Stardoc

Stardoc and its sequels—also collectively known by the title of the first book—are a series by American romance novelist S.L. Viehl that are best described as part Space Opera and part Medical Drama.

The ten books in the series are:

Stardoc
Beyond Varallan
Endurance
Shockball
Eternity Row
Rebel Ice
Plague of Memory
Omega Games
Crystal Healer
Dream Called Time

Viehl's duology Bio Rescue and Afterburn, the stand-alone novel Blade Dancer, and several short stories are set in the same universe, and have some overlap in cast.

Tropes used in Stardoc include:

Abusive Precursors: The Jxin. You don't find out the full extent of their status as such until fairly late in the series.
Accidental Marriage: First, Cherijo Grey Veil and Kao Torin. Later subverted by the son of the Patriarch of Furin: The proposal is an entirely symbolic act of (entirely feigned) gratitude.
Back from the Dead: Kao, in Dream Called Time, thanks to Maggie. Quite conveniently, he's forgotten everything after a point shortly before meeting Cherijo.
Bizarre Alien Biology: The series absolutely revels in it. Jorenians alone have green blood, twelve-chambered hearts, unusually large and complex spleens that are a vital organ to the species, compartmentalized stomachs, and built-in cartilaginous subdermal "body armor."
Blue Skinned Space Babe: Jorenians are arguably an entire race of these.
Burial in Space: Jorenian tradition, as seen in Stardoc, is for the dead to be ejected from the ship on a course that will result in cremation by stellar or planetary atmosphere. As seen in Plague of Memory, it doesn't always go as planned.
Cosmic Retcon: The main plot of Dream Called Time.
Cunning Linguist: Duncan.
Dead Guy on Display: Jorenian warriors do this to anyone who threatens their families.
Death of the Hypotenuse: Poor, doomed Kao.
Designer Babies: Are explicitly illegal, thanks to some laws that Joseph Grey Veil got pushed through. After all, he can treat his clones as shittily as he damn well pleases that way.
Disposable Fiance: See above.
Fantastic Racism: Terrans have a mostly-deserved bad reputation for being rabid xenophobes. Extraterrestrials can only even visit Terra on a limited basis, and certainly aren't allowed to live here legally, resulting in underground communities of aliens and "breeds". As a result, no one likes us much, either.
Flatline Plotline: Cherijo instigates one in order to break up with Xonea in Beyond Varallan. Justified in that she's basically unkillable.
Gay Aesop: Plague of Memory contains an in-universe one.
Half-Human Hybrid/Nonhuman Humanoid Hybrid: Oh, so many of them.
Humans Are the Real Monsters
Interspecies Romance: Between Kao and Cherijo in Stardoc. There's also Ilona/Dhreen in Eternity Row, and Qonja/Hawk in Plague of Memory.
"It's Not Rape If You Enjoyed It": Played disturbingly straight more than once.
Mister Seahorse: This is how Thgill's species in Blade Dancer reproduce. Also comes up in Stardoc, when someone naïvely presumes the same of both humans and Jorenians.
Omniglot: Duncan can learn alien languages telepathically by making physical contact with the alien in question.
Opposite Gender Clone: Cherijo is one of Dr. Joseph Grey Veil. This was ostensibly for the purpose of Wife Husbandry, but it turned out that it was due to the Jxin meddling.
Pair the Spares: The "real" Jarn marries Kao in the alternate timeline.
Planet Terra
Ret-Gone: Cherijo and Duncan go back in time to retcon the meddling of the Jxin. They end up creating an alternate timeline in which the only real evidence of their existence is the fact that...well, they're there. And so, somehow, is Marel.
Romantic False Lead: Kao and arguably Xonea (although it was pretty clear from the outset that the latter was a matter of convenience and going nowhere) for Cherijo. One could stretch a point and call Jarn one for Duncan.
Screw Yourself: Grey Veil fancied himself too good for anyone except his Opposite Gender Clone.
- He's also implied to have anally raped one of his male clones to infect the latter with syphilis. All in the name of science, of course.
Veganopia: Jorenians are, for the most part, vegetarians (despite being a pastoralist culture whose ancestors were predators). Zigzagged in that they're portrayed as both an entire race of Cultured Warriors and/or Warrior Poets and as a Superior Species (by default).
Villain with Good Publicity: Dr. Joseph Grey Veil, and how.
Wife Husbandry: Turned out to be exactly why Grey Veil created Cherijo in the first place. (Maybe.)
Yandere. Ktarka, so much. Xonea is Flanderized into this in later books.