A series of Dutch women were injected with the wrong sperm.

A Dutch medical center has launched an investigation after discovering that 26 women's eggs were mistakenly injected with sperm at an in vitro fertilization clinic.

A “procedural error” occurred between mid-April 2015 and mid-November 2016, the University Medical Center (UMC) in Utrecht confirmed.

Illustration: BBC.

“During the fertilization process, sperm from one couple undergoing treatment may have been injected into the eggs of 26 other couples,” the Guardian quoted a UMC statement.

“Therefore, there is a possibility that the egg was fertilized by sperm from someone other than the intended father.” Although the chance of a mistake is very small, the possibility “still cannot be ruled out,” the center said.

Half of the 26 women treated for infertility at UMC became pregnant or gave birth. The center notified the couples about the incident.

Mistakes in IVF procedures are not uncommon. In 2012, a Singaporean mother sued a medical center for negligence after mistaking her husband’s sperm for a stranger’s.

In 2010, a Chinese woman also gave birth to a child with skin and hair color completely different from her Caucasian husband.

According to Vietnamnet