Pregnancy outcomes and risk factors for preeclampsia in dichorionic twin pregnancies after in vitro fertilization: a five-year retrospective study

Background Both in vitro fertilization (IVF) and preeclampsia (PE) were associated with placental dysfunction. Although IVF can increase the incidence of PE, the pregnancy outcomes and risk factors for preeclampsia in dichorionic twin pregnancies conceived via IVF remain unclear. This study aimed to investigate the pregnancy outcomes and the risk factors for preeclampsia in dichorionic twin pregnancies conceived through IVF compared to those conceived after natural conception (NC). Methods This retrospective observational study enrolled 181 dichorionic twin pregnancy women with preeclampsia from 2016 to 2020. According to the mode of conception, they were allocated into IVF (n = 117) and NC groups (n = 64). The clinical characteristics of preeclampsia and pregnancy outcomes between the two groups were compared by using Student's t test, chi-square test, and Fisher's exact test, and logistic regression models were used to obtain adjusted odds ratios (aOR) with 95% confidence intervals (CI) for risk factors of early-onset preeclampsia. Results The incidence of early-onset PE and growth discordance in dichorionic twin pregnancies with PE is significantly higher in IVF-PE group than in NC group (78.60% vs 43.80%, P < 0.001, 11.10% vs 25.00%, P = 0.015). We found that IVF (aOR = 4.635, 95% CI: 2.130-10.084, P < 0.001) and growth discordance (aOR = 3.288; 95% CI: 1.090-9.749, P < 0.05) increased the incidence of early-onset PE. Conclusions In preeclamptic dichorionic twin pregnancies, IVF and growth discordance were associated with the increased incidence of early-onset PE. The underlying mechanism for the relationship between IVF and early-onset PE or growth discordance may be placental dysfunction.