Amniotic fluid S100B protein in mid-gestation and intrauterine fetal death

Fetal death in the mid-trimester of pregnancy is unexplained and no reliable markers are available to identify atrisk women. We aimed to assess use of _ fetoprotein and S100B concentrations in amniotic fluid as markers. We did a case-control study in 758 healthy women undergoing amniocentesis at mid-gestation, of whom 12 had a spontaneous intrauterine fetal death before 28 weeks, and 746 matched controls. Concentrations were corrected for gestational age by conversion to multiples of median (MoM) of healthy controls of the same gestational age. Concentrations of S100B, but not _ fetoprotein, were significantly higher (p<0\u20220001) in women who later had spontaneous fetal death (median 4\u2022431 MoM [95%CI 3\u2022605\u20136\u2022197]) than in controls (1\u2022000 MoM [1\u2022062\u20131\u2022121]). Sensitivity, specificity, and positive and negative predictive values of S100B as a diagnostic test were 100%, suggesting that measurement of this protein at amniocentesis could be useful to identify at-risk women

Non protein bound iron concentrations in amniotic fluid

OBJECTIVES: To investigate whether amniotic fluid concentrations of non protein bound iron (NPBI) vary with growth in healthy fetuses and also offer a reference curve in the second trimester of pregnancy. DESIGN AND METHODS: Amniotic fluid concentrations of NPBI were measured by HPLC in 118 women with physiological singleton pregnancies, who underwent amniocentesis for fetal karyotype between weeks 15 and 18 of gestation. RESULTS: NPBI increased progressively from weeks 14--15 to weeks 15--16, peaking at 17--18 weeks of gestation. NPBI values regressed positively with gestational age (GA). Multiple linear regression analysis between NPBI, as dependent variable, and various fetal parameters, as independent variables, showed a statistically significant regression coefficient with GA, bi-parietal diameter and transverse cerebellar diameter. CONCLUSIONS: The present data constitutes the first quantification of NPBI concentrations in amniotic fluid under physiological conditions. Correlations with GA and ultrasound fetal biometry suggest that NPBI may play a role in fetal growth