Claire and Norah Saloky didn't know many siblings like them who share a birthday — until their middle school organized a special yearbook photo in March.
The Saloky sisters, who are fraternal twins, learned they are one of 16 sets of twins (plus two sets of triplets) among the 892 students at Poquessing Middle School in Lower Southampton.
As startling as that number sounds, get ready for another double take.
Nearby Maple Point Middle School has 33 sets of twins. Pearl Buck Elementary School, also in Middletown, has 21 sets of twins and a set of triplets. Neshaminy High School has 40 sets of twins.
Altogether, the Neshaminy School District has 175 sets of twins, five sets of triplets and one set of sextuplets among its 8,300 students.
The situation is not unusual, either. Once a rarity, multiple births have become so common that school district officials were stunned to learn as much as 7 percent of students in some schools are a twin or triplet.
"Honestly, our principals were not even aware of the high incidence of twins in their schools. It's just not on their radar for any reason," said Marie Reynolds, director of communications for the Mount Laurel School District in Burlington County, New Jersey, where there are more than 100 sets of twins in kindergarten through eighth grade. "As a mother of twins, I can tell you that you almost forget they are 'multiples' once they are out of the double stroller. It doesn't hit you again until the first year of college tuition."
The popularity of fertility treatments and assisted reproductive technologies, especially among women over age 35, in the 1980s and into the 1990s paved the way for an increase in multiple birth rates not previously seen since the start of U.S. birth record keeping, according to the U.S. Centers for Disease Control and Prevention. The annual twin birth rate has slowed in recent years, but still remains far above where it was for most of the 20th century, when twins occurred in just 19 of every 1,000 live births.
The drastic increase in twins created a need to understand what experiences and challenges these students may have as they enter the school system. It has prompted some school districts — even some states — to revise, or create, formal policies for classroom placement. The trend also resurrected debate among educators over whether keeping multiples separate or together is best for academic and social development.
Did you know?
The 2020 graduating class at New Trier High School in Winnetka, Illinois, has the world's record for most pairs of twins in the same academic year in one school, which is 44. The same class also had a set of triplets, which gave them the record for most multiples in a single academic year in one school.
The birth of the world's first test-tube baby in 1978, followed by the first U.S. test tube baby birth in 1981, opened the gates to a new reproductive technology known as in vitro fertilization. Twin deliveries jumped 76 percent in the U.S. between 1980 and 2012 to 33 out of every 1,000 live births. The twin birth rate reached a record high in 2014 of 34 out of every 1,000 live births before dipping to 33 in 2016, according to the most recent federal data.
Research suggests that twin and higher-order multiple births are more common among older women who delay pregnancies; the demographic phenomenon accounted for one-third of the increase since 1980. The rest of the increase was attributed to infertility treatments that involved implanting multiple embryos or ovulation-stimulating medications and an increase in survival rates of infant twins and higher-order multiples.
In addition to an increase in twin births, the use of in vitro fertilization is attributed to a 400-percent increase the birth of triplets and higher-order multiples between 1980 and 1998, when the numbers peaked at 1 in every 515 births, according to federal data. Those birthrates have since plummeted more than 40 percent, to 1 in every 880 births, according to 2016 National Center for Health Statistics data. The decline appears associated with changes in assisted reproductive technologies and practices, such as reducing the number of embryos implanted.
Advances in reproductive technology also appear to have helped stabilized twin birth rates since 2009. The Society for Assisted Reproductive Technology has noted the percentage of patients implanting only one embryo increased to roughly 10 percent; a decade earlier, two-thirds of in vitro fertilization cycles implanted three or more embryos to increase the chances that at least one egg would develop.
State trends in the birth of multiples have mirrored what's happened nationally.
New Jersey experienced the third-biggest increase in twin births nationwide between 1980 and 2009, when the rate more than doubled from 20 per 1,000 births to 44, according to CDC data.
Burlington County and nearby Gloucester County each had the fifth-highest percentage of multiple births among residents between 2015 and 2017, according to the New Jersey State Health Assessment Data. A little more than 4 percent of women in those counties gave birth to multiples during those two years. At 5 percent of all births, Warren County had the highest percentage of multiple births in the Garden State.
Pennsylvania experienced a similar doubling of its twin birth rate, which increased from 18 out of every 1,000 births to 36 per 1,000 births between 1980 and 2009, according to the CDC.
Those statistics are obvious in some schools.
In the K-8 Eastampton Township School District in New Jersey, 3 percent — 20 out of 600 district students — is a twin. Similarly, Tabernacle School District has 13 sets of twins and a set of triplets among its 700 students.
This year, Mount Laurel School District has 103 sets of twins among the roughly 4,200 students in pre-K through eighth grade. Half of those family ties are at the upper elementary and middle schools, where there are 52 sets of twins combined.
Bensalem School District has 85 sets of twins and two sets of triplets among its roughly 6,500 students. The largest concentration of twins is among the six elementary schools where there is an average of eight sets of twins per school.
Every academic grade in five of the six Centennial School District schools has at least one set of twins. The only exception is second grade at McDonald Elementary School, which has none. Three of the seven sets of triplets in the district attend William Tennent High School, where roughly 6 percent of the current junior class has a twin or triplet.
"I was shocked at the number," said Michelle Bisacquino, assistant executive to Centennial's assistant superintendent. "I'm also a twin, but growing up we didn't have that many twins in our schools. Times sure have changed."
Pennsbury School District counts five sets of triplets and 181 sets of twins among its student body; every school has at least one set of twins. The nearly 3,000 high school students include 52 sets of twins.
Even small school districts haven't escaped the trend.
New Hope-Solebury School District has only 1,300 students, but it has one of the highest incidence of twins, according to school data. There are 32 sets of twins and roughly half are at the high school.
Fraternal twins and Poquessing Middle School eighth-graders Becca and Sammy Quinlan don't think 16 sets of twins attending one school is a big deal.
"If they were all identical that would be a lot ..." Becca Quinlan said.
"But fraternal, eh," Sammy Quinlan finished.
Together or separate?
This year the Quinlan sisters, who are in the sixth grade, are in the same gym class and study hall. But sharing a class rarely has happened since kindergarten, they said.
Which is exactly what they would prefer, the sisters added.
Neshaminy School District is among those with an official policy that generally gives parents of multiples the option to keep those siblings together or apart. Others, like Pennsbury and Mount Laurel, don't have specific classroom placement guidelines for students who are multiples.
At Hartford Upper Elementary School in Mount Laurel, where 27 sets of twins are among the school's 966 fifth- and sixth-graders, Principal Marques Stanard has staff survey parents of twins each summer before making decisions about classroom placement. Typically, about half the parents want twins separated, at least part of the day, he said.
"So they can have a little bit of independence," Stanard said. "As far as educationally, it doesn't really impact them just for the fact they are twins. But we take great care in being proactive with parents. We don't assume where they would want them."
Common past practice has been for schools to place twins in separate classrooms; a 1992 study — when the multiple-birth boom was still in its infancy — indicated that 84 percent of twins were in separate classrooms, according to researchers at the University of Missouri-Kansas City.
But the Missouri researchers found the basis for determining classroom placement had not been well researched, nor had its consequences on academic and emotional development. Other recent studies that focus on twins' school issues have yielded mixed findings.
Some studies suggest that separation is best to help children develop independently without the influence of a sibling classmate. Separation also can decrease the chance of twins being compared to each other or negatively labeled as a way to distinguish between them, and reduces sibling rivalry and competition.
Other research suggests that twins and multiples do better academically, socially and emotionally, when they are kept together. A 2004 University of Wisconsin and Institute of Psychiatry at King's College in London study found that separating twins and multiples at a young age can lead to withdrawal, anxiousness and emotional distress. Current research concludes separating twins in school before they are emotionally ready can lead to internalizing issues and behavior problems.
Psychologist Nancy Segal is a nationally recognized expert in twins, and founder and director of the Twin Studies Center at California State University at Fullerton. She believes schools should not take a one-size-fits-all policy with class placement for twins and multiples, but that decisions should be made cooperatively, including the views of parents and children.
Teachers can encourage twins in the same classroom to develop new relationships by placing them in different groups, which gives them a chance to meet new people, but also have an opportunity to see that their sibling is OK, Segal added.
"There is little question that debates over what constitutes the optimal educational setting for twins will continue," Segal said. "Taking into account each pair's unique situation cannot be stressed enough."
A 2012 study on educating multiples in classrooms found 86 percent of parents of twins believe their children should not be separated at school.
Among them is Angela Kearns, a 36-year-old Falls mother of two sets of fraternal twins, the result of fertility treatments.
Fifth-graders Adreeyona and Joey, and second-graders Julian and Jazlyn, attend Oxford Valley Elementary in Falls, where they are among seven sets of twins. Every year since the oldest twins were in kindergarten, Kearns and her husband have requested they be assigned the same class.
So far it has worked out great, she said. The twins are a good support system for each other in and out of class, especially with school work. She said she has never heard complaints the twins are a distraction or discipline problem, and her oldest twins have separate friends and different outside interests.
Still, Kearns said she feels pressured by teachers who stress separate classrooms are better for the twins. This year she said she considered separating Adreeyona and Joey to prepare them for middle school, but decided against it. At this point, Kearns plans to request keeping the older twins together when they enter middle school next year.
Both sets of twins tell her they like the arrangement, too, she added.
"I'd never keep them together if they didn't want to be together," she said.
Ten-year-old twins Owen and Izzy Dixon are fifth-graders at Hartford in Mount Laurel. They've shared the same classes since kindergarten.
Izzy described sharing a classroom with her brother at school as "all right;" Owen, not so much anymore, though it does have advantages, he said.
"Whenever I forget my homework, I can copy hers," he said.
Fellow fifth-graders Ilijah and Isabella Nunez, 11, have not shared a classroom since pre-kindergarten, which is how Isabella prefers it.
"I like being myself," said Isabella, who is 30 minutes older than her brother. "He gets more attention because he is the youngest."
Ilijah, though, was lukewarm about the separation.
"It's so-so," he said. "Sometimes, I miss my sister."