How common are multiple births like twins and triplets in S'pore?
Theresa Tan for The Straits Times
When banking professional Ng Han Siang and his wife Janice Chen married nine years ago, having children was not part of their immediate plans.
They later decided to have one child.
"I was scared I would regret missing out on the joy of having children," said Ms Chen, 42, who used to work in the banking sector.
What they did not expect was to have their wish granted threefold.
On her first round of in-vitro fertilisation at the age of 40, she conceived triplets, after having two embryos, or fertilised eggs, placed in her womb.
"I was very shocked, but happy. It's unbelievable," she said.
Today, she and her husband are the proud parents of a girl named Pei Xuan and two boys, Jie Rui and Jie Le.
The Ng triplets were among 12 sets born in 2024 here, the highest number since 2017, when the same figure was recorded.
In 2023, eight sets of triplets were born, and there were six sets in 2022.
While 2024 saw an uptick in the number of triplets, an analysis of data from 1994 to 2024 by The Straits Times based on official statistics from the annual report on registration of births and deaths showed that higher-order multiple births have fallen significantly over the years.
A multiple birth is when a single pregnancy results in more than one baby, such as twins, while higher-order multiple births means having three or more babies, such as triplets and quadruplets.
Doctors attribute the decline of higher order multiple births to the fact that many couples transfer just one embryo during IVF, given that advances in IVF laboratory techniques have improved pregnancy rates.
Another reason is the cap on the number of embryos that can be transferred in a single assisted reproduction cycle, limited to a maximum of two except in certain cases, to reduce the risk associated with multiple pregnancies.
From 2015 to 2024, 86 sets of triplets were born - about half the 177 sets recorded in the previous decade between 2005 and 2014.
Only 13 sets of quadruplets were born here between 1994 and 2024, with the most recent in 2012.
Singapore's largest multiple birth took place in 1998, when a couple had five boys and a girl. The sextuplets were conceived through an assisted reproductive technology called gamete intrafallopian transfer, or Gift.
Twins, however, remain more common.
Between 2015 and 2024, a total of 5,161 pairs of twins were born. This is slightly higher than the 5066 pairs recorded between 2005 and 2014.
Single embryo, fewer multiple births
Dr Suresh Nair, medical director of Seed of Life, Fertility and Women's Care Medical Centre, said that in the past, doctors transferred multiple embryos to maximise pregnancy rates.
Today, however, doctors say many patients opt for only one embryo to be placed in the woman's womb.
Dr Liu Shuling, director of KKIVF Centre at the KK Women's and Children's Hospital (KKH), said improved IVF laboratory techniques and higher pregnancy rates have made single embryo transfer the preferred choice.
With a single embryo transfer, the chances of having a multiple pregnancy is less than 1 per cent, she said.
Transferring two embryos raises the chances to 20 per cent, she said, citing KKIVF Centre data.
Dr Tan Heng Hao, medical director at Thomson Fertility Singapore (Novena), said patients are generally willing to choose a single embryo transfer, especially when the embryo quality is high.
He said: "Most patients are quite receptive once we explain the risks associated with multiple pregnancies."
Adjunct Associate Professor Arundhati Gosavi, a senior consultant at the Obstetrics and Gynaecology department at National University Hospital, said implanting more embryos does not proportionally increase the chance of pregnancy but greatly raises the likelihood of twins or triplets.
She added: "Hence, the approach is quality over quantity: selecting the best embryo for transfer."
Doctors say that policy changes have also led to the fall in the number of higher-order multiple births.
Since April 2011, not more than two embryos can be transferred in a single assisted reproduction cycle to reduce the risk associated with multiple pregnancies.
A Health Ministry (MOH) spokesperson said exceptions to this rule can be considered only when all these conditions are met:
- The woman has to be 37 years of age or older
- She has undergone at least one stimulated cycle where no oocytes, which are eggs retrieved from her ovaries, were collected, or none of the retrieved oocytes developed into a blastocyst, an early stage of an embryo.
- All three embryos to be transferred are not past the cleavage stage, which are early-stage embryos which typically occur three days after fertilisation.
The MOH spokesperson said: "These patients have fewer reproductive options, and limiting the developmental stage of embryos to cleavage-stage embryos helps to manage the risk of multiple pregnancies."
Before the 2011 change, a maximum of three embryos were allowed in a single cycle, with some exceptions, The Straits Times previously reported.
Doctors said the transfer of three embryos is now very rare.
Dr Nair said 2024's bumper crop of 12 sets of triplets could be a random fluctuation.
But he added that as a significantly higher number of women undergo IVF and other fertility treatment at older ages, even rare outcomes such as triplet births could rise in absolute numbers.
More babies, more risk
The MOH spokesperson said multiple pregnancies contain significant risks for both mothers and babies.
This includes preterm birth complications, maternal health issues such as gestational diabetes and hypertension, and fetal complications including low birth weight and long-term developmental disabilities.
Ms Chen's doctor had initially suggested multi-fetal pole reduction, a procedure that reduces the number of babies in a pregnancy with triplets or more to twins or a single baby.
Two of her babies share one placenta, raising the risks of complications such as twin-to-twin transfusion syndrome, where uneven blood flow between the fetuses can cause organ damage or even death.
Multi-fetal pole reduction helps to lower the high risks of losing the pregnancy, stillbirth, or the babies being born too early.
The couple decided to keep all three, despite their fears and concerns.
Ms Chen said: "I'm Buddhist, and we don't take away any life. And they are my babies."
Fortunately, her pregnancy went smoothly, despite frequent breathlessness and swollen feet. She also gained almost 30kg during her pregnancy.
Ms Chen did her IVF treatment at a private clinic, but delivered in KKH given the hospital's expertise in managing multiple pregnancies.
The couple recalled their relief when the triplets were born.
Pei Xuan and Jie Rui weighed 2kg at birth, while Jie Le was 1.9kg.
Mr Ng, 41, said: "It was magical the first time I saw them."
Ms Chen quit her banking job to look after the trio, who attend infant care. The family manages without a domestic helper.
Raising triplets is a lot of work, but seeing them grows makes it all worthwhile, she said.
She said: "When one of them cries, the other two will also cry. I get very stressed when all three of them cry together."
Her 16-month-old triplets each have distinct personalities. She describes her daughter as obedient and bubbly, while her older son likes to read books and learns things fast. Her youngest son is active and curious.
"I feel joy when I see how they interact with each other. They play with each other and giggle and giggle," she said.
