Natural IVF is for those who are naturally ovulating, and medication is unlikely to help get more than one egg. It is particularly helpful for those with a very low ovarian reserve. With natural IVF the egg that grows naturally every month is collected, without the use of medication.

Mild IVF is used when there is no benefit of using high doses of stimulation medication, therefore, reducing the risks. It is recommended for those with good ovarian reserve and a high likelihood of producing a sufficient number of eggs. It is also especially suitable for those who have a high risk of OHSS.