At the end of May, a mother in eastern Uganda gave birth to a boy with four legs and four arms. While I’m sure seeing her son for the first time was a shock, I keep wondering about the birth itself. It’s hard enough to give birth to a child with half as many limbs. Recently, the baby, Paul, underwent a pioneering surgery in which he was separated from what doctors diagnosed as a parasitic twin.
Paul’s mother gave birth at home, and as you can imagine, she and her family lit out for the nearest hospital immediately, fearing that they had been the victims of witchcraft and would be ostracized by their community. The regional hospital wasn’t equipped to deal with the situation, so they sent the family to the Kampala, the capital of Uganda, to the Mulago Hospital. That’s where doctors determined that the extra limbs were a result of something called parasitic twinning, which is pretty much just what it sounds like — a twin which, rather than growing normally, or even conjoining in typical Siamese twin fashion, never fully developed. The twin’s head and heart never developed, but some parts of it — the limbs — did, and those parts essentially relied on Paul’s blood and body to keep them alive.
Paul displayed abnormalities beyond the extra limbs — he and his parasitic twin were joined at the pelvis, sharing the same pelvic girdle. Paul’s heart was on the right side, not the left, and his liver was on the left, not the right. It’s not entirely clear how or why this happens, but it’s related to mirroring. Mirror Image Twins are identical twins with opposite features that literally reflect those of the other: one is right-handed while the other is left-handed, for example, and in certain situations something called situs reverus or situs inversus can occur, which is when one twin’s organs are on the opposite side of the body. Scientists believe this happens when a fertilized egg splits later than usual, somewhere around the 10-day mark.
Conjoined twins develop in fewer than 1 in 50,000 pregnancies, and parasitic twins develop less often than that, although doctors at Mulago Hospital say they’ve seen a disproportionate number of conjoined twins over the past few years. In the case of parasitic twins, one of the twins stop developing some time during the pregnancy, for reasons not fully understood. Whatever body parts had developed on the parasitic twin then attach themselves to the living twin. This has happened before, including a number of years ago in India.
Doctors decided that Paul should go home and grow for a few months before they performed the surgery. A couple of weeks ago, a team of surgeons, anesthesiologists, and nurses operated on Paul to remove the extra limbs. The surgery seems to have been a success, with one of the surgeons reporting that “there were no intra-operative or post-operative complications and mild blood loss.” Because of the pelvis he and his twin shared, it’s possible that he’ll need future surgeries, but for now, Paul seems to be healing well and is eating normally.
In some cases, babies with eight limbs are thought to be gods, reincarnations of the eight-limbed Hindu goddness Lakshmi.