There are exercises that a woman can perform, with a physicians consent, both during and after pregnancy that help protect you while still pregnant and speed up your recovery after giving birth.
One of the most direct ways pregnancy impact's a woman's body is a weakening of her core, especially the lower abdominal muscles. These muscles automatically stretch to accommodate a growing uterus, and might be further impacted by changes in the posture as the belly grows. If you don't work on regaining that core strength you can develop a wide array of physical ailments like lower back pain or sciatica, and might have a harder time during subsequent pregnancies. Consult with your physician or physical therapist on what exercises you can safely perform during and after the pregnancy.
As a general rule you want to focus on safe core exercises that work the lower abdominal area and the pelvic floor.
Another common issue during pregnancy is fluid retention. The swelling that is common with pregnancy can lead to join issues such as carpel tunnel syndrome or De Quervain's disease, especially during the last trimester. If you experience symptoms like wrist pain, numbness and tingling in the hands or pain when you move your thumb, you should ask your physician about seeking Physical Therapy to alleviate those symptoms.