The couple are believed to be struggling to conceive a sibling for 20-month-old daughter Suri and plan to visit LA's Cedars-Sinai Medical Centre later this month for advice.
Now quotes a source as saying: "Katie is so upset. They both really want another child but it just doesn't seem to be happening. She says they have been trying since last summer. Tom and Katie have decided to go and see a specialist."
Cruise also has two adopted children - Connor, 12, and 14-year-old Isabella - with ex-wife Nicole Kidman, but reportedly wants another son to add to the family.
Holmes was rumoured to be pregnant last June and July, but recently said she was in "no particular rush" to have another child.