Here, I'll go first. I rarely spoke directly to the Croissant while he was baking, in English or in French. Not out loud, at least--I'd "think" to him, addressing certain thoughts to him, figuring that he'd hear my voice plenty regardless. I'd rub and pat my belly, especially in response to his movements. My husband did talk directly to him (in English) through my navel, though, hoping to familiarize him with the sound of his voice.
Since I had stopped teaching at that point and wasn't speaking French regularly as part of my daily routine, I realized eventually that he wasn't hearing much of his soon-to-be-second language (except when I was taking care of Carl). But, unconvinced that speaking French aloud to my unborn child would better prepare him for linguistic gymnastics, and loathe to add yet another item to my pregnancy to-do list*, I opted not to force myself to do something that felt unnatural and thus turn my passion for the French language into yet another chore.
What about y'all? And can anyone cite research that addresses the effects of speaking to babies in utero?
*Speaking of all the things that incipient mothers are guilted into doing, have you ever read What to Expect When You're Expecting? Well, don't. Especially not the "Best-Odds Diet" chapter. As if a pregnant woman has the time or energy or inclination to fix meals with three different colors of vegetables each time, organ meats, and homemade bread, all copiously sprinkled with wheat germ and tofu flakes! (Plus Ed would have moved out if I had confronted him with bean curd--he's tofuphobic.)