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The Journal of Obstetrics and... Aug 2021Postpartum hemorrhage (PPH) has remained the leading cause of maternal mortality. While anemia is a leading contributor to maternal morbidity, molecular, cellular and... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Postpartum hemorrhage (PPH) has remained the leading cause of maternal mortality. While anemia is a leading contributor to maternal morbidity, molecular, cellular and anemia-induced hypoxia, clinical studies of the relationship between prenatal-anemia and PPH have reported conflicting results. Therefore, our objective was to investigate the outcomes of studies on the relationships between prenatal anemia and PPH-related mortality.
MATERIALS AND METHODS
Electronic databases (MEDLINE, Scopus, ClinicalTrials.gov, PROSPERO, EMBASE, and the Cochrane Central Register of Controlled Trials) were searched for studies published before August 2019. Keywords included "anemia," "hemoglobin," "postpartum hemorrhage," and "postpartum bleeding." Only studies involving the association between anemia and PPH were included in the meta-analysis. Our primary analysis used random effects models to synthesize odds-ratios (ORs) extracted from the studies. Heterogeneity was formally assessed with the Higgins' I statistics, and explored using meta-regression and subgroup analysis.
RESULTS
We found 13 eligible studies investigating the relationship between prenatal anemia and PPH. Our findings suggest that severe prenatal anemia increases PPH risk (OR = 3.54; 95% CI: 1.20, 10.4, p-value = 0.020). There was no statistical association with mild (OR = 0.60; 95% CI: 0.31, 1.17, p-value = 0.130), or moderate anemia (OR = 2.09; 95% CI: 0.40, 11.1, p-value = 0.390) and the risk of PPH.
CONCLUSION
Severe prenatal anemia is an important predictive factor of adverse outcomes, warranting intensive management during pregnancy. PROSPERO Registration Number: CRD42020149184; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=149184.
Topics: Anemia; Female; Humans; Maternal Mortality; Oxytocics; Postpartum Hemorrhage; Postpartum Period; Pregnancy
PubMed: 34002432
DOI: 10.1111/jog.14834 -
American Journal of Obstetrics and... May 2023Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard.... (Review)
Review
Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard. The condition has been attributed to the passage of fetal colonic content (meconium), intraamniotic bleeding with the presence of heme catabolic products, or both. The frequency of green-stained amniotic fluid increases as a function of gestational age, reaching approximately 27% in post-term gestation. Green-stained amniotic fluid during labor has been associated with fetal acidemia (umbilical artery pH <7.00), neonatal respiratory distress, and seizures as well as cerebral palsy. Hypoxia is widely considered a mechanism responsible for fetal defecation and meconium-stained amniotic fluid; however, most fetuses with meconium-stained amniotic fluid do not have fetal acidemia. Intraamniotic infection/inflammation has emerged as an important factor in meconium-stained amniotic fluid in term and preterm gestations, as patients with these conditions have a higher rate of clinical chorioamnionitis and neonatal sepsis. The precise mechanisms linking intraamniotic inflammation to green-stained amniotic fluid have not been determined, but the effects of oxidative stress in heme catabolism have been implicated. Two randomized clinical trials suggest that antibiotic administration decreases the rate of clinical chorioamnionitis in patients with meconium-stained amniotic fluid. A serious complication of meconium-stained amniotic fluid is meconium aspiration syndrome. This condition develops in 5% of cases presenting with meconium-stained amniotic fluid and is a severe complication typical of term newborns. Meconium aspiration syndrome is attributed to the mechanical and chemical effects of aspirated meconium coupled with local and systemic fetal inflammation. Routine naso/oropharyngeal suctioning and tracheal intubation in cases of meconium-stained amniotic fluid have not been shown to be beneficial and are no longer recommended in obstetrical practice. A systematic review of randomized controlled trials suggested that amnioinfusion may decrease the rate of meconium aspiration syndrome. Histologic examination of the fetal membranes for meconium has been invoked in medical legal litigation to time the occurrence of fetal injury. However, inferences have been largely based on the results of in vitro experiments, and extrapolation of such findings to the clinical setting warrants caution. Fetal defecation throughout gestation appears to be a physiologic phenomenon based on ultrasound as well as in observations in animals.
Topics: Infant, Newborn; Pregnancy; Female; Humans; Meconium Aspiration Syndrome; Meconium; Amniotic Fluid; Chorioamnionitis; Pregnancy Complications; Inflammation; Heme
PubMed: 37012128
DOI: 10.1016/j.ajog.2022.11.1283 -
American Journal of Perinatology Aug 2017Risk factors for placental abruption have changed, but there has not been an updated systematic review investigating outcomes. We searched PubMed, EMBASE, Web of... (Review)
Review
Risk factors for placental abruption have changed, but there has not been an updated systematic review investigating outcomes. We searched PubMed, EMBASE, Web of Science, SCOPUS, and CINAHL for publications from January 1, 2005 through December 31, 2016. We reviewed English-language publications reporting estimated incidence and/or risk factors for maternal, labor, delivery, and perinatal outcomes associated with abruption. We excluded case studies, conference abstracts, and studies that lacked a referent/comparison group or did not clearly characterize placental abruption. A total of 123 studies were included. Abruption was associated with elevated risk of cesarean delivery, postpartum hemorrhage and transfusion, preterm birth, intrauterine growth restriction or low birth weight, perinatal mortality, and cerebral palsy. Additional maternal outcomes included relaparotomy, hysterectomy, sepsis, amniotic fluid embolism, venous thromboembolism, acute kidney injury, and maternal intensive care unit admission. Additional perinatal outcomes included acidosis, encephalopathy, severe respiratory disorders, necrotizing enterocolitis, acute kidney injury, need for resuscitation, chronic lung disease, infant death, and epilepsy. Few studies examined outcomes beyond the initial birth period, but there is evidence that both mother and child are at risk of additional adverse outcomes. There was also considerable variation in, or absence of, the reporting of abruption definitions.
Topics: Abruptio Placentae; Asphyxia Neonatorum; Blood Transfusion; Cerebral Palsy; Cesarean Section; Female; Fetal Growth Retardation; Humans; Hypoxia, Brain; Infant, Low Birth Weight; Infant, Newborn; Maternal Mortality; Perinatal Mortality; Postpartum Hemorrhage; Pregnancy; Premature Birth; Recurrence; Stillbirth
PubMed: 28329897
DOI: 10.1055/s-0037-1599149 -
Diagnostics (Basel, Switzerland) Jan 2022The microbiome is vital for the proper function of the gastrointestinal tract (GIT) and the maintenance of overall wellbeing. Gut ischemia may lead to disruption of the... (Review)
Review
The microbiome is vital for the proper function of the gastrointestinal tract (GIT) and the maintenance of overall wellbeing. Gut ischemia may lead to disruption of the intestinal mucosal barrier, resulting in bacterial translocation. In this systematic review, according to PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines, we constructed a search query using the PICOT (Patient, Intervention, Comparison, Outcome, Time) framework. Eligible studies reported in PubMed, up to April 2021 were selected, from which, 57 publications' data were included. According to these, escape of intraluminal potentially harmful factors into the systemic circulation and their transmission to distant organs and tissues, in utero, at birth, or immediately after, can be caused by reduced blood oxygenation. Various factors are involved in this situation. The GIT is a target organ, with high sensitivity to ischemia-hypoxia, and even short periods of ischemia may cause significant local tissue damage. Fetal hypoxia and perinatal asphyxia reduce bowel motility, especially in preterm neonates. Despite the fact that microbiome arouse the interest of scientists in recent decades, the pathophysiologic patterns which mediate in perinatal hypoxia/asphyxia conditions and gut function have not yet been well understood.
PubMed: 35054381
DOI: 10.3390/diagnostics12010214 -
JMIR MHealth and UHealth Feb 2023To solve the disadvantages of traditional fetal monitoring such as time-consuming, cumbersome steps and low coverage, it is paramount to develop remote fetal monitoring.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
To solve the disadvantages of traditional fetal monitoring such as time-consuming, cumbersome steps and low coverage, it is paramount to develop remote fetal monitoring. Remote fetal monitoring expands time and space, which is expected to popularize fetal monitoring in remote areas with the low availability of health services. Pregnant women can transmit fetal monitoring data from remote monitoring terminals to the central monitoring station so that doctors can interpret it remotely and detect fetal hypoxia in time. Fetal monitoring involving remote technology has also been carried out, but with some conflicting results.
OBJECTIVE
The review aimed to (1) examine the efficacy of remote fetal monitoring in improving maternal-fetal outcomes and (2) identify research gaps in the field to make recommendations for future research.
METHODS
We did a systematic literature search with PubMed, Cochrane Library, Web of Science, Embase, MEDLINE, CINAHL, ProQuest Dissertations and Theses Global, ClinicalTrials.gov, and Open Grey in March 2022. Randomized controlled trials or quasi-experimental trials of remote fetal monitoring were identified. Two reviewers independently searched articles, extracted data, and assessed each study. Primary outcomes (maternal-fetal outcomes) and secondary outcomes (health care usage) were presented as relative risks or mean difference. The review was registered on PROSPERO as CRD42020165038.
RESULTS
Of the 9337 retrieved literature, 9 studies were included in the systematic review and meta-analysis (n=1128). Compared with a control group, remote fetal monitoring reduced the risk of neonatal asphyxia (risk ratio 0.66, 95% CI 0.45-0.97; P=.04), with a low heterogeneity of 24%. Other maternal-fetal outcomes did not differ significantly between remote fetal monitoring and routine fetal monitoring, such as cesarean section (P=.21; I=0%), induced labor (P=.50; I=0%), instrumental vaginal birth (P=.45; I=0%), spontaneous delivery (P=.85; I=0%), gestational weeks at delivery (P=.35; I=0%), premature delivery (P=.47; I=0%), and low birth weight (P=.71; I=0%). Only 2 studies performed a cost analysis, stating that remote fetal monitoring can contribute to reductions in health care costs when compared with conventional care. In addition, remote fetal monitoring might affect the number of visits and duration in the hospital, but it was not possible to draw definite conclusions about the effects due to the limited number of studies.
CONCLUSIONS
Remote fetal monitoring seems to reduce the incidence of neonatal asphyxia and health care costs compared with routine fetal monitoring. To strengthen the claims on the efficacy of remote fetal monitoring, further well-designed studies are necessary, especially in high-risk pregnant women, such as pregnant women with diabetes, pregnant women with hypertension, and so forth.
Topics: Infant, Newborn; Pregnancy; Female; Humans; Cesarean Section; Asphyxia; Labor, Induced; Fetal Monitoring; Prenatal Care
PubMed: 36811944
DOI: 10.2196/41508 -
Frontiers in Pediatrics 2021It is fundamental to diagnose fetal acidemia as early as possible, allowing adequate obstetrical interventions to prevent brain damage or perinatal death. The visual...
It is fundamental to diagnose fetal acidemia as early as possible, allowing adequate obstetrical interventions to prevent brain damage or perinatal death. The visual analysis of cardiotocography traces has been complemented by computerized methods in order to overcome some of its limitations in the screening of fetal hypoxia/acidemia. Spectral analysis has been proposed by several studies exploring fetal heart rate recordings while referring to a great variety of frequency bands for integrating the power spectrum. In this paper, the main goal was to systematically review the spectral bands reported in intrapartum fetal heart rate studies and to evaluate their performance in detecting fetal acidemia/hypoxia. A total of 176 articles were reviewed, from MEDLINE, and 26 were included for the extraction of frequency bands and other relevant methodological information. An open-access fetal heart rate database was used, with recordings of the last half an hour of labor of 246 fetuses. Four different umbilical artery pH cutoffs were considered for fetuses' classification into acidemic or non-acidemic: 7.05, 7.10, 7.15, and 7.20. The area under the receiver operating characteristic curve (AUROC) was used to quantify the frequency bands' ability to distinguish acidemic fetuses. Bands referring to low frequencies, mainly associated with neural sympathetic activity, were the best at detecting acidemic fetuses, with the more severe definition (pH ≤ 7.05) attaining the highest values for the AUROC. This study shows that the power spectrum analysis of the fetal heart rate is a simple and powerful tool that may become an adjunctive method to CTG, helping healthcare professionals to accurately identify fetuses at risk of intrapartum hypoxia and to implement timely obstetrical interventions to reduce the incidence of related adverse perinatal outcomes.
PubMed: 34408993
DOI: 10.3389/fped.2021.661400 -
International Journal of Molecular... Apr 2024Preeclampsia, a serious complication of pregnancy, involves intricate molecular and cellular mechanisms. Fetal microchimerism, where fetal cells persist within maternal... (Review)
Review
Preeclampsia, a serious complication of pregnancy, involves intricate molecular and cellular mechanisms. Fetal microchimerism, where fetal cells persist within maternal tissues and in circulation, acts as a mechanistic link between placental dysfunction and maternal complications in the two-stage model of preeclampsia. Hormones, complements, and cytokines play pivotal roles in the pathophysiology, influencing immune responses, arterial remodeling, and endothelial function. Also, soluble HLA-G, involved in maternal-fetal immune tolerance, is reduced in preeclampsia. Hypoxia-inducible factor 1-alpha (Hif-α) dysregulation leads to placental abnormalities and preeclampsia-like symptoms. Alterations in matrix metalloproteinases (MMPs), endothelins (ETs), chemokines, and cytokines contribute to defective trophoblast invasion, endothelial dysfunction, and inflammation. Preeclampsia's genetic complexity includes circRNAs, miRNAs, and lncRNAs. CircRNA_06354 is linked to early-onset preeclampsia by influencing trophoblast invasion via the hsa-miR-92a-3p/VEGF-A pathway. The dysregulation of C19MC, especially miR-519d and miR-517-5p, affects trophoblast function. Additionally, lncRNAs like IGFBP1 and EGFR-AS1, along with protein-coding genes, impact trophoblast regulation and angiogenesis, influencing both preeclampsia and fetal growth. Besides aberrations in CD31+ cells, other potential biomarkers such as MMPs, soluble HLA-G, and hCG hold promise for predicting preeclampsia and its complications. Therapeutic interventions targeting factors such as peroxisome PPAR-γ and endothelin receptors show potential in mitigating preeclampsia-related complications. In conclusion, preeclampsia is a complex disorder with a multifactorial etiology and pathogenesis. Fetal microchimerism, hormones, complements, and cytokines contribute to placental and endothelial dysfunction with inflammation. Identifying novel biomarkers and therapeutic targets offers promise for early diagnosis and effective management, ultimately reducing maternal and fetal morbidity and mortality. However, further research is warranted to translate these findings into clinical practice and enhance outcomes for at-risk women.
Topics: Humans; Pre-Eclampsia; Female; Pregnancy; Placenta; Biomarkers; MicroRNAs; Hormones; Trophoblasts
PubMed: 38674114
DOI: 10.3390/ijms25084532 -
The Cochrane Database of Systematic... Jun 2015Maternal caffeine consumption during pregnancy may have adverse effects on fetal, neonatal and maternal outcomes. (Review)
Review
BACKGROUND
Maternal caffeine consumption during pregnancy may have adverse effects on fetal, neonatal and maternal outcomes.
OBJECTIVES
This review investigates the effects of restricting caffeine intake by mothers on fetal, neonatal and pregnancy outcomes.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (16 January 2015), scanned bibliographies of published studies and corresponded with investigators.
SELECTION CRITERIA
Randomised controlled trials (RCTs) including quasi-RCTs investigating the effect of caffeine and/or supplementary caffeine versus restricted caffeine intake or placebo on pregnancy outcomes.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.
MAIN RESULTS
Two studies met the inclusion criteria but only one contributed data for the prespecified outcomes. Caffeinated instant coffee (568 women) was compared with decaffeinated instant coffee (629 women) and it was found that reducing the caffeine intake of regular coffee drinkers (3+ cups/day) during the second and third trimester by an average of 182 mg/day did not affect birthweight (g) (mean difference (MD) 20.00, 95% confidence interval (CI) -48.68 to 88.68; one study, 1197 participants; low quality evidence), preterm birth (risk ratio (RR) 0.81, 95% CI 0.48 to 1.37; one study, 1153 participants; low quality evidence) or small-for-gestational age (RR 0.97, 95% 0.57 to 1.64; one study, 1150 participants). Risk of bias was moderate in both studies.Two outcomes were assessed and assigned a quality rating using the GRADE methods. Evidence for these two outcomes (birthweight and preterm birth) was assessed as of low quality, with downgrading decisions due to the relatively small sample sizes and the wide confidence interval of the one included trial that contributed data. Neither of the studies reported on any of the other primary outcomes (low birthweight; first trimester fetal loss; perinatal mortality; fetal hypoxia; fetal tachycardia) or on any of the reviews neonatal or maternal outcomes.
AUTHORS' CONCLUSIONS
There is insufficient evidence to confirm or refute the effectiveness of caffeine avoidance on birthweight or other pregnancy outcomes. There is a need to conduct high-quality, double-blinded RCTs to determine whether caffeine has any effect on pregnancy outcome.
Topics: Birth Weight; Caffeine; Central Nervous System Stimulants; Coffee; Female; Humans; Infant, Newborn; Infant, Small for Gestational Age; Pregnancy; Pregnancy Outcome; Premature Birth; Randomized Controlled Trials as Topic
PubMed: 26058966
DOI: 10.1002/14651858.CD006965.pub4 -
The Cochrane Database of Systematic... May 2015Fetal scalp blood sampling for lactate estimation may be considered following identification of an abnormal or non-reassuring fetal heart rate pattern. The smaller... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Fetal scalp blood sampling for lactate estimation may be considered following identification of an abnormal or non-reassuring fetal heart rate pattern. The smaller volume of blood required for this test, compared with the more traditional pH estimation, may improve sampling rates. The appropriate use of this practice mandates systematic review of its safety and clinical effectiveness prior to widespread introduction.
OBJECTIVES
To evaluate the effectiveness and risks of fetal scalp lactate sampling in the assessment of fetal well-being during labour, compared with no testing or alternative testing.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2015).
SELECTION CRITERIA
All published and unpublished randomised and quasi-randomised trials that compared fetal scalp lactate testing with no testing or alternative testing to evaluate fetal status in the presence of a non-reassuring cardiotocograph during labour.
DATA COLLECTION AND ANALYSIS
We used the standard methodological procedures of the Cochrane Pregnancy and Childbirth Group. Two review authors independently assessed the studies.
MAIN RESULTS
The search identified two completed randomised controlled trials (RCTs) and two ongoing trials. The two published RCTs considered outcomes for 3348 mother-baby pairs allocated to either lactate or pH estimation of fetal blood samples when clinically indicated in labour. Overall, the published RCTs were of low or unclear risk of bias. There was a high risk of performance bias, because it would not have been feasible to blind clinicians or participants.No statistically significant between-group differences were found for neonatal encephalopathy (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.32 to 3.09, one study, 2992 infants) or death. No studies reported neonatal seizures. We had planned to report death with other morbidities, for example, neonatal encephalopathy; however, the data were not available in a format suitable for this, therefore death due to congenital abnormality was considered alone. The three reported neonatal deaths occurred in babies with diaphragmatic hernias (n = 2) or congenital cardiac fibrosis (n = 1). All three babies had been randomised to the pH group and were not acidaemic at birth.There were no statistically significant differences for any of the pre-specified secondary fetal/neonatal/infant outcomes for which data were available. This included low Apgar score at five minutes (RR 1.13, 95% CI 0.76 to 1.68, two studies, 3319 infants) and admission to neonatal intensive care units (RR 1.02, 95% CI 0.83 to 1.25, one study, 2992 infants), or metabolic acidaemia (RR 0.91, 95% CI 0.60 to 1.36, one study, 2675 infants) considered within the studies, either overall or where data were available for those where fetal blood sampling had occurred within 60 minutes of delivery.Similar proportions of fetuses underwent additional tests to further evaluate well-being during labour, including scalp pH if in the lactate group or scalp lactate if in the pH group (RR 0.22, 95% CI 0.04 to 1.30, two studies, 3333 infants;Tau² 1.00, I² = 58%). Fetal blood sampling attempts for lactate and pH estimation were successful in 98.7% and 79.4% of procedures respectively in the one study that reported this outcome.There were no significant between-group differences in mode of birth or operative birth for non-reassuring fetal status, either for all women, or within the group where the fetal blood sample had been taken within 60 minutes of delivery (for example, caesarean section for all enrolled, RR 1.09, 95% CI 0.97 to 1.22, two studies, 3319 women; operative delivery for non-reassuring fetal status for all enrolled RR 1.02, 95% CI 0.93 to 1.11, one study, 2992 women).Neither study reported on adverse effects of fetal scalp lacerations or maternal anxiety.
AUTHORS' CONCLUSIONS
When further testing to assess fetal well-being in labour is indicated, fetal scalp blood lactate estimation is more likely to be successfully undertaken than pH estimation. Further studies may consider subgroup analysis by gestational age, the stage of labour and sampling within a prolonged second stage of labour. Additionally, we await the findings from the ongoing studies that compare allocation to no fetal blood sample with sampling for lactate and address longer-term neonatal outcomes, maternal satisfaction with intrapartum fetal monitoring and an economic analysis.
Topics: Acidosis; Biomarkers; Blood Specimen Collection; Cardiotocography; Female; Fetal Death; Fetal Distress; Fetal Hypoxia; Heart Rate, Fetal; Humans; Hydrogen-Ion Concentration; Labor, Obstetric; Lactic Acid; Pregnancy; Randomized Controlled Trials as Topic; Scalp
PubMed: 25929461
DOI: 10.1002/14651858.CD006174.pub3 -
The Cochrane Database of Systematic... Mar 2010Fetal blood sampling for lactate estimation may be considered following identification of an abnormal or non-reassuring fetal heart rate pattern. The smaller volume of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Fetal blood sampling for lactate estimation may be considered following identification of an abnormal or non-reassuring fetal heart rate pattern. The smaller volume of blood required for this test, compared with the more traditional pH estimation, may improve sampling rates. The appropriate use of this practice mandates systematic review of its safety and clinical effectiveness prior to widespread introduction.
OBJECTIVES
To evaluate the effectiveness and risks of fetal scalp lactate sampling in the assessment of fetal well-being during labour, compared with no testing or alternative testing.
SEARCH STRATEGY
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (November 2009).
SELECTION CRITERIA
All published and unpublished randomised and quasi-randomised trials that compared fetal scalp lactate testing with no testing or alternative testing to evaluate fetal status in the presence of a non-reassuring cardiotocograph during labour.
DATA COLLECTION AND ANALYSIS
Two review authors assessed the studies independently.
MAIN RESULTS
The two identified randomised trials considered outcomes for 3348 mother-baby pairs allocated to either lactate or pH estimation of fetal blood samples in labour. There were no statistically significant differences for any fetal/neonatal/infant outcomes, including low Apgar score at five minutes, admission to neonatal intensive care units or neonatal encephalopathy, or for low umbilical arterial pH, base deficit or metabolic acidaemia. There was a statistically higher success rate for lactate compared with pH estimation (risk ratio 1.10, 95% confidence interval 1.08 to 1.12, n = 2992). There were no significant between-group differences in mode of birth or operative birth for non-reassuring fetal status. No studies reported outcomes of maternal satisfaction with fetal monitoring, anxiety, length of hospital stay or economic analysis.
AUTHORS' CONCLUSIONS
When further testing to assess fetal well-being in labour is indicated, fetal scalp blood lactate estimation is more likely to be successfully undertaken than pH estimation. Action cut-off lactate values need to consider the lactate meter used. Further studies may consider sub-group analysis by gestational age, the stage of labour and sampling within a prolonged second stage of labour. Additionally, future studies may address longer-term neonatal outcomes, maternal satisfaction with intrapartum fetal monitoring and an economic analysis.
Topics: Acidosis; Biomarkers; Blood Specimen Collection; Cardiotocography; Female; Fetal Distress; Fetal Hypoxia; Heart Rate, Fetal; Humans; Hydrogen-Ion Concentration; Labor, Obstetric; Lactic Acid; Pregnancy; Randomized Controlled Trials as Topic; Scalp
PubMed: 20238343
DOI: 10.1002/14651858.CD006174.pub2