There are very limited studies and understanding of the complications during twin pregnancy that occurs due to CHM. Thus, this study aims to study Complete Hydatidiform Mole (CHM) in association with the placenta and normal fetus during twin pregnancy. The study also focuses on understanding the obstetric and perinatal outcomes of fetus and mother due to GTN (gestational trophoblastic neoplasia).

The study uses data from EMBASE, MEDLINE, PubMed, and grey literature. The researchers collected publications between May 1980-2019, and they used a protocol to design a priori and PROSPERO registration. They chose abstracts with four and more cases with confirmed histopathology and data regarding pregnancy outcomes and GTN. They used the Newcastle-Ottawa scale and meta-analysis for the study.

Out of the collected 344 abstracts, 14 (244 cases) studies were eligible. There was an 80.8% incidence of complications in the ongoing pregnancies. The complications include preeclampsia, vaginal bleeding, and hyperthyroidism. Among these studies, there were 91 live births (50%) and 34% of them with GTN diagnosis. Thus, it was found that heterogeneity was significant in cases with preeclampsia, showing complications due to GTN.

Mothers with a twin pregnancy and CHM had higher perinatal complications, even with a normal fetus. There was a high fetus death rate, and 1/3rd of the live births developed GTN.