Superfetation: When A Woman Becomes Pregnant While Being Pregnant

by hridika ahire

Superfetation: When A Woman Becomes Pregnant While Being Pregnant

April 20, 2021

Bringing A New Life On Earth

Bringing a new life into this world and continuing one’s family name is important to most people. While carrying a child into the world is the most beautiful thing one can ever witness, it is also extremely tough. The excruciating long hours of pain and nine long months of carrying a whole life inside of your own body takes a lot of work. 


Most people think that getting pregnant is a straightforward task. While that may be accurate for some people but for others, it can be pretty tricky. The man might not have strong enough sperms, or the woman might not have a healthy vagina. She could miscarry even if she could get pregnant or might suffer from Polycystic Ovary Syndrome (PCOS), making it extremely difficult to conceive. But miracles and marvels are a common sight in the world of biology, with the existence of twins and conjoined twins as an example. The latest miracle that has left the scientific community dumbstruck is a woman who got pregnant while being pregnant.

A woman conceives during different menstrual periods and apart from the gestational age, the twins will have different weights, heights, and even blood types.

Rebecca Roberts

Rebecca Roberts, a 39-year-old British woman, was diagnosed with superfetation. Superfetation is the formation of a fetus with a pre-existing fetus already present. While Rebecca and her husband were at their 12-week ultrasound appointment, the doctor noticed that Rebecca was carrying another, less developed baby.

David Walker, Rebecca’s obstetrician, told the Washington Post, “We were concerned because the second twin was much smaller. Only after regular screenings, we noticed that the growth rate was consistently three weeks behind, a case of superfetation.” According to Dr Ilina Pluym, an assistant professor at the University of California, Los Angeles stated that the condition is extremely rare. 

Superfetation and Ovulation

Superfetation is more common in fish, rodents, and bunnies, but only a handful of women have been through it. This condition is rare because once a woman is pregnant, her hormones do not permit her to become pregnant again. However, women who have been undergoing fertility treatments have a higher risk of something like this happening.

Women ovulate once per cycle, and during these cycles, one or more eggs are released simultaneously. If the woman has sex during this period, it becomes easier for a man’s sperm to successfully fertilize the eggs. These eggs are then implanted in the uterus, and the pregnancy begins, and ovulation stops. When two eggs are released at the same time, twins are conceived during the same ovulation period. However, in Rebecca’s case, the egg fertilized and implanted in her uterus during her ovulation, but she ovulated for a second time. Another egg was fertilized, became another embryo and got planted in the uterus.

Medical literature has registered about ten cases of pregnant women who got pregnant again during their first pregnancy.

The Risks For The Baby

Rebecca had taken one dose of fertility drugs which could have been the reason why superfetation took place. It is common knowledge that when one takes fertility drugs and in an In Vitro fertilization (IVF), twins or triplets are probable. Although, no one thought that superfetation would ever take place. Rebecca says it is a “medical marvel.”

Rebecca and her husband Rhys were worried about baby no. 2, who is named Rosalie. They feared that since the baby was so tiny and was far behind her big brother Noah, baby no. 1, her health might be affected either in the womb or after birth. Even the fear of losing a child in itself is heartbreaking. 

Growth of Baby no. 2

Through regular tests and screening, baby Rosalie was found to be growing consistently. While some women can go through vaginal birth of twins, it is often risky, and therefore most doctors suggest a cesarean.

In Rebecca’s case, she, and her babies, were at risk because one of them was premature. Therefore, in September 2020, both the babies were brought into this world through the cesarean method. Both the babies, however, had different neonatal intensive care units (NICU)

Superfoetation occurs when the pregnant body releases an egg within the first few weeks of the first pregnancy, and this egg is fertilised which causes the second pregnancy.

Birth of Noah and Rosalie

Baby Noah was born at 4 pounds, 10 ounces, and baby Rosalie was born at a mere 2 pounds, 7 ounces. Rebecca said, “She was a tiny, tiny baby that fit in our hands.” She also said that it was a tough time for the family as the babies were kept in separate hospitals. They had to travel between both the hospitals daily too, after going through a major operation. 

Since Noah was still a bigger baby, he was able to go home in three weeks whereas Rosalie had to stay in Intensive care for 95 days. Rhys says that “She (Rosalie) is a little trooper. She’s got her own little personality, but I have no real worries at all.” All’s well that ends well, right?


Recommended for you

Leave a Comment

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More