The first-ever womb transplant in the UK has been hailed as the "dawn of a new era" in fertility treatment.
A 40-year-old woman, who already had two children, decided to help her 34-year-old sister, who had been born without a uterus.
Now, six months on, the recipient is having periods and is preparing to eventually have her own embryos implanted, already created via IVF with her own eggs.
Professor Richard Smith, one of two lead surgeons during the operations, said it had been a "massive success", describing the joy he shared with the sisters during a clinic one month on.
"We were all in tears - it was a very, very emotional," he said.
"I think it was probably the most stressful week of our surgical careers, but also unbelievably positive.
"The donor and recipient are just over the moon."
The recipient lives in England, and she and her sister do not wish to be named.
The surgery was carried out one Sunday in early February at Oxford's Churchill Hospital by a team of more than 30 staff.
The operation to remove the donor's womb lasted more than eight hours.
Before the uterus was taken out, surgeons had already begun operating on her younger sister and after a further nine hours and 20 minutes, the transplant was complete.
The surgery was funded by Womb Transplant UK at a cost of £25,000, which included paying the NHS for theatre time and the patients' hospital stay.
Surgeons and medical staff were not paid for their time.
"I'm just really happy that we've got a donor, who is completely back to normal after her big op, and the recipient is… doing really well on her immunosuppressive therapy and looking forward to hopefully having a baby," said Prof Smith, who is the charity's clinical lead.
The transplant is expected to last for a maximum of five years before the womb will be removed.
The chair of the British Fertility Society, Dr Raj Mathur, described it as "a remarkable achievement".
"I think it's the dawn of a new age, a new era in treating these patients," said the consultant gynaecologist.
"You have got to remember some of these patients are the most difficult fertility situations that you can imagine - they are either born without a uterus or they have lost the uterus for reasons of cancer or other problems, for instance in labour.
"Up until now we have really not had any way of helping them other than surrogacy."
Isabel Quiroga, consultant surgeon at the Oxford Transplant Centre, and fellow lead during the operations, said they had been ready to attempt the first transplant before the pandemic.
"We are just delighted that this day has come," she said.
"The whole team worked extremely well - it was an incredibly proud moment."
For now, the plan is to focus on living donations from a relative with up to 30 transplants a year, but many women have come forward to offer their wombs.
"We have women contacting the charity… such as young women who say: 'I don't want to have children, but I would love to help others have a child' or 'I've already had my children I would love other women to have that experience'," said Miss Quiroga.
Other countries, including Sweden and US, have already carried out womb transplants, ultimately resulting in successful births.
A second UK womb transplant on another woman is scheduled to take place this autumn, with more patients in the preparation stages.