Signs of a twin conception (3) bleeding in the first trimester

I was being interviewed by the BBC on one occasion about womb twin survivors. The interviewer, a young Irishman doing his best to be interesting at 6am on a subject he know virtually nothing about, scoffed, "There is no proof, just a bit of bleeding......"

"The bleeding is the proof" I countered.  And it is proof. [See here]

In a twin pregnancy the bleeding is caused by the  detachment of the placenta of one twin after death and when there are two separate chorions (di-chorionic.)

The most common identifiable causes of vaginal bleeding during early pregnancy include spontaneous abortion and ectopic pregnancy. [more]

Bleeding during pregnancy can be a sign of miscarriage but does not necessarily mean that miscarriage is imminent. Studies show that anywhere from 20-30% of women experience some degree of bleeding in early pregnancy. Approximately half of pregnant women who bleed do not have miscarriages.[more]

When a pregnant woman carrying twins has bleeding early on in the pregnancy but twins are delivered, this can mean where was a triplet who didn't make it to birth, so the twins are both womb twin survivors.