Reduce or substitute chest exercises
Chest exercises are not a problem after childbirth, but in some cases, enlarged or engorged breasts make chest exercises difficult and painful. Take it easy on exercises that concentrate on the pectoral muscles, and stop doing them if painful. Exercises that require you to lie on your chest on a bench should be excluded, or substituted with seated exercises. This is the same for floor exercises.
Hand grips and wrist positioning for tendonitis
Pregnancy brings on tendonitis for some women, which makes exercise more difficult. In my case, it became so bad that I could not snap buttons on baby clothes, or open baby food jars with my right hand, and gripping heavy weights was painful. It lasted for many months so I changed hand/wrist positions, as well as lightened the weights during exercises to reduce pain.
Exercise becomes a balancing act
After 40 weeks of shifted center of gravity; a woman's center of gravity shifts again. The heavy belly is gone, but balance takes time to regain. Even body weight lunges and squats can cause you to topple, so it's important to adjust your stance and use something to support your balance.
Flexibility and stretching
In general, women and girls are more flexible than boys and men. Also, teenage girls have more anterior cruciate ligament (ACL) injuries than boys due to increased relaxin their bodies. Hormones, such as relaxin, is increased in a woman's body during and after having baby, so flexibility and stretching are important to keep track of. Stretching should be done with care so that you don't over stretch and injure yourself.
Low impact exercise for incontinence
Embarrassing as it sounds, incontinence is a problem for women after having a baby. While some women only suffer slightly, this was one of my most pressing issues during exercise after my children's births. High impact exercises that required me to jump were changed to low impact exercises. I also changed my chin ups and dips to assisted chin ups and dips because the gravitational pull, along with my body weight, was too much pressure and would cause an incident. I decreased heavy weights to lighter ones so I would not strain, as well.