title: Stillbirths at Term: Case Control Study of Risk Factors, Growth Status and Placental Histology.
abstract: OBJECTIVE
  To investigate the proportion of stillbirths at term associated with abnormal growth using customized birth weight percentiles and to compare histological placental findings both in underweight stillborn fetuses and in live births.
  
  
  METHODS
  A retrospective case-control study of 150 singleton term stillbirths. The livebirth control groups included 586 cases of low-risk pregnancies and 153 late fetal growth restriction fetuses. Stillbirths and livebirths from low-risk pregnancies were classified using customized standards for fetal weight at birth, as adequate for gestational age (AGA; 10-90th percentile), small (SGA; <10th percentile) or large for gestational age (LGA; >90th percentile). Placental characteristics in stillbirth were compared with those from livebirths using four categories: inflammation, disruptive, obstructive and adaptive lesions.
  
  
  RESULTS
  There was a higher rate of SGA (26% vs 6%, p<0.001) and LGA fetuses (10.6% vs 5.6%, p<0.05) in the stillbirth group. Among stillbirth fetuses, almost half of the SGA were very low birthweight (≤3°percentile) (12% vs 0.3%, p<0.001). The disruptive (7.3% vs 0.17%;p<0.001), obstructive (54.6% vs 7.5%;p<0.001) and adaptive (46.6% vs 35.8%;p<0.001) findings were significantly more common in than in livebirth-low risk. Placental characteristics of AGA and SGA stillbirth were compared with those of AGA and FGR livebirth. In stillbirths-SGA we found a higher number of disruptive (12.8% vs 0%; p<0.001), obstructive (58.9% vs 23.5%;p<0.001) and adaptive lesions (56.4% vs 49%; p 0.47) than in livebirth-FGR.
  
  
  CONCLUSIONS
  The assessment of fetal weight with customized curves can identify fetuses which have not reached their genetically determined growth potential and are therefore at risk for adverse outcomes. Placental evaluation in stillbirths can reveal chronic histological signs that might be useful to clinical assessment, especially in underweight fetuses.
authors.affiliation: Department of Sciences for the Health of Women and Children, Careggi Hospital, Florence, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Mecacci
authors.affiliation: Department of Sciences for the Health of Women and Children, Careggi Hospital, Florence, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Serena
authors.affiliation: Department of Health Sciences, San Paolo Hospital Medical School University of Milan, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Avagliano
authors.affiliation: Department of Biomedical, Experimental and Clinical Sciences-Division of Obstetrics and Gynaecology, University of Florence, Florence, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Cozzolino
authors.affiliation: Department of Sciences for the Health of Women and Children, Careggi Hospital, Florence, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Baroni
authors.affiliation: Department of Sciences for the Health of Women and Children, Careggi Hospital, Florence, Italy.
authors.forename: Marianna Pina
authors.initials: MP
authors.lastname: Rambaldi
authors.affiliation: Department of Sciences for the Health of Women and Children, Careggi Hospital, Florence, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Simeone
authors.affiliation: Department of Biomedicine, Careggi Hospital, Florence, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Castiglione
authors.affiliation: Department of Biomedicine, Careggi Hospital, Florence, Italy.
authors.forename: Gian Luigi
authors.initials: GL
authors.lastname: Taddei
authors.affiliation: Department of Health Sciences, San Paolo Hospital Medical School University of Milan, Milan, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Bulfamante
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D020567:Fetal Weight / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D050498:Live Birth; D008297:Male; D010920:Placenta / Q000473:pathology / Q000503:physiopathology*; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D050497:Stillbirth; D047929:Term Birth / Q000502:physiology*