In this large, nationwide population-based cohort study, a preconception BMI in the category of underweight, overweight, or obesity in either or both parents was associated with a higher risk of various adverse birth outcomes, including perinatal death and birth defects. Therefore, maintaining a healthy weight for both parents before pregnancy is key to perinatal wellbeing.

In this large, nationwide population-based cohort study, a preconception BMI in the category of underweight, overweight, or obesity in either or both parents was associated with a higher risk of various adverse birth outcomes, including perinatal death and birth defects. Therefore, maintaining a healthy weight for both parents before pregnancy is key to perinatal wellbeing.