Geshaefer,
Congratulations and relax. Other members have already noted that there have been several retrospective studies; one of them was a look at pregnant women who had been treated in a hyperbaric chamber. No abnormalities have ever been reported. That said, you don't want your child to be the first, so she should not dive again while she's pregnant. Ditto my cross-town compadre (@uncfnp, my son is wearing a hand-me-down Heels shirt today): get her on prenatal vitamins, find a good OB and start saving for college.
Best regards,
DDM