The aim of this study is to assess if an early therapeutic management focused on the mother-baby interaction using Interaction Guidance Therapy (IGT) with video feedback, brings an improvement of the maternal sensitivity in the interaction but also a decrease of the post-traumatic maternal symptoms.

Post Natal Post traumatic stress is known as a disorder that impaired maternal mental health but also development of motherhood and the construction of the bond to the baby through interactive disturbances.

The investigators will screen, among women who had a traumatic perception of an event related to the pregnancy or the childbirth, those who still present posttraumatic stress symptoms at 4 weeks post-partum. Four weeks from the traumatic event is the minimum delay to qualify a PTSD.

After randomization IGT versus Treatment As Usual (TAU), the investigators planned an early therapeutic intervention, 3 sessions at 8, 10 and 12 weeks of post-partum.

The investigators will assess the effect of the IGT on Maternal sensitivity and on the intensity of post-traumatic stress symptoms at 3 month post-partum and 1year.

The investigators will compare the efficacy of Interactive Guidance Therapy, a parent-infant psychotherapy using video feed back versus a dyadic treatment conduct as usual (TAU) in women who present a post traumatic stress disorder related to childbirth or pregnancy.

The main assessment is the maternal sensitivity, assessed during a video recorded free play interaction between the mother and the baby and rate with the Coding of interactive Behaviour (CIB).

This is a Single Blind Randomized clinical trial. Only the rating of the (CIB), which is the primary end point, will be done blind for the treatment the dyad received.

The randomization will proceed after the inclusion visit and the first assessment that take place at 6 weeks of post partum.

The following assessments will take place at 4 months and 12 months. The investigators will conduct a national multicentre study with 5 inclusions centres, which are all child psychiatry unit specialized in perinatal period and already train or in training for the IGT method.

• Pre-screening in post partum ward or during post partum consultation.
• Pre Inclusion at 5 (+-1) weeks to assess PTSD with Post traumatic checklist (PCL -5)
• Inclusion and First assessment at 6 weeks post partum
• Randomization: 3 session of IGT or TAU at 8 weeks, 10 weeks and 12 weeks Assessment at 4 months (+/-2W) and 12 months (+/- 1M)

Inclusion Criteria:

For the mother:

1. Mother over 18 years old, who gave birth to a healthy child
2. Mother having a PCL-5 score higher than > 31, 5 +/- 1 week after delivery and the traumatic event is related to childbirth or pregnancy.
3. Mother Speaking and reading French,
4. Mother with signed consent
5. Mother with rights open to social security
6. Mother and Father consent to the participation of the baby

For the father:

1. holder of parental authority
2. Speaking and reading French
3. Consent to self-reported questionnaires

Exclusion Criteria

1. PTSD not related to pregnancy or birth.
2. Child's health situation who impact the feasibility of the protocol, with a risk of hospitalization of more than 3 days between 6 and 12 weeks of life
3. Childbirth under 34 weeks of gestational age
4. Twins
5. Stillbirth
6. Any mother's acute, somatic or psychiatric clinical condition not compatible with the research procedure