Maternal serum ferritin at 11- to 13-week gestation in spontaneous early preterm delivery.

OBJECTIVE: To examine the potential value of maternal serum level of ferritin in the first trimester of pregnancy in the prediction of spontaneous early preterm delivery. METHODS: Maternal serum concentration of ferritin at 11-13-week gestation was measured in a case-control study of singleton pregnancies delivering phenotypically normal neonates, including 30 cases with spontaneous delivery before 34 weeks and 90 matched controls delivering after 37 weeks. The median multiple of the median (MoM) serum ferritin in the two outcome groups was compared. RESULTS: The median serum ferritin MoM was not significantly different in the spontaneous early preterm delivery group compared with the term delivery group (1.143, interquartile range [IQR] 0.578-2.383 vs. 1.059, IQR 0.641-1.644, p = 0.725). CONCLUSIONS: Measurement of maternal serum ferritin at 11-13 weeks is unlikely to be useful in screening for spontaneous early preterm delivery.

Maternal serum α-fetoprotein at 11-13 weeks' gestation in spontaneous early preterm delivery.

OBJECTIVE: To examine the potential value of maternal serum level of α-fetoprotein (AFP) in the first trimester of pregnancy in the prediction of spontaneous early preterm delivery. METHODS: Maternal serum concentration of AFP at 11-13 weeks' gestation was measured in a case-control study of singleton pregnancies delivering phenotypically normal neonates, including 33 cases with spontaneous delivery before 34 weeks and 99 matched controls delivering after 37 weeks. The median multiple of the median (MoM) serum AFP in the two outcome groups was compared and the bivariate gaussian distributions were simulated in a previously described screened population of 33,370 pregnancies to estimate the performance of screening for early delivery by a combination of maternal characteristics and obstetric history with serum AFP. RESULTS: In the preterm delivery group compared to the term delivery group, the median serum AFP MoM was higher (1.33 vs. 0.97, p = 0.006). The estimated detection rate of preterm delivery, at a false-positive rate of 10%, from maternal characteristics and obstetric history was 27.5% and this increased to 36.0% with the addition of serum AFP. CONCLUSIONS: Measurement of serum AFP at 11-13 weeks improves the prediction of early preterm delivery provided by maternal characteristics and obstetric history.

Prediction of spontaneous preterm delivery from maternal factors, obstetric history and placental perfusion and function at 11-13 weeks.

OBJECTIVE: To develop a model for prediction of spontaneous delivery before 34 weeks based on maternal factors, placental perfusion and function at 11-13 weeks' gestation. METHODS: Two groups of studies: first, screening study of maternal characteristics, serum pregnancy-associated plasma protein-A (PAPP-A), free ß-human chorionic gonadotrophin (ß-hCG) and uterine artery pulsatility index (PI). Second, case-control studies of maternal serum or plasma concentration of placental growth factor (PlGF), placental protein 13 (PP13), a disintegrin and metalloprotease 12 (ADAM12), inhibin-A and activin-A. Regression analysis was used to develop a model for the prediction of spontaneous early delivery. RESULTS: Spontaneous early delivery occurred in 365 (1.1%) of the 34 025 pregnancies. A model based on maternal factors could detect 38.2% of the preterm deliveries in women with previous pregnancies at or beyond 16 weeks and 18.4% in those without, at a false positive rate (FPR) of 10%. In the preterm delivery group, compared with unaffected pregnancies there were no significant differences in the markers of placental perfusion or function, except for PAPP-A which was reduced. CONCLUSIONS: Patient-specific risk of preterm delivery is provided by maternal factors and obstetric history. Placental perfusion and function at 11-13 weeks are not altered in pregnancies resulting in spontaneous early delivery.

Maternal serum progesterone-induced blocking factor at 11-13 weeks' gestation in spontaneous early preterm delivery.

OBJECTIVE: Progesterone-induced blocking factor (PIBF) may be the mediator of the pregnancy maintenance effects of progesterone. The aim of this study is to investigate the potential value of measuring the maternal serum concentration of PIBF at 11-13 weeks' gestation in the prediction of spontaneous early preterm delivery. METHOD: The maternal serum concentration of PIBF at 11-13 weeks was measured by enzyme-linked immunosorbent assay in 25 singleton pregnancies which subsequently delivered spontaneously before 34 weeks, and 75 controls who delivered at or after 37 weeks. The values in the 2 groups were compared by the Mann-Whitney U test. RESULTS: The median maternal serum concentration of PIBF in women who subsequently delivered before 34 weeks (157.5, interquartile range 99.5-208.8 ng/ml) was not significantly different from the control group delivering at term (167.5, interquartile range 105.0-212.0 ng/ml; p = 0.519). CONCLUSIONS: In women who have a spontaneous early preterm delivery, the maternal serum levels of PIBF are not altered at 11-13 weeks of gestation.

Maternal serum placental protein 13 at 11-13 weeks of gestation in preeclampsia.

OBJECTIVE: To examine the potential value of maternal serum concentration of placental protein 13 (PP13) at 11-13 weeks' gestation in screening for preeclampsia (PE). METHODS: Serum PP13, PAPP-A and uterine artery pulsatility index (PI) were determined in a case-control study of 208 cases that developed PE including 48 that required delivery before 34 weeks (early-PE) and 416 unaffected controls. RESULTS: Serum PP13 levels, expressed as multiples of the median (MoM) in the unaffected group, were significantly reduced in early-PE (0.83 MoM) but not in late-PE (0.96 MoM). In both early- and late-PE serum PAPP-A (0.55 and 0.84 MoM) was reduced and uterine artery PI (1.61 and 1.25 MoM) was increased. In PE pregnancies there was a significant association between serum PP13 and both uterine artery PI and serum PAPP-A (p < 0.0001 for both). Logistic regression analysis demonstrated that serum PP13 did not improve significantly the prediction of early-PE provided by a combination of maternal factors, uterine artery PI and PAPP-A. CONCLUSION: PP13 is implicated in the pathogenesis of impaired placentation and subsequent development of early-PE but measurement of this placental product is unlikely to be useful in screening for the disease at 11-13 weeks.