Fetal fibronectin status and cervical length in women with threatened preterm labor and the effectiveness of maintenance tocolysis.

OBJECTIVE: To assess the effect of maintenance tocolysis in women who are at high or low risk for preterm delivery according to fetal fibronectin (fFN) status and cervical length (CL). STUDY DESIGN: We compared the risk of preterm delivery in fFN pos and fFN neg women and in women with a CL <15 mm and ≥15 mm, by using the Cox regression. Differences between the effectiveness of maintenance tocolysis in high- and low-risk women were assessed by using an interaction term. RESULTS: 122 fFN tests were taken, of which 50 were fFN pos. CL was measured in 236 women, of whom 52 women had a CL <15 mm. The median gestational age at delivery was lower in fFN pos women; fFN pos women had a higher hazard for preterm delivery at any point of time (HR 4.7; 95% CI 2.9 to 7.6). Comparable results were seen for CL. Neither fFN status nor CL did alter the effect of maintenance tocolysis, which was ineffective in the total randomized group, on the risk of preterm delivery (p for interaction = 0.87 for fFN and 0.18 for CL). CONCLUSION: Maintenance tocolytic therapy with nifedipine is ineffective and not dependent on fFN or CL status.

Predictive Factors for Delivery within 7 Days after Successful 48-Hour Treatment of Threatened Preterm Labor.

Objective The aim of this study was to assess which characteristics and results of vaginal examination are predictive for delivery within 7 days, in women with threatened preterm labor after initial treatment. Study Design A secondary analysis of a randomized controlled trial on maintenance nifedipine includes women who remained undelivered after threatened preterm labor for 48 hours. We developed one model for women with premature prelabor rupture of membranes (PPROM) and one without PPROM. The predictors were identified by backward selection. We assessed calibration and discrimination and used bootstrapping techniques to correct for potential overfitting. Results For women with PPROM (model 1), nulliparity, history of preterm birth, and vaginal bleeding were included in the multivariable analysis. For women without PPROM (model 2), maternal age, vaginal bleeding, cervical length, and fetal fibronectin (fFN) status were in the multivariable analysis. Discriminative capability was moderate to good (c-statistic 0.68; 95% confidence interval [CI] 0.60-0.77 for model 1 and 0.89; 95% CI, 0.84-0.93 for model 2). Conclusion PPROM and vaginal bleeding in the current pregnancy are relevant predictive factors in all women, as are maternal age, cervical length, and fFN in women without PPROM and nulliparity, history of preterm birth in women with PPROM.

History of preeclampsia is more predictive of cardiometabolic and cardiovascular risk factors than obesity.

OBJECTIVE: To determine to what extent a history of preeclampsia affects traditional cardiometabolic (insulin resistance and dyslipidemia) and cardiovascular (hypertension and micro-albuminuria) risk factors of the metabolic syndrome irrespective of BMI. STUDY DESIGN: In a retrospective case-control study we compared 90 formerly preeclamptic women, divided in 3 BMI-classes (BMI 19.5-24.9, 25.0-29.9, ≥30.0kg/m(2)) to 30 controls, matched for BMI, age and parity. Cardiometabolic and cardiovascular risk factors (WHO-criteria) were tested 6-18 months post partum. Statistical analysis included unpaired t-tests, Mann-Whitney U test, or Chi square test and two-way ANOVA. RESULTS: Constituents of the metabolic syndrome (glucose, insulin, HOMAIR, HDL-cholesterol, triglycerides, blood pressure, micro-albuminuria) were higher in formerly preeclamptic women than in BMI-matched controls. Resultantly, traditional risk factors were more prevalent in formerly preeclamptic women than in controls (insulin resistance 80% vs 30%, dyslipidemia 52% vs 3%, hypertension 24% vs 0%, micro-albuminuria 30% vs 0%). Cardiometabolic risk factors increased with BMI, to the same extent in both groups. Formerly preeclamptic women had metabolic syndrome more often than their BMI-matched controls (38% vs 3%, p<0.001). CONCLUSION: Traditional risk factors of the metabolic syndrome are more prevalent in formerly preeclamptic women than in BMI-matched controls and increase with BMI to the same extent in both groups. A history of preeclampsia seems to be a stronger indicator of cardiovascular risk than obesity per se.

Low Plasma Volume in Normotensive Formerly Preeclamptic Women Predisposes to Hypertension.

Formerly preeclamptic women are at risk for cardiovascular disease. Low plasma volume may reflect latent hypertension and potentially links preeclampsia with chronic cardiovascular disease. We hypothesized that low plasma volume in normotensive formerly preeclamptic women predisposes to hypertension. We longitudinally studied n=104 formerly preeclamptic women in whom plasma volume was measured 3 to 30 months after the preeclamptic pregnancy. Cardiovascular variables were assessed at 2 points in time (3-30 months postpartum and 2-5 years thereafter). Study population was divided into low plasma volume (≤1373 mL/m(2)) and normal plasma volume (>1373 mL/m(2)). Primary end point was hypertension at the second visit: defined as ≥140 mm Hg systolic or ≥90 mm Hg diastolic. Secondary outcome of this study was change in traditional cardiovascular risk profile between visits. Variables correlating univariately with change in blood pressure between visits were introduced in regression analysis. Eighteen of 104 (17%) formerly preeclamptic women who were normotensive at first visit had hypertension at second evaluation 2 to 5 years later. Hypertension developed more often in women with low plasma volume (10/35 [29%]) than in women with normal plasma volume (8/69 [12%]; odds ratio, 3.2; 95% confidence interval, 1.4-8.6). After adjustments, relationship between plasma volume status and subsequent hypertension persisted (adjusted odds ratio, 3.0; 95% confidence interval, 1.1-8.5). Mean arterial pressure at second visit correlated inverse linearly with plasma volume (r=-0.49; P<0.01). Initially normotensive formerly preeclamptic women have 17% chance to develop hypertension within 5 years. Women with low plasma volume have higher chance to develop hypertension than women with normal plasma volume. Clinically, follow-up of blood pressure seems warranted in women with history of preeclampsia, even when initially normotensive.

Aerobic Exercise Training in Formerly Preeclamptic Women: Effects on Venous Reserve.

UNLABELLED: In women with a history of preeclampsia, low plasma volume (≤1373 mL/m(2)) is associated with recurrent preeclampsia and chronic hypertension. Interventions that improve volume reserve may reduce these risks in formerly preeclamptic women. In this study, we examined the effects of aerobic exercise training on venous reserves in 24 normotensive formerly preeclamptic women and 20 controls. Before and after 12-week aerobic exercise training, we measured plasma volume with albumin indicator dilution technique and venous compliance with venous occlusion plethysmography. Venous compliance and hemodynamic responses were assessed dynamically during graded head-up tilt (HUT). Formerly preeclamptic women had lower pretraining plasma volume and venous compliance than controls (1348±78 versus 1529±112 mL/m(2); P<0.01 and 0.04±0.02 versus 0.07±0.01 mL·dL(-1)·mm Hg(-1); P<0.01, respectively). Blood pressure decreased comparably between groups in response to HUT (P=0.11); the increase in heart rate in response to HUT was however more pronounced in preeclamptic women than in controls (P=0.01) Training increased plasma volume comparably in both groups (+180 versus +135 mL/m(2), P=0.22) and similarly physical fitness (+3.4 and +3.7 mL·min(-1)·kg(-1), P=0.43). Venous compliance increased twice as much in formerly preeclamptic women than in controls (supine +0.02 versus +0.01 mL·dL(-1)·mm Hg(-1); P<0.01). After training, HUT decreased mean blood pressure comparable with pretraining responses in both groups, whereas both groups fulfilled the HUT testing at a persistently lower heart rate. These results demonstrate that 12 weeks of aerobic exercise training improve venous reserve in postpartum women. Training normalized plasma volume and venous compliance in formerly preeclamptic women to pretraining levels of controls. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00900458.

Guideline-based development of quality indicators for prevention and management of postpartum hemorrhage.

INTRODUCTION: To systematically develop a set of guideline-based quality indicators for postpartum hemorrhage (PPH) as a tool to measure guideline adherence in actual PPH care. MATERIAL AND METHODS: A Rand-modified Delphi procedure was used to systematically achieve consensus among a panel of 22 experts on PPH care on recommendations extracted from evidence-based guidelines, Managing-Obstetrics-Emergencies-Trauma (MOET) instructions and international literature. The selected recommendations were individually rated on health gain (prevention of maternal mortality and morbidity) and overall efficiency by the expert panel. Subsequently, consensus about the most important recommendations to measure quality of PPH care among the panel members was reached, followed by a final approval. Last, definition of the final set by critical appraisal of the recommendations regarding measurability took place. The main outcome measure was a set of valid quality indicators for prevention and management of PPH. RESULTS: From the 69 extracted recommendations, 50 were selected and translated into 22 quality indicators on professional performance (n = 17) and organization of PPH care (n = 5). The professional performance indicators covered all fields of PPH care, such as prevention (n = 2) and management of PPH, including communication and documentation (n = 4), monitoring and prevention of shock (n = 3), use of blood products (n = 3) and treatment of PPH (n = 5). Organizational indicators (n = 5) were clustered into protocols and agreements, audit, accessibility and documentation. CONCLUSIONS: This study describes a stepwise systematic development of 22 performance and organizational indicators to use for measuring the whole care process of prevention and management of PPH.

Cardiovascular effects of aerobic exercise training in formerly preeclamptic women and healthy parous control subjects.

OBJECTIVE: Women who have had preeclampsia demonstrate higher prevalence of metabolic syndrome (MetS), impaired vascular function, and increased sympathetic activity and are at increased risk of cardiovascular disease. The aim of this study was to assess the effects of 12 weeks of exercise training (70-80% maximum volume of oxygen utilization) in women who had had preeclampsia on physical fitness, components of MetS, vasculature, and autonomic functions compared with healthy control subjects. STUDY DESIGN: Our prospective case-control study included 24 normotensive women who had had preeclampsia and 20 control subjects who were matched for age and postpartum interval (all 6-12 months after delivery). Before and after training, we measured all components of MetS (ie, BP, lipids, glucose/insulin, and albuminuria), carotid intima media thickness (IMT) and brachial and superficial femoral artery endothelial function that used flow-mediated dilation (FMD). Autonomic activity was quantified with power spectral analysis (low-frequency/high-frequency power [LF/HF] ratio). RESULTS: At baseline, women who had had preeclampsia demonstrated higher values of most components of MetS. Compared with the control subjects, women who had had preeclampsia had increased IMT (580 ± 92 µm vs 477 ± 65 µm, respectively), impaired endothelial function (FMD brachial artery, 5.3% ± 2.2% vs 10.8% ± 3.5%, respectively; FMD superficial femoral artery, 4.9% ± 2.1% vs 8.7% ± 3.2%, respectively) and increased LF/HF power ratio (2.2 ± 1.0 vs 1.3 ± 0.4, respectively; all P < .05). In both groups, exercise training decreased values of most components of MetS and IMT, improved FMD, and concurrently reduced LF/HF. Despite these improvements, vascular and autonomic variables did not normalize by 12 weeks of training in women who had had preeclampsia. CONCLUSION: This study demonstrates that exercise training in women who had had preeclampsia and control subjects improves components of MetS, endothelial function, vascular wall thickness, and autonomic control. Nonetheless, trained women who had had preeclampsia only reached a cardiovascular status that is comparable with sedentary healthy control subjects.

Impaired effect of relaxin on vasoconstrictor reactivity in spontaneous hypertensive rats.

Relaxin is thought to be involved in vasodilation to pregnancy by increasing endothelium-dependent vasodilation and compliance, and decreasing myogenic reactivity. Primary (essential) hypertension predisposes to circulatory maladaptation and subsequent gestational hypertensive disease. This study aimed to determine that vascular responses to chronic exposure to relaxin are impaired in young female rats with primary hypertension. In 10-12 weeks old Wistar-Hannover rats (WHR) and spontaneous hypertensive rats (SHR), we determined vascular responses in isolated kidney and mesenteric arteries after 5-days of chronic exposure to relaxin (4 µg/h) or placebo. SHR show decreased sensitivity to phenylephrine (by 67%, p<0.01) and renal perfusion flow (RPFF, by 19%, p<0.01), but no changes in flow-mediated vasodilation, myogenic reactivity or vascular compliance. In WHR, relaxin stimulated flow-mediated vasodilation (2.67 fold, from 48 ± 9 to 18 ± 4 µl/min, p = 0.001), inhibited myogenic reactivity (from -1 ± 2 to 7 ± 3 µm/10 mmHg, p = 0.01), and decreased sensitivity to phenylephrine (28%, from 1.39 ± 0.08 to 1.78 ± 0.10 µM, p<0.01), but left compliance and RPFF unchanged. NO-blockade by L-NAME diminished most relaxin-mediated responses. In SHR, the vasodilator effects of relaxin were blunted for myogenic reactivity and sensitivity to phenylephrine, with similar effects on flow-mediated vasodilation, compliance, RPFF and equal Rxfp1 (relaxin family peptide receptor) gene expression, as compared to WHR. Primary hypertension blunts both the relaxin-induced inhibition of myogenic reactivity and α-adrenergic vasoconstrictor response, independent from Rxfp1 gene expression, while the relaxin-dependent enhanced flow-mediated vasodilation remains intact. This implies selective resistance to relaxin in young subjects suffering from primary hypertension.

Fetal aortic distensibility, compliance and pulse pressure assessment during the second half of pregnancy.

The objective of the study was to measure fetal aortic pulse wave velocity and lumen diameter waveforms and subsequently calculate local distensibility, compliance and pulse pressure. A dedicated algorithm for optimizing lumen diameter assessment from radiofrequency ultrasound data is described. Biplane raw data were obtained from a matrix array transducer. We evaluated 83 confirmed, normally developing pregnancies at 22-38 wk. Fetal aortic pulse wave velocity (PWV, m/s) = 0.047 × gestational age (wk) + 1.241, and the distensibility coefficient (1/kPa) = 1/(1.04 × PWV(2)). The logarithm of the local compliance index (mm(2)/kPa) and the pulse pressure (kPa) were both linearly related to gestational age as 0.022 × GA (wk) - 0.343 and 0.012 × GA (wk) + 0.931, respectively. In conclusion, fetal aortic elastic properties can be derived from phase-sensitive radiofrequency data and multiline diameter assessment. Future studies may shed further light on the developmental origins of vascular health and disease.

A randomized controlled trial on the value of misoprostol for the treatment of retained placenta in a low-resource setting.

OBJECTIVE: To evaluate the efficacy and safety of misoprostol among patients with retained placenta in a low-resource setting. METHODS: A prospective, multicenter, randomized, double-blind, placebo-controlled trial was carried out in Tanzania between April 2008 and November 2011. It included patients who delivered at a gestational age of 28 weeks or more and had blood loss of 750 mL or less at 30 minutes after delivery. Sublingual misoprostol (800 µg) was compared with placebo as the primary treatment. Power analysis showed that 117 patients would be required to observe a reduction of 40% in the incidence of manual removal of the placenta (MRP; P=0.05, 80% power), the primary outcome. The secondary outcomes were blood loss and number of blood transfusions. RESULTS: Interim analysis after recruitment of 95 patients showed that incidence of MRP, total blood loss, and incidence of blood transfusions were similar in the misoprostol (MRP, 40%; blood loss, 803 mL; blood transfusion, 15%) and placebo (MRP, 33%, blood loss 787 mL, blood transfusion, 23%) groups. The trial was stopped because continuation would not alter the interim conclusion that misoprostol was ineffective. CONCLUSION: Treatment with misoprostol was found to have no clinically significant beneficial effect among women with retained placenta. CLINICAL TRIAL REGISTRATION: Current Controlled Trials ISRCTN16104753.

Recommendations for pregnancies in patients with crigler-najjar syndrome.

During pregnancy, the developing foetus in mothers with Crigler-Najjar type 1 and 2 is exposed to raised levels of unconjugated bilirubin, with the risk of neurotoxicity. We describe two pregnancies in a patient with Crigler-Najjar type 2, who was carefully monitored prior to and during pregnancy and phototherapy adjusted to maintain serum bilirubin levels below 200 µmol/l and the bilirubin/albumin molar ratio below 50%. Both pregnancies resulted in normal delivery of healthy infants who had normal neurological development. A review of all reported pregnancies in Crigler-Najjar patients and a set of recommendations are presented.

Effect of maintenance tocolysis with nifedipine in threatened preterm labor on perinatal outcomes: a randomized controlled trial.

IMPORTANCE: In threatened preterm labor, maintenance tocolysis with nifedipine, after an initial course of tocolysis and corticosteroids for 48 hours, may improve perinatal outcome. OBJECTIVE: To determine whether maintenance tocolysis with nifedipine will reduce adverse perinatal outcomes due to premature birth. DESIGN, SETTING, AND PARTICIPANTS: APOSTEL-II (Assessment of Perinatal Outcome with Sustained Tocolysis in Early Labor) is a double-blind, placebo-controlled trial performed in 11 perinatal units including all tertiary centers in The Netherlands. From June 2008 to February 2010, women with threatened preterm labor between 26 weeks (plus 0 days) and 32 weeks (plus 2 days) gestation, who had not delivered after 48 hours of tocolysis and a completed course of corticosteroids, were enrolled. Surviving infants were followed up until 6 months after birth (ended August 2010). INTERVENTION: Randomization assigned 406 women to maintenance tocolysis with nifedipine orally (80 mg/d; n = 201) or placebo (n = 205) for 12 days. Assigned treatment was masked from investigators, participants, clinicians, and research nurses. MAIN OUTCOME MEASURES: Primary outcome was a composite of adverse perinatal outcomes (perinatal death, chronic lung disease, neonatal sepsis, intraventricular hemorrhage >grade 2, periventricular leukomalacia >grade 1, or necrotizing enterocolitis). Analyses were completed on an intention-to-treat basis. RESULTS: Mean (SD) gestational age at randomization was 29.2 (1.7) weeks for both groups. Adverse perinatal outcome was not significantly different between groups: 11.9% (24/201; 95% CI, 7.5%-16.4%) for nifedipine vs 13.7% (28/205; 95% CI, 9.0%-18.4%) for placebo (relative risk, 0.87; 95% CI, 0.53-1.45). CONCLUSIONS AND RELEVANCE: In patients with threatened preterm labor, nifedipine-maintained tocolysis did not result in a statistically significant reduction in adverse perinatal outcomes when compared with placebo. Although the lower than anticipated rate of adverse perinatal outcomes in the control group indicates that a benefit of nifedipine cannot completely be excluded, its use for maintenance tocolysis does not appear beneficial at this time. TRIAL REGISTRATION: trialregister.nl Identifier: NTR1336.

[Maternal pulmonary oedema due to the use of atosiban in cases of multiple gestation]. / Maternaal longoedeem bij gebruik van atosiban bij meerlingzwangerschap.

BACKGROUND: Nifedipine is used as a first choice tocolytic agent in many Dutch hospitals, but its use is discouraged in multiple gestations. Atosiban, a selective oxytocin receptor antagonist that rarely causes systemic side effects, is used as an alternative. CASE DESCRIPTION: A 32-year-old primigravida with spontaneous triplet pregnancy was admitted at 33 3/7 weeks for threatened preterm labour. For tocolysis, atosiban was administered for 48 hours together with betamethasone for foetal lung maturation. One day after treatment with atosiban she developed dyspnoea caused by pulmonary oedema. After a caesarean section and furosemide treatment the pulmonary oedema resolved. Analysis showed that atosiban was a likely cause of the pulmonary oedema. CONCLUSION: Every patient with multiple gestation is at increased risk of pulmonary oedema. Any tocolytic agent may elicit that response, even the relatively safe atosiban.

Co-occurrence of cardiovascular and prothrombotic risk factors in women with a history of preeclampsia.

OBJECTIVE: Formerly preeclamptic women are at increased risk for remote cardiovascular and thrombotic diseases. We studied co-occurrence of cardiovascular and prothrombotic risk factors within a cohort of formerly preeclamptic women and tested if prevalence of these risk profiles related to onset of preeclampsia in previous pregnancy. METHODS: We evaluated 1,297 nonpregnant formerly preeclamptic women (6-12 months postpartum) for the presence of four risk profiles: circulatory risk profile (hypertension or latent hypertension [low plasma volume, increased vascular resistance, or both]; metabolic syndrome (World Health Organization criteria); thrombophilia (factor V Leiden, prothrombin mutation, or protein C or S deficiency); and hyperhomocysteinemia. Trends between prevalence of these four profiles and onset of preeclampsia were studied using linear regression analysis. RESULTS: After exclusion of 63 women (4.9%) because of incomplete data, 1,234 women were included. One or more risk profiles were detected in 958 of 1,234 (77.6%) formerly preeclamptic women. Circulatory risk profile was more prevalent (66.1%) than hyperhomocysteinemia (18.7%), metabolic syndrome (15.4%), or thrombophilia (10.8%). Prevalence of circulatory risk profile, metabolic syndrome, and hyperhomocysteinemia decreased significantly with gestational age at delivery, whereas thrombophilia did not (P=.22). There was minimal overlap (less than 2%) between metabolic syndrome, thrombophilic profile, and hyperhomocysteinemia. CONCLUSION: Circulatory risk profile is present in two thirds of formerly preeclamptic women. Metabolic syndrome, thrombophilia, and hyperhomocysteinemia are prevalent in 10-20%. There is considerable overlap between circulatory risk profile and other profiles, but not among the three other profiles. Prevalence of these risk factors, except thrombophilia, decreases with gestational age at delivery in preceding pregnancy. LEVEL OF EVIDENCE: : II.

Unexplained first trimester recurrent pregnancy loss and low venous reserves.

BACKGROUND: More than half of recurrent pregnancy loss (RPL) remains unexplained. We hypothesized that women with a history of unexplained RPL (URPL) have low venous reserve. METHODS: Case-control study in 12 women with a history of URPL, 11 healthy nulliparous controls and 12 primiparous controls with a history of uncomplicated pregnancy. To quantify venous reserve, we measured plasma volume (PV, ml/m(2)) and venous compliance in forearm and calf (VC(arm), VC(calf), (ml/dl)/mmHg) during the follicular phase of the menstrual cycle. Mean arterial blood pressure (mmHg) was measured by oscillometry. Arterial demand was evaluated by cardiac index (CI, (l/min)/m(2)). RESULTS: Baseline characteristics were comparable between groups. All groups had similar CI. Women with a history of RPL had 14% and 9% lower mean PV compared with nulliparous and primiparous controls (P < 0.01 and P = 0.04, respectively). In women with URPL, the mean VC(arm) was 25% and 32% lower compared with nulliparous and primiparous controls (P = 0.04 and P < 0.01, respectively), while the mean VC(calf) was 29 and 22% lower compared with the two control groups (P < 0.01 and P = 0.03, respectively). CONCLUSIONS: Women with URPL have lower venous reserves when compared with controls at comparable arterial demand. Interventions that increase venous reserve may improve pregnancy outcome.

Impaired fetal growth and low plasma volume in adult life.

OBJECTIVE: To estimate whether normotensive women who were born small for gestational age have low plasma volume in adult life, which is associated with later chronic hypertension. METHODS: In 280 normotensive women with a history of hypertension in pregnancy, we recorded recalled gestational age and weight at birth and measured plasma volume (I-human serum albumin indicator dilution method). To correct for possible confounders, we recorded recent obstetric history and measured in each individual all constituents of the metabolic syndrome (World Health Organization criteria), sex hormones (progesterone and estradiol), renal function, and cardiac performance at rest (echocardiography). We estimated daily activity level with a validated questionnaire (Short Questionnaire to Assess Health-enhancing physical activity). We studied the relation between women's own birth weight centile and her adult plasma volume (mL) and adjusted for the effects of confounding variables using multiple linear regression analysis. RESULTS: Birth weight correlated positively with adult plasma volume (P<.001). Linear regression analysis demonstrated that each 10 centile change in birth weight is associated with an average change of 46.6 mL (95% confidence interval [CI] 30.8-62.3) in adult plasma volume. This association persisted after adjustment for confounding factors (current body surface area, mean arterial pressure, total vascular resistance, glomerular filtration rate, and a total 24 hours of sodium output). After adjustment, each 10 centile change in birth weight was associated with an average change of 32.1 mL (95% CI 19.6-44.6) in adult plasma volume. Birth centile contributes 14% to the variation in total adult plasma volume. CONCLUSION: Impaired fetal growth is associated with low plasma volume in adult life. LEVEL OF EVIDENCE: II.

Comparison of two point-of-care testing (POCT) devices for fetal lactate during labor.

BACKGROUND: Point-of-care testing (POCT) of fetal scalp blood lactate is used as an alternative for pH analysis. Lactate measurements have not been standardized and values vary with each device used. The aim of this study was to evaluate the performance of two POCT lactate meters for intrapartum use. METHODS: Analytical performance of StatStrip Lactate (Nova Biomedical) and Lactate Pro (Arkray) was evaluated using CLSI EP10. Both POCT meters were compared with our lactate reference method (RapidLab 860; Siemens Healthcare Diagnostics) using fetal scalp and neonatal cord blood. Deming regression analysis was performed. RESULTS: StatStrip Lactate coefficients of variation (CVs) were 5.1%, 5.0% and 2.6% at 0.9, 7.5 and 14.1 mmol/L lactate, respectively. CVs for Lactate Pro were 10.7%, 5.2% and 5.7% at 1.7, 4.1 and 6.4 mmol/L lactate, respectively. Consecutive lactate measurements in 37 fetal scalp and 122 cord blood samples revealed different test characteristics for the two POCT devices. In fetal scalp blood: StatStrip Lactate=1.13*RapidLab-0.39 (R(2)=0.907) and Lactate Pro=0.95*RapidLab-0.03 (R(2)=0.823). In cord artery blood: StatStrip Lactate=1.08*RapidLab-0.09 (R(2)=0.810) and Lactate Pro=0.72*RapidLab+0.59 (R(2)=0.807). CONCLUSIONS: Overall performance of both Lactate Pro and StatStrip Lactate was good, with StatStrip Lactate having smallest CVs and closest correlation to our reference method. Both StatStrip Lactate and Lactate Pro can be used as a lactate POCT device for obstetric use.

Scalp blood lactate for intra-partum assessment of fetal metabolic acidosis.

OBJECTIVE: To study to what extent the fetal scalp blood lactate concentration during labor correlates with fetal scalp pH and base deficit, and metabolic acidosis at birth, and to suggest lactate cut-off values to serve as indicators for either reassurance or immediate intervention. DESIGN: A retrospective observational study. SETTING: Labor ward at a university medical center. SAMPLE: Fetal scalp and cord blood samples with acid-base and lactate values from 486 singleton pregnancies beyond 34 weeks' gestation. METHODS: The relation between lactate, pH and base deficit (BD) in fetal scalp blood was tested by Spearman's rho correlation coefficient. Lactate cut-off values indicating either reassuring fetal status or immediate intervention were estimated using percentile distribution and compared with pH and BD. MAIN OUTCOME MEASURES: Metabolic acidosis, defined as umbilical cord artery pH below 7.05 and BD calculated for the blood compartment above 12 mmol/l. RESULTS: After 127 (21%) exclusions, 486 cases were available for analysis. Fetal lactate values increased with evolving metabolic acidosis. Lactate concentration correlated with both pH (r=-0.50, p<0.01) and BD (r=0.48, p<0.01). Lactate <5.4 mmol/l indicated reassuring fetal status, whereas lactate ≥6.6 mmol/l indicated metabolic acidosis. Fetal lactate correlated better with either the absence or presence of metabolic acidosis at birth than did fetal pH and BD. CONCLUSIONS: In the case of a non-reassuring fetal heart rate, fetal scalp blood lactate provides more accurate information on fetal acid-base status than does pH and/or BD.

Prepregnancy low-plasma volume and predisposition to preeclampsia and fetal growth restriction.

OBJECTIVE: To estimate whether recurrence risks of preeclampsia, preterm birth, and fetal growth restriction relate to prepregnancy plasma volume. METHODS: We conducted a retrospective cohort study in 580 formerly preeclamptic women and a control group. In all women we measured plasma volume (iodine-human serum albumin indicator dilution method) in the nonpregnant state. One hundred seventy-eight normotensive (formerly preeclamptic) women had a subsequent pregnancy within the study period (1996-2008). Odds ratios (ORs) for recurrent preeclampsia, preterm birth, and small for gestational age (SGA) neonates were estimated, using multivariable logistic regression with adjustment for confounders. RESULTS: Plasma volumes were lower in women who developed recurrent preeclampsia (1,241±158 mL/m², 17% lower compared with women in the control group) than in women without recurrent preeclampsia (1,335±167 mL/m², 11% lower compared with women in the control group). Logistic regression analysis demonstrated that each 100-mL/m difference in plasma volume was associated with an OR of 0.6 (95% confidence interval [CI] 0.5-0.8) to develop recurrent preeclampsia in subsequent pregnancy. Risk of preterm delivery (before 37 weeks of gestation) depended on preeclampsia in subsequent pregnancy, the adjusted hazard ratio for preterm birth was 0.9 (95% CI 0.7-1.1) for each 100-mL/m² change in plasma volume. Risk of delivering an SGA neonate was independent of recurrent preeclampsia. Each 100-mL/m² change in plasma volume was associated with an adjusted OR of 0.8 (95% CI 0.5-0.9) to deliver an SGA neonate in subsequent pregnancy. CONCLUSION: The risk of recurrent preeclampsia and fetal growth restriction in subsequent pregnancy relates inversely and linearly to prepregnancy plasma volume.