Insect repellent may cause birth defects

Using insect repellent during early pregnancy could increase the risk of male birth defects.

Hypospadias is a birth defect that causes the premature shortening of the urethra carrying urine from the bladder to the tip of the penis.

Use of insect repellent during the first trimester of pregnancy appears to increase the risk of boys developing the defect by around one to two births in every 500.

Hypospadias has so far been associated with low birthweight, stillbirth, older mothers, poor fertility and smoking.

Insect repellents containing N,N-diethyl-m-toluamide, known as DEET, can be harmful and cross the placenta.

Researchers believe the chemicals enter the bloodstream affecting the developing fetus.