When pregnancy results from In Vitro Fertilisation (IVF) there is a higher than average chance of conceiving twins. Multiple births are common in this kind of infertility treatment as multiple eggs are fertilised at the same time and transferred back into the uterus. Historically this has resulted in the highest chance of falling pregnant, though strides are being made every day towards being able to minimize the possibility of multiple births. There are two sides to multiple births. A positive is that where a patient has been striving to conceive for years hoping to start a family, having two or more children at once may be a blessing. An unfortunate aspect of multiple births is that they often result in babies with lower than average birth weight or other complications. Through single embryo transfer (SET), IVI are pushing towards an option with the highest chance of conception for the patient and the healthiest chance at life for the baby.