Sanskar
Garbhadhan
The first sanskar joins the wish for a child with restraint and responsibility.
When
In married life, before a couple seeks to conceive.
Garbhadhan is the first of the sixteen sanskars. It is not only about conception. It is a resolve that a life, if it comes, should come with intention, restraint, and responsibility.
Families do not all keep it in the same form. Somewhere it is a sankalp and a few mantras; somewhere it is the blessing of elders. This page is a general introduction. Ask your own priest for the rite of your shakha.
This is a general introduction. Sequence, materials, and timing change with family, region, and shakha. Your priest and your own custom have the last word.