LASIK eye surgery during pregnancy is not advised. Perhaps the most important issue is that your prescription sometimes changes during pregnancy. This is thought to be due to hormonal alterations that make the body retain more fluid, causing a swelling of the lens inside the eye. So you may get a little more nearsighted or develop more astigmatism as long as your hormones are elevated. Don't forget that your hormones remain elevated even after the birth of your child if you breastfeed.
Another problem is that your surgeon will frequently prescribe mild sedation during the surgery, and you'll need to take antibiotic and cortisone drops before and after the operation. All of these drugs are absorbed into the bloodstream through the mucous membranes, and they potentially could have a detrimental effect on the baby, especially in the first trimester.
And there's also the issue of radiation from the laser. While this is not a great risk because the exposure is limited, it is still something you should consider. For each of these issues the risk is unknown, but since this is elective surgery, why take the chance?