There are no high-level evidence studies (Cochrane review, meta-analysis, consensus conference) for all of these issues, and it is therefore sometimes difficult to make sense of the available data.

Increasingly, pregnant women ask this question during preparation for breastfeeding: antenatal colostrum expression. This is a practice studied in very specific cases (notably gestational diabetes), but which is becoming more widely disseminated with the appearance of dedicated equipment, influencer marketing, and strong enthusiasm on social media.