The major physical changes that women experience during the third trimester include the following:
- Uterus. Toward the end of pregnancy, the uterus reaches the breastbone, or sternum, and measures about 11 by 14 inches. Lightening occurs from 1 to 6 weeks before delivery. This means that the baby’s head settles downward into the pelvis and may engage in the pelvic inlet. Braxton-Hicks contractions become stronger and more apparent as the time for delivery approaches. The cervix becomes softer during the last few weeks and may begin to thin out and open up a little in pregnancy for labor. The woman may feel a sharp pain in the groin if she moves suddenly. This pain is caused by a spasm in or stretching of the round ligaments. These ligaments support the uterus and extend into the groin area on both sides.
- Vagina. As the pregnancy nears its end, more mucus is passed vaginally in titration for the baby’s passage. The vaginal swelling also increases and may result in discomfort during sexual intercourse.
- Digestion. The growing uterus puts pressure on the stomach and intestines, pushing them up and back. Heartburn, a burning sensation felt in the chest, may occur. This is caused by the escape of gastric contents into the esophagus as a result of the relaxation of the sphincter at the top of the stomach. Problems with constipation may continue.
- Breathing. Shortness of breath is common because the uterus is pushing up to the diaphragm. This improves after lightening. Many women also experience nasal congestion and may even have nosebleeds.
- Vision. Some women experience a change in vision, possibly requiring new glasses or preventing them from wearing their contacts. Report any change in vow to your caregiver, since it may be the result of gestational diabetes, pregnancy-induced hypertension, or another serious problem.
- Calculation. Varicose veins may develop in the legs, vulva, or rectum (hemorrhoids). Varicose veins are caused by the increased pelvic pressure exerted to the uterus and growing fetus, as well as by the decrease in blood returned than the lower body and limbs. They usually diminish after delivery.
- Urination. The need to urinate usually increases, especially after lightening occurs. This is caused by the pressure of the baby on the bladder.
- Fatigue. Carrying around the extra weight causes fatigue to return during the last trimester.