“It’s adjustable, yes?” Standing in a dressing room in the opera house in Montpellier, France, in May, the soprano Maya Kherani tugged at the waistband of her tiered skirt. A draper kneeling behind her shook out the hem while the costume designer looked on with satisfaction.“We’re lucky,” she said, cupping her hands around the smooth orb of her belly. “It works for the character.”Kherani considered herself fortunate not because she had landed the role of Autonoe, a lead in “Orfeo,” by the Baroque composer Antonio Sartorio. Instead, Kherani, who gave birth on Sunday, was relieved to discover that her costumes in this modern-dress production came with elasticated waists and flat shoes that would make it bearable to sing and act while 32 weeks pregnant.Better yet: The stage director Benjamin Lazar decided to incorporate her pregnancy into the staging, making it the driving force behind her character’s quest to win back her errant lover.“It works dramaturgically really well for my character,” Kherani said in a FaceTime interview from Montpellier. “In my gestures and in the staging, I am referencing the pregnancy. Everyone’s really supportive, which is not always the case.”In most musical professions, pregnant women — not their employers — determine how long they continue to work. When opera singers want to perform pregnant, however, they rely on the good will and skill of a creative team: drapers who add strategic ruching to costumes; stage directors who might change a risky piece of stage business or adapt their concept to include the pregnancy.All too often, though, pregnant singers lose work. And yet opera is a rare business in which pregnancy and childbirth can directly and positively affect the core product — the voice. The science behind the phenomenon is still poorly understood, but it is such a noticeable and common occurrence that it has become something of a truism in opera: After childbirth, the voice seems enriched with warmth, creaminess and depth of color.Kherani found her voice improved after becoming pregnant. “You learn to use a wider base of breath support including the back muscles,” she said, “which I think every singer is trying to access, but I have been forced to.”Sam Hellmann for The New York TimesChanging bodies, of course, go along with the changing voices. A growing number of women in the industry are speaking out about what they feel are cancellations motivated by their appearance rather than sound. Officially, opera houses say they are concerned about safety. Francesca Zambello, the artistic director of Washington National Opera, said, “As a general rule we are interested in the safety and well-being of all artists working for us.” The Metropolitan Opera said in a statement that “if a pregnant singer wishes to perform, we make sure it is safe for them to do so.”But not all cancellations reflect the wishes of the pregnant singer. The mezzo-soprano Sasha Cooke said in a video interview she was removed from a production weeks before opening when the company learned she was pregnant, and that she lost a role at another opera house after her management told the company she would be in her second trimester during the performances. A fellow singer later told her the production would have required Cooke to go down a slide, but Cooke said safety was not mentioned in the cancellation, nor was she consulted.“The industry still views you as their property,” Cooke said. “Your choices are their choices.”Like other singers who were eager to speak about pregnancy and motherhood in opera, Cooke asked me not to name the companies that canceled her contracts. In part, this was because of fear of retribution. But also, as the soprano Kathryn Lewek told me before her last performance in the Met’s recent run of Mozart’s “Magic Flute,” the goal was not to shame or remove certain administrators or directors. “We want to help bring about change,” she said.More than five years after the #MeToo movement sparked an overdue investigation of sexual harassment and misconduct in classical music, the field is buzzing with voices calling for more equity around pregnancy and parenthood. The soprano Julia Bullock, who gave birth to her first child last year, has taken to Instagram to post about performing as a lactating mother. The mezzo J’Nai Bridges publicly shared her decision to freeze her eggs at a time in her career when she is a sought-after Carmen — a notably physical role. Social media is especially vital for singers because so many are freelancers, lacking the organized lobbying power of unions and working much of the year on the road.After a singer gives birth, Kherani said, “All the support and alignment creates a stronger foundation for the breath, and that can result in a richer tone.”Sam Hellmann for The New York TimesOn Facebook, the Momology private discussion groups for mothers in the performing arts are bursting at the seams. The classically trained Broadway singer Andrea Jones-Sojola, who created the first group in 2010, caps membership at 500 for each group to create a cohesive support network. This year, she opened a fifth. Jones said pregnancy-related cancellations are an important thread. “A lot of women were afraid to make it known publicly,” she said. “They were afraid to fight for themselves.”Singers also turn to each other for advice on how to navigate technical challenges during pregnancy. Many report doing their best work in their second and sometimes third trimesters, after symptoms like nausea and fatigue have abated and other physiological changes enhance their vocal power. Much of that power comes from the muscles and tissue singers learn to activate for what is known as appoggio, the internal support they lean on to control the breath flow. For some women, the presence of the unborn baby is like a corset they can push against.Dr. Paul Kwak, an ENT specialist who works with opera singers, said voices are affected by the hypervascular state the body enters in pregnancy as it creates more blood vessels and increases blood flow through tissue. Because the tissue and muscle in the vocal folds can become engorged with that extra blood, he said, “it can change the ways the vocal folds themselves oscillate.” At the same time, changes to the abdominal cavity create pressure on the bottom of the diaphragm. “Some women like it,” Dr. Kwak said, “they feel they have a support there, a shelf to push against.”Lewek, who sang the role of Queen of the Night in “The Magic Flute” through two pregnancies, described the experience as one of adjusting “to the fact that a human is taking up square footage in this very delicate part of my anatomy where I work.” By the second trimester, she said she felt as if she were performing “on steroids.” “Everything was so easy,” she said, “high notes just came shooting out of me.”Many singers said the improvement of the voice after childbirth may be the result of integrating tools used during pregnancy into their vocal technique. “You learn to use a wider base of breath support including the back muscles,” Kherani said, “which I think every singer is trying to access, but I have been forced to.” The changes in her body’s center of gravity also made her hyperaware of her posture, another important factor in singing. After a singer gives birth, she said, “All the support and alignment creates a stronger foundation for the breath, and that can result in a richer tone.”Dr. Kwak said richness was a difficult factor to study scientifically. A singer’s vocal tone, or timbre, is shaped by the tissue in her mouth, tongue, pharynx and face, he said, adding that it was possible this tissue became more supple after pregnancy. But studying its changes during and after pregnancy isn’t easy. “That’s why it’s such a mystery,” he said.Many female singers report doing their best work in their second and sometimes third trimesters, after symptoms like nausea and fatigue have abated and other physiological changes enhance their vocal power.Sam Hellmann for The New York TimesRecovering from childbirth can be traumatic for many singers, who have to reacquaint themselves with a body that has changed most radically in the very area that is the powerhouse of their art. The soprano Erin Morley said she lost 30 pounds in the first week after each of her three deliveries. “I found it much easier to sing during my second and third trimesters than I did during the fourth trimester,” she said, echoing many mothers I asked about their recovery following childbirth.Six weeks after delivering her first child by cesarean, Lewek performed the Queen of the Night at the Met. (Morley sang the role of Pamina, the Queen’s daughter, having just given birth to her third, and the two singers spent their breaks breastfeeding in the same dressing room.) The week before rehearsals started, with her “entire support system slashed in half” by surgery, Lewek was still able to sing only up to a high G, a full octave below what Mozart’s music required.With the help of a physical therapist, she devised a workaround. “I found a diaphragmatic rather than muscular way of supporting staccati in Queen of the Night,” she said, “that, overall, I would never want to sustain my entire singing career. But it got me through that gig and it opened up a new set of skills.” Her tone, too, opened up, after the births of each of her children, when she said she noticed “a blossoming of the tone quality of my voice that now has lent itself to bigger repertoire.”She wondered: “Was it the pregnancies that really changed my voice, or was it the recovery?”Lewek said she was fortunate that she was able to perform her star role in the “Magic Flute” up until being eight and a half months pregnant with her first child. But during that same pregnancy, she was abruptly removed from a different role, shortly after she had shown up to rehearsals with a visible baby bump. Citing safety concerns involving the set, the company urged her to withdraw, she said, even though she felt comfortable with what the production required of her. When the company added financial incentives and promises of a future role, she relented.“It wasn’t my decision,” Lewek said, “but my agent said I should grab the offer and run.”Morley said she lost a major role because of concerns she wouldn’t fit through a trap door in the set. And during a later pregnancy she lost a role because it required singing an aria standing on a chair in what would have been her second trimester. “I was really considering making a statement,” she said, “but these were companies I wanted to work with again, and I was very worried that there would be repercussions.” Besides, her contract was paid, which she knew was not always the case in such situations. “It felt kind of like dirty money,” she said. “Like they were paying me so I would not talk.”One singer who went public was Julie Fuchs, after she was booted from a production of “The Magic Flute” two years ago at Hamburg State Opera, where she would have sung the role of Pamina four months into her first pregnancy. When Fuchs announced on social media that she was out of the production, her feed lit up with outrage. Many commentators suggested misogyny was to blame for the company’s decision, although the director, Jette Steckel, was a woman. After arbitration, Fuchs settled with the company under terms that do not allow her to speak about the case.The company said the production’s flight scenes made it unsafe for a pregnant Pamina. “The legal situation for the protection of the expectant mother is clear,” its director of artistic management, Tillmann Wiegand, said in a statement at the time, “and we will never take a health risk, even if only a risky scenic action could take place on the stage.”Kherani at home with her daughter Eila and husband Zaafir.Sam Hellmann for The New York TimesInnovations in set design and technology can make opera stages a risky work environment. Wagnerians are especially likely to find themselves airborne. Morley said she came to an agreement with the Met to bow out of a planned Ring Cycle during her first pregnancy because as one of the Rhinemaidens she would have had to fly in a harness. But when Zambello learned of the pregnancy of a Valkyrie in a Washington National Opera production, she adapted her concept. While the other Valkyries made their entrance by parachute, she had this singer run onstage trailing hers. “I said, ‘OK, you are the nonflying Valkyrie,’” Zambello said. “They were all wearing flight jumpsuits and I said, ‘we’ll just make yours baggier.’”The mezzo Isabel Leonard was in her first trimester when she sang Cherubino in “Marriage of Figaro” at the Met, a trouser role — a male character sung by a woman. A dancer from childhood, she said she wasn’t showing at the time and told no one.Leonard said reconciling the rights of pregnant singers and theatrical standards required a more honest and open conversation. “We are storytellers,” she said. “How far into realism are we going? There has to be a bigger discussion within companies, production by production.”Those channels of communication may open up as more singers enter the administrative suites of opera houses. Bullock, a founding member of American Modern Opera Company, said her organization was looking into formalizing financial support for artists who needed to travel with young children. For a recent tour in Europe, her contract included a per diem, accommodations and travel fare for her infant and designated caregivers.“I can’t really expect that from every arts institution where I work,” Bullock said. “But if you want my presence fully, so that I can really do the job that you’ve hired me to do, this is a part of it.”The soprano Christine Goerke joined Detroit Opera as associate artistic director in 2021. She credits motherhood with propelling her into the dramatic lead roles in Wagner and Strauss she is now known for. “It allowed me to reach into these bigger roles in a way that suddenly felt like that’s where I belonged,” she said of the changes to her voice postpartum.A vocal champion of parents’ rights in opera, she said she recognized the complexity of the situation. “Now that I am on both sides of the desk, I can see the different sides of this. It is difficult to have a pregnant Octavian,” she said, referring to a trouser role in Strauss’s “Rosenkavalier.” However, she continued, “before a snap decision is made, I would like to see conversations between the artist who is pregnant and the director and bring in other people. It may be that you can come up with a different solution.”Many singers said opera houses were beginning to be more attuned to the needs of singers who are traveling with children. They might provide information on local nanny services and playgrounds or retain the services of a pediatrician along with the ENT who is on call in every theater. Lewek said together with other mothers she was preparing a list of best practices to improve equity for pregnant artists and parents in opera houses. She would like to see unilateral cancellations become a thing of the past.“This is not Hollywood. There is another priority why we’re hired to do the job,” she said. “It’s the voice.” More