Pregnancy and childbirth can wreak havoc on your body, and many women find it's harder to lose weight after having kids. Your ability to gain a flat stomach depends in part on your body type and genetic makeup, and some women are never able to have a flat stomach, even if they don't have kids. But with regular exercise, a healthy diet and positive lifestyle choices, you'll be able to slim down and may be able to achieve toned abs and a flat tummy.

Why Weight Loss Is Hard

Losing weight is always challenging, because you'll have to burn 3,500 calories for every pound you want to lose. But pregnancy can complicate matters. Moreover, the sheer amount of weight women gain during pregnancy -- anywhere from 11 to 40 pounds depending upon your starting weight, according to the American Congress of Obstetricians and Gynecologists -- means you'll have to spend weeks or months trying to shed fat, even if you're highly active and fit.

Pregnancy and Your Belly

During pregnancy, your stomach stretches, and this can leave you with loose skin that leaves your stomach looking pudgy even after you've lost weight. If you have complications during birth, you might be required to stay on bedrest or avoid exercise after delivery, and this can delay your weight-loss goals. If you have a C-section, the doctor will cut through your abdominal muscles to get to your baby, and some women find that this makes it harder to tone the stomach.

Burning Fat

Some women become focused on targeted stomach exercises after pregnancy, but cardiovascular exercise is a much more effective way to burn fat-building calories. Try activities such as running or walking with your baby, taking a mommy and me aerobics class or swimming, jumping rope or cycling. Breastfeeding helps you burn additional calories, and can help you shed even more weight after you give birth.

Building Muscle

Building muscle won't necessarily make your stomach look flat, but it will make it look more toned as you shed weight. Muscle can also help you burn more calories, since muscle burns more calories than fat. Try exercises such as situps, crunches, captain's chair exercises and bicycle crunches to get your abs working.