Spain faces up to its twin phenomenon

Multiple births have increased by 287% since fertility treatment was introduced

María and Juan Antonio with their twins María and Juan.
María and Juan Antonio with their twins María and Juan.PACO PUENTES
Victoria Torres Benayas

“I was working on a TV program to do with the menopause when I got a WhatsApp message from my girlfriend who had just been to her first scan,” says Antón Cruces, 39. “‘Everything’s okay. Don’t worry,’ it said. Then 30 seconds later, ‘Honey, there are two of them’. I wrote back, ‘Two gynecologists? Great! It’s a good idea to get a second opinion.’ Which is when I realized that I was about to be the father of two human beings.”

Antón and Raquel Lubians, 36, were not expecting this.

“There are no twins in our families, so we were even more surprised,” says the scriptwriter from Pontevedra, who subsequently started a blog called “Letters to 1985” about being a first-time father to more than one.

Nobody would argue that having two or more children at once is harder than having one at a time. But the state doesn’t appear to be taking this on board

In the case of María Izquierdo, 42, and Juan Domínguez, 41, there was reason to suspect something like this, since they had undergone IVF treatment.

“We went in for the beta results [which measures the pregnancy hormone level in the blood] and the nurse told us they were positive and ‘pretty high’,” says María, who is a regional representative of the United Left party and a councilor in Mairena de Aljarafe (Seville). “So she asked how many embryos the clinic had implanted, and we said two. Then she said, ‘Hmm, I have a feeling…’ and 15 days later, it was confirmed.”

Both families are part of a phenomenon that has filled Spain with twin buggies over the last few years. Juan Antonio and María’s twins – Juan and María – are just two of the 18,746 twins born in 2014, the most recent statistics available. Antón and Tomás, Antón and Raquel’s seven-month-old twins, are among the multiple births of 2015. According to data from Spain’s National Statistic Institute (INE), multiple births accounted for 2.29% of all births in 2014 with 9,493 twins, 117 triplets and two quadruplets or more. In other words, 22.9 of every one thousand births were multiple.

These statistics mean that Spain is a frontrunner in Europe when it comes to multiple births, according to a 2013 study of 29 countries published in the European Perinatal Health Report using 2010 data. Only Cyprus, with 25.1 multiple births per thousand, the Czech Republic with 21 and Denmark with 20.9, are ahead of Spain. Comparing this study with another one released in 2008 with 2004 data, multiple births have fallen everywhere except in Spain, where they have increased.

Raquel Lubians and Antón Cruces, with twins Antón and Tomás.
Raquel Lubians and Antón Cruces, with twins Antón and Tomás.

In spite of the scope of this trend, Spain doesn’t even have a register of multiple births. The INE keeps a record of single parent families and the health service has a register of large families. But no one keeps track of multiple birth families.

To find the number of multiple births, it is necessary to resort to the INE’s birth register. Between 1999 and 2014, 262,302 twins were born – both identical and fraternal. That figure rose from 10,914 in 1999 to 18,746 in 2014. And 2009 was a bumper year with 19,674 multiple births, after which the numbers went into decline, possibly as a result of the crisis.

If all the multiples lived in one city, it would be the size of Gijón, and if we threw in the parents, we would be talking about the size of Málaga, the sixth-biggest city in Spain.

Why so many multiple births? “The main reason is fertility treatment,” says María De La Calle, head of the multiple birth unit at La Paz, Spain’s hospital of reference on this matter. In fact, between 1983 – the year in which fertility treatment was introduced in Spain – and 2014, the number of twins has tripled, rising a full 287% from 3,349 to 9,493.

“Increasingly we have children later – Italy has the highest number of mothers over 35 in Europe with 34.7%, followed by Spain with 29.5%. So it’s becoming more and more common to resort to fertility treatment,” says De La Calle. “Spain conducts the third-highest number of fertility treatments in Europe, behind France and Germany.”

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At the same time, the mother’s age is a risk factor: she is four times more likely to get pregnant with twins naturally between the ages of 25 and 35.

Other factors include the country of origin. “Black people have the highest possibility of having twins, and Asians the lowest,” says De La Calle, adding that having children also increases one’s chances, as does a genetic tendency on the mother’s side. It’s also the case that more twins are born naturally to bigger women, and that diet could also play a role. “This theory is very fashionable but there is no scientific evidence to support it,” De La Calle observes.

How many twins are test tube babies? It’s hard to say. The data on fertility treatment is sketchy, as there has been no pressure on public health centers and private clinics to release their records. The last report from the Spanish Fertility Society (SEF) offers data from 2013, and only 50% of the centers offering artificial insemination and 63% of those offering IVF participated. According to this report, more than 100,000 treatments were completed (78,942 IVF and 29,550 artificial insemination) but between 25% and 30% of the patients were foreigners.

Most multiple pregnancies result from IVF because in 71% of cases, two embryos are transferred to the patient – the law allows up to three. But according to De La Calle, “even if only one embryo is transferred, the pharmacology increases embryonic division in the early stages, producing identical twins.”

This is why 22.86% of IVF pregnancies produce twins while, with artificial insemination, this drops to 11%. In total, the probability of having twins is 20.9%, or one in five, a figure that De La Calle raises to “between 40% and 50%, according to the records in La Paz.”

The likelihood of having fraternal twins naturally is 1.1% and this figure drops to only 0.4% for identical twins.

De La Calle says it’s a shame that couples are immediately being offered the transfer of two embryos, even when it’s not necessary. “When it wasn’t limited to three embryos, they would transfer five or six,” says Agustín Ballesteros, President of the SEF and director of an IVF clinic in Barcelona. “Today three is still on the cards, but it has been going down as the treatment becomes more effective. Though the number of twins is still high, it has dropped in the last 10 years from 30% to 20.9%.”

Twin buggies are an increasingly familiar presence on Spanish streets.
Twin buggies are an increasingly familiar presence on Spanish streets.Kike Para

Why do people keep opting for the transfer of two embryos? “Because the chances of success go up,” says Ballesteros. “On patients using their own embryos, with just one the success rate is 25% and with two it’s 41%.”

In his opinion, part of the problem lies with the clinics, which recommend it because they do not monitor the pregnancy after conception and they’re not aware of the risks. The other part lies with the patient, who doesn’t consider the complications and the cost. In the end, couples prefer the “risk” of twins than the risk of not getting pregnant.

“The treatments aren’t easy. They’re expensive, so patients try to optimize their chances – previous efforts have failed and there’s a certain urgency,” says Ballesteros.

This was María and Juan Antonio’s case. The doctors recommended the transfer of two embryos but the choice was ultimately theirs. “I was racked with doubt. On one hand, I told myself, ‘what a lot of work, it’ll kill me,’ and on the other I thought twins would be good. My partner had clear ideas. He said, ‘If we’re going to get into this, we might as well have two.”

Ballesteros insists that the patient needs to know that there is not much difference between using one embryo or two. “Years ago, a lot of embryos were lost through freezing. Nowadays, they’re vitrified so the rate of survival is very high and they are equally effective.”

A future with fewer twins

In the future, the aim is to reduce the number of twins by moving toward the transfer of a single embryo to produce one healthy baby. “We are still working to convince doctors and patients that in most cases one embryo is enough,” he says. “But there’s a stumbling block, which is the pre-implantation diagnosis. We can’t analyze the embryo freely because of legal hurdles and because it is a very expensive process. But to transfer just one, we need to be sure it’s the best possible embryo.”

The treatments aren’t easy. They’re expensive, so patients try to optimize their chances

Agustín Ballesteros, head of Barcelona IVF clinic

Meanwhile, De La Calle would like fertility centers and patients to be more aware of the hazards involved after conception. “The first thing you need to know is that these are high-risk pregnancies, as much for the mother as the baby,” she says. “In general, they increase all the risks of a normal pregnancy. The risks they don’t have are overdue pregnancies and overweight babies. But there is more diabetes, more high blood pressure, more preeclampsia, more thrombosis…”

As far as the babies are concerned, they are generally premature. Around 70% of them are born before 37 weeks. “The very premature ones who are born under 28 weeks and weigh less than a kilo are seven or eight times more common among twins than in single births, and the most worrying,” says De La Calle, who adds that “30% of children in neonatal intensive care are twins.”

Very premature babies have digestive, neurological and respiratory problems, some of which can have long term repercussions, according to De La Calle. For example, 15% of multiple births happen before 34 weeks, which means their lungs have not matured. Fortunately, this wasn’t the case for either María or Raquel – they both gave birth at 37 weeks.

What do so many twins mean for society? “A greater drain on health and family resources,” says De La Calle. But apart from this, there is no way of knowing. At least not yet. “So far in Spain there has been no sociological study,” says María Isabel Jociles Rubio, a sociology professor at Complutense University in Madrid who has been involved in the investigation of embryo donation.

“You would have to ask the parents of twins if they are happy,” says Ballesteros. Because despite the hard work, María and Antón wouldn’t change a thing. “Being a parent of twins requires extra patience and more light-heartedness, not taking things too seriously, being aware that the difficult moments will pass and things will get better,” says María, who considers the experience “hard but very worthwhile”.

Meanwhile, Antón laughs at the question: “The best thing about being a parent of twins? The peace and quiet at home,” he says.

English version by Heather Galloway.

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