system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] If a man drank a polyjuice potion to transform into a woman then had sex with a man, would conception be possible? What would happen to the embryo when the potion wore off? If pregnant woman drank a polyjuice potion made from a man what would happen to her fetus?
gpt
Conception would be possible if the woman who provided the body matter happened to be fertile at the time. The embryo would irrevocably disappear once the potion wore off. 

You *may possibly* be able to carry it to term by constantly dosing yourself with Polyjuice, as it would be quite odd if each dose reset you to *exactly* the form of the body-matter-provider at the time it was harvested (for instance, you could have instant perfect healing that ignored Dark magic damage by going into battle Polyjuiced and then dosing yourself with Polyjuice like a healing potion; more prosaically, technically, that would restore you to the form of someone who hasn't just swallowed Polyjuice - unless of course the magic doesn't depend on having Potion inside you).

A pregnant woman who drank Polyjuice made from a man - or indeed a non-pregnant woman - would turn into that man for the duration, then back to her original form, foetus and all. Magic has a "memory" of what Transfigured things were like, which is why you can unTransfigure things, and it's very high-fidelity: McGonagall could restore Draco Malfoy even though his body and brain had been transformed into an ordinary ferret.