What can we change before IVF? The things you control.

A healthy weight comes first, for her and for him.

Being very underweight or very overweight can stop ovulation, lower sperm quality and make IVF harder. Weight also raises pregnancy risks such as diabetes and high blood pressure. You do not need a crash diet; very strict eating can stop ovulation on its own. Your doctor sets a target from your tests and your history, and small steady changes count. Dr Vani ranks the factors couples can influence in this order.

Yes. Smoking harms fertility in both partners, and the NHS advises no alcohol when you are trying to get pregnant.

Smoking is linked with lower fertility, earlier menopause and a higher chance of miscarriage. That includes beedis, chewing tobacco, gutka and paan with tobacco, not just cigarettes. For him, smoking and heavy drinking lower sperm quality. Stopping is hard, and help works better than willpower alone. If either of you drinks most days, cut down now, not the week before treatment.

Yes, a little: steady sleep supports the hormones that run the cycle and sperm production, though sleep is not a treatment.

The part of the brain that sets your body clock also signals the ovaries and testes. Long-term short or broken sleep is linked with less regular cycles and poorer semen. Aim for about seven hours, at regular times, in a dark room, with screens off before bed. Shift work is worth mentioning to your doctor, because it can change how cycles are tracked. Loud snoring or waking unrefreshed can mean sleep apnoea, which is treatable and worth checking.

Start folic acid now, and get thyroid, blood sugar, blood pressure and vitamin D checked and corrected.

Take a folic acid tablet every day before you conceive; ask your doctor for the dose, as some women need more. Thyroid problems, diabetes and high blood pressure are common, often silent, and affect both fertility and pregnancy. Bring every medicine and supplement you take, for both of you, to the first visit. Some are fine, some should change before pregnancy, and some 'fertility' supplements add nothing but cost.

No. Worry during treatment has not been shown to lower the chance of pregnancy.

Stress is on Dr Vani's list because it wears you down, not because it makes cycles fail. Couples are often told to 'relax', and it only adds guilt. What helps is what helps any hard season: sleep, some movement, time together that is not about fertility, and someone to talk to. Gentle, regular exercise such as walking or yoga is fine during most of treatment; ask before anything strenuous in a stimulation cycle.

The same things, starting about three months ahead, because sperm take about two to three months to be made.

A change he makes today shows in the semen about three months later. So stop smoking and tobacco, cut alcohol, move towards a healthy weight, sleep regularly, and keep tea and coffee moderate. Tell the doctor about any medicines, including testosterone or bodybuilding supplements, which can stop sperm production. A semen analysis in the first round tells you where he is starting from.