNA freely floating in your bloodstream. A cfDNA test can detect many more chromosome abnormalities than the traditional screen tests, plus your baby’s sex and Rh factor. Since the cell-free DNA test is less accurate for low-risk mothers, the Society for Maternal-Fetal Medicine and the American College of Obstetricians and Gynecologists do not recommend this test for low-risk women.
This week also opens the window for a chorionic villus sampling. This is a diagnostic test to determine if a baby has chromosome abnormalities like Down syndrome and genetic disorders like cystic fibrosis. A CVS is available between 10 to 13 weeks. The most common method is transcervical, where an ultrasound guides a thin catheter through the cervix to your placenta. The other method is a transabdominal approach, where an ultrasound guides a long thin needle through the abdomen to your placenta. The level of accuracy is high, at 98-99%, but this test does not measure the severity of these disorders.
Tip for Dads and Partners
By week 10, more prenatal tests are available. Taking tests can create a lot of anxiety for mom. This is a big reason why you should make it a priority to attend prenatal appointments. Getting less than ideal results back can be difficult, especially if mom is alone in that appointment. You being by her side can be a tremendous support and comfort.
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