I always knew my wife had the makings of royalty.

I just didn’t know that the connection would surface through the sufferings of a pregnant duchess.

My princess, Mary Kay, took keen note this week as the Duchess of Cambridge — the former Kate Middleton — was hospitalized with a severe form of morning sickness.

You see, Mary Kay went through that once. Well, twice. I mean three times. OK, OK, we had FOUR kids, and it was ALL MY FAULT that she spent two full months suffering from nausea and vomiting each time.

Mary Kay is thinking of writing her a letter. One that says, “I feel for you.” Because people just don’t understand what it’s like. You say “morning sickness” and folks think you just eat a few crackers first thing in the morning, deal with a little rumbly tumbly and you’re good to go.

But this isn’t “morning” sickness. This is “intense, all day, every day for two months, I’ll never eat again, I’ll kill my husband if I ever get my strength back” sickness – hyperemesis gravidarum.

“Wish I had known there was a name for this,” my wife said in a recent email to me. It might have validated her experience, given her a way to describe it to skeptics, made her feel less like “a weakling.”

In 1985, when she was about four weeks along, we found out that Mary Kay was pregnant.

Our first child! Suddenly, our lives had changed, and what a joy it was.

But within days, the sickness — we’ll call it Beelzebub — arrived. And it does come suddenly. Note the picture in Tuesday’s World-Herald showing a glamorous Kate playing field hockey in fashionable high-heeled boots last Friday. By Monday she was in the hospital.

In Mary Kay’s case, she quickly became dehydrated and soon spent three or four days in the hospital, hooked up to an IV. She was sent home but was back almost immediately for three or four more days. She came back home and spent most of the next six weeks with Beelzebub — weak, dehydrated, battling severe nausea, eating ever so little and, frankly, feeling like others saw her as a different kind of “weak.”

In Kate’s case, at least one website that refers to her routinely as a “diva” offered that her baby announcement of course had to be “dramatic,” as if she had wanted it that way. If they only knew.

Eventually, Mary Kay’s nausea abated, and six months later, on Christmas Eve 1985, a beautiful baby boy was born, no worse for the wear.

Mary Kay was hospitalized for about a week and spent two months severely ill and dehydrated again in 1987 and 1990 before our daughters were born wonderfully healthy. Note that we were buoyed then and now by research indicating that women who suffer from severe nausea and vomiting during pregnancy are less likely to have a miscarriage.

By late 1994, insurance companies apparently had determined that hyperemesis gravidarum didn’t require hospitalization, so a home health nurse came to our house, started Mary Kay on an IV, deputized me as an RN so that I could change her IV tubing every day and left us to our own devices. Mary Kay spent weeks on our living room couch, tied to an IV, with a bucket by her side.

Ultimately our baby was born healthy, but not before Mary Kay’s gallbladder was removed while she was seven months’ pregnant.

By now you’re wondering why we have four kids, why Mary Kay went through it all.

Because she — and the women who go through this, some for much longer than two months — are saints on Earth. Mary Kay’s fears of being perceived as “weak”? She’s the strongest person I’ve ever known. She was open to the blessings God had in store for us, even if those blessings each included a two-month visit from Satan himself. But we got the better of ol’ Beelzebub. Our children, now ages 17 to 26, are the joys of our lives, even if we don’t tell them that often enough.

Dear Kate: We’re praying for you. Once you get through this, labor and delivery will be child’s play, so to speak, with a beautiful baby to greet you at the end of it. It’s just icing on the cake that he or she might be a future king or queen. You’re strong. Hang in there. It’s worth it!

Bob McDonald, a deputy Money editor at the World-Herald, wrote this guest blog for momaha.com

* * *