This recommendation is an update of one of the 49 recommendations that were published in the WHO recommendations on antenatal care for a positive pregnancy experience. The recommendation was developed initially using the standardized operating procedures described in the WHO handbook for guideline development. In summary, the process included: (i) identification of priority question and outcomes; (ii) retrieval of evidence; (iii) assessment and synthesis of the evidence; (iv) formulation of recommendation; and (v) planning for the implementation, dissemination, impact evaluation and updating of the recommendation. This recommendation was identified by the Executive Guideline Steering Group (GSG) as a high priority for updating in response to new evidence on this question.