The second trimester lasts and everything goes much easier. Toxemia and mood swings are not as much expressed. The baby is growing faster while your belly becomes rounder more every day. The tests, that you will submit to, will give you the assurance that everything is fine with your baby. It’s the time of serenity for you. But you need be careful about your nourishment and gaining weight as well as the control of your blood pressure.
Your Baby At the 16th Week
Your little baby is now about 12 cm long from head to bottom and weighing about 100 g. That means he/she has doubled the weight in the last 2 weeks. He/she developed in every way. Turning the head and holding the neck straight is a common activity for your baby by this age. Most of the activities are developed as he steps in the rapid growth stage. That means that he will mostly grow from now on, although there are still some things that will change till his birth. He will gain the fat underneath the skin while becoming chubby over the upcoming weeks. Blood composition has been completely formed. Blood type and the Rhesus factor can be already determined.
At the 16th week, your baby has already learned to breathe. He/she inhales and exhales small amounts of amniotic fluid. That helps to develop the lungs. It isn’t still the real breathing process; because your baby is supplied with oxygen through the umbilical cord via mother’s blood, as well as it will be up to his birth. Heart of your baby works intensively. Heart rate is about 150 bpm. Also, his/her liver begins performing its digestive function. The kidneys work actively by now, so your baby pees one time per hour.
He can now hear and recognize your voice as well as feel the light through your belly.
Ultrasound At the 16th Week
Now you already know the procedure at the ultrasound examination. It has become a common examination for you. But baby’s performing is more and more exciting; due to his/her activity development which is massively distinctive during the last three weeks. Because the nervous system is making new connections to the muscles and reflexes are being developed, his/her facial muscles are working more precisely. So, it is possible to see your baby frowning, squinting or even smiling or sucking his/her thumb. Baby’s bones are hardened, those kicks will get stronger and stronger, but you can’t feel that yet unless you are pregnant with the second baby. If so, you have all the chances to feel the fetal movements. He/she often plays using new skills, usually playing with the umbilical cord as well as trying grasp with his/her tiny hands.
Now you can find out the gender of the baby, whether you will be having a boy or a girl when you decide to have a 3D ultrasound examination. By doing the 3D ultrasound you would be able to see all of this more clearly.
Screening Tests At the 16th Week
At this stage, a doctor may send you for a blood test named Quad screen that will assess some chromosomal abnormalities. The Quad screen is a second-trimester screening that assesses the risk of a baby being born with Down syndrome, Trisomy 18, or open neural tube defects. Alpha-fetoprotein (AFP), Total beta-human chorionic gonadotropin (total ß-hCG), Unconjugated Estriol (uE3), Inhibin-A are substances measured in the blood serum.
It is recommended to get done between 15th and 20th week of pregnancy. The Quad screen isn’t a 100% accurate and may come with false negative or false positive results. It has an approximate accuracy rate of 80%-85% for Trisomy 21 and Trisomy 18. Depending on the results of the Quad screen and the sonogram, further diagnostic testing such as amniocentesis may be recommended. It analyzes the amniotic fluid that shows a picture of your baby’s chromosomes named the karyotype. The karyotype will show malformed chromosomes, as well as the normal ones.
Your doctor will locate a pocket of amniotic fluid by an ultrasound and he must be sure that it is a safe distance from both baby and the placenta. Your doctor will clean your belly with antiseptic fluid, then guide a long, thin hollow needle into your stomach, through the abdominal wall, and into the fluid sac. About 30 ml of amniotic fluid will be drawn into the needle. It is enough for the analysis. As you can see, amniocentesis is an aggressive procedure. But you might have to opt for an amniocentesis if you are 35 years old or more on your due date, and if your nuchal scan or your first-trimester screen, or your recent quad screen have results outside of the normal range. All is the risk of having a child with a chromosomal abnormality and it rises with your age. Amniocentesis is recommended between the 14th and 20th week of a pregnancy.
You At the 16th Week
Your hormonal status has been established. You are full of energy, but calm and tranquil even though you feel light dizziness and fatigue after some activities. Anxiety is gone as well as the preoccupation about miscarriages. Your appetite is better; therefore, you can gain a little weight. Gaining from 2.5 to 5 kg is normal at this stage of your pregnancy, but be careful about gaining more than normal, since obesity can be a risk factor for some disorders during the pregnancy. Your belly is noticeably now. The strip, which leads from the navel to the pubis, is darker now. Pigmentation may occur even on the forehead, cheeks, nose, and around the eyes. These changes will disappear upon completion of the pregnancy.
The breasts are bigger as well and nipples are getting darker and wider while you can feel a certain tension in them.
If your pregnancy is normal, you may not feel any pain or malaise. If you notice something like that, you should consult your doctor.