BACKGROUND AND PURPOSE:

• Twins are delivered earlier compared to singletons and therefore overall rates of preeclampsia between twin and singleton pregnancies may underestimate risk of preterm preeclampsia in twins compared to singletons
• Francisco et al. (Ultrasound in Obstetrics and Gynecology, 2017) sought to determine
  • gestational age at delivery in dichorionic (DC) and monochorionic (MC) twin pregnancies, with and without preeclampsia
  • relative risk of total and preterm preeclampsia compared with that in singleton pregnancies

METHODS:

• Prospectively collected data to study adverse outcomes in twin pregnancies
• Patients with twin gestation who had entered care in the first trimester and had aneuploidy screening
• Inclusion criteria: phenotypically normal live or stillborn babies at ≥ 24 weeks’ gestation
• Singleton controls from 93,297 singleton pregnancies that were examined in the same hospitals

RESULTS:

• 1,789 DC and 430 MC twin pregnancies
• Incidence of preeclampsia was 2.3% in singletons, 8.1% in DC twins, 6.0% in MC twins
• Compared with singletons, relative risk of total preeclampsia was 3.5 for DC twins and 2.6 for MC twins
• Incidence of delivery < 37 weeks’ gestation was 5.5% in singletons, 46.5% in DC twins, 91.4% in MC twins
• Incidence of preterm preeclampsia (< 37 weeks’ gestation) was 0.6% in singletons, 5.5% in DC twins, 5.8% in MC twins
• Relative risk of preterm preeclampsia was 8.7 for DC twins, 9.1 for MC twins
• The hazard ratio for DC and MC twin pregnancies relative to singleton pregnancies were 14 and 23, respectively

CONCLUSION:

• DC and MC twins have similar relative risk for preterm preeclampsia
• Twins have a significantly higher risk of preterm preeclampsia compared to singletons

Learn More – Primary Sources:

Hidden high rate of pre-eclampsia in twin compared with singleton pregnancy.

Related ObG Topics:

ASPRE Trial: A Combined Risk Algorithm and Use of Aspirin to Prevent Preterm Preeclampsia

Aspirin Treatment for Women at Risk for Preeclampsia – ACOG, SMFM and USPSTF Recommendations

Diagnosing Preeclampsia – Key Definitions and ACOG Guidelines

Do Twins or Singletons Have a Higher Rate of Preterm Mortality?

Does Maternal Age Affect Outcomes in Twins?