Pregnant and lactating people may need more protein than previously recommended — 1.66 to 1.77 grams of protein per kilogram of body weight per day (g/kg/day) seems to be ideal,[1][2] with 1.5 g/kg/day being the lower threshold for maintaining a positive nitrogen balance.[3] Furthermore, some studies have observed that supplementing with protein during pregnancy seems to reduce infant health risks, including low gestational weight, low birth weight, and stillbirth.[4]
While there haven’t been any studies on whey protein supplementation for pregnant/lactating people per se, there’s some evidence that maternal consumption of dairy protein — and in particular whey protein — may benefit infant weight and body composition.[5]
However, whey protein (and other protein) powders come with the risk of being possibly contaminated with heavy metals or other pesticides. After all, dietary supplements (including protein powders) aren’t regulated by the Food and Drug Administration (FDA). Some protein powders may also include added sugar and other ingredients that pregnant/lactating people may want to avoid. The best advice: read the labels carefully, and always discuss any supplements with your obstetrician/gynecologist (OB/GYN) or other healthcare professional before implementing any dietary changes.