Stability of inhibin A and unconjugated oestriol in the second trimester of pregnancy.

BACKGROUND: The introduction of a second trimester quadruple test for fetal Down's syndrome adds the measurement of serum inhibin A (InhA) and unconjugated oestriol (UE3) to the existing repertoire of alphafetoprotein and intact human chorionic gonadotrophin. The aim of this study was to assess the stability of InhA and UE3 in whole blood and serum. METHODS: To determine whole blood stability, five extra blood specimens were obtained from each of 10 women attending an antenatal clinic. Samples were stored at room temperature for either two hours, one, three, five or seven days and centrifuged prior to analysis. Serum stability was studied by the analysis of surplus serum from 14 routine second trimester screening samples: seven stored at room temperature and seven stored at 4°C. An aliquot from each specimen was analysed two hours, one, three, five or seven days post centrifugation. Specimens were analysed for InhA and UE3 using the Beckman Access 2(®) Immunoassay analyser. RESULTS: No significant difference (P > 0.05) was shown in InhA or UE3 concentrations between the initial time point on the day of venepuncture and each of the subsequent analyses at one, three, five and seven days following collection for either whole blood or serum. CONCLUSIONS: InhA and UE3 are stable in whole blood and serum for seven days.

Decreased serum levels of kisspeptin in early pregnancy are associated with intra-uterine growth restriction and pre-eclampsia.

OBJECTIVE: To investigate whether pregnancies with development of subsequent pre-eclampsia and intra-uterine growth restriction are associated with altered levels of kisspeptin in maternal serum in the second trimester. STUDY DESIGN: Retrospective case-control study of 16-20 week serum samples matched for duration of storage at -70 degrees C. Levels of kisspeptin were measured in serum from women with pregnancies with subsequent development of pre-eclampsia (n = 57), intra-uterine growth restriction (n = 118), and matched controls (n = 317). RESULTS: Serum kisspeptin levels were significantly lower in those women who subsequently developed pre-eclampsia than in controls [median (quartile range) 1109 (449) vs 1188 (365) pg/mL, p = 0.029] and in those with intra-uterine growth restriction [1164 (386) vs 1188 (365) pg/mL, p = 0.016]. CONCLUSIONS: Kisspeptin levels are lower in maternal serum in the second trimester, in pregnancies associated with placental dysfunction. The differences in kisspeptin are modest, so although not forming a single screening marker in pre-eclampsia and intra-uterine growth restriction, measurement of kisspeptin may be useful in combination with other markers. Understanding the role of kisspeptin in the establishment of the placenta may further our knowledge of the mechanisms underlying placental function.

Maternal serum activin, inhibin, human chorionic gonadotrophin and alpha-fetoprotein as second trimester predictors of pre-eclampsia.

OBJECTIVE: To compare the serum levels of human chorionic gonadotrophin (hCG), alpha-fetoprotein, activin A, inhibin A and inhibin isoforms containing pro and alphaC in the second trimester serum of women who subsequently developed hypertensive disorders of pregnancy with those who remained normotensive throughout pregnancy. DESIGN: Retrospective case-control study of 15-20 week serum samples matched for duration of storage at -20 degrees C. SETTING: Antenatal clinics at a teaching hospital in Scotland. SAMPLE: Second trimester serum samples of 39 women who subsequently developed pre-eclampsia, 31 who subsequently developed pregnancy-induced hypertension and 155 women who remained normotensive throughout pregnancy. MAIN OUTCOME MEASURES: hCG, alpha-fetoprotein, activin A, inhibin A and inhibin pro-alphaC serum levels. RESULTS: Activin A levels in serum were significantly elevated in women who later developed pregnancy-induced hypertension (26% increase compared with controls) and hCG levels were significantly elevated in women who later developed pre-eclampsia (24% increase compared with controls). alpha-Fetoprotein, inhibin A and inhibin pro-alphaC levels were not significantly elevated in the patient groups compared with their controls. CONCLUSIONS: A combination of analyses including second trimester serum activin A and hCG may yet prove to be helpful predictors of women at risk of hypertensive disorders of pregnancy. While the results proved significant, the effects reported in this study are too modest compared with natural variability to be useful as screening tools on their own.