Selective Reduction of Multiple Pregnancies Into Singleton Pregnancy: Treatment Analysis for Fetal Position.

BACKGROUND

The rise in assisted reproductive technology has increased the prevalence of high-risk triplet pregnancies. Dichorionic triamniotic (DCTA) triplets-where a monochorionic-diamniotic (MCDA) twin pair shares a placenta-carry significant risks, including twin-to-twin transfusion syndrome. Although reducing a multifetal pregnancy to a singleton via MFPR leads to better outcomes, how the location of the reduced fetus within the uterus affects the success of the pregnancy is not addressed in current clinical guidance.

OBJECTIVES

This study compares obstetric outcomes based on the location of the reduced MCDA twin pair (superior vs. inferior position) in DCTA triplet pregnancies.

METHODS

A retrospective analysis was conducted on 200 patients who underwent MFPR to a singleton between 2013 and 2024. Patients were divided into Group A (MCDA pair located farther from the cervix/superior) and Group B (MCDA pair located closer to the cervix/inferior). Primary outcomes included miscarriage rates (before 24 weeks) and gestational age at delivery.

RESULTS

Group A demonstrated a significantly lower miscarriage rate (4.1% vs. 17.9%, p = 0.001) and a higher mean gestational age at delivery (38.38 vs. 37.36 weeks, p = 0.015) compared to Group B. Additionally, the incidence of low birth weight was significantly lower in Group A (10.3% vs. 26.6%, p = 0.004). No significant differences were found in perinatal death or Apgar scores between the groups.

CONCLUSIONS

In DCTA pregnancies, reducing the MCDA twin located farther from the cervix is associated with lower miscarriage rates and improved gestational outcomes.