Leanne Allen, 37, of Gosport, Hampshire, was evaluated by doctors for renal problems when they discovered a newborn baby, which she delivered 24 hours later.

According to current medical estimates, the small wonder was one of two twins who miraculously survived while her sister died in a miscarriage six months earlier.

Leanne and her husband Kevin, 35, didn’t even have time to tell their children Jayme, 14, and Mitchell, 12, about Harley’s birth on July 7, this year.

The infatuated couple called the premature kid a “real miracle” and quickly changed their way of seeing life and place of living in preparation of the unexpected birth.

Leanne, a housewife, experienced months of weariness, high blood pressure, and swollen legs.

When doctors said they had “found something they wanted to talk about” during an MRI scan, she was confused.

She added: “My kidneys and bladder were examined during my renal scan, but after that, the woman began asking me things that felt out of context.”

“She then said that she needed to tell me what she had discovered during the scan.”

“I immediately panicked, believing she had discovered a tumor. She then informed me that I was pregnant, and I almost fell out of bed.”

“I was in complete amazement when she continued by saying that I was 31 weeks pregnant.”

“She got me some water while briefly displaying the baby on the television. After that, my daughter was born, and 30 hours later I was getting ready for surgery.”

“I loved her so much even though I had only known she existed for two days when I touched her small head for the first time.”

Kevin, the store manager, added: “We went from a kidney scan to being pregnant to giving birth in less than 30 hours. I still have a hard time believing I have a new baby.

Kevin made the decision to have a vasectomy after Leanne miscarried in January because he didn’t want to grow their family.

Unaware that she was pregnant, Leanne went on a hen do in Barcelona and even drank a few rum and cokes before returning on July 3.

On July 6, as her fluid retention and kidney discomfort worsened, she was set up for an MRI scan.

Shocked when Kevin learned over the phone that Leanne was pregnant, he left right away for Portsmouth’s Queen Alexandra Hospital to be at her side.

Pre-eclampsia, a potentially deadly condition, was discovered, and on July 7 a C-section was carried out after a day of unsuccessful attempts to control her dangerously high blood pressure.

Following their brief encounter, Kevin went home to pick up the kids, who were staying with friends and were unaware of their mother’s pregnancy. Baby Harley was immediately sent to the NICU.

When they notified their son and daughter about the unexpected 3lb 8oz delivery, the parents captured their son and daughter’s reactions on camera.

Because everything happened so quickly and with such a shock, Kevin recalls, “we didn’t want to inform anyone until we knew she was okay.”

Doctors now believe that Leanne’s kidney, blood pressure, and edema problems were caused by a combination of her pre-eclampsia and pregnancy.

Harley, was in critical care due to her early delivery, but she returned home in a few weeks.

Leanne said, “When I was finally permitted to meet my little one, I was stunned by how little she was.”

“The days that followed were difficult since I could only touch her in the incubator and we were on different wards.”

“She was doing so well, though, that she stopped requiring oxygen and started drinking small amounts of milk through her tube.”

“I finally got to give her a hug on day four after her lines were taken out.”

“Harley seems to be progressing well, and I hope there won’t be any long-term effects from the ignorance of my pregnancy or from her early entry into the world.”

Kevin has quickly bought and borrowed everything from cribs and car seats to diapers and bibs in preparation for the unexpected new family member.

He said that it is simply absolutely mind-boggling to consider how different their lives were just a week ago.

“There has been a flurry of feelings. Harley truly is a miracle.”

We had no plans to start a family, and I had the snip, but the instant we lay eyes on her, our hearts melted, and we were head over heals in love.