You can generally start expressing colostrum by hand from around 36 to 37 weeks of pregnancy. It is recommended to hand express and not use a pump at this stage. Expressing colostrum before this time is usually advised against as it might stimulate preterm labor. Before starting, especially if there are any pregnancy risks like preterm labor or low-lying placenta, it is important to consult with a healthcare provider. Expressing colostrum antenatally can be beneficial particularly for mothers with diabetes, those having planned cesarean birth, or if the baby may have feeding difficulties after birth. The expressed colostrum can be collected and stored for use when the baby is born if needed.