The Keli Lane series probed a disturbing theory about her secret pregnancies.

Keli Lane was 21 when she gave birth to daughter Tegan at Sydney’s Auburn Hospital in September 1996. Two days later, she attended a friend’s wedding alongside her boyfriend Duncan Gillies, but there was no sign of the baby, no acknowledgement the child had ever existed.

In 2010, a jury determined that Keli had murdered the newborn. Yet no body or weapon has ever been found, and Keli, who is currently serving 18 years in Silverwater Women’s Correctional Centre, maintains her innocence. In her version of events, Tegan’s father, a man named Andrew Morris/Norris (Keli is not certain which) with whom she’d been having a casual affair, took the baby home from hospital with the intention of raising her. This man has never been located.

Instead, Keli’s conviction hinged largely on circumstantial evidence, including a series of lies she’d told about secret pregnancies.

Tegan was the result of one of five pregnancies the Australian water polo player had experienced in just seven years; all of which went undetected by her family, friends, teammates, and even Gillies. The fate of the other four later became known: two were terminated, two were carried to term and the babies adopted out.

These unwanted pregnancies, and her concealment of them, was a critical element of the high-profile trial. One of the many loose ends from the case that investigative journalist Caro Meldrum-Hanna attempted to tie up in recent ABC documentary series, Exposed: The case of Keli Lane.

The pursuit of an answer, Caro told Mamamia‘s No Filter podcast, led her to a particularly disturbing theory.

Abortion doping.

“It’s a performance enhancing thing in women’s sport where you fall pregnant and you experience this window of incredible performance, basically. And then you carry the pregnancy to a certain point and then terminate, and you keep doing that over and over again. It’s this natural drug, essentially,” she said.

“I went down that rabbit hole… thinking, ‘Was she getting up to that? Could that be part of it?'”

What is abortion doping?

The concept of abortion doping is based on the unproven theory that the surges in oestrogen and progesterone that pregnant women experience may improve their athletic endurance.

Rumours of the practice first surfaced during the Cold War era, during which western media alleged a number of Soviet Bloc countries had abused and impregnated young athletes to gain a perceived advantage at the 1956 and 1960 summer Olympics.

It was never proven. But then, in 1994, German television station RTL aired an interview with Soviet gymnast Olga Kovalenko (nee Karaseva), a gold medallist from the 1968 Mexico Olympics who leant new weight to the rumours.

As The Sunday Times reported, “Kovalenko claimed that the practice was widespread among champion Soviet athletes during the 1970s. She said girls as young as 14 were ordered to have sex with their coaches if they had no steady boyfriend. In her own case, she added, ‘I was told that if I refused I would not have been sent to the Games.'”

But in an extraordinary twist, Kovalenko later claimed it wasn’t her in the interview, that the network had spoken to an impostor.

The disputed interview had been the only ‘confirmation’ of abortion doping.

Ultimately, Caro Meldrum-Hanna and her team concluded the concept didn’t fit with Keli Lane’s story.

“Pattern didn’t make sense,” she said. “[She was] carrying the children for too long and then, obviously, continued to carry [three of] them to full term.”

The closest Exposed came to an explanation for Keli’s unwanted pregnancies and her attitude toward them came from the athlete’s past.

Speaking to the series, Keli revealed that she had been sexually assaulted – date raped – when she was just 15 years old.

“I was quite young, I was intoxicated. I think the lack of ownership… I don’t think I valued my body and my choices and my boundaries, because everybody just seemed to be so frivolous with it,” Keli said.

“And I think for whatever reason me feeling out of control, that all contributed to my choices… falling pregnant and not knowing how to manage it.”