After watching a coworker innocently ask a woman who wasn't expecting, "When are you due?", I've developed a simple rule for this:<p>If she tells you she's pregnant: <i>Congratulate her.</i><p>If she doesn't: <i>Keep your mouth shut.</i><p>Seriously, if you want to target expectant mothers, let them register for a discount program. <i>Diapers are expensive!</i> Any marketing effort that begins, "We think you might be pregnant..." is doomed.