Occasionally during the delivery process, a birth defect like cleft lip is discovered, which went undetected on antenatal ultrasound. In these instances, the parents, who are dealing with an unexpected outcome, may instinctively look for something the mother may have been exposed to during pregnancy. Without a doubt, certain environmental toxins can cause a plethora of birth defects, but many birth defects are considered multifactorial, meaning that multiple causes contributed to the process rather than one specific cause.
