Impact of Growth Discordance in Twins on Preeclampsia: based on chorionicity.

Abstract Background Despite extensive investigations over the last decade, preeclampsia (PE) remains an unpredictable pregnancy complication causing perinatal morbidity and mortality worldwide, particularly in twin pregnancies. Objective This study aimed to determine the relationship between growth discordance in twin pregnancies and the risk for PE, based on chorionicity. Study Design This was a retrospective single-center study in which 2122 women with twin pregnancies who were admitted to a tertiary hospital between January 2013 and June 2016 were included. Growth discordance was defined as a twin birth weight difference ≥20%. Logistic regression models were used to analyze the associations between twin growth discordance and gestational hypertension-PE (GH-PE) risk. In addition to logistic regression analyses of all subjects, stratified modeling by twin chorionicity (dichorionic (DC) and monochorionic (MC)) was conducted. Further analysis was performed to estimate the associations between growth discordance degree and GH-PE risk in MC and DC twin pregnancies. Results The prevalence of growth discordance was 17.6%. In all subjects, twin growth discordance was associated with increased risk of GH-PE risk. After stratified by twin chorionicity, growth discordance was associated with an increased risk for GH-PE (AOR=1.84; 95% CI, 1.26-2.67) and PE (AOR=1.82; 95% CI:1.21-2.73;), including mild PE (AOR=1.86; 95% CI: 1.02-3.37), severe PE (AOR=1.78; 95% CI: 1.06-2.97; P Conclusions Growth discordance is associated with a high risk for PE in DC but not MC twin pregnancy. Additionally, the prevalence of PE increases significantly with increasing degree of discordant growth, reflecting a dose-response relationship in DC twin pregnancy.