Are you interested in learning about the physical changes, symptoms, baby development, and more during your Pregnancy Week 16? We provide a complete guide in this article.

Today, we will discuss pregnancy week 16, week by week. The 16th week of pregnancy marks a crucial milestone in fetal development, as the fetus experiences significant growth, more than doubling its weight in the coming weeks. This period of rapid growth is often referred to as the growth spurt.

Fetal Development Week by Week During Pregnancy
Fetal Development Week by Week During Pregnancy

Baby’s Development at Pregnancy Week 16

The 16th week of pregnancy falls within the third week of the second trimester. At this stage, the pregnancy is in the fourth month. By 16 weeks, the fetus begins to resemble a human baby in appearance. However, it appears thin because it has not yet developed fat stores, and its skin remains translucent, allowing the visibility of blood vessels underneath.

By this time, the fetus’s spine and back muscles become more organized. As a result, the fetus can straighten its neck and head more than before. While moving inside the womb, it may even touch the umbilical cord or the amniotic sac. If anyone thinks that holding onto the umbilical cord this way might disrupt necessary blood flow, remember that the fetus will release it before anything like that happens.

The size of the baby in the womb can be compared to a pear this week. At this point, the height of the embryo is approximately 4.57 inches or 11.6 centimeters, and it weighs about 3.53 ounces or 100 grams approximately. As we reach week 16 of pregnancy, several changes occur in the natural development of the fetal limbs.

During this week, the fetus’s eyes can move slightly left and right, and they become sensitive to light, although both eyes remain closed most of the time. The small earlobes of the fetus are now almost fully developed. So, if you speak to the fetus in the womb at this time, it might hear you. Research has shown that during pregnancy, if a mother repeatedly plays a specific sound, the same sound might help the baby recognize it after birth.

The fetal heart starts pumping about 23 liters of blood daily at this time. As the fetus grows, the amount of blood pumped increases, reaching approximately 1798 liters by about 40 weeks.

Under the fetus’s nose, the creation of the filtrum occurs, forming a bow-like shape on its upper lip. The umbilical cord is now fully developed, typically consisting of one vein and two arteries, providing the fetus with necessary nutrients and oxygen. This cord is encased in a gelatinous substance called Wharton’s jelly. Additionally, the fetal circulatory and urinary systems begin their respective functions. Nerve development continues as well. If the fetus is female, millions of eggs may start forming in her ovaries from now on.

comprehensive guide to pregnancy week 16
comprehensive guide to pregnancy week 16

Physical Changes and Symptoms of Week 16 of Pregnancy

In the pregnancy week 16, the mother’s uterus continues to grow larger, weighing approximately 8.5 ounces or 0.25 kilograms more. Along with this, the placenta also grows, and the mother’s body produces more amniotic fluid, which protects the fetus from various infections and shocks in the womb. During this time of pregnancy, the uterus surrounds the fetus with approximately 7.5 ounces or 0.2 kilograms of amniotic fluid.

Many mothers, especially those who have been pregnant before, may feel slight movements from the baby at this time. This is called quickening. However, if this is your first pregnancy, you may not recognize the baby’s movements until around 18 to 20 weeks. Nevertheless, whether you recognize it or not, the fetus is now surrounded by amniotic fluid and is regularly moving around.

During the 16th week of pregnancy, both the fetus’s weight and the mother’s weight continue to increase. If someone doesn’t notice any change in the size of their belly, there’s usually no cause for concern. Diastasis recti is when an abnormal gap forms between the abdominal muscles, visible as wavy lines on the skin, usually seen around the belly button area.

However, during pregnancy, diastasis recti can occur in the midline or in the vaginal area. Varicose veins may cause itching or discomfort, but these are usually not significant risks. If medical attention is needed, it can often wait until after childbirth. In some cases, diastasis recti can lead to blood pooling in the veins of the abdomen, known as superficial venous thrombosis. When this happens, the veins become swollen and warm to the touch, and the surrounding area may turn red and feel painful. If these symptoms are observed, it’s important to seek prompt medical advice from a specialist.

During pregnancy, the body experiences about a 30 to 50 percent increase in blood flow. This increased blood flow can give the mother’s face a brighter appearance. Additionally, due to hormone production in the mother’s body, oil glands may work overtime, resulting in a shiny complexion. This is often referred to as pregnancy glow. Leg cramps usually begin in the second trimester of pregnancy and may increase in intensity as the pregnancy progresses, coinciding with the growth of the mother’s belly. Cramps may occur more frequently in the evening, but they are generally more severe at night. The increase in size of the uterus during pregnancy and the weight gain in the body can put extra pressure on the blood vessels in the legs, causing them to constrict and slowing down blood circulation from the feet to the heart. As a result, blood flow in the legs slows down, leading to cramps in the feet.

During pregnancy, most mothers experience heartburn—it’s a very common and natural physiological phenomenon. This heartburn can occur solely in the chest at times or solely in the throat, or in both places. Research has shown that problems tend to be more prevalent during the birth of the first child. Many experience problems during pregnancy similar to those of their first time. Although heartburn during pregnancy is a common symptom among normal occurrences, it doesn’t have any significant harmful effects, yet it can still be a cause of considerable discomfort. Heartburn during pregnancy and its related gas issues usually begin in the second or third trimester, but in some cases, it can start earlier. This problem can persist throughout the entire duration of pregnancy.

During pregnancy, the main reason for constipation is the increase in the level of progesterone hormone. Due to the progesterone hormone, the muscles in the mother’s body become relaxed. As a result of the relaxation of the digestive system muscles, mothers may experience difficulty digesting food, leading to constipation. Iron supplements are often advised to most pregnant women, and as a side effect of these supplements, constipation can occur.

Around the 16th week of pregnancy, maternal gastrointestinal symptoms tend to decrease, which can make sleeping problems for mothers quite normal. Consequently, mothers may feel more energetic. However, sometimes during this time, mood swings can occur. Between weeks 15 to 20 of pregnancy, the uterus of the mother becomes significantly larger, which can create pressure on the veins. If the mother lies flat, it can hinder blood flow, leading to compression of the inferior vena cava vein, which can cause discomfort.

After passing the 16th week of pregnancy, lying on your back for a long time may feel like losing consciousness because the weight of the baby puts pressure on all the veins at that time. Sleeping on your back during pregnancy, especially lying on the left side, is considered the safest. Lying on the left side is good for your baby because it provides nourishment and facilitates the placenta to easily deliver nutrients to the baby.

However, regardless of how comfortable you feel, it’s essential to position yourself for sleep in a way that not only supports your head but also allows your belly and legs to rest equally comfortably. Using a pillow under your back and hips can help alleviate some of the various discomforts of pregnancy and provide a bit of relief for a more peaceful sleep.

Read Also: Pregnancy Week 15.