This is just my interpretation, but I always assumed that since the Eldar have greater awareness and control of their bodies, they knew when they were (or were not) likely to conceive and could act appropriately according to their wishes at the time. This assumes that an elf woman's reproductive system is similar to that of humans, it must at least be compatible.

(IIRC this method of "family planning" is the only one accepted by the Catholic church, so it's possible that Tolkien was aware of this even if he never hinted at it in this context. Such matters were never discussed in his time.)

: : : Nevertheless, let me hazard one extrapolation for the board:
: : Elven sex was a rare event, occuring no more frequently than
: : pregnancy among the Second-born.
: : : Perhaps one of the consequences made by Elves who became mortal
: : would be to become sexually active as the Second-born...

: I think more would have become mortal then, with such incentive;-)

I can't imagine that the Eldar, being such a gentle, compassionate and expressive race, would not cherish this most profound aspect of a loving relationship, certainly early in the marriage (mere centuries!). But perhaps they do tire of it eventually, and we as contemporary humans, cannot comprehend this? Or perhaps the physical expression of love, which for us is paramount, develops into something even more spiritual with the Eldar? IIRC Tolkien indicates something to this effect?

just my humble toughts,

Anne Shepard