A cement composition can include water; cement, wherein less than 75 w/w % of the total amount of the cement is Portland cement; and a fluid loss additive, wherein the fluid loss additive comprises a polymer network having at least one branching point formed with a monomer and a cross-linking agent that comprises at least three active functional groups. The cement can also be a non-Portland cement. The monomer can be a vinyl ester-based monomer that is polymerized with the cross-linking agent to form the polymer network. The cement composition can be used in an oil and gas operation.