Hi, K.,
I've spent hundreds of hours reading and talking to medical practitioners including reproductive endocrinologists, immunologists, perinatologists, nurses, acupuncturists, etc. because I struggled with infertility and went through several rounds of high-tech and low-tech infertility treatment. I've never heard of any "tummy workouts" negatively impacting fertility. Keep up the good work in your exercise regimen.
I gained more weight than I should have (40 pounds, and I'm only 5'3") for a variety of reasons during my first pregnancy. I was ordered not to exercise the first four months of my pregnancy, so I did not exercise for almost half of that pregnancy. I ate too many high-calorie foods, esp. dessert, probably as a result of giving into temptation around Thanksgiving and Christmas and taking prednisone, which often makes people gain weight and increases people's appetite, which makes people gain weight. The weight gain and two c-sections have left me with a kangaroo pouch that I will never get rid of. I weigh 106 pounds and exercise with a trainer but still have that pouch!
Best wishes,
Lynne E