Reproduction, Division of Labor, Dialectical Materialism

According to Marx-Engels, the husband-wife relation is the foundation of Private Property, or, equivalently, Division of Labor, and, hence, Contradiction.  Thus, the foundational Negation of the Negation is the abolition of Private Property, and, equivalently, of Division of Labor.  However, while the result of the former is clear, i. e. the Collectivization of Property, that of the latter is less so.  For, it is unclear what the Negation of the reproductive process might consist in, i. e. unlike Private Property, Reproduction involving two sexes must surely continue.  One possibility is that what is negated is the antagonistic relation between the parties to the reproductive process, leaving a healthier diversification of that labor, e. g. that they are conceived as playing complementary, rather than antagonistic, roles.  On that basis, Dialectical Materialism, in general, can be re-conceived as constituted by complementary moments.  In other words, Marx-Engels do not seem to consider that Dialectic Materialism itself is an underdeveloped version of a process that, upon the achievement of Socialism, reaches full maturity.