In any long term colony, with hard constrained resources, a lot of individual rights will have to fall below the collective requirements. The collective needs will have to supercede the individual. It’s a classic “Tragedy of the commons” situation, otherwise.
Mandatory pregnancy is likely not one of them however. More likely mandatory birth control, with all pregnancies being planned. There will also likely be strong incentives to widen the gene pool.
E.g. A couple might be allowed 1 child by default, with additional requiring either that they already have a useful level of general diversity, or that doner eggs or sperm are used.
Even simple financial incentives could achieve the same effects, if done right.