Amy Schumer rose to fame telling jokes that made hilarious, self-deprecating light of lackluster sex, bad boyfriends and other foibles of young adulthood that she ingeniously flipped into more serious observations on sexism, modern feminism and a culture obsessed with body image.

She’s one of those comedians for whom a stretch of personal satisfaction, including marriage to an incredibly nice man, might be seen as a threat to the brand — like the old joke about playing a country song backward, in which the singer gets his wife back, his dog back, his job back and his trailer back. Is Schumer still as sharply funny in the midst of her own happy ending? “Maybe I’ll document it or something,” Schumer says, tearfully talking to the video camera on her phone, in 2018, as a way of spontaneously marking her own reaction to the news that she and her husband, Chris Fischer, are expecting a baby.

Thus begins a revealing and engagingly cathartic three-hour documentary series, “Expecting Amy” (streaming Thursday on HBO Max), which follows several concurrent gestation processes — the birth of a child, the birth of an hour-long comedy special and a breakthrough in her marriage. Filmed largely on phone cameras by Schumer and Fischer (and some of Schumer’s closest confidantes, including her sister, Kim), “Expecting Amy” lets as much as possible hang out there for all to see. Having joked so long about her vagina, she’s now inviting us to see what else it can do.

Schumer’s pregnancy becomes something of a waking nightmare, after what she thought of as the “cute” phase of morning sickness extends itself into full-on hyperemesis gravidarum, which means sustained vomiting and dehydration for the next nine-plus months, many of which Schumer spends on a 60-city comedy tour.

Her sense of humor remains very much intact through it all. At an early ultrasound appointment, when she and Fischer learn that their baby has grown to the size of a pea, Schumer cautions against body-shaming the fetus once it becomes the size of a lima bean.

“There’s going to be a whole new set of material that’s going to be more relevant to her,” one of Schumer’s collaborators, Kevin Kane, observes. We watch as Schumer publicly reveals her pregnancy and begins to incorporate impending motherhood into her act. Trying not to throw up on stage, she jokes about those movies where a pregnant lady darts off to the women’s room once, and is next seen in baggy overalls while she joyfully paints the nursery walls.

There may, in fact, be too much of this kind of thing to sustain “Expecting Amy” through a full three hours. Seen one documentary about a stand-up comedy tour, seen them all. Far more interesting is the deep dive on Schumer and Fischer’s relationship and the story of how someone who touted herself onstage as an unlovable disaster (even titling her semi-autobiograpical 2015 comedy film “Trainwreck”) found such a genial and considerate partner — albeit one who is sometimes too laid back or emotionally guarded. Schumer encourages him to see a specialist, who diagnoses him as mildly autistic, which also becomes part of her evolving material for the comedy special, called “Amy Schumer: Growing,” which was released on Netflix last spring.

By the time “Expecting Amy’s” real star at last arrives — Gene Fischer, all eight pounds and whatever ounces of him — viewers will find themselves fully invested in the delivery, a visceral experience that won’t come as a surprise to anyone who has already appreciated Schumer’s frankness about her body. Indeed, the series works best as an authentic look at what it’s like to be two humans engaged in the complicated, messy business of making a new human. You wind up feeling like a good friend who’s been invited along to Lenox Hill Hospital for a first look at the newborn.

Of course, we’ll have to get in line behind Oscar winner Jennifer Lawrence, who has also come by to hold the baby, which sort of snaps us back into the celebrity sphere. And Schumer, still in the delirium of it all, makes certain to tell the camera that we’re in a sacred space — the same suite in which Beyoncé gave birth to her first child.

Expecting Amy (three episodes) available for streaming Thursday on HBO Max.