Bloodchild, Octavia E. Butler
"Bloodchild" describes the unusual bond between a race of insect-like lifeforms called the Tlic and a colony of humans who have escaped Earth and settled on the Tlic planet. When the Tlic realize that humans make excellent hosts for Tlic eggs, they establish the Preserve to protect the humans, and in return require that every family choose a child for implantation.
In several interviews as well as in her afterword to "Bloodchild", Butler explains the different situations that led her to write the story. To begin with, she wanted to "write out" her fear of her body being invaded by a parasitic insect, specifically the botfly. She also wanted to write about a human male becoming pregnant; about the risks to his body as well as what it would take for him to have maternal feelings towards his alien brood, and so she ended crafting a story about a symbiotic, loving relationship between two very different species.