Week 16

My Baby's Development

Your baby now measures about 4.7 inches (12cm) in length from crown to rump and weighs about 3.9 ounces (110g). Your baby can hold his or her head erect. The development of the muscles on face allows it a variety of expressions (such as squinting and frowning).

My Body

Between weeks 16 and 18, your health care provider may request a maternal blood screening test (known as "triple marker" test or "triple screen"). In the mother's blood, it measures the pregnancy hormones (hCG and estriol) and the levels of alpha-fetoprotein (AFP), a protein produced by the fetus. When the level of an additional substance (inhibin-A) is also measured, the test is called a quadruple screen. These tests can tell moms whether their babies are at risk for (not whether they have) neural tube defects (such as spina bifida or chromosomal abnormalities such as Down syndrome). Out of every 1,000 women who take these tests, about 50 women will have abnormal results. Only 1 or 2 women will actually have babies with a problem. Consult your health care provider about the risks and advantages of these tests.