A study in the latest issue of The Lancet by researchers at the Imperial College School of Medicine in London, England, involved women with a complication where a fetus fails to develop. Instead, a potentially-malignant tumor forms in the womb. It's called a hydatidiform mole.
They occur in about 1-3 per 1,000 pregnancies, and about 16 percent of them become malignant. Twin pregnancies with a healthy fetus and a hydatidiform mole are rare - they occur in about 1-in-20,000-100,000 pregnancies. In many of these cases, women are advised to terminate the pregnancy in order to have the hydatidiform mole removed.
In this study, researchers assessed 77 twin pregnancies with hydatidiform moles to determine the risks to the mother and baby if the pregnancy continued and compared them to women who terminated their pregnancies.
The study included 24 women with a hydatidiform mole and a healthy fetus who decided to have an abortion and 53 women in the same condition who continued their pregnancies.
Of those 53 women, two had to terminate their pregnancies due to severe pre-eclampsia, and 23 had miscarriages. Of the remaining 28, the pregnancies lasted 24 weeks or more and there were 20 live births.
Chemotherapy to treat malignant disease was necessary in 16 percent of the women who terminated their pregnancy, compared to 21 percent who didn't terminate.
The researchers say their study shows that women with twin pregnancies complicated by a hydatidiform mole who continue their pregnancy have a 40 percent chance of a successful birth.