Demonstration of the Presence of a Carbonyl Stress in the Hair Follicles of Postpartum Women

Inclusion Criteria: Criteria related to the Population: * Pregnant woman (≥ 33 weeks of amenorrhea) * Woman aged between 18 and 40 years (included) * Phototype I to IV included according to Fitzpatrick's classification * Affiliation to a French social security scheme or benefiting from such a scheme * Signed informed consent form Exclusion Criteria: Criteria related to the Population: * High risk or pathological pregnancy, according to the opinion of the investigator * Deprivation of liberty by administrative or judicial decision or subject under guardianship * Impossibility, according to the investigator, to comply with the requirements of the protocol * Linguistic or psychic incapacity to sign informed consent * Concomitant participation in a clinical study that may interfere with the results of the study, according to the opinion of the investigator (excluding observational studies) Criteria related to Pathology : * Alopecia causing hair loss on the upper part of the scalp * Dermatological pathology or evolving cutaneous lesion in the scalp * Known history of hepatitis B and C, HIV * Past or present neoplastic condition * Acute evolving pathology * Gestational diabetes treated with insulin Criteria related to Treatments: * Treatment of general thyroid disorders initiated or modified for less than 3 months prior to inclusion (or change of specialty for less than 3 months) * Systemic treatment affecting hair growth taken for at least 4 weeks during the 3 months prior to inclusion * Systemic treatment: nonsteroidal anti-inflammatory drug, corticosteroid, antibiotic, antihistamine taken for 5 consecutive days within 2 weeks prior to inclusion or that may interfere with the results of the study according to the investigator, * Dermal use, for at least 4 weeks, of Minoxidil, Aminexil within 3 months prior to inclusion * Dermal use in the 4 weeks prior to inclusion, of any product that may be active on the hair follicle and scalp or may affect the dosage of carbonyl compounds (including hair dyes) * Last shampoo less than 2 days before the inclusion and application of styling / care products (gel, lacquer, wax, conditioner ...) or water between the last shampoo and the inclusion