Pregnant

HIS FAVORITE NOSH IS THE PICKles-and-ice-cream combo. He's delighted with his suddenly glowing complexion. He gets anxious and whiny when his significant other leaves him home alone too much. He is, of course, pregnant. But you've probably guessed all that. The marketing campaign has left little doubt about

Junior's central joke. Sure, this is formulaic, describe-it-in-one-sentence movie-making, but nevertheless, there is a certain irresistible curiosity about seeing Arnold Schwarzenegger mime the rituals of expectant motherhood. Go ahead, surrender to it. It won't make you a better person, but it might, very briefly, make you a happier one.

Schwarzenegger is a scientist named Dr. Alex Hesse. With hustling Larry Arbogast (Danny DeVito, Schwarzenegger's Twins costar), he has developed a drug that promises to help women carry difficult pregnancies to full term. The Food and Drug Administration refuses them permission to test it, so they steal an embryo, fertilize it and implant it in Alex's abdomen. After which nature -- if that's the word we want -- takes its course. The Kevin Wade-Chris Conrad screenplay takes some humorless pains to make this science fiction plausible, and it's smart of director Ivan Reitman to be patient with all that. The more that Schwarzenegger's predicament seems real, the funnier it is.

Schwarzenegger gives a soberly befuddled performance as a man pleasantly surprised, and ultimately transformed, by the play of alien hormones to which he's host. Giddiness (and most of the film's knockabout comedy) is left to Emma Thompson as a bright, klutzy fellow scientist, and she is a lovely reminder of our screwball yesteryears. Like all concerned with Junior, she refuses to let it rest lazily on its concept. The result is a high-energy farce that is more endearing and, yes, more believable than it has any right to be.