Low Plasma Mannose Binding Lectin (p-MBL) Level is a Risk Factor for Recurrent Pregnancy Loss (RPL)
Condition: Recurrent Miscarriage; Spontaneous Abortion; Mannose-Binding Lectin Deficiency; Habitual Abortion; Pregnancy Complications; Pregnancy Loss; Recurrent Pregnancy Loss
MeSH terms: Abortion, Spontaneous; Pregnancy Complications; Fetal Death; Abortion, Habitual; Recurrence
Study type: Observational

Summary: 
      The present study is based on the hypothesis, that recurrent pregnancy loss (RPL) is
      associated with abnormal plasma mannose binding lectin (p-MBL) level. Secondarily, p-MBL
      level may affect the reproductive and the perinatal outcome in the first pregnancy following
      RPL. Thus, the present study aim to examine whether MBL should be a biomarker for women at
      risk for RPL and, secondarily, affect the reproductive and perinatal outcome, and thereby
      help clinicians identify fragile women who need intensified perinatal care.
    

Detailed description: 
      Recurrent pregnancy loss (RPL), defined as 3 or more consecutive pregnancy losses before 22
      weeks of gestation, is a multifactorial disorder affecting 1-3% of all females of
      reproductive age. The underlying cause of RPL remain unknown in up to 50% of patients. Some
      of these patients may be affected by an aberrant immune system.

      Low p-MBL levels have been associated with RPL, while relations to high p-MBL levels have
      been poorly studied. Reports concerning association between maternal p-MBL levels and
      perinatal outcomes including birth weight and gestational age are conflicting. Low p-MBL
      level may possess a negative effect by promoting an unfavorable immune response against
      foreign cells such as fetal/trophoblast cells.

      This study is a single center a combined cross-sectional and prospective cohort study, that
      aims to investigate wether high and/or low p-MBL levels are associated with RPL (primary
      outcome) and whether it affects reproductive outcome in the first pregnancy following
      admission and the perinatal outcome in the first birth before and after admission (secondary
      outcome). If such associations exist, p-MBL could become an biomarker for the early
      identification of women with need for intensified perinatal care.

      The study sample consists of Danish women admitted to the Centre for Recurrent Pregnancy Loss
      of Western Denmark. The study group includes 267 women with RPL. P-MBL levels in patients are
      compared to those of 185 female blood donors of fertile age with unknown reproductive
      history. The association between low p-MBL level and successful reproductive outcomes is
      analyzed with logistic regression adjusted for confounding variables (age, BMI and smoking).
      The perinatal outcomes in first birth (>22 weeks of gestation) before and after admission are
      compared between RPL subgroups according to their p-MBL level; low (≤500 ug/l), intermediate
      (501-3000 ug/l), and high (>3000 ug/l) p-MBL levels.

      Female patients in the study group will have a blood sample taken at their first meeting in
      the the Centre for Recurrent Pregnancy Loss of Western Denmark before they become pregnant,
      and they will be followed until delivery of the first child after RPL, if pregnancy after RPL
      is achieved, or until end of study March 2021. Data on perinatal outcomes of pregnancies
      before and after RPL were collected at the first consultation, from hospital records, and,
      when needed, completed by telephone or e-mail correspondence.
    

Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Women fulfilling the eligibility criteria will have p-MBL level measured from a blood
        sample when first admitted to the Centre for Recurrent Pregnancy Loss of Western Denmark
        and will be followed until delivery of the first child following the consecutive pregnancy
        losses, if pregnancy is achieved during the study period.
      
Biospecimen description: 
      Blood samples from the female patients and blood donors
    
Keywords: Mannose binding lectin; Perinatal outcome; Recurrent pregnancy loss