Many a pregnant woman has gazed down with wonder at their belly, and marveled at just how much their body has changed. For supermodel Heidi Klum, however, what happens postpartum is an equally marvelous sight.

“Just as it’s a miracle that you can grow a human being in your belly, it’s a miracle that your body goes back to normal again,” she notes in the cover story for the first quarterly edition of Page Six Magazine, available now.

It’s something the 36-year-old Project Runway host is no doubt reminding herself of in the closing weeks of her fourth pregnancy. “It’s hard when you don’t fit in your things anymore,” she concedes. “The last month is unbelievable, how rapidly your stomach goes.”

The baby she expects in mid-October — a girl — will more than make up for it, however. “I don’t think you ever get back to exactly the way you were, but you do get close,” she says. “I’m happy with that. Especially when you see your kid for the first time.”

Calling husband Seal a “gentle giant,” Heidi said she is looking forward to incorporating her newest daughter into the couple’s ever-growing brood. “If you come to our house in L.A., you’ll see that it’s not a big, museum-like house where you can’t touch anything or sit anywhere,” Heidi goes on to explain. “It’s a family house, where three children are living. We have toys all over the place.”

Baby girl will join big siblings Leni, 5, Henry, 4 tomorrow, and Johan, 2 ½, at home.

— Missy