For some context, at least 15% of pregnancies end in miscarriage (over 23 million worldwide per year), and although there are recognized causes and risk factors, such as embryo aneuploidy, exposure to air pollution and pesticides, age (<20 and >35 for women, >40 for men), smoking, very low or high BMI, etc., the role of dietary choices in miscarriage has not been well established and may provide a modifiable lifestyle factor. The authors of this recent review were selective in the type of study they included as well as the type of dietary intervention. For example, they excluded diets used for specific diseases (such as a gluten-free diet for celiac disease) to avoid possible confounders.
Overall, a protective effect of fruit, vegetables, seafood, dairy products, eggs and cereal was observed, while a diet that was high in refined foods, processed meat or sugar substitutes increased the risk. The largest protective effect was observed with fruit and vegetable intake; a high intake of fruit was associated with a 61% lower risk, and vegetables had a 41% lower risk. A diet rated as higher in healthy foods or with a high antioxidant content was associated with a 57% lower risk, versus nearly a doubling in risk with a high intake of processed foods.