Monochorionic triamniotic (MCTA) triplet pregnancy is a rare entity (estimated incidence: 1 per 100,000 births) [1] . Monozygotic triplets occur when a fertilized ovum splits into two or more genetically identical embryos. The chorionicity of monozygotic triplets is determined by the timing of division of the fertilized ovum [2] . Most previously reported monochorionic triplet pregnancy cases were conceived through assisted reproductive techniques [3] .

To the best of our knowledge, seven reported cases of spontaneously conceived MCTA triplet pregnancy were associated with complications such as feto-fetal transfusion syndrome, congenital anomalies, or acardiac fetuses [4] [5] [6] [7] .

There is no clinical guidance for the management of MCTA triplet pregnancy in which the only main complication is selective intrauterine growth restriction (sIUGR) [8] . Monochorionic multiplets are at increased risk, mainly due to associated vascular communications in the placenta [9] . An imbalance in the net blood flow across the placental vascular communications from one fetus to another results in fetal transfusion syndrome [10] . This syndrome is a serious complication of monochorionic multiple gestations. Our case is one of the rare pregnancies with Spontaneous Monochorionic Triamniotic Triplet Pregnancy.

A 28-year-old Saudi pregnant woman un-booked (obstetric history: para one) presented to the emergency room at 26 weeks of gestation with symptoms of anemia. She had no significant medical history. Her first child was a baby girl delivered one year ago per vaginally. Her past gynecological history was unremarkable. There was no history of medication use before pregnancy. She had conceived spontaneously. Physical examination revealed no abnormality. Her body mass index was 22 kg/m², and her blood group was O positive. Hemoglobin was 7.8 g/dL. A vaginal swab showed normal flora. All other laboratory parameters were within the normal range. The patient was admitted to the antenatal ward. She received one unit of packed red blood cells. Ultrasound examination revealed MCTA triplet pregnancy. All fetuses showed normal amniotic fluid and normal umbilical artery Doppler findings. The estimated fetal weight was 848 g, 891 g, and 1 kg, respectively. The patient was managed conservatively with a plan to monitor fetal growth every two weeks and Doppler twice weekly as an inpatient. She completed dexamethasone doses for lung maturity. On the 8^th day of admission, the patient complained of labor pain. The patient was evaluated immediately by the obstetrician on call. Per abdomen, examination revealed palpable contractions. Per vaginal examination, she was revealed to have 2 cm cervical dilatation. The patient explained that she was in labor and emergency cesarean section should be done. The patient consented and agreed. Emergency Cesarean section was performed, and three girls were delivered with a single placenta (birth weight: 820, 925, and 960 grams, respectively).

Triplet 1 was born with an Apgar score of 7, 8, and 8 at 1, 5, and 10 minutes, respectively. She was admitted to the neonatal intensive care unit (NICU) for 64 days because of several complications. She developed respiratory distress syndrome, hyperbilirubinemia, and mild retinopathy of prematurity.

Triplet 2 was born with an Apgar score of 4, 6, and 7 at 1, 5, and 10 minutes, respectively. She died after 61 days of NICU admission due to cardiovascular arrest. In addition, she developed gram-negative sepsis, infective endocarditis, necrotizing enterocolitis, and thrombocytopenia.

Triplet 3 was born with an Apgar score of 3, 6, and 6 at 1, 5, and 10 minutes, respectively. She was admitted to NICU for 71 days. During her stay, she developed hyperbilirubinemia, moderate retinopathy of prematurity, seizure, and sepsis.

Monochorionic triplet pregnancy is a rare entity. Most reported cases were achieved by assisted reproductive technologies [1] .

Type of chorionicity is a well-known determinant of perinatal outcomes. Monochorionic type is associated with a higher risk of perinatal complications.

Complications such as selective intrauterine growth restriction (sIUGR), twin-to-twin transfusion syndrome (TTTS), and twin anemia polycythemia sequence (TAPS) are reasonable indications for selective fetal reduction, as they can relieve the complications and alleviate the burden of higher-order multiple fetal gestations [8] .

In a study, dichorionic triamniotic triplets were shown to have a 5.5-fold higher risk of mortality than trichorionic triamniotic gestation and a higher risk of delivery at gestational age of <30 weeks and birth weight of <1000 g than those of trichorionic triamniotic pregnancies [11] . Furthermore, monochorionic triamniotic triplets were at a significantly higher risk of intrauterine death and neonatal death than trichorionic triamniotic triplets. Moreover, dichorionic triamniotic triplets showed five-fold higher odds of neurological morbidity in comparison to trichorionic triamniotic triplets [12] .

In a case series wherein three MCTA triplets underwent cord occlusion for twin reversed arterial perfusion (TRAP), laser photocoagulation was found to be superior to expectant management for MCTA complicated with TTTS [13] .

Early antenatal registration and close monitoring of such cases can help improve the outcomes; however, our patient was not booked for antenatal care. Close monitoring with serial ultrasound can allow the physician to notice any fetal deterioration, even in more unpredictable sIUGR, such as Type III [8] .

According to a study, abnormal ductus venosus Doppler findings are associated with adverse outcomes in monochorionic-diamniotic twins, which may be equally applicable to a case of MCTA [14] .

The data showed t that the overall perinatal mortality rate was 151.5 per 1000 births [15] . Another report showed even higher than the figures (51.5 - 97/1000) reported by other investigators [16] .

This data is consistent with the observation that perinatal mortality rates for multiple pregnancies increased with increasing prematurity. But unlike the studies on triplet and twin pregnancies [17] [18] (Figures 1-3).

MCTA triplet pregnancy is a rare condition. Monochorionic pregnancy is associated with a higher risk of fetal morbidity and mortality. Greater awareness of these complications will facilitate better management. Early antenatal booking and serial ultrasound can help improve the outcomes.

All authors made equal contributions in preparing, writing, and editing the manuscript.

The authors have no conflicts of interest to declare.

Al Hazmi, A.H., Tayeb, O., Al Mutairi, A. and Asiri, M. (2023) Spontaneous Monochorionic Triamniotic Triplet Pregnancy: A Case Report. Open Journal of Obstetrics and Gynecology, 13, 1075-1080. https://doi.org/10.4236/ojog.2023.136092