The risk of preterm birth in vanishing twin: A multicenter prospective cohort study

PLoS One. 2020 May 29;15(5):e0233097. doi: 10.1371/journal.pone.0233097. eCollection 2020.

Abstract

Objective: To evaluate not only the risk of total preterm birth (PTB) but also spontaneous preterm birth (sPTB) and indicated preterm birth (iPTB) in vanishing twin (VT).

Study design: This is a secondary analysis of a multicenter prospective cohort study. In 12 different healthcare institutions, women with singleton pregnancies were enrolled in early pregnancy and followed up till delivery.

Results: A total of 4,746 women were included in the final analysis, and. the frequency of VT was 1.1% (54/4746). VT group had a higher risk for total PTB (PTB<34 weeks, 2.1% vs. 14.8%, p<0.001; PTB<32 weeks, 1.6% vs. 13.0%, p<0.001; PTB<28 weeks, 0.9% vs. 13.0%, p<0.001) than singleton group. The VT group had increased risk for both sPTB and iPTB (<34 weeks, <32 weeks, and <28 weeks), and this increased risk for sPTB and iPTB in VT group remained significant even after controlling for confounders such as maternal age, parity, pre-pregnancy BMI, and mode of conception.

Conclusion: Vanishing twin can be an independent risk factor for both sPTB and iPTB when compared with singleton pregnancy.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Mass Index
  • Female
  • Gestational Age
  • Humans
  • Infant, Newborn
  • Maternal Age
  • Pregnancy
  • Pregnancy, Twin
  • Premature Birth / epidemiology*
  • Premature Birth / etiology
  • Prospective Studies
  • Risk Factors

Grants and funding

This study was supported by The National Health Clinical Research Program Grant from the KHIDI, Republic of Korea (HC15C1336) and by Seoul National University Hospital research fund (grant number 03-2019-0410). This study was presented at the 28th World Congress on Ultrasound in Obstetrics and Gynecology, Singapore, October 20-24, 2018.