The research here is consistent and rarely passed on: most couples report a marked drop in relationship satisfaction across the transition to parenthood. Knowing that in advance does not prevent it, but it does prevent the second, worse problem — concluding that the drop means you chose wrong.

The Gottmans' work on new parents traced where it goes. Sleep disappears, which removes the capacity to be generous at exactly the moment more generosity is required. The division of labour gets renegotiated by default rather than by discussion, usually in whoever's favour the first six weeks happened to fall. And the couple stops being a couple in any observable way: every remaining unit of attention goes to the baby, correctly, and the relationship becomes logistics conducted in a whisper on a landing.

The failure is rarely a single fight. It is that both people are working extremely hard on the same project and have stopped saying so to each other. Resentment in this period is almost always the sound of invisible effort — each convinced the other cannot see what they are carrying, both correct, neither with the energy to make the case. Meanwhile any suggestion of couple time reads as one more demand on a person with nothing left.

What holds up is smaller than date night, which is usually unaffordable in every sense for a while. Narrate the labour out loud, so it stops being invisible — saying what you did today is not boasting, it is data your partner does not otherwise have. Protect one twenty-minute stretch where the subject is not the child. And renegotiate the split explicitly rather than letting it set by accident, because whatever arrangement survives these months tends to become the arrangement for years.

If you are in it: tonight, tell each other one thing you did today that the other did not see. That is the whole exercise, and it does more than it sounds like it should.

SourceGottman, J. M. & Gottman, J. S. (2007). And Baby Makes Three. Crown.