What to expect… when you’re expecting to expect? Social media mamas-to-be are abuzz about “trimester zero,” a pre-pregnancy plan that some experts say is seriously misguided. “Trimester zero is a ‘hot new topic’ in the world of OB and fertility that suggests there’s a critical three-month window before conception where you need to optimize everything — diet, supplements, lifestyle — to improve egg quality and fertility outcomes,” Dr. Jaime Knopman , Director of Fertility Preservation for CCRM