It is actually the exact opposite. A council of elders was put in charge to save male babies, not kill them. Too many healthy male babies were killed by their parents.

Disabled babies were allmost always left to die in ancient times, that was not the issue. Infanticide was a problem for spartan manpower im regards to the military.

The spartans did not toil the land or build things. They were landlords, wariors, writers, poets. Quite lazy asses, drunk and feasted a lot. They did not work.

Every spartan family was given a lot with thralls to work on. Thralls grew food and delievered to the spartan landlord living in the capital communual barracks.

Yet if there were too many male children, there was trouble. A land lot cannot be divided in too many small pieces, or a warrior cannot live off it and hold his station in society. Thus male babies were killed off.

In time spartan elders worried about their numbers relative to the slaves in their land and neigbouring powers. Thus regulation was set in motion to keep up the right balance in population control.