The infant is paving its way to doing some major development in the forthcoming few weeks. By 16th week of pregnancy the infant would be able to hold its head a bit straighter, and its eyes finally move into the final posture in the front of the head and, on the other side, ears are getting the same, and now the infant focuses its attention on complicated blood circulation that matters a lot. The infant's heart pumps 25 quarts of blood every day. Well, this is not bad at all, especially for the one that is smaller than the grapefruit!

The infant starts growing hair and continues to do so as its mother continues her pregnancy week by week. The mother will not be able to tell which color hair the unborn has until after birth and even then the newborn's hair might fall out and alter colors altogether at least once in the first few weeks of its new life! The same goes true for the infant's eye color. Some infants are born with blue eyes those over the times, turn darker during first few months of life!

By pregnancy week 16 the umbilical cord now firmly attaches to the infant's abdomen as well that provides important nutrients to the little one. At this juncture the infant's legs start growing longer as compared to the arms! The mother should no longer get a discernable waistline by pregnancy week 16. Well, nothing to worry about! It comes back some day and most of the women enjoy in this blossoming roundness. While the mother is not huge by any stretch of the vision, she is beginning to look more and more pregnant each day passes. By now, the mother may consider shopping for some maternity dressings, though she might not be able filling them out for a couple of weeks more. Some shops offer maternity clothes in different sizes and patterns that can adapt second vs. third trimester infants.

The maternity size generally corresponds with the sizes mother were before she got conceived, provided she has not gained any unusual amounts of weight. Maybe, the most exciting period of pregnancy is feeling the infants flickering. The mother may be able to make out tiny movements by pregnancy week 16. Many pregnant women have stated this experience as akin to butterflies flickering away in the abdomen at pregnancy week 16 though some may feel this earlier. At first the mother may dismiss such feeling as gas, but be aware, the unborn is actually swimming inside its warm swimming pool in the womb.

Even at pregnancy week 16, not all women experience their infant's flickering, so one should not panic if she doesn't recognize the infant’s movements during 16th week of pregnancy. It might take some more weeks before the mother feels the first fluttering of the infant. If this is not women’s first delivery or pregnancy, she is more susceptible to feel movements earlier in the pregnancy.

During some time between weeks 16-18 the mother undergoes an alpha-fetoprotein test (AFP). AF is a protein which comes from fetal urine and occupies in the amniotic fluids. The health care provider can measure the amounts of AFP in the amniotic fluids by a simple blood test. High levels of AFP may indicate some problems with the fetus that includes elevated risks for spinal cord issues the two most common of what include a condition known as Spina bifida. This condition involves the central nervous system or it can also result in other condition Down syndrome that can involve an abnormal number of chromosomes. An abnormal test doesn’t reflect that there has been something wrong with the infant; it simply means to the health care provider that something may be awry. If the AFP test turns back positive the health care provider might order an amniocentesis or ultrasound for confirming diagnosis.