Lifestyle changes that may help include aiming for a normal weight if you’re underweight or overweight, stopping smoking, avoiding heavy alcohol use, and avoiding illegal drugs as well as prescription narcotic pain medications. High caffeine intake may increase the risk of miscarriage, based on a single study – stick to one cup of brewed coffee a day and decaf for the rest (no espresso-based drinks). There are no well-proven herbs or supplements, but Coenzyme Q10 (CoQ10) 500 – 1000 mg a day, may help older women. Vitamin D levels should also be checked as there is some evidence that low levels can have a wide variety of effects on the body.