Sure, you’ve heard sneaky jokes about getting pregnant while pregnant, but it’s true. This phenomenon is known as superfetation. Does that mean you should stop having sex in pregnancy? Of course not, mama. It doesn’t work like that. It doesn’t occur in everyone, though you might be at risk. Find out more about superfetation and its occurrence. 

What is superfetation?

Superfetation (also spelt superfoetation and superfœtation) is the simultaneous occurrence of more than one stage of developing offspring in the same animal. It is not believed that it occurs naturally in humans. However, there have been reported cases of possible superfetation in humans.

In mammals, it manifests as the formation of an embryo from a different oestrous cycle while another embryo or fetus is already present in the uterus. It is known as superfecundation when two separate fertilisation instances occur during the same menstrual cycle.

Superfetation is claimed to be common in some species of animals. In mammals, it can occur only where there are two uteri, or the oestrous cycle continues through pregnancy.

Is superfetation a normal occurrence in mammals?

The phenomenon is known to occur in some mammals, such as badgers and mink, but it’s highly unusual in humans. “It’s incredibly rare, and there aren’t many reports on this,” says Christine Greves, MD, an ob-gyn in Orlando, Florida. “It’s so rare that I can’t even give you a statistic on it.”

That’s because once a woman is pregnant, hormone changes typically prevent her body from continuing to ovulate, Dr Greves explains. But if a woman does ovulate again, and that egg becomes fertilised and implants in her uterus, she can carry a double pregnancy.

Would the babies be born at the same time?

Yes. The babies’ age difference was discovered after both children were delivered naturally in the earliest known cases. These days, the condition shows up during an ultrasound, giving the mother and the medical team time to plan the delivery – usually a planned c-section since only one of the babies is full-term.

Is superfetation dangerous?

Yes, it has various complications for the mother. Some of them are:

• Gestational diabetes
• High blood pressure and proteinemia

Preterm babies have more complications than the mother. Some of them include:

• Difficulty in breathing
• Low birth weight
• Difficulty in feeding
• Movement and coordination problems
• Bleeding in the brain

Though there are few occurrences in humans, it’s not common. Your chances are more if you opt for an assisted conception and you’re pregnant without knowing.

Ensure to carry out relevant tests to confirm you aren’t pregnant before going for an IVF. Despite the dangers, it’s still possible to birth two healthy babies.