The second trimester of pregnancy consists of weeks 13 to 24. Many women consider this trimester to be easier than the first, in part because the moodiness of early pregnancy sometimes lessens. Although many symptoms, such as nausea and fatigue, begin to disappear, a number of more evident changes will emerge. Common changes and symptoms of the second trimester include:

• Expanding abdomen. As pregnancy progresses, the uterus becomes heavier and expands to create room for the fetus. By the 12^th week of pregnancy, the growing uterus may cause a woman’s abdomen to slightly protrude. In addition, women may gain up to 4 pounds (1.8 kilograms) a month until the end of pregnancy. The uterus will continue to enlarge throughout pregnancy as the expectant mother gains weight and the fetus continues to grow. By the 20^th week of pregnancy, the expanding uterus will extend to the level of the navel.
  
  
• Continued breast growth. As pregnancy progresses, the breasts begin to prepare for breastfeeding. Estrogen and progesterone stimulate the milk producing glands in the breasts to enlarge. A small amount of fat may also accumulate in the breasts. As a result, there may be as much as 1 pound (454 grams) of breast tissue, and the woman’s bra size may increase up to two cup sizes. The breasts may continue to be tender during this period of the pregnancy. Pregnant women may improve their comfort by wearing proper fitting and supportive bras.
  
  
• Tingling. Many woman experience tingling and numbness in the fingers during pregnancy. This is due to swelling of tissues in the narrow passages in the wrists. These sensations often disappear after delivery.  
  
  
• Itchiness. Many women experience itchiness as their pregnancies progress. This is due to hormones and stretching skin in areas such as the abdomen. Some women also develop itchiness and redness on their palms and the soles of their feet. These symptoms usually vanish after delivery. Women may benefit from moisturizing and using soaps for sensitive skin. In addition, women should avoid taking hot showers or baths, which can cause dryness. Since heat rash can worsen itching, women should also avoid becoming overheated. Women experiencing itching in combination with nausea, vomiting, loss of appetite, jaundice (yellowing of the skin and whites of the eyes) or fatigue should contact their obstetrician-gynecologist (ObGyn) immediately. This may be a sign of cholestasis, a condition that indicates a serious liver disorder.
  
  
• Nasal problems. During pregnancy, the lining of the nose and airway may swell as more blood flows to the mucus membranes. This can result in restricted airflow. In addition, hormones affect the tissues of the throat, mouth and nose. As a result, pregnant women may experience snoring, congestion and nosebleeds. Women may benefit from drinking water, sleeping on their sides and using a cool mist humidifier in their bedroom. Although these conditions are typically harmless, women should contact their ObGyn when nosebleeds occur often or continue longer than a few minutes.
  
  
• Dizziness. A woman may experience dizziness, lightheadedness or fainting at any time during her pregnancy. These symptoms may be especially noticeable early in the second trimester. This is due to the additional blood heading toward the uterus and legs and the dilation of blood vessels in response to hormones. Occasional dizziness may occur until the volume of blood expands to fill the vessels. Women may benefit from avoiding prolonged standing, lying on their left side (to relieve pressure on blood vessels) and rising slowly after sitting or lying down. In addition, women should avoid sitting or standing in one position for an extended period of time.
  
  
• Leg and foot cramps. It is common for pregnant women to experience leg cramps during the second and third trimesters. Frequently occurring at night, these cramps may result from the pressure the uterus applies to the veins that return blood from the legs. Changes in circulation and stress on the leg muscles due to carrying additional weight may also be to blame. In addition, cramps may also be due to changes in the way the body metabolizes (processes) calcium. Women may benefit from stretching the affected muscle or walking, and consuming an adequate amount of calcium.
  
  
• Vaginal discharge. Pregnant women may produce a thin, white vaginal discharge (leukorrhea). Consisting of cells from the vaginal lining and normal vaginal moisture, this type of discharge is not a cause for concern although the amount may be greater than before pregnancy. However, women should contact their ObGyn if they produce a strong-smelling green or yellowish vaginal discharge or any vaginal discharge accompanied by redness, itching or irritation. These symptoms may indicate a vaginal infection.
  
  
• Bleeding gums. The increased blood circulation experienced during pregnancy can cause the gums to soften. As a result, a woman may have minor bleeding when she brushes her teeth or flosses. Pregnant women may benefit from flossing daily and brushing with a soft bristled toothbrush. Women experiencing persistent bleeding from the gums should contact their dentist.
  
  
• Braxton Hicks contractions. During the second trimester, the uterus may begin flexing to build up strength. As a result, a woman may feel contractions in her lower abdomen and groin. These contractions, known as Braxton Hicks contractions, are usually painless and unpredictable. Women should immediately contact their ObGyn when contractions become painful or regular. This may be a sign of premature labor.
  
  
• Glowing skin. Pregnant women may experience a “healthy glow” resulting from the increase of blood circulation. In addition, some areas of the skin may continue to increase in pigmentation, including the nipples.

Major developments in the fetus continue to occur during this trimester, including the complete formation of many chief organs, such as the heart. In addition, the mother may be able to feel the fetus move.

Major fetal developments during the second trimester include:

Week 14

• The fetus’s gender can often be identified during an ultrasound
  
  
• The fetus is able to hear

Week 16

• The fetus’s fingers are able to grasp
  
  
• The fetus moves more vigorously, and the mother is able to feel it
  
  
• The fetus’s body begins to fill out as the result of fat depositing beneath the skin
  
  
• Hair emerges on the head and skin, including eyebrows and eyelashes 
  
  
• The placenta (the organ that connects the fetus to the uterus to provide oxygen and nutrients and to remove waste products) is completely formed

Weeks 23 to 24

• The fetus is potentially capable of surviving outside the uterus