Pregnancy will put any marriage to the test.
Nausea, stress and deadlines, reexamining your priorities, in-laws pressuring you to do this and that. It can make for physically and mentally challenging times.
It can also bring expectant couples closer together.
Well into their second trimester, Kate Middleton and Prince William are cruising to parenthood more demonstrably (and demonstratively) in love than ever.
"They're much more touchy-feely than they were," notes royal photographer Mark Stewart. "They've always been close, but it is much more pronounced."
"There appears to be a new, deeper bond between them."