title: Blood leucocyte count in the human fetus.
abstract: Total and differential leucocyte counts were measured in cord blood samples obtained by cordocentesis (n = 316) or at elective caesarean section (n = 11) from normal fetuses of between 18 and 40 weeks' gestation. The total fetal leucocyte count increased exponentially from 2.8 x 10(9)/l at 18 weeks to 11.8 x 10(9)/l at term. The lymphocyte and monocyte counts increased linearly and the number of neutrophils increased exponentially from a mean value of 0.2 x 10(9)/l at 18 weeks to 0.8 x 10(9)/l at 31 weeks and then 8.5 x 10(9)/l at term. Early myeloid cells, eosinophils, and basophils were observed in 24%, 55%, and 15% of the blood films respectively; they contributed less than 2% to the total leucocyte count and there were no significant changes with gestation. The physiological leucopenia observed in fetuses early in the third trimester may partly explain the predisposition of premature neonates to infection.
authors.affiliation: King's College School of Medicine and Dentistry, Harris Birthright Research Centre for Fetal Medicine, London.
authors.forename: N P
authors.initials: NP
authors.lastname: Davies
authors.forename: A G
authors.initials: AG
authors.lastname: Buggins
authors.forename: R J
authors.initials: RJ
authors.lastname: Snijders
authors.forename: E
authors.initials: E
authors.lastname: Jenkins
authors.forename: D M
authors.initials: DM
authors.lastname: Layton
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D001772:Blood Cell Count; D004804:Eosinophils; D005312:Fetal Blood / Q000166:cytology*; D005865:Gestational Age; D006801:Humans; D007958:Leukocyte Count; D007962:Leukocytes; D009000:Monocytes; D009504:Neutrophils