One in 15 Million Inside the Rare Birth Doctors Called “Unheard Of”
Four identical sisters, one shared placenta, and a Brisbane mother who wasn’t even planning another baby — the story behind the pregnancy doctors say may be even rarer than the odds suggest.
Jenitar Sau Na’amoana wasn’t trying to make medical history. She and her husband, Jortham, already had four children between the ages of one and ten and weren’t planning on a fifth. Then came the ultrasound that changed everything: not one more baby, but four — identical girls, all from a single fertilized egg that split not once, but twice.
“Monozygotic quadruplets are estimated at one in every 15 million pregnancies,” said Dr. Alexa Bendall, the maternal-fetal medicine specialist at Royal Brisbane and Women’s Hospital who cared for Na’amoana throughout the pregnancy. “But to share the same placenta, this is unheard of.”
“We always said that if we could get her to 28 weeks, we would be doing well.” — Dr. Alexa Bendall
That distinction — sharing a single placenta — is what turned a rare pregnancy into a genuinely dangerous one. Identical twins and higher-order multiples happen when a single embryo splits during early cell division, giving each resulting baby the same genetic blueprint. What varies, and what matters enormously to doctors, is whether each fetus ends up with its own placenta or whether they’re forced to share. Na’amoana’s four daughters were monochorionic — all four drawing blood and nutrients through one shared vascular network.
That arrangement creates a real risk doctors call unequal blood distribution: one fetus can end up receiving more blood flow than it needs while another is starved of it, raising the chances of growth restriction, cardiac strain, or worse. With four fetuses sharing a single connection instead of the usual two, the medical team treated the pregnancy as extremely high-risk from the moment they confirmed the placental structure, beginning close monitoring at 10 weeks and admitting Na’amoana for continuous inpatient care at 25 weeks so specialists could track blood flow through the shared vessels in real time.
The target the team set for themselves was 28 weeks — a milestone that matters far more in neonatology than the round number suggests. Every additional week a baby spends developing in utero meaningfully improves the odds for their lungs, their brain, and their overall chances of coming home healthy. Babies born before 28 weeks face a steeper climb, with higher risks of respiratory distress and bleeding in the brain from underdeveloped blood vessels. On July 14, at 28 weeks and four days, Na’amoana delivered by emergency cesarean section: Emily, Harriet, Catherine, and Alexa — the last named for the doctor who’d guided the family through months of uncertainty.
All four girls are now in the hospital’s neonatal intensive care unit, where the work of finishing what the womb didn’t have time to complete continues. At 28 weeks, a baby’s lungs have only just begun producing the surfactant that keeps air sacs from collapsing; their nervous systems are still laying down rapid growth; their blood vessels remain fragile enough to need careful pressure monitoring; and without much body fat yet, they depend on incubators to hold a stable temperature. Hospital staff describe all four sisters as stable and doing well, with the expectation that they’ll remain in NICU care until they reach the developmental equivalent of full term — likely several more weeks, if not longer.
For the Na’amoana family, the arithmetic of daily life has changed just as dramatically as the medical odds did. A household of six is now a household of ten, and the family has launched a fundraising campaign to help cover the medical, travel, and everyday costs of caring for four newborns who may need hospital-level support well past a typical NICU stay.
Cases like this one are rare enough that most obstetricians will never see one in an entire career — RBWH specialists described it as one of the most unusual deliveries the hospital has ever managed. But behind the statistic is a more ordinary story: a family that wasn’t expecting this, a medical team that spent months buying time one week at a time, and four sisters now doing the last stretch of their growing outside the body that started them all from a single cell
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