For a select few women, this could be the difference between a baby, and not. I’ll say it again: C-sections can cause infertility. Catherine Woulfe writes.

This feature was made possible thanks to reader contributions via the Spinoff Longform Fund. Click here to support our investigative journalism.

In October 2014 I had the kind of caesarean section where your bed gets whipped down to theatre by an orderly cursing “fuck, fuck, fuck” as he runs for the lift. The kind where there is no talk of consent let alone risk, and the anaesthetist has time only to ask: “are you allergic to any medication?” before slamming you under. The kind where you don’t see your little boy born.

I still cry when I talk about it. I’m crying now. But hey, as they say, we survived.

Our son was conceived the first month we tried. When he was nearly two we started trying again.

Very soon he will be four.

These last two years have been grim, numbing, month after month of nothing, nothing, nothing, bookended by very early miscarriages.

Various GPs were optimistic but by last summer, I was not: I referred myself to Fertility Associates. They carried out tests and asked lots of questions and put us in that catch-all category, unexplained infertility.

First I took clomiphene, a sledgehammer of a drug that prompts the ovaries to release more eggs. I miscarried a few days after the positive test. As the clots dropped out of me I dropped too, and spent weeks at the bottom of the sea.

We pulled out the big guns: IVF. At many times during that process an ultrasound wand gets stuck up inside you so the specialists can count eggs and measure follicles and things; one of those times, the doctor saw fluid in my uterus. The fluid most certainly should not have been there. Yet there it was again at my next ultrasound a few days later. On our specialist’s advice we decided to proceed with egg collection, but freeze any embryos until we could figure out what that fluid was, and deal with it.

On the way home I googled some variation on “fluid uterus fertility”. Holy shit, I said to my husband. Love, there’s a thing that happens where a caesarean scar heals in a weird way and makes you infertile.

Holy shit, I said, scrolling, scrolling, all that confusion and loss abruptly crystallising, clicking into place. It was the c-section.

MRI confirmed the diagnosis. I had a caesarean scar defect, also known as a niche, pouch, isthmocele, diverticulum or caesarean scar syndrome.

Picture a tiny cave, a pocket scooped out of the muscly inside wall of the uterus.

Now picture it filling up with period blood every month and holding onto that blood for a week or so, while also weeping its own inflammatory nasties into the mix.

It’s objectively gross. Medical professionals call the mixture “cytotoxic” and that’s a word you don’t want anywhere near your uterus: it means “toxic to living cells”. Sperm are living cells. So are embryos.

On top of that, the constant inflammation caused by the defect had likely changed the nature of my uterine lining, making implantation – the bit where the embryo burrows in and pregnancy technically occurs – much more difficult.

In short, this thing was comprehensively zapping our chances. And not just ours.

As I interviewed specialists and read through the medical literature I came to understand this is a condition on the cusp. Right now hardly anyone knows about it. Many of those who do are convinced – even in the absence of gold-standard randomised controlled trials – that it’s causing infertility, and that it’s time to start informing women.

“Knowledge is power,” said Dr Farr Nezhat, a pioneering obstetric and gynaecological surgeon who heads a private clinic in New York City. “I definitely think women should know, and I don’t believe you are going to scare anybody.” Wellington fertility specialist Dr Simon McDowell thinks I might, actually, but still comes down firmly on the side of informed consent. He works at Fertility Associates (he has not treated me) and spoke on behalf of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

“I do think this is a cause of infertility, I do, and I think it’s one that is probably unrecognised in many situations,” he said. In other words: there are women out there who, like me, have no idea this thing is stopping them getting pregnant.

“I think the College position is that women should be informed, absolutely.”

The trick is to convey information about risk and symptoms in a way that doesn’t cause undue anxiety and over-treatment, McDowell said.

Off we go.

If you’ve had a caesarean section, there’s a good chance you have a defect. In one study researchers scanned 162 women after the procedure and found that after one c-section the risk of defect was as high as 61%. After three c-sections things got very black and white: a woman’s looking at a 100% risk.

We don’t know for sure what causes defects, although aside from multiple c-sections, we know that having a retroflexed (backwards-facing) uterus increases the risk. It’s thought that if a woman is well into labour when a c-section becomes necessary a defect is more likely to form, because the uterine wall thins during labour and is less able to knit back together properly.

Surgical techniques have also been red-flagged. Single closure – in which the delivering obstetrician uses one “bite” of the needle to stitch closed the two layers of the uterine wall – saves time but has been repeatedly identified as possibly contributing to defects. It remains the norm in some countries. In New Zealand, McDowell assured me, obstetricians are trained to carry out double closure, where they stitch the layers closed one at a time.

He emphasised that defects are usually not a problem.

It’s thought that for about one in three women, a defect will cause abnormal bleeding. Some will have chronic pelvic pain, pain during sex or extraordinarily painful periods.

Dr Ceana Nezhat in Atlanta, Georgia stressed that these side effects, in themselves, can be significant. “In the last year I have seen over 10 patients experiencing pain and irregular bleeding with various degrees of caesarean scar defect.”

(Nezhat is the medical director of training and education as well as director of minimally invasive surgery and robotics at Northside Hospital, which delivers more babies – 21,000 per year – than any other community hospital in the US. He is one of three Nezhat brothers who contributed to this story.)

None of those interviewed for this story would take a punt at how often defects cause infertility. It’s a hole in the data, perhaps the most significant one.

But they all point to the very big number hanging over the top of all this: the c-section rate.

Our most recent figures are from 2015 and that year in New Zealand, the rate hit 25%. That’s 14,859 women.

How many of those now have a defect? Let’s be optimistic and use the bottom of a sprawling 19-84% range often cited in the literature. Our best-case scenario, for that year, is 2,823 defects.  Hundreds of those women are likely in pain, or experiencing strange bleeding. We don’t know how many of them are now infertile. But it can be fixed.

Surgeons have been successfully repairing caesarean scar defects for 17 years. One paper, published in January, put the number of reported cases – that is, repairs that doctors have written about in medical journals – at about 1,200 since 2005. Sometimes surgeons come at the defect with instruments inserted through the cervix. This is called hysteroscopy. The other option, which I had, is laparoscopy: basically, the surgeon attacks the defect – delicately, of course – from the smooth outside wall of the uterus. To find the defect, surgeons often insert a tiny torch through the cervix, shine it at the uterine wall, and look for the spot where it glows brightest.

Much of the recent literature about defects focuses on which type of fix is better. On the face of it they’re both astonishingly good, but McDowell warned that all we have to go on so far are case reports. “We talk about five levels of evidence and that’s level five evidence.”

As in bad end?

“Bad end.”

The crux of it is we don’t have the counterfactuals: how many women would have fallen pregnant without the surgery? McDowell said the numbers of suitable candidates for treatment are so low as to make it almost impossible to garner the statistical firepower necessary for a randomised controlled trial.

And, he agreed, no infertile woman is going to put her hand up for a trial that could see her drafted into the control (non-treatment) group.

So here’s where we are.

In a 2016 paper two Canadian experts examined data from 32 trials and found that after surgery to correct a defect, symptoms of spotting and bleeding resolved in upwards of 60% of women. As for fertility?

Laparoscopic repair carried a success rate – a pregnancy rate – of 86%. The hysteroscopic surgeries led to a pregnancy rate of 77.8% to 100%.

The authors couch these numbers in caution: “Treatment should be reserved for selective cases,” they write – and only after eliminating other possible causes of bleeding or infertility. As I read this bit I picture McDowell nodding furiously.

He said he would have operated on me, but I’m a rarity – a textbook candidate for surgery. Young and healthy, spontaneous conception first time around; weird bleeding since c-section; secondary infertility with other causes ruled out; defect confirmed.

When we first spoke McDowell had never offered surgery to remove a defect – he’d not struck a case where he’d been convinced it would help. A few days later he emailed: “This is a bit crazy, but I saw someone this morning who will need a repair … The most profound defect I’ve ever seen. She is having spotting almost daily for most of the month. We simply cannot put an embryo back until that is sorted!”

My gremlin was excised three weeks ago, leaving me with four tiny cross-shaped scars on my tummy (“kisses on your tummy, Mummy!”) plus a bigger one through my belly button.

The defect had eaten so far into my uterine wall it was easy for my surgeon to see the light shining through from inside. The wall was just 2mm thick, which according to the literature makes my defect “significant”. Membrane, my surgeon called it – not muscle.

Q&A: Caesarean scar defects and fertility: what you need to know

At this point, I am obliged to mention two scary, but rare aspects of these defects.

First: defects provide another site (along with the fallopian tubes) for an ectopic pregnancy. Like those in the tubes, such a pregnancy is unviable and extremely dangerous for the woman. Susan Willman, a fertility specialist from California, explained: “In this situation, the placenta implants on the defect, which does not have the normal layers of endometrium and muscle wall and the risk is that the pregnancy causes internal bleeding early in the pregnancy.”

Nightmare scenario: that bleeding is misdiagnosed as an ongoing miscarriage and surgeons unwittingly perform a D&C, scraping an already precariously thin uterine wall.

In New York, Dr Farr Nezhat is treating two women who have had caesarean scar pregnancies terminated and are awaiting surgical repair of the defect. “It is better to repair and correct it before getting pregnant,” he said, firmly.

Second problem: defects – even those that are asymptomatic – can cause the uterine wall to be so thin that it ruptures during pregnancy or labour, causing internal bleeding that can threaten the life of both baby and mother. Willman said the incidence of this is thought to be about 1%. I was told if either of my pregnancies had made it to the third trimester I’d have been at severe risk of rupture.

Terrifying, I said. Right, Willman agreed. “I had a patient who lost the baby. She was cleared for labour. And so when she went into labour, she took her time packing her bag to get to the hospital. [Her scar defect] ruptured at home and the baby delivered out of the rupture and was dead on arrival. It was horrible. Horrible.”

Unsurprisingly, Willman is adamant that this thinning of the uterine wall deserves more attention – perhaps pregnant women who have had a c section should be routinely scanned, she said, to help determine whether they are a good candidate for vaginal birth.

If a caesarean scar defect is a dark, confounding pocket, data on the condition in New Zealand is a black hole. A vacuum. It’s baffling. Here’s the best I can do: my surgeon, Sunil Pillay, has performed six other defect repairs since 2009. Five of these women went on to become pregnant. He seems to be the go-to defect guy – he has heard of only one other specialist who has performed the surgery, in Hamilton (our calls to confirm this, and to other fertility clinics, have not been returned).

Emeritus Professor Charlotte Paul, an epidemiologist at the University of Otago, sees two factors in play here.

“First, newly recognised or suspected complications of surgery are not routinely reported,” she said in an email. Medicines are subject to a long-established national reporting system, linked in turn to the international oversight of the World Health Organisation (WHO).

For medical devices there are fewer safeguards in place, but Medsafe has set up a system to monitor adverse events. It has the power to recall products from the market.

Surgical complications take what could charitably be called a scenic route.

“These are likely to be reported in the medical journals and, when there is sufficient evidence, bodies responsible for developing guidelines would incorporate information in their guidance.”

For caesarean section, that body would be the Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

The college is yet to develop any guidelines around the defects, Simon McDowell confirmed. He suspects that will happen in the next few years, but due to what’s likely to be a continued lack of good evidence, they could be “a bit waffly” – along the lines of “be aware and seek help if you’re concerned”.

We’re not alone in the lack of guidelines. Japan is the only country I’ve come across that has made a decent start. Three years ago the Japan Society of Obstetrics and Gynecology were surveying hundreds of hospitals and fertility clinics about their experiences and success rates, and testing new diagnostic criteria.

Back to Charlotte Paul and her second theory about the lack of awareness, let alone clinical clarity, around defects. Simple: “perhaps the evidence is not yet strong enough.”

She put this to a contact at the WHO, Cape Town ob-gyn Dr Thabo Matsaseng.

“There is some evidence that subfertility may be a secondary outcome of caesarean section uterine scars defects,” he responded. “Before any recommendation could be made by WHO, a systematic review would need to be undertaken.” (We have sent questions direct to the WHO and await a response.)

In my head, McDowell’s nodding again.

He makes the point that if problematic defects were anything but very rare, we’d see that infertility coming through in the massive studies that scrutinise fertility rates after caesarean section.

This is a fraught, tangled area of research. Results – and interpretations – vary widely.

Late last year Edinburgh researchers crunched the data from 80 previous studies, giving them a sample of almost 30 million women. They concluded that a c-section makes subfertility 1.6 times more likely, and that for every 1,500 women who have a c-section, 166 will be left with subfertility.

French obstetrician Olivier Donnez and co-authors, in a well-regarded 2017 Fertility and Sterility paper, boil it down thus: “The risk of infertility [after caesarean section is] estimated to be between 4% and 19%.” They echo other academics in stressing that even if the truth lies at the bottom end of that range, “it nevertheless has a considerable impact in view of the large numbers of [caesarean sections] performed globally”.Susan Willman’s reading of the literature is that caesarean sections compromise fertility in 5-10% of women. She’s looking at massive studies that throw up correlations between c-sections and infertility – and at IVF studies that are able to zoom in more closely.

One such study, published in 2016, followed 975 women through two rounds of treatment. The first time, just over half of the women gave birth via c-section. When these women came back to try for another child – using embryos frozen during their first treatment – they were less likely to manage a viable pregnancy than those who had given birth vaginally. The difference was significant: 53% versus 62%.

Here’s the problem: the factors that prime a woman to have a caesarean section – age, in particular – also tend to prime her for infertility. These “confounding factors” are not always accounted for in the studies (some are in the IVF one, as are many in the Edinburgh study) but McDowell believes they account for the gap in fertility between women who have c-sections and those who have vaginal births. If women like me are in that data, they’re huddled in a corner, out of sight.

His takeaway: “There’s been no definitive causal link between caesarean section and subfertility, or trouble getting pregnant.”

So. Should women be routinely checked for scar defects after c section? No. He’s sure on that. “You’ll find a problem which doesn’t exist … You’ll end up trying to fix people who aren’t broken. The vast majority of people with a niche will get pregnant without any problem whatsoever so if you start checking them, you add anxiety and concern.”

Worse: we may wind up over-treating women. Corrective surgery carries its own risks and “should be quite an uncommon procedure.”

Informing women, on the other hand, should be routine, but it should be done thoughtfully. He wouldn’t want women who need a caesarean section to avoid it because of defects. He would certainly inform them of the risk, though.

He would have a slightly different conversation, perhaps, with a woman wanting a caesarean purely for convenience, or to protect her pelvic floor. (Neither scenario happens often, he emphasised.)

“I think it should be talked about there. It should be a reason [not to do a c-section]. You know: first do no harm. It’s conceivable that if someone has an unnecessary caesarean section they then unnecessarily have infertility. That’s possible.”

First do no harm. He keeps coming back to it. “You only do something if you know it is necessary. Hence, we shouldn’t routinely treat niches and we shouldn’t routinely do a caesarean section. We should just make sure we make good decisions.”

What about women reading this story and thinking they may have a scar defect? “My advice would be what I would say to all women: have kids early, and if you’re not having success seek help from a specialist. And don’t assume that you’re going to have problems getting pregnant because you had a caesarean section – but a well-trained fertility specialist will consider that as a possible cause.”

But most GPs don’t know about defects, McDowell believes, and even some fertility specialists don’t give the condition the consideration it deserves.

What I’ve gleaned from infertility forums is that my story is typical of women with a problematic scar defect. We tend to blunder around in the dark, clutching at clomiphene and IVF and acupuncture and organics, before finally – if we’re lucky – fluking a diagnosis.

“My doc didn’t believe me, so I literally had to take to PubMed and print out literature for him, because it is not commonly known or understood,” wrote one woman in 2015.

Last year, another wrote this: “After several years trying and [being] told I had unexplained secondary infertility the scar defect was only identified by a routine scan … after many invasive investigative surgeries. I too had constant brown bleeding and fluid in the c section pouch … I too am wondering why the the consequences of these defects are only now coming to light.”

In November, a mum called Michelle shared her long, harrowing story on the website of a US specialist known to be experienced with scar defects (I asked him for comment and haven’t heard back). She was initially told she was likely in menopause, or suffering from cancer. Even after a defect was finally diagnosed, finding a surgeon was a battle:

“I went to six doctors here in Houston, after all, this is Houston with one the best medical centres in the world. Only one of the doctors had performed the surgery one time.” She ended up flying to Chicago for the op.

Susan Willman estimates only about a third of fertility specialists – fertility specialists – in the United States have heard of defects and what they can do to fertility. The website of the clinic she headed until recently is the only one I’ve found that gives patients good information about defects.

“I think the actual numbers [of women with fertility compromised by a defect] are small,” she told me. “But I do think it deserves increased awareness.”

Of all those interviewed for this story, Dr Camran Nezhat, a prominent surgeon based in Northern California and known for his work with endometriosis and minimally-invasive surgery, has by far the most experience with treating caesarean scar defects. He performed the first laparoscopic repair of a defect in 2001, and estimates he’s performed corrective surgery on more than 50 women since (Willman has had four patients with problematic defects and performed one surgery; Farr Nezhat has repaired six in the last two years; Ceana Nezhat, nine).

Nezhat has not stopped to formally collate his data but “consistently the result has been very positive”, he said.

“The majority of the patients get pregnant soon after the required three month healing period following surgery.”

How do all these women find Nezhat?

It’s mostly word of mouth, he said. Women telling their friends: women who are proactive and have the resources to do their own research.

“We’re close to Silicon Valley. Patients here are highly educated and do their research prior to seeking out a specialist.”

He has never spoken to a reporter about caesarean scar defects, or seen them mentioned in mainstream media (nor have I, unless you count a perfunctory piece that ran in regional papers in India last week). He was eager to help with this story and with my defect. He offered to perform my surgery, to advise my surgeon. Women have come to him from Australia seeking his expertise, he said.

I asked him whether the science is strong enough at this point to really be relied on. Are we in a position that we can say: yes, this is causing infertility and it can be fixed?

“There is no question. Definitely the science is there.”

Yet awareness is not.

“The majority of reproductive endocrinologists and infertility specialists don’t even know about it. I have seen it over and over. They are not aware that this entity exists.

“A lot of physicians don’t believe it causes problems and don’t refer their patients. And a lot of patients end up giving up. But some patients, when they try IVF they do not get pregnant, then their physicians refer them.” In recent years he’s noticed more referrals.

Still: all those women giving up; all those women, trying and trying. I asked Nezhat if he shares my frustration, my sense of urgency.

“Absolutely.”

His feelings transcend even the constraints of academic writing. Here he is as lead author in a Fertility and Sterility paper published in praise of Donnez’s, heralding it as “a critical rebirth” in the literature.

“Caesarean scar defects have been described for 20 years, and laparoscopic repair has been performed for over 15 years; yet patients may have pain, bleeding, and infertility for years before they find a physician who is familiar with the diagnosis, let alone the treatment of a niche.”

The defects are “currently underdiagnosed and may consequently be left untreated at a staggering rate,” he wrote.

“There remains a paucity of quality literature on and attention given to the topic. In this day and age, the media spreads viral stories at an explosive pace, yet acceptance of medical and surgical treatments still lags decades behind their discoveries.”

Nezhat told me he saw the same lag when he pioneered minimally invasive surgery – a variety of which I had, with the tiny incisions and startlingly short recovery time.

“There are many techniques that my team and I invented more than 30 years ago and they were associated with opposition for many years. Now, the whole world wants to do them.”

Likewise, Nezhat predicts the repair of defects is going to become a very common procedure. “Just give it time, perhaps, 10 to 15 years.” That sounds like a long time.

“This is the history of medicine: everything takes a long time.”

Here’s what I’d like to see happen right now. Every person quoted in this story backs me on it, albeit McDowell tentatively.

Add a sentence or two to the pamphlets women take home from hospital after having a c-section. Something informative but not too alarming. Along the lines of: “For a minority of women defects in the caesarean scar can cause infertility. If you’re struggling to conceive, or if you have unusual pain, bleeding or spotting, tell your doctor.”

Too much? Consider the warnings directed at pregnant women and new parents, every step of the way. We are warned about drinking while pregnant, about sushi, sugar, weight gain, paracetamol, sleeping on one’s back, sleeping with baby. A heads-up on risk and symptoms of defects would be just one more for the list.

“You’re right,” said McDowell. “I think that’s a fair point.”

What he knows, and I now understand in my bones, is that in the infertility game, it all comes down to time. Time is two lines on a pregnancy test. Time is getting to haul the high chair out of the garage. Time is a little brother or sister.

Two months, now, before we’re cleared for launch. We plan to transfer one of the embryos frozen back in autumn.

For us, an early diagnosis could have saved two years, two miscarriages and a stack of cash. It could have changed the shape of our family. Even if everything proceeds at pace, our children will be waving at each other across a five-year age gap.

Of course, those two lost years could still prove to be the difference between one baby and two. I’m 35.

The journal references cited are linked throughout the text above.

C-sections can cause infertility. Pass it on.

Update 22 May 2020: Catherine conceived naturally shortly after this piece was published and her pregnancy and second c-section were problem-free, although she has been told any future pregnancy would be dangerous due to thinning of the uterine wall around the site of the defect. She was successful in her ACC claim for treatment injury – including for the cost of infertility treatment prior to diagnosis – and advises anyone in a similar position to get a lawyer involved. 

Her little girl Leonie is about to turn one. 

You can read more here, and contact the author on bycatherinewoulfe@gmail.com

Q&A: Caesarean scar defects and fertility: what you need to know

This feature was made possible thanks to reader contributions via the Spinoff Longform Fund.
Click below to support our investigative journalism