• Mothers self-efficacy: spanish validated version of Breastfeeding Self-Efficacy Scale-Short Form (BSES-SF) [ Time Frame: At five points: week 28 - 40 pregnancy (T1); and 10 days (T2); 2 months (T3); 4 months (T4); and 6 months (T5) after birth ]
  Changes on maternal breastfeeding self-efficacy using the Spanish validated version of Breastfeeding Self-Efficacy Scale-Short Form (BSES-SF). BSES-SF is a 14 item, unidimensional, self-report instrument developed to measure a mother's confidence in her ability to breastfeed. All items are presented with a 5-point Likert-type scale where 1 indicates "not at all confident" and 5 indicates "always confident" (scores: minimum 14 and maximum 70). Higher scores indicate higher levels of breastfeeding self-efficacy.
• Professionals self-efficacy in relation to their ability to support breastfeeding mothers: APCLA Scale (Professional Self Efficacy for Breastfeeding Care Scale) [ Time Frame: At three points: before professional training (the same day that the intervention begins) (T1); 3 months (T2) and 6 months (T3) after the beginning of the intervention ]
  Changes on professional self-efficacy in relation to their ability to support breastfeeding mothers using the Professional Self Efficacy for Breastfeeding Care Scale (Autoeficacia Profesional para los Cuidados en Lactancia, APCLA). APCLA scale is a 14 item, unidimensional, self-report instrument developed to measure a professional's confidence in her/his ability to support a breastfeeding mother. All items are presented with a 5-point Likert-type scale where 1 indicates "not at all confident" and 5 indicates "always confident" (scores: minimum 14 and maximum 70). Higher scores indicate higher levels of breastfeeding support self-efficacy. This scale was constructed and validated in Spanish based on the Spanish version of BSES-SF

• Proportion of participants mothers/mothers invited to participate (Feasibility) [ Time Frame: Baseline ]
  Proportion of participants mothers/mothers invited to participate to measure the recruitment process of the CRIAA program
• Duration in minutes of the breastfeeding workshop (Feasibility) [ Time Frame: Baseline ]
  Duration in minutes of the breastfeeding workshop (scheduled time v/s time used) to measure the implementation of the CRIAA program
• Participants recruitment. Participants that complete the intervention/total of participants recruited (Feasibility) [ Time Frame: At two times: Baseline (T1) and at the end of the intervention at 6 moths of age of the child (T2) ]
  Participants that complete the CRIAA Program/total of participants recruited to measure participant's retention of the CRIAA program
• Acceptability of the intervention by mothers [ Time Frame: At six months of age of the child, when intervention is over ]
  Explored by semi-structured interviews, without using any scale. The script of the interviews will contain questions about positive and negative aspects of the program perceived by participant mothers
• Acceptability of the intervention by professionals [ Time Frame: At two times: Three months post intervention begins by semi-structured interviews (T1) and when study is over, an average of 10 months, by a focus group (T2) ]
  Explored by semi-structured interviews and focus group with professionals
• Acceptability of participation in decision making by mothers and their partner/relative [ Time Frame: At five points: week 28 - 40 pregnancy (T1); and 10 days (T2); 2 months (T3); 4 months (T4); and 6 months (T5) after birth ]
  Changes on perceived participation in decision making related to the child's type of feeding, using the Spanish validated version of CollaboRate. It is a short and self-applying generic instrument that allows measuring user participation in a particular health decision (Cronbach's alpha> 0.89). It consists of three questions with alternative answers with a likert scale of 1 to 7. In this project, both the mothers and the partner /relative will be asked about their participation in the decision to feed the child. The version that will be used is validated in Chilean population (CollaboRate Chile)

• Proportion of participants mothers/mothers invited to participate (Feasibility) [ Time Frame: Baseline ]
  Proportion of participants mothers/mothers invited to participate to measure the recruitment process of the CRIAA program
• Duration in minutes of the breastfeeding workshop (Feasibility) [ Time Frame: Baseline ]
  Duration in minutes of the breastfeeding workshop (scheduled time v/s time used) to measure the implementation of the CRIAA program
• Participants that complete the CRIAA Program/total of participants recruited (Feasibility) [ Time Frame: At two times: Baseline (T1) and at the end of the intervention at 6 moths of age of the child (T2) ]
  Participants that complete the CRIAA Program/total of participants recruited to measure participant's retention of the CRIAA program
• Acceptability of the intervention by mothers [ Time Frame: At six months of age of the child, when intervention is over ]
  Explored by semi-structured interviews, without using any scale. The script of the interviews will contain questions about positive and negative aspects of the program perceived by participant mothers
• Acceptability of the intervention by professionals [ Time Frame: At two times: Three months post intervention begins by semi-structured interviews (T1) and when study is over, an average of 10 months, by a focus group (T2) ]
  Explored by semi-structured interviews and focus group with professionals

• Breastfeeding
• Self Efficacy

• Experimental: Intervention
  Participants will receive the standard prenatal care and invited to participate of a breastfeeding workshop during the third trimester of pregnancy, with active and intentional participation of the pregnant woman and her partner/relative; based on adult education methodology. In addition, women participants will have continuous support during their breastfeeding process, up to 6 months of the child's life, through a virtual support group (whats-app), where they will receive messages that promote their self-efficacy in relation to their ability to breastfeed and may ask questions that are related to breastfeeding. Professionals in this group will be train before delivering the intervention.
  Intervention: Behavioral: Breastfeeding support
• No Intervention: Standard Care
  This group will receive the standard pre and postnatal regular care, for mother and child. Professionals who provide direct care will maintain their usual attention.

Inclusion Criteria:

• Being in physiological pregnancy in the third trimester
• Speak Spanish
• Give informed consent

Exclusion Criteria:

• Pathology during pregnancy that entails difficulties for breastfeeding
• Multiple pregnancy
• Breastfeeding especial situations (cleft lip and palate, congenital heart disease and newborn's hospitalization)
• Preterm birth (at <37 weeks gestation)