'I'm a mother of 'twins'. They were conceived 18 days apart.'

Six years ago, Sandra Searle sat in a fertility clinic with her husband David wondering if she would ever become a mum. Just a few years later the couple are juggling a busy and joy-filled life as parents of four kids under five. 

Not only did Sandra and David's dreams of parenthood come true following a cancer diagnosis and fertility challenges, but they recently welcomed ultra-rare 'superfetation twins' - conceived 18 days apart - to their family. 

"I wanted to share our unique story to give people hope," Sandra tells Mamamia about her journey to becoming a mum of 'medical miracle' twins.

"There are so many sad stories associated with fertility treatment, but good stuff happens too! Despite the odds."

Back in 2015, life looked very different for the married couple after doctors diagnosed David with testicular cancer. He endured surgery and months of chemotherapy before getting the all-clear. They froze some of David's sperm just a few days before he started treatment "just in case", and were also told to wait for 12 months before trying for their longed-for family.

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"We soon realised that we weren't able to conceive naturally and the fertility clinic discovered I had a low egg count which added to our conception woes. We then went through a year of fertility treatments before starting our first round of IVF. 

"Only six of my eggs survived the first retrieval process that resulted in one embryo which was implanted. It was a nail-biting week before we discovered I was pregnant! Our daughter Georgia was born in August 2018 and we were immediately besotted! We knew we would have to do it all again."

After Sandra stopped breastfeeding Georgia at 12 months, she returned to the fertility clinic. This time they retrieved just three eggs that resulted in two healthy embryos. 

"After another anxious wait, we were overjoyed to be given good news: I was pregnant again and our son Fred was born in June 2020. While we adapted to life as a family of four, we froze the last embryo, for possible future use."

In 2022, when Georgia was four and Fred was two, Sandra and David felt like it was a good time to go ahead and implant their final frozen embryo.

"We thought, let's just give it a crack and if it doesn't work, we can move on. But when I started the IVF cycle in August with the fertility clinic following what seemed like my 'normal' period, we didn't know that I was actually already pregnant!

"It was more good news, but I was surprised when I began to feel nauseous almost as soon as I found out I was pregnant from the IVF clinic. We assumed it must be the different medication, as I typically hadn't felt sick until around six weeks. They also told me my levels were very high and asked if we had unprotected sex during the cycle, which we hadn't. With the unusual results, there was concern perhaps the pregnancy was ectopic, so they sent me for a scan.

"The sonographer was very surprised to discover that there was a seven and half week old baby with a heartbeat alongside the expected five-week-old embryonic sac! It made no sense."

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The director of the clinic arrived to confirm the findings of 'superfetation twins' - a condition so rare there have only been 10 reported cases worldwide.

What it meant for Sandra was that despite all the tests and her regular period, Sandra had conceived naturally approximately 18 days before the embryo was implanted by the clinic. Surprise and joy soon turned to shock and concern as the couple worried the 'twins' wouldn't survive.

"Throughout the first trimester, we didn't know if we were going to get the end with the two babies. We went back to the clinic for blood tests every week and all was well, but at my seven-week ultrasound where they confirmed a heartbeat for the younger baby, I started spotting. I'd never experienced that before in my two other pregnancies and it panicked me. I thought one might not hold on much longer. 

"Thankfully, the scan revealed both pregnancies were okay and then I had to explain this whole wonderful story to my obstetrician."

Sandra continued to be reviewed regularly due to the spotting and was diagnosed with placenta previa.

"It was a really challenging pregnancy because mentally I couldn't prepare myself for twins because I was always that maybe it wasn't going to happen. That something would go wrong. I didn't actually feel better until I reached a gestation where I knew the babies could be delivered.

"My obstetrician told me before Christmas last year that I needed to prepare myself to go into the hospital early for bed rest because of the unusual situation. I wasn't allowed to leave the Perth metro area because she said if I began to haemorrhage I needed to be at a hospital within 20 minutes. It was scary."

Thankfully, the bleeding stopped just after Sandra surpassed 20 weeks. She was no longer in the highest-risk category and could stay at home a while longer. 

"They did not admit me to the hospital until the younger twin was 33 weeks. Considering we had been planning for the birth from 24 weeks - this felt like an incredible feat!

"Initially, my obstetrician wanted to get me to 39 weeks with the older twin and 37 and a half weeks for the younger twin because she was trying to find the right balance of delivering both babies at a good gestation, while also trying to keep me safe. Mentally I was hoping to have them earlier as it had been such a stressful pregnancy with all the scans and worrying -  but I knew it was right for the babies.

"In the end, however, they actually came two weeks early as I went into labour naturally. My scheduled c-section turned into an emergency one and our superfetation twins, Poppy and Michael were born on April 11, 2023. Poppy was our eldest twin born at 37 weeks and four days weighing 3010g and Michael, the youngest was born at the gestation of 35 weeks weighing 2045g."

The twins. Image: Supplied.

The c-section itself was successful but there were some terrifying moments, especially for the younger twin Michael, who was born weighing much less than expected.

"Poppy was delivered first and when she came out, she cried. Michael actually flatlined and was rushed off straightaway by a paediatrician. Thankfully, he only needed breathing support for a few hours but because he was premature at 35 weeks, his arrival was definitely more challenging. Both of them were in NICU for the first three days but came around really quickly, which was a huge and wonderful relief."

Three months on from their dramatic arrival and the twins are going well. Sandra says they are settling into life at home with their older "besotted" siblings and that Michael is even beginning to catch Poppy up.

"They sleep in the same cot at night, a separate cot for day naps and we have a twin pram where they can lie side-by-side. They look incredibly different to me but they look a lot like their siblings. Michael was tiny in comparison to Poppy but now they're they're actually looking quite similar in size, which is good to see. 

"Developmentally, you can tell that they're nearly three weeks apart. Poppy started smiling around the six-week mark and we had to wait a good couple of weeks for Michael to catch up so it was weird because you don't get to experience that same joy at the same time. I'm imagining that's just going to happen the whole way through the first year and then the milestones will even out."

While parenting four kids is busy, Sandra says that David taking four months off work in his role as a school teacher, has actually been great for the family.

"I've always really enjoyed the postpartum period, which I know is weird but I love newborns! I love how tiny they are and so we've actually been really enjoying our time together."

The story of the twins' ultra-rare conception and birth is still much talked about in the local community and beyond. 

"Michael had to have a hip scan at our local hospital recently and the sonographer commented about him being one of 'those twins'. 

"They are famous!"

Laura Jackel is Mamamia's Family Writer. For links to her articles and to see photos of her outfits and kids, follow her on Instagram and TikTok.

Feature Image: Little Rabbit Photography.