The second trimester of a pregnancy is often the easiest and most comfortable, but that doesn't mean that a woman doesn't experience many physical changes during this time. The second trimester is referred to as the "honeymoon of pregnancy". Most of the unpleasant symptoms that occur in the first trimester have ceased, like the morning sickness, but Mom isn't so big as to be uncomfortable. This is actually the time that most pregnant women choose to go on vacation before the baby arrives.
The uterus continues to grow in the second trimester, and by the 20th week, has reached the height of Mom's navel. The risk of miscarriage drops significantly during the first trimester, and after the 20th week, which is considered the halfway point of the pregnancy, the loss of a baby is no longer considered a miscarriage, but a stillbirth. After about the 24th week, every attempt will be made to save the baby should Mom go into labor, though this can vary. Mom will also begin to feel her baby move during this time, which is one of the greatest joys of being pregnant.
Breasts continue to grow as well during the second trimester. Some women even find it necessary to purchase a larger size bra or use a sleeping bra, which is similar to a sports bra for bed time. Women may also notice darkening of the areola and nipples, and that the areolas and nipples have become enlarged. Some women also find that their nipples have become harder. All of this happens in preparation for breastfeeding once the baby is born.
As the baby continues to grow and the uterus moves upward, Mom's heart enlarges and moves slightly. The upward pressure causes the heart to move slightly to the left and the heart enlarges to accommodate the increased blood volume that is seen throughout pregnancy. By the end of the pregnancy, the mother's blood volume has increased by up to 50 percent. The heart returns to normal size and position shortly after birth. Increased pressure on the blood vessels in the lower part of the body leads to swelling in the legs and feet. To relieve swelling, an expectant mother can lay on her left side with her feet slightly elevated, or she can try compression stockings.
As the uterus continues to grow, the pressure on the bladder continues to increase. Urinary tract infections become more common because the growing baby can put pressure on the ureters, the tubes that transport urine from the kidneys to the bladder, causing blockages. During the second trimester, kidney function reaches its maximum level. The kidneys will continue to function at their maximum capacity until after delivery. The growing baby also places pressure on the inferior vena cava, the major blood vessel to the lower part of the body, when the mother is laying down, reducing kidney function. The reason that women are told to lay on their left side during pregnancy is to minimize the pressure on this vital blood vessel.
A woman will breathe faster during the second trimester of pregnancy. The body has to work harder to keep the level of carbon dioxide in the blood down and the increased upward pressure on the lungs from the growing baby makes that a little harder. Most women won't notice much of the respiratory changes that occur, although some may get winded much easier if they exert themselves.
The second trimester is when pregnant women begin to experience heartburn. The reason for this is that the growing uterus begins putting upward pressure on the stomach. When combined with a relaxed esophageal sphincter, caused by those pesky pregnancy hormones, the result is stomach acid forced up the esophagus, otherwise known as heartburn. Most over-the-counter antacids are safe during pregnancy, but Mom should talk to her doctor for recommendations because some can be rather high in sodium, which can cause swelling.
During the second trimester, Mom may notice many skin changes. Pregnancy masking, called melasma is the darkening of the skin on the forehead and cheeks, looking somewhat like a mask. Also common is the development of the linea nigra, which is a dark line from the navel all the way down the abdomen. Stretch marks may also develop around the abdomen and other parts of the body. While there is nothing Mom can do to prevent these skin changes, they are temporary and most will go away after the pregnancy.
Hormones continue to fluctuate during the second trimester. Mom may notice an increase in perspiration and mood swings. During the second trimester, Mom may also develop gestational diabetes, which can lead to problems in the pregnancy if not controlled. Unlike other types of diabetes, however, gestational diabetes goes away after birth. Mom will have to be tested for gestational diabetes during the second trimester.
As the pregnancy progresses, particularly at the end of the second trimester, the mother may begin to notice some irregular pains in her lower abdomen. These are called Braxton Hicks contractions and are nothing to be concerned about. Round ligament pain is also common as the ligaments struggle to support the increasing size of the uterus. Backaches are also quite common due to Mom's growing belly and shifting center of gravity. Maternity massages can help substantially relieve discomfort and is safe for most women.
As always, if a woman notices any bleeding of fluid leaking from the vagina, or has contractions that occur at regular intervals she should call her doctor. Other warning signs include fever, dizziness or fainting and decreased fetal movement.
The second trimester really is the best part of the pregnancy, so Mom should enjoy every moment of it because it will be over before she knows it.