Association Between Plasma Level of Mannose Binding Lectin and Human Reproduction

Inclusion Criteria: fulfil one of the following: * 3 consecutive pregnancy losses after spontaneous conception * 3 consecutive pregnancy losses after assisted reproductive technology treatment (ART) including IVF, ICSI and FET * 3 failed embryo transfers characterized by no achieved pregnancy (after 3 cycles with minimum 1 embryo transfer of a good-quality embryo in each cycle.) Exclusion Criteria: * Age \<18 or \>45 years * AMH \<4.0 pmol/l unless donor egg in previous cycles * Significant uterine malformation * Known endometrial pathologies including intrauterine endometriosis, adenomyosis, hyperplasia or polyps * Known chromosomal abnormalities * Pregnancy \>9 weeks of gestation at the time collecting the blood sample