Certolizumab in Recurrent Implantation Failure (RIF)

Inclusion Criteria: * Women aged 18-40 years * Idiopathic, male or tubal factor infertility * Unexplained recurrent implantation failure defined as consecutive failure to obtain clinical pregnancy after at least transfers of 3 good-quality embryos (Istanbul criteria) * Affiliation to a French social security system (beneficiary or legal) * Informed and signed consent Exclusion Criteria: Known cause of RIF among the following: * Genetic parental anomalies * Non-gestational diabetes mellitus of type I and II, * Infectious disease * Antiphospholipid syndrome * Sickle cell disease * Diffuse adenomyosis * No contraindication to Freeze-thaw embryo transfer (FET) treatment Linked to certolizumab: * Hypersensitivity to the active substances or to any of the excipients * Primary or secondary immunodeficiency (history of or currently active) * Active uncontrolled infection * Active tuberculosis * Cardiac insufficiency (moderate to severe, New York Heart Association (NYHA) III/IV classes) * Any malignant neoplasm except adequately treated basal or squamous cell carcinoma of the skin * Immunization with a live/ attenuated vaccine within 4 weeks prior to baseline or simultaneously with treatment * Cytopenia as defined by platelet count \< 100 × 109/L (100,000/mm3), hemoglobin \< 85 g/L (8.5 g/dL; 5.3 mmol/L), absolute neutrophil count \< 2.0 × 109/L (2000/mm3), lymphocyte count \< 0.5 × 109/L (500/mm3) * Liver cytolysis (AST / ALT \> 5 N) * Insufficient kidney function, as defined by a serum creatinine of more than 3 mg/dL or creatinine clearance of 20 ml/min or less * Demyelinating neurological disease Linked to rifampicin and isoniazid (RIFINAH®) * Hypersensitivity to the active substances or to any of the excipients * Porphyria * Decreased blood-clotting from low vitamin K * Liver cytolysis (AST / ALT \>5 N) * Combination with bictegravir, cobicistat, daclatasvir, dasabuvir, delamanid, grazoprevir / elbasvir, protease inhibitors boosted by ritonavir, isavuconazole, ledipasvir, lurasidone, midostaurine, ombitasvir / paritaprévir, praziquantel, rilpivirine, sofosbuvir, velpatasvir, voriconazole, voxilaprevir * Acute hepatitis, hepatic failure or chronic hepatic disease * Acute nephropathy Contraindication to anti-pneumococcal vaccination (Pneumovax®) \- Hypersensitivity to the active substances or to any of the excipients Other criteria: * Absence of health insurance (include AME) * Subject under guardianship or curatorship * Subject deprived of their liberty by a judicial or administrative decision * Participation in another interventional study or being in the exclusion period at the end of a previous study.