Taking a prenatal multivitamin is a good idea when trying to conceive, as it can help minimize the risk of vitamin deficiencies. Factors that can affect conception include age, diet, stress, smoking, alcohol consumption, weight, previous surgeries or infections, and frequency of sexual intercourse. It is generally recommended to try for a year before investigating any potential fertility issues. Starting a prenatal vitamin three months before trying to conceive is also recommended, especially for the folic acid it contains.