Stay with Me by Ayobami Adebayo; 2017. Hardcover.

Yejide and Akin have been married since they met and fell in love at university. Though many expected Akin to take several wives, he and Yejide have always agreed: polygamy is not for them. But four years into their marriage--after consulting fertility doctors and healers, trying strange teas and unlikely cures--Yejide is still not pregnant. She assumes she still has time--until her family arrives on her doorstep with a young woman they introduce as Akin's second wife. Furious, shocked, and livid with jealousy, Yejide knows the only way to save her marriage is to get pregnant, which, finally, she does--but at a cost far greater than she could have dared to imagine. Stay With Me asks how much we can sacrifice for the sake of family.