In conservative societies such as Egypt, an "intact" hymen - the thin tissue that may partially cover the vagina - is still widely seen as confirming virginity.
For brides, a torn hymen can lead to shaming by relatives or in-laws. In the worst cases, it can motivate so-called honour killings, which are usually committed by victims' relatives.
"This is our duty as doctors - to protect girls from murder and from the social stigma they are subjected to because of the hymen," said the gynaecologist, Layla, who asked to use a pseudonym so she could speak freely about her work.
Surgically repairing or reconstructing the hymen - known as a hymenoplasty - is legal in Egypt but unaffordable for most, costing up to 20,000 Egyptian pounds ($1,270) – about twice the average monthly wage.
For women in rural areas such as Upper Egypt, where attitudes tend to be ultra-conservative, accessing the procedure is even more difficult.
Healthcare services are limited and few women have the means to pay for the surgery.
Layla travels regularly to Egypt's far-flung provinces to perform hymenoplasties for about a third of the usual price.
"I announce on my (Facebook) page that I'm going to a certain governorate from such-and-such a day ... people book an appointment, and I do the operations at (their) home," she said.
"There are girls who can't find doctors in Upper Egypt, and this subject is very difficult to talk about or raise awareness there because it's a very conservative society," she told the Thomson Reuters Foundation by phone.
Over the last nine years, she has performed some 1,500 operations, about a third of which she carried out free-of-charge for particularly vulnerable women, she said.
Egypt's health ministry and its National Council for Women, which do not have data on hymenoplasties or honour killings, declined to comment.
Human rights groups say thousands of women and girls are killed across the Middle East and South Asia each year by family members angered at perceived damage to their "honour".
'UNTIL SOCIETY CHANGES'
While hymenoplasty is legal and relatively safe if conducted by a certified gynaecologist, it remains controversial in Egypt.
Randa Fakhr El-Deen, executive director of the NGOs' Union on Harmful Practices against Women and Children, runs sexual health education workshops teaching participants – among other things – that hymens can be torn through sport or car accidents.
Others view the surgery as a pragmatic way to help protect women from the risk of honour violence or shaming.
"Until society changes its perspective on this issue, women should be really encouraged to do them," said Reda Eldanbouki, a lawyer and executive director of the Women's Center for Guidance and Legal Awareness, a feminist NGO.
The religious stance on hymen reconstruction in Muslim-majority Egypt is also unclear, with some clerics insisting it should only be permissible in cases of rape.
But a scholar at Dar al-Iftaa, a leading Egyptian Islamic institute, told a recent Facebook broadcast that women seeking to change course in their lives after having had pre-marital sex could also get a hymenoplasty.
"One of the cases in which hymen repair is legitimate is ... if the girl was deceived and wants to repent," said Ahmed Mamdouh, director of the institute's Department of Sharia Research.
Growing anxious as her wedding day drew near, 26-year-old Nour Mohamed pinned her hopes on a herbalist offering a concoction he said would stimulate bleeding during intercourse - giving the impression that her hymen had torn.
After breaking up with her boyfriend several years ago, she was under pressure from her family to marry, but needed a low-cost way to let her husband-to-be think she was a virgin.
"It was a nightmare - I would have either been killed or exposed by my husband. I could not afford a hymenoplasty and this herbal treatment was my only hope," she said.
Asking to remain anonymous, even though his work is legal, Mohamed's herbalist said he had treated about 4,000 patients from Egypt and thousands more from Algeria and Morocco.
He charges 2,000 Egyptian pounds, but said he waived the cost in some cases to help women at risk from violence.
Without giving details, Mohamed said the herbal treatment had worked for her.
Cairo-based gynaecologist Amira Ibrahim Abou Shady said people marketing herbs and "magic recipes" online were "cashing in on desperate girls who are trying to recover what they have lost".
"They take advantage of psychological pressures that control the girl after she loses her virginity," she said, adding that surgery was the only way to restore the hymen.
While it could take decades to change deep-rooted beliefs about virginity and stamp out honour killings, Fakhr El-Deen called for a nationwide campaign to tackle misconceptions about the significance of the hymen.
"We are talking about lives here, and they do matter," she said.