Let’s assume they’re all ~16-17. This is at – above the age of consent where I live, though I understand it is different in other places.
Uta
– Uta has an argument with his grouchy s/o one night, when they don’t want to eat a drunken man.
– They stomp off, and Uta races after them. After more bickering – in which his s/o definitely echo’s Yomo’s insults about Uta’s tiny glasses – his s/o confesses that they are late.
– Uta freaks. He goes straight to the nearest drugstore to buy a test, and allows his s/o to wait outside to avoid being linked to it. His s/o quietly thanks him, argument forgotten.
– They then go to Uta’s home, where he and his s/o discover together that s/o is pregnant.
– His s/o wants to have kids someday, but they are unsure that now is a good time. And Uta is unsure he ever wants kids, but he’s certainly not going to force his s/o to decide.
– I suspect his s/o would want to have the child, but not raise it at their age. So they’d need to find a ghoul family to adopt them (Itori can help). If they can’t, they might have an abortion and be very sad about it.
– Uta will be comforting, and try to kick anyone who mocks his pregnant s/o’s ass. I say ‘try’ because s/o is pretty damn good at kicking ass themselves. They joke that hormones are their fuel.
– Uta will be very relieved once the kid is born, and their s/o does not decide to keep them. This is a paranoia he’s been feeling for months. Cue more arguing that he didn’t talk to his s/o about it. 😛
Yomo Renji
– His s/o is a ghoul who stirs his wild side. Yomo would never risk dating a human.
– Yomo finds out because another ghoul sniffs his s/o and asks bluntly if he and his s/o know they’re pregnant. His s/o’s phony attempts to laugh it off – and the panic in their eyes – tell Yomo everything. Even before Yomo takes them somewhere private to talk.
– Yomo panics a bit, but his s/o shakes him. They remind him that Hikari got pregnant with Touka out of wedlock, so she will probably help, not judge them.
– Yomo would really hope his s/o decides to have the baby. He has a secret fatherly, soft side that his s/o likes to tease him about.
– This is how Yomo and Uta became friends. Yomo’s s/o needed help and Itori had oodles of resources, and Itori naturally told Uta.
– Uta then decided to make peace with Yomo and become his friend. Though Yomo’s hormonal s/o may have seen them together, assumed Uta meant harm, and tried to attack him.
Tsukiyama Shuu
– He finds out when classmate Chie shows him a picture of his human s/o in the bathroom with a pregnancy test. To be fair, the s/o wanted Chie to tell Shuu because they were scared.
– Since his lover is a human classmate, Tsukiyama knows that odds aren’t good. But he will sit down with them and ask what they want to do. He’ll probably cry the entire time, and he will be comforting.
– If they do want to have the child, he feels guilty that he’s unsure whether to tell them he’s a ghoul, thereby increasing chances of survival, or not.
– Chie will ferret as much information on clinics, hospitals, and doctors as necessary.
– Unfortunately for Shuu, Matsumae finds out and immediately schedules Tsukiyama to sit down with his father.
– Mirumo sighs and informs his son he already knows. Tsukiyama is embarrassed and distressed and unsure what to do.
– Mirumo will certainly support them in whatever way he can, and he won’t be judgmental. After all, Shuu is already facing consequences, so why become angry?
– If Shuu really loves his s/o, Mirumo willl even encourage Shuu to confess the truth about his ghoul nature.
– Mirumo will pay for doctor’s visits, an adoption agency, or an abortion, depending on what the couple decide.
Arima Kishou
– his s/o is a human he met undercover in class, while investigating the Lantern murders. His s/o calls him to come over late at night, and tearfully tells him the news.
– Arima is terrified, because he can just imagine what Tsuneyoshi and V would say and do to his s/o. And their kid, should the kid be born.
– He also has to fear that the child will either be miscarried, or die early because of its heritage.
– He will still allow his s/o to make their decision. If they want to have the kid, he will begin making plans to help them escape any suspicions of V.
– If s/o eventually decides on an abortion, he supports them and stays with them. To be honest, he will hope for this – for their sake.
– Either way, unfortunately, V does find out, and Arima has to ask Eto Yoshimura to spirit his s/o away to safety. Eto gives him hell for this, but she’s surprisingly comforting to a human who was/is pregnant with a partially-ghoul child.
– His s/o definitely joins ccg and helps investigate V later in life. They may meet again, possibly with a child in tow.
Mercy and Magic 