An obstetrician on why those closest to Keli Lane might not have noticed she was pregnant.

Keli Lane was in her final year of high school when she fell pregnant for the first time.

It was 1992, and she told only one person about the pregnancy: her boyfriend at the time, Aaron Tyack. Lane chose to have an abortion, and according to Tyack, the decision left her “very upset”.

The event, he said at Lane’s trial almost 18 years later, “played on her mind”.

Lane had a second abortion in her late teens, followed by three pregnancies in her early twenties, all of which she carried to term. She didn’t tell anyone about these pregnancies, concealing them from the people closest to her.

When part one of the ABC’s three-part investigation, Exposed: The Case of Keli Lane, aired at the end of September, a familiar conversation was reignited: how did Keli Lane, by the time she was 24, manage to carry three pregnancies to term, and give birth to these babies, without her friends or family noticing?

Speaking to Mamamia‘s Mia Freedman on No Filter, journalist Caro Meldrum Hanna argued that, in fact, some people around Lane did notice. They just didn’t do anything about it.

Anne Bain, the team manager of the Australian water polo squad which included Lane, told Exposed, “talk was everywhere”.

“A few times the girls had said to me they thought Keli Lane was pregnant,” she said.

In particular, Bain describes one day at the pool, witnessing as Keli stood up and took off her towel. “She was side on to me and I’m a mum. I said, ‘she’s pregnant’.”

Speaking to Mamamia, Hanna said Lane wore baggy clothes and, “from all accounts, she did carry her pregnancy differently than most of us visualise a pregnant body”.

The journalist told Mia Freedman that Lane carried ‘high,’ and therefore didn’t show in that “classic sort of egg shape” we might be used to.

But still – anyone who has been pregnant, or knows a woman who has been pregnant – will struggle to understand how a young woman could conceal three full-term pregnancies. Lane’s parents, who she lived with, her boyfriend, who she continued to sleep with, and a number of her friends, who she socialised with, regularly consuming alcohol, all claim to have not noticed.

I spoke to two obstetricians about how, physiologically, Keli Lane was able to hide these pregnancies. Did her athletic build mask the extent of her baby bump? Is height or body shape a factor when it comes to how much women ‘show’ during pregnancy?

Melbourne-based obstetrician, fertility specialist and gynaecologist Dr Joseph Sgroi said the way each woman carries a pregnancy is “unique”.

“It’s a combination of not only the build of the woman but the position of the baby, the size of the baby, and also the other dimensions – the breasts, the tummy, the hips, and of course the clothing a woman wears. They’re all going to have an impact.”

Dr Sgroi said the size of a woman’s baby bump has a lot to do with “how the bits of the puzzle are all going together,” but acknowledged that there could be cases where “very athletic abdominal muscles… are sort of splintering everything in”.

Physiologically, the placenta might also be sitting in front of the baby, meaning a woman might not show until later in the pregnancy.

But perhaps the biggest factor, Dr Sgroi said, is that we’re used to seeing women celebrate the fact they’re pregnant, and not intentionally try to hide their physical changes with clothing.

“Most people are happy about their pregnancies, and therefore will show off their belly bump as soon as they possibly can,” he said.

“But I think unfortunately for some women, who, whether they’re caught up in issues of domestic violence or the pregnancy has been a result of some horrible event such as rape or after a violent episode, or they’ve got mental health issues, they might as a result of that… they’re wanting to conceal the pregnancy. It may be because of shame, it may be because of guilt, it may be for a whole multitude of reasons, that the average woman who’s celebrating her pregnancy can’t understand.”

Fertility specialist and consultant obstetrician and gynaecologist, Dr Alex Polyakov, said he has “never come across a case where a pregnancy was concealed up to delivery”.

"Denial is not common but happens occasionally," he said. "Most people would obviously be pregnant from 16-20 weeks onwards."

Dr Polyakov did acknowledge that a woman may take longer to 'look pregnant' during their first pregnancy, as opposed to subsequent pregnancies, because their abdominal muscles are not yet stretched.

"Women often comment that they look more pregnant in their second and subsequent pregnancies because abdominal muscles are stretched and the shape of the uterus is more visible," he said. "So for example most women may not look pregnant up to 16 weeks in the first pregnancy but would show at 14 weeks in the second."

In the case of Keli Lane, Polyakov said her being "super fit may have prolonged the time that she would not show".

"It is also important to consider the size of the baby, some are bigger than others and would result in more prominent bump sooner," he added.

From looking at photos of Lane in her early twenties, as well as taking note of the comments made by both her parents in Exposed, it's clear that Lane's choice of clothing played a major role in concealing her pregnancy. Perhaps her athletic build, and physiological anomalies such as the placenta sitting in front of the baby also meant the signs of her pregnancy weren't as obvious to the people around her.

Ultimately, we're not used to seeing women attempt to conceal their pregnancy, as it's usually a time in a woman's life that calls for celebration. Perhaps many more women could hide full-term pregnancies from the people around them, if they had a strong incentive to do so.