Hammond, who won the seat of Perth at last year's federal election, is the father to two healthy daughters but the couple have also experienced three early-term miscarriages.

His wife, Lindsay, is now 10-weeks pregnant.

"Except it isn't our third child. It is actually our sixth child," he wrote in The West Australian.

"Three times in a row we felt the excitement and joy of that positive test. Three times in a row we felt the nerves of the days and weeks in which Lindsay remained pregnant. And three times in a row we felt the sorrow, grief and loss - when her dreaded cramping came and we lost our babies in the first trimester."

Hammond said that while he understands why some wish to mourn in private, he fails to understand the suffering that can occur when prospective parents do so in secret, "under the cover of some arbitrary non-disclosure period of seeing out the first trimester," he said.

The politician, 41, who replaced the retiring incumbent member for Perth Alannah MacTiernan last year, said the reasons for announcing their pregnancy earlier than the "right" time of 12 weeks was due to his busy schedule as a Federal "fly-in, fly-out" parliamentarian.

"Being away from home is made much easier in the knowledge that even though we are only at the 10-week mark, our family and friends know that Lindsay is pregnant, and she has all the support around her that we could possibly hope for - just in case something goes wrong.

"I'm hoping that we get to a point where women and couples feel as if they can publicly embrace the uncertainty of the first trimester - if they want to - in the knowledge that whatever happens, it will all be OK. Eventually," he said.

Hammond has been applauded on social media for sharing his family's story.