Is it possible to get pregnant while already pregnant? Apparently, science says yes.
Most people know that a woman gets pregnant when a sperm fertilizes an egg released from an ovary. The fertilized egg then gets attached to the uterine lining and becomes a fetus eventually. It is also commonly believed that women can't get pregnant while they are pregnant. However, as surprising at it sounds, they can. The process is called superfetation. This happens when a woman gets pregnant for the second time after the initial pregnancy, according to Healthline. Another egg gets fertilized by a sperm and gets implanted in the womb days or weeks after the first one. These babies are considered as twins since they could be born on the same day.
This phenomenon came to light when 31-year-old Jessica Allen from Perris, California gave birth to what she thought were twins. However, after delivering the babies she realized that the children had different skin tones. A DNA test also revealed that the babies were not twins at all, but half-brothers, according to Health.com. Jessica was a surrogate for a Chinese couple. Initially, the doctor thought that the embryo from intended parents split into two making them identical twins, according to Insider.
She was going to be paid $30,000 for the baby, which would have helped the mother of two to become a stay-at-home mom. “I was a bit scared, but I heard the Lius [Chinese couple] were thrilled to be having twins,” Allen, 31, told the Express UK. “My $30,000 payment, including expenses - which I received in installments by check each month - was increased by $5,000 for the second child. Not once during the pregnancy did any of the medical staff provided by the agency say that the babies were in separate sacs. As far as we were concerned, the transferred embryo had split in two and the twins were identical," she had said.
One boy was the biological son of Jessica and husband, Wardell Jasper, while the other was the Chinese couple's. However, this is a very rare phenomenon. "It's incredibly rare, and there aren't many reports on this," Dr. Christine Greves, an ob-gyn in Orlando, Florida, told Health. "It's so rare, in fact, that I can't even give you a statistic on it."
The couple had initially been forced to give up their child but eventually won custody of their biological child. The bizarre situation shed light to the reproductive miracle observed only a handful of times in history. It is more likely to happen to badgers and mink than humans!
"It's hard to find any literature on this poorly understood and mystical topic," Dr. Sherry Ross, an ob-gyn in Santa Monica, California, told Health. "Superfetation goes against what we know medically about getting pregnant spontaneously. The truth is not all medical phenomena have a logical explanation," she said.
In 2015, an Australian woman, Kate Hill, gave birth to two girls on the same day but they weren't twins. The sisters were conceived 10 days apart.
“Superfetation is extremely rare—I had fallen pregnant and my body had spontaneously released another egg, giving the embryos different gestational ages,” Hill told Self. “What makes this case even more rare is that my husband and I only had intercourse one time [in the possible time period of conceiving the girls]—his sperm stayed alive for 10 days to fertilize the second egg released.”
It is so rare that until then, only 10 cases of superfetation had been observed. Dr. Greves said that in a previous case in the US doctors found a four-week difference between the two fetuses. "This would go with the fact that ovulation can occur every 28 days," she explains. However, different gestational ages isn't enough proof. Even twins can have differences, making them grow at a different pace from each other.
One child could be getting more nutrients than the one leading to better growth, appearing older or bigger. "If that's the case, it could look like superfetation, but it wouldn't necessarily be due to that," she says. And enough cases of that have been observed.