What makes it strange is not the world-building or the sci-fi nature of the pregnancy. What makes it strange is how entirely traditional, even 1950s traditional, it can be.
The entire sub-genre backs up my contention from an earlier Why Yaoi post:
The lack of pushy gender roles is one reason I can never be entirely snippy about those readers who like yaoi series with androgynous boys. For all I know, they turned to yaoi because they got tired of being told that they shouldn't be reading romance novels where girly girls get looked after by manly men. Yaoi is an escape not only from confining conservative roles but from pressuring progressive ones.
In one MPreg universe, the men who can become pregnant (omegas) also have to deal with prejudice, some of which I discuss here. They fight for the right to get degrees and have jobs and marry whomever they wish.
Ultimately, however, it's all about that baby. If this emphasis on child-rearing showed up in traditional romance, it would quite honestly be heavily criticized for "holding women back" or "confining them to feminine roles." As a sub-genre, I don't think anybody knows what to do with it. (Like most Americans don't know what to do with yaoi.)
I am an advocate of people being able to make of fiction what they will. That is, I think it is entirely acceptable for women and men to read MPreg romances for the sake of the classic, traditional motifs that put babies and family at the forefront of the human experience.
Having said that, after reading about eight of these novels, I have to admit the tropes are a little ham-handed.
So here is my suggestion for a MPreg novel. Has it been done before? Probably. But at least it doesn't include some of the tiresome tropes of the eight prior novels:
Simon is the alpha, the male who can impregnate. And he doesn't know it. Unlike nearly every other alpha in the books that I've read, he is not well-off, his family is not well-off, and nobody in his vicinity is a power-broker. He is a small-town guy who knows about alphas and omegas from the news but has very little experience with that world directly. "Coming out" was a huge deal for him and frankly traumatizing enough.
Rafe is the omega and unlike in every book I've read, he comes from a loving, supportive wealthy family. His fathers have a semi-arranged marriage where the marriage was arranged, but they had to sign off on it. It proved to be very happy (unlike in every book that I've read). Rafe has alpha and omega siblings and everybody gets along.
The parents settled money on each of their children at birth, so Rafe has his own income. He uses it to fund various educational programs, including an archaeological dig. He is not a dilettante; running charities may sound easy, but if a person actually takes a hands-on approach, it can be extremely time-consuming.
Rafe's parents suggest an arranged marriage for him, and he claims he isn't adverse (unlike every omega in every book I've read who feels personally attacked by the idea). In truth, in his heart of hearts, Rafe would love to have an ordinary gay relationship with someone--like Buffy wants to be an ordinary girl--but he knows how unlikely that is, so, eh, whatever.
The parents interview the prospective groom, Todd. Todd comes across as a decent human being (unlike every arranged-marriage groom in every book I've read). However, Rafe has to sign off on the agreement, so the prospective groom--Todd--goes out the archaeological dig that Rafe is funding and where Simon is working. Rafe is unaware, until Todd shows up, that his dads already put the arranged marriage into motion.
Seeing Simon and Rafe together does not send Todd into a jealous tailspin (unlike in every book I've read). But it does concern him. Todd's arranged marriage with Rafe is his last chance to live the jet-setting lifestyle that he has gotten used to. His family is tired of his dilettante ways. Either someone else takes care of Todd, or he gets a job.
It isn't that Todd is an alcoholic or a druggie or even promiscuous, all of which the fathers would have found out in their background check. It is that he adores being a sophisticated man of the world who jets around to different "events": skiing in the Alps in the winter; summering in the Hamptons, etc.
He doesn't understand that Rafe actually works; he thinks Rafe is like him life-style-wise. He mistakenly assumes that "philanthropy" is this cute thing that Rafe does between jet-setting, not something that actually involves Rafe reviewing proposals, checking budgets, and cutting off funds when necessary.
Todd's sense that Simon is no good for Rafe increases when Rafe gets pregnant (which does happen, despite protection, in every book I've read--apparently, birth control in these alternate universes is sue-ably ineffective). Simon has no idea, and Rafe doesn't tell him. Todd understandably sees all this as irresponsible.
Eventually, Todd takes Simon out to the island or the dig or the desert or somewhere away from camp and confronts Simon with Rafe's pregnancy. Flummoxed Simon denies it, which justifies Todd in his own mind to be anti-Simon; he lashes out. During their fight, Simon falls. Todd leaves him, driving the jeep back to camp. Todd is a villain but he is the type of villain who convinces himself that not doing anything is not the same as actually doing something. "I didn't hurt Simon. It's his fault he fell. What can I do about it? Nobody will be able to get him out of that ravine anyway."
Todd is bad but not wholly evil. He feels terrible guilt and takes himself off to town for the day. So Rafe can't ask Todd anything when he realizes Simon is missing.
Instead Rafe realizes that to find Simon he will have to rely on his omega senses, enhanced due to the baby (this is in many of the books). He will have to tap into the part of him that is physically drawn to "his" alpha, not just his boyfriend. It's his internal climax, a block that he has to overcome. And he does it, and he finds Simon.
And Simon finally accepts the reality of a pregnant boyfriend (which happens in every
book) and Rafe and Simon get married (which happens in every book). And the baby is healthy (which happens in every book). And everybody is thrilled (which sometimes happens in every book).