The third trimester of your pregnancy spans from week 26 to the birth of your baby. Although your due date marks the end of your 40th week, a full-term pregnancy can deliver between the 37th and 42nd weeks of pregnancy. During this final trimester, your baby grows larger and the body organs mature. The baby moves frequently, especially between the 27th and 32nd weeks.
At the end of the third trimester, your baby will most often settle into a head-down position in your uterus, preparing for birth. This position will likely cause you some discomfort as you get close to delivery.
Your third trimester is a time of rapid weight gain for your baby. The baby's increasing size and the many changes your body goes through to prepare for labor and delivery may cause the following to occur.
Many physical changes occur during your third trimester. While most of these changes are to be expected, you should call your doctor if you experience any of the following symptoms.
The American Academy of Pediatrics recommends that all pregnant women be screened for group B strep bacteria between 35 and 37 weeks of pregnancy. This type of bacteria is carried by 10% to 30% of pregnant women and is found most often in the vagina and the rectum. Your doctor will talk with you about the risks this bacteria poses to you and your baby and how to prevent them.
Because you can pass the group B strep bacteria to your baby during pregnancy, delivery, or after birth and a baby infected with group B strep may end up with blood, lung, brain, and spinal-cord infections, it is especially important to be screened for this type of bacteria.
The group B strep test involves taking a culture from your vagina, perineum, and rectum during pregnancy. The results of the culture are available within two days. If your test comes back positive, your doctor will recommend that you take antibiotics during your labor to minimize the risk of passing group B strep to your baby.
During your third trimester, your baby will more than double in size. In fact, by the ninth month, your baby may be gaining more than a half-pound per week.
Here's what your baby is doing during the seventh month of your pregnancy:
At the end of the eighth month, your baby is 18 inches long and weighs approximately 5 pounds. Other developments include:
Here's what your baby is doing the ninth and final month of your pregnancy: