Comparison of outcomes of monochorionic twin pregnancies conceived by assisted reproductive technology vs. spontaneous conceptions: A systematic review and meta-analysis

BACKGROUND: This review aimed to assess if monochorionic twin pregnancies conceived by assisted conception have worse maternal and neonatal outcomes as compared to those conceived naturally. METHODS: Datasets of PubMed, ScienceDirect, CENTRAL, Embase, and Google Scholar were searched for studies comparing maternal and neonatal outcomes of monochorionic twin pregnancies conceived by assisted vs. spontaneous methods. RESULTS: Eight studies comparing 337 assisted with 2,711 spontaneously conceived monochorionic twin pregnancies were included. Meta-analysis revealed that the mode of conception of monochorionic twin pregnancies had no impact on the risk of hypertensive disorders of pregnancy (HDP) (OR: 1.36 95% CI, 0.73, 2.54 I(2) = 9% p = 0.03), twin-twin transfusion syndrome (TTTS) (OR: 0.83 95% CI, 0.52, 1.31 I(2) = 0% p = 0.42), and very preterm delivery (OR: 1.18 95% CI, 0.74, 1.88 I(2) = 41% p = 0.49). We noted no statistically significant difference in the mean birth weights (MD: −17.66 95% CI, −157.23, 121.91 I(2) = 82% p = 0.80), risk of intra-uterine death (OR: 0.90 95% CI, 0.51, 1.60 I(2) = 36% p = 0.73) and small for gestational age between the two groups (OR: 0.92 95% CI, 0.67, 1.26 I(2) = 0% p = 0.59). There was an increased risk of caesarean sections (OR: 1.34 95% CI, 1.00, 1.80 I(2) = 0% p = 0.05) and neonatal death with assisted conceptions as compared to spontaneous conceptions (OR: 2.35 95% CI, 1.11, 5.01 I(2) = 37% p = 0.03). CONCLUSION: Monochorionic twin pregnancies conceived via assisted reproductive technology have a heightened risk of cesarean section and neonatal deaths. However, there is a need for further studies to supplement current evidence. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=325133, identifier: CRD42022325133.