C-type natriuretic peptide in complicated pregnancy: increased secretion precedes adverse events.

CONTEXT: C-type natriuretic peptide (CNP), a vasoactive product of the endothelium, is markedly increased during placentation in ovine pregnancy and is further stimulated by nutrient restriction. Whether CNP products change in human pregnancy is unknown. OBJECTIVES: The objective of the study was to compare serial changes in maternal plasma CNP peptides during normal pregnancy with changes in pregnancy complicated by adverse events and relate these to fetal growth and placental CNP content. DESIGN: This was a prospective observational study undertaken in a tertiary care center. METHODS: We studied changes in maternal plasma aminoterminal proCNP (NTproCNP) and CNP at monthly intervals, fetal growth, and placental and umbilical plasma CNP peptides in 51 women, 28 of whom experienced an adverse event and 23 were uneventful. Age matched healthy nonpregnant women served as a reference range for NTproCNP. RESULTS: Compared with nonpregnant women, maternal plasma NTproCNP in an uneventful pregnancy was significantly reduced from first sampling (16 wk gestation) until 36 weeks. In contrast, in complicated pregnancy, levels did not decline and were significantly higher (P < .001 by ANOVA) than in normal pregnancy from 20 weeks. Highest values occurred in women later developing hypertension and fetal growth disorders. Placental concentration of NTproCNP was unrelated to maternal NTproCNP but strongly correlated with cord plasma levels. CONCLUSIONS: Maternal NTproCNP is significantly raised in women who later exhibit a range of obstetric adverse events. Lack of association with placental concentrations suggests that these changes represent an adaptive response within the maternal circulation to a threatened nutrient supply to the fetus.

An assessment of predictive value of the biophysical profile in women with preeclampsia using data from the fullPIERS database.

INTRODUCTION: Pre-eclampsia is associated with increased risk to both the mother and fetus. Effective monitoring of the fetal condition is essential to the management of women with pre-eclampsia. The biophysical profile (BPP) is one monitoring tool available to clinicians. AIMS AND OBJECTIVES: To compare the BPP test with cardiotocography/non-stress test (CTG/NST) alone for their ability to predict fetal acidemia at birth or a composite adverse perinatal outcome among women with preeclampsia and to estimate the effect of BPP assessment on mode of delivery and birth outcome. METHODS: Secondary analysis of a prospective cohort of women with preeclampsia. The predictive ability of the tests was assessed based on sensitivity, specificity, positive and negative likelihood ratios (LR+, LR-). Women assessed with the BPP were compared with matched controls not assessed with the BPP to determine the odds of Cesarean delivery or adverse perinatal outcomes after adjustment for potential confounders. RESULTS: Five out of 89 women (5.6%) had an abnormal BPP; 18 out of 89 (20.2%) had an abnormal CTG/NST. Fetal acidemia was diagnosed in 13 fetuses (14.6%); composite adverse perinatal outcome in 68 fetuses/infants (76.4%). Both tests had relatively poor predictive performance for both outcomes (LR+ between 2.50 and 3.90 and LR- between 0.64 and 0.93). Assessment with the BPP was positively associated with fetal acidemia (adjusted OR 4.84; 95% CI 1.33-17.66). CONCLUSION: The BPP and CTG/NST alone were poor predictors of perinatal outcome in this cohort; multiple tests should be considered when assessing fetal risk in women with preeclampsia.

PIERS proteinuria: relationship with adverse maternal and perinatal outcome.

OBJECTIVE: To examine the ability of three different proteinuria assessment methods (urinary dipstick, spot urine protein:creatinine ratio [Pr/Cr], and 24-hour urine collection) to predict adverse pregnancy outcomes. METHODS: We performed a prospective multicentre cohort study, PIERS (Preeclampsia Integrated Estimate of RiSk), in seven academic tertiary maternity centres practising expectant management of preeclampsia remote from term in Canada, New Zealand, and Australia. Eligible women were those admitted with preeclampsia who had at least one antenatal proteinuria assessment by urinary dipstick, spot urine Pr/Cr ratio, and/or 24-hour urine collection. Proteinuria assessment was done either visually at the bedside (by dipstick) or by hospital clinical laboratories for spot urine Pr/Cr and 24-hour urine collection. We calculated receiver operating characteristic area under the curve (95% CI) for each proteinuria method and each of the combined adverse maternal outcomes (within 48 hours) or adverse perinatal outcomes (at any time). Models with AUC ≥ 0.70 were considered of interest. Analyses were run for all women who had each type of proteinuria assessment and for a cohort of women ("ALL measures") who had all three proteinuria assessments. RESULTS: More women were proteinuric by urinary dipstick (≥ 2+, 61.4%) than by spot urine Pr/Cr (≥ 30 g/mol, 50.4%) or 24-hour urine collection (≥ 0.3g/d, 34.7%). Each proteinuria measure evaluated had some discriminative power, and dipstick proteinuria (categorical) performed as well as other methods. No single method was predictive of adverse perinatal outcome. CONCLUSION: The measured amount of proteinuria should not be used in isolation for decision-making in women with preeclampsia. Dipstick proteinuria performs as well as other methods of assessing proteinuria for prediction of adverse events.