A British woman lost three of her four quadruplets due to an unusual pregnancy complication, but her remaining child was born healthy.
Tracy Allcock, 40, was traveling with her family in Turkey in July 2014 when she discovered she was five weeks pregnant, the Daily Mail reported on Oct. 27.
Allcock, already a mother of five, was taken aback by the surprising news.
"I was getting stomach cramps but I just thought it was because we were on [vacation]," Allcock told the Daily Mail. "I had no idea I was pregnant."
"I’ve already given birth to five children, so I knew what it felt like to be pregnant," she said. "But this felt different."
Allcock explained that she and her husband, Sean, had no plans to add to their family, and that they had been using contraceptives.
Doctors, who first believed that Allcock was carrying twins, discovered that she was experiencing a rare ectopic pregnancy in which one of the embryos had implanted in her fallopian tube instead of her uterus, according to the Daily Mail. The other embryo was growing normally in her utuerus.
Doctors told Allcock that she had to undergo an emergency surgery to stop the fallopian tube from rupturing, which would potentially endanger both her life and the life of the fetus in her uterus.
Surgeons then successfully removed the embryo from Allcock's fallopian tube without harm to the remaining fetus, the Daily Mail reported.
"When the surgeon came to see me afterwards and told me he had never performed such an operation before, I was so relieved that both the baby and I had survived," Allcock said.
"When I saw his heartbeat on the scanner I cried with relief. It was so amazing that he had hung on throughout the operation to remove his sibling."
She gave birth to a healthy baby boy, George, in March 2015.
When Allcock and her family returned home to Shropshire, England, after the operation, scans taken at 10 weeks and 20 weeks into the pregnancy showed two more empty embryonic sacs in her womb, neither of which had a heartbeat.
The discovery revealed that Allcock had actually been carrying quadruplets, not twins as the doctors had originally thought. Of these four embryos, only one ultimately survived.
Jane Denton, director of the Multiple Birth Foundation in England, told the Daily Mail that, while it was unusual for an embryo to implant in the fallopian tube during a twin pregnancy, the condition was "extremely rare" for a quadruplet pregnancy.
'We have never heard of another case like this," Denton told the Daily Mail.
"It is probable that three embryos were fertilized, then one split into two and went into her fallopian tube to cause the ectopic pregnancy," she said.
Allcock said she was shocked by the news that she had been pregnant with quadruplets, but grateful that at least one of her babies had survived.
"I couldn’t believe it when doctors told me what they had found — to have conceived quadruplets whilst I was on the contraceptive pill is remarkable," she told the Daily Mail.
"It makes George’s survival even the more amazing — to think that I had been pregnant with four babies and he is the only survivor. He is truly a miracle."
Ectopic pregnancies occur in 1 out of about 90 cases in the U.K. every year, according to statistics published by the country's National Health Service.