A Russian medical team has documented the first recorded case of monochorionic quadruplet girls in the country’s medical history.
The four identical female infants, born from a single fertilized ovum and sharing one placenta, were delivered by planned cesarean section at 32 weeks’ gestation. Their birth weights were 1,360 g, 1,400 g, 1,570 g and 1,640 g.
Such pregnancies are worth studying because monochorionic quadruplets carry elevated risks of complications for both mother and infants, including preterm birth and problems related to sharing a single placenta. Documenting each case adds to the small pool of clinical data that guides prenatal monitoring and delivery decisions.
Before this report, researchers knew that monozygotic quadruplets are extremely rare. The incidence is estimated at roughly 1 in 15.5 million births worldwide. Only about 15 such cases had appeared in modern medical literature. No confirmed identical quadruplet births had previously been recorded in Russia.
The study is a single case report. The team described events as follows: a woman in St. Petersburg sought routine prenatal care; early ultrasound scanning showed a monochorionic quadruplet pregnancy with all four fetuses sharing one placenta; the pregnancy was tracked with repeated ultrasounds that measured fetal growth, amniotic fluid volume and any early signs of twin-to-twin transfusion syndrome; at 32 weeks the infants were delivered by cesarean section; the placenta was examined immediately afterward; the mother’s postoperative course and the infants’ short-term stability were recorded.
The results showed four live female infants with the birth weights listed above and lengths between 37 cm and 41 cm. Apgar scores were appropriate for gestational age. All four were admitted to the neonatal intensive care unit for standard preterm care. The placental examination confirmed monochorionicity and found no major vascular anomalies at initial review. The mother recovered without complications, and the infants stabilized quickly.
The authors concluded that the case “contributes valuable data to the limited global literature on monochorionic quadruplets” and noted that it “underscores improvements in obstetric ultrasound access and high-risk pregnancy management across the country.” They added that long-term follow-up of the infants will be needed to understand their health trajectory.
The researchers themselves pointed out the study’s narrow scope. Because this is a report of one pregnancy only, the findings cannot be generalized. The paper does not include long-term health data for the infants or any comparison with other cases. It also does not examine possible genetic or environmental factors that might have led to the zygote splitting.
Reference
Case Report: First Recorded Birth of Monochorionic (Identical) Quadruplet Girls in Russia. A. Petrov, MD; E. Ivanova, MD; Neonatal Intensive Care Team, Maternity Hospital No. 17, St. Petersburg, Russia. Rare Obstetric Phenomena, April 2026.
