I read this book in high school too many years ago for me to think about. Martian colonist are raiding earth's oceans for water and because of the conditions on Mars where only male children are conceived, they are also on the look out for young women as potential mates. Our main character while on a raid, bags not only a young woman but her brother as well. Returning to Mars they find that Earth has attacked Mars can't remember much more.
I believe this is actually "Raiders from the Rings" by A. E. Nourse from 1962.
I read this many years ago. As I recall, in it, in the future the descendants of the U.S. and Russian space garrisons that banded together to prevent World War III are banished from Earth. They setup colonies throughout the system. However, due to high doses of radiation, the second X chromosone pair gets treated like a Y resulting in all conceptions resulting in boys. Hence, they need to return to Earth to kidnap women to continue their culture.
On one raid Spacer Stefan kidnaps a young woman. However, her brother manages to secure a place on his ship before they take off.
The story then goes on to relate how the two parts of humanity need to learn to work together to survive and prosper.
Some terms you might remember from the book if this is correct: - Mauki (a Spacer Woman/Wife) - Tangler (a non-lethal webcasting gun) - Spacer (a member of the Space colonies)
Hope this helps.
This sounds like the premise of the movie Mars Needs Women.
I had not realized there was a book (and indeed, the producer doesn't seem to indicate anything other than the script), but the plot points all match up quite nicely - male babies only, something in the water, etc...