Subclassification of small-for-gestational-age fetus using fetal Doppler velocimetry

Our purpose was to determine whether small-for-gestational-age (SGA) fetus can be divided to subclassified groups using fetal Doppler velocimetry. Fifty-four pregnant women with SGA infant delivered after 37 weeks of gestation were studied. After 24 weeks of gestation, fetal middle cerebral artery puslatility index (MCAPI) and umbilical artery pulsatility index (UAPI) were measured at 2- to 3-week intervals using Doppler ultrasound. Perinatal outcomes [operative delivery due to fetal distress, abnormal fetal heart rate (FHR) pattern, meconium staining, low Apgar score (<7), neonatal acidosis (umbilical artery blood pH <7.15), neonatal intensive care unit (NICU) admission due to neonatal asphyxia, and decreased amniotic fluid] were compared in subclassified SGA groups using fetal Doppler velocimetry. The number of SGA fetuses with normal MCAPI and UAPI (normal SGA group) was 39, and those with significantly low MCAPI but normal UAPI (eventful SGA group) 15, respectively. Birth age and birth weights in the eventful SGA group were significantly earlier and lower than those in the normal SGA group, respectively (p < 0.05, and p < 0.005). There were significant increases in operative deliveries, abnormal FHR patterns and decreased amniotic fluid in eventful SGA group, when compared with events related to normal SGA group. However, there were no significant differences in meconium staining of amniotic fluid, low Apgar score, neonatal acidosis, and NICU admission between the two groups. These results suggest that SGA fetus with abnormally low MCAPI but normal UAPI has more poor perinatal outcomes, compared with that with normal MCAPI and UAPI.     

Apgar score, meconium and acidaemia at birth in small-for-gestational age infants born at term, and their relation to neonatal neurological morbidity

Summary. Neonatal neurological morbidity was studied in relation to Apgar score, meconium stained amniotic fluid and acidaemia at birth in 247 small-for-gestational age (SGA) maturely born infants. SGA infants, and especially the severely SGA infants and those born abdominally, showed higher rates of neurological morbidity, acidaemia and meconium stained amniotic fluid than appropriate-for-gestational age (AGA) controls. The examined indicators of asphyxia at birth showed slightly higher correlation coefficients with the 'neonatal neurological optimality score'(NNOS) in SGA, than in AGA term infants, but the percentage of explained variance was low, except in the 23 infants born abdominally. In this group poor neurological outcome was restricted to the 14 infants who showed signs of fetal hypoxaemia diagnosed by decelerative fetal heart rate (FHR) patterns. In 11 of them, FHR decelerations occurred antepartum. These FHR abnormalities appear to be better predictors for the neonatal neurological outcome than indicators of asphyxia at birth.     

Apgar score, meconium and acidaemia at birth in small-for-gestational age infants born at term, and their relation to neonatal neurological morbidity

Neonatal neurological morbidity was studied in relation to Apgar score, meconium stained amniotic fluid and acidaemia at birth in 247 small-for-gestational age (SGA) maturely born infants. SGA infants, and especially the severely SGA infants and those born abdominally, showed higher rates of neurological morbidity, acidaemia and meconium stained amniotic fluid than appropriate-for-gestational age (AGA) controls. The examined indicators of asphyxia at birth showed slightly higher correlation coefficients with the 'neonatal neurological optimality score' (NNOS) in SGA, than in AGA term infants, but the percentage of explained variance was low, except in the 23 infants born abdominally. In this group poor neurological outcome was restricted to the 14 infants who showed signs of fetal hypoxaemia diagnosed by decelerative fetal heart rate (FHR) patterns. In 11 of them, FHR decelerations occurred antepartum. These FHR abnormalities appear to be better predictors for the neonatal neurological outcome than indicators of asphyxia at birth.     

Significance of meconium-stained amniotic fluid in the preterm population.

OBJECTIVE: Numerous studies have assessed the significance of meconium-stained amniotic fluid (MSAF) at term. However, to date, there has been very little documentation on the incidence and significance of meconium in the preterm population. Our objective was to define the incidence of MSAF in patients delivering prematurely (<37 weeks) and examine its association with underlying fetal acidosis, Apgars and admission to the neonatal intensive care unit (NICU). METHOD: All patients delivering at a single tertiary care center between June 1994 and September 1997 were reviewed for the presence of meconium and gestational age <37 weeks at delivery. Maternal demographics and birth outcomes including cord gases, Apgar scores and admission to the NICU were collected. Exclusion criteria included multiple gestations, breech presentations, fetal anomalies and patients not in labor. RESULTS: Out of a total of 9570 patients there were 506 (5.3%) preterm births meeting the inclusion criteria, of whom 24 (4.8%) had MSAF noted either during labor or at delivery. Comparing the preterm group with and without meconium, there were no differences in maternal age, gravidity, rate of Cesarean section, or gestational age at delivery. Cord pH (7.27 meconium vs. 7.29 no meconium) and base excess (-5.1 meconium vs. -4.0 no meconium) were similar in both groups. There were no clinically significant differences in mean Apgar scores at 1 and 5 minutes. However, an increased number of NICU admissions were noted in the group with meconium (75% vs. 53%, p=0.04). CONCLUSION: The incidence of meconium staining of the amniotic fluid in labor in the preterm population is less than 5% and by itself is not a significant marker of fetal acidosis.     

Labor induction versus expectant management for postterm pregnancies: a systematic review with meta-analysis

OBJECTIVE: To compare routine labor induction with expectant management for patients who reach or exceed 41 weeks' gestation. DATA SOURCES: Computerized databases, references in published studies, and textbook chapters in all languages were used to identify randomized controlled trials (RCTs) evaluating induction and expectant management of labor for postterm pregnancies. METHODS OF STUDY SELECTION: We identified RCTs that compared induction and expectant management for uncomplicated, singleton, live pregnancies of at least 41 weeks' gestation and evaluated at least one of the following: perinatal mortality, mode of delivery, meconium-stained fluid, meconium aspiration syndrome, meconium below the cords, fetal heart rate (FHR) abnormalities during labor, cesarean deliveries for FHR abnormalities, abnormal Apgar scores, and neonatal intensive care unit (NICU) admissions. The primary outcomes assessed were cesarean delivery rate and perinatal mortality. TABULATION, INTEGRATION, AND RESULTS: Sixteen studies met inclusion criteria for this review. For each study with binary outcomes, an odds ratio (OR) with 95% confidence intervals (CIs) was calculated for selected outcomes. Estimates of ORs for dichotomous outcomes were calculated using fixed and random-effects models. Homogeneity was tested across the studies. Compared with women allocated to expectant management, those who underwent labor induction had lower cesarean delivery rates (20.1% versus 22.0%) (OR 0.88; 95% CI 0.78, 0.99). Although subjects whose labor was induced experienced a lower perinatal mortality rate (0.09% versus 0.33%) (OR 0.41; 95% CI 0.14, 1.18), this difference was not statistically significant. Similarly, no significant differences were noted for NICU admission rates, meconium aspiration, meconium below the cords, or abnormal Apgar scores. CONCLUSION: A policy of labor induction at 41 weeks' gestation for otherwise uncomplicated singleton pregnancies reduces cesarean delivery rates without compromising perinatal outcomes.     

Risk factors for meconium aspiration in meconium stained amniotic fluid.

Meconium aspiration syndrome (MAS) is a life-threatening respiratory disease in infants born through meconium stained amniotic fluid (MSAF). The purpose of this study was to determine risk factors for MAS in the newborns of mothers who had meconium stained amniotic fluid in labour. A retrospective study of all full-term pregnancies with MSAF from May 2003 to October 2004 was designed at a teaching hospital. Development of MAS was the primary outcome. Maternal details, mode of delivery and neonatal details (Apgar score, reassuring or non-reassuring fetal heart rate tracing and birth weight) were evaluated. During the study period, there were 2,603 deliveries of whom 302 (11.6%) had MSAF. MAS developed in 64 of these infants (21.1%). Compared with healthy neonates with MSAF, those with MAS had higher rate of non-reassuring fetal heart rate (FHR) tracing, thick meconium and Apgar score < or =5 at 5 min. The neonatal birth weight was lower in the MAS group, maternal age, parity, gestational age and mode of delivery were not significantly different in the two group. We found the severity of meconium, low Apgar score at 5 min and non-reassuring FHR tracing was associated with MAS in MSAF pregnancies.     

第一产程异常胎心监护图形与新生儿结局的关系

目的　探讨第一产程异常胎心监护图形与新生儿结局的关系。方法　回顾分析 2 0 0 2年 8月至 2 0 0 3年 6月在我院足月单胎头位分娩产妇 ,第一产程中胎心率 (FHR)异常图形 2 1 7例 (观察组 )和FHR正常图形的2 6 9例 (对照组 )的临床资料。结果　第一产程异常FHR图形的发生率为 4 4 7% ,常见类型为轻度变异减速(6 4 5 % )、基线变异减弱 (2 1 6 % )和轻度心动过速 (1 2 0 % )。晚期减速、基线变异减弱和重度变异减速是导致新生儿窒息的危险因素。观察组羊水过少 (5 1 % )、脐带缠绕 (2 2 6 % )、羊水粪染 (1 0 6 % )、新生儿窒息 (6 5 % )、新生儿转入NICU(1 0 1 % )的发生率和剖宫产率 (31 8% )明显高于对照组 (P <0 0 5 )。结论　第一产程异常FHR图形的发生率较高 ,其中晚期减速、基线变异减弱、重度变异减速与新生儿窒息的发生相关 ,其他图形可在严密监护下继续试产     

The heightened significance of prolonged bradycardia associated with intrauterine growth retardation

The significance and management of prepartum bradycardia is not well established in prepartum fetal assessment. The incidence of prolonged bradycardia was 3.5% (45 per 1284), defined as a decrease of greater than or equal to 40 beats per minute of the fetal heart rate (FHR) below the baseline for at least 2 minutes. Thirty-two maternal, fetal, and FHR tracing characteristics were examined to study correlations between the variables, the presence of the bradycardia, and neonatal outcome. Neonatal outcome was evaluated by dividing the population into two groups. Group 1 consisted of infants with 1-minute Apgar scores less than 6 and NICU admissions greater than 24 hours. Group 2 comprised infants with 1-minute Apgar scores greater than 6 and no NICU admission or less than 24 hours NICU admission. IUGR was diagnosed in 40% of the patients. Statistically significant associations were found for correlations between Group 1 infants and IUGR (P less than .05), oligohydramnios (P less than .05), cesarean section rate (P less than .04), and the presence of meconium (P less than .01). There were no fetal heart rate characteristics found to be significantly associated with IUGR or neonatal outcome. The data do not support the need for immediate delivery in patients with prolonged prepartum bradycardia, but its presence does warrant a workup for intrauterine growth retardation.     

早发子痫前期患者血浆胎盘生长因子水平与围生结局的研究

目的:探讨早发型子痫前期(EOPE)患者血浆胎盘生长因子(PlGF)水平与围生结局的关系。方法:纳入经剖宫产终止妊娠的125例EOPE患者。双抗体夹心酶标免疫分析法(ELISA)检测分娩当日血浆PlGF水平,根据EOPE患者血浆PlGF水平分为:≤12 pg/ml为PlGF≤12 pg/ml组(n=64),12 pg/ml为PlGF12 pg/ml组(n=61);测定新生儿出生后1小时内外周动脉血血气分析及乳酸(LAC)水平。比较两组患者血常规及生化指标及与围生结局的关系。结果:(1)PlGF≤12 pg/ml组患者Hb、HCT、24小时尿蛋白定量、尿素氮(BUN)、肌酐(Cr)水平高于PlGF12 pg/ml组(P0.05);而白蛋白(ALB)水平低于PlGF12 pg/ml组,差异均有统计学意义(P0.05)。(2)PlGF≤12 pg/ml组分娩孕周小于PlGF12 pg/ml组;而羊水过少、羊水粪染、小于胎龄儿(SGA)的比例均高于PlGF12 pg/ml组,差异均有统计学意义(P0.05)。(3)PlGF≤12 pg/ml组新生儿出生体质量、1分钟Apgar评分、pH值、血钙、碱剩余(BE)均低于PlGF12 pg/ml组;而LAC水平高于PlGF12 pg/ml组;新生儿入住NICU的天数多于PlGF12 pg/ml组,差异均有统计学意义(P0.05)。结论:EOPE患者PlGF测定对于预测围生结局具有一定临床价值,PlGF≤12 pg/ml的高危EOPE患者发生肾功能受损明显增加,羊水过少、羊水粪染、SGA及新生儿窒息比例增加,且新生儿更易发生酸碱失衡及物质代谢紊乱,临床需要加强关注。     

The effects of maternal obesity on perinatal outcomes among those born small for gestational age*

Background: Maternal obesity has been associated with higher birth weight. Small for gestational age (SGA) neonates born to obese women may be associated with pathological growth with increased neonatal complications.

Methods: This was a retrospective cohort study of all non-anomalous singleton neonates born in Texas from 2006–2011. Analyses were limited to births between 34 and 42 weeks gestation with birth weight?≤10th percentile. Results were stratified by maternal pre-pregnancy BMI class. The risk for stillbirth, neonatal death, neonatal intensive care unit (NICU) admission and five?minute Apgar scores?<7 were estimated for each obesity class and compared to the normal weight group. Multivariable logistic regression analyses were performed to control for potential confounding variables.

Results: The rate of stillbirth was 1.4/1000 births for normal weight women, and 2.9/1000 among obese women (p?0.001, aOR: 1.83 [1.43, 2.34]). The rate of neonatal deaths among normal weight women was 4.3/1000 births, whereas among obese women it was 4.7/1000 (p?=?0.94, aOR: 1.10 [0.92, 1.30]). A dose-dependent relationship between maternal obesity and stillbirths was seen, but not for other neonatal outcomes.

Conclusion: Among SGA neonates, maternal pre-pregnancy obesity was associated with increased risks for stillbirth, NICU admission and low Apgar scores but not neonatal death.     

Perinatal outcomes of isolated oligohydramnios at term and post-term pregnancy: a systematic review of literature with meta-analysis

Objective

The management of isolated oligohydramnios (IO) in post/term pregnancies is controversial. The aim of this paper was to review outcomes of term and post-term pregnancies with IO versus normal amniotic fluid (AF) at labor assessment.

Study design

A search in PubMed, Medline, EMBASE, and reference lists was performed. Inclusion criteria for articles selection: singleton pregnancy, definition of olgohydramnios as AFI <5 cm, AF assessment at 37–42 gestational weeks. Exclusion criteria: fetal malformations, preterm delivery, premature rupture of membranes, intrauterine growth restriction. Perinatal outcomes were: obstetric intervention for non-reassuring fetal heart rate (cesarean section, operative delivery), meconium-stained AF, Apgar score <7 at 5 min, umbilical artery pH <7.0, small for gestational age infants (SGA), admission to neonatal intensive care unit (NICU) and perinatal death. Meta-analysis compared outcomes of pregnancies with IO vs normal AF. Inter-studies heterogeneity was tested. Pooled odds ratio (OR) and 95% confidence interval (95% CI) were calculated. Differences between the two groups were considered significant if 95% CI did not encompass 1. MOOSE guidelines were followed.

Results

Four articles provided 679 (17.2%) cases with IO and 3264 (82.8%) with normal AF. Obstetric interventions occurred more frequently in the IO than normal AF group (IO: 89/679, 13% vs normal; AF: 166/3354, 5%; OR: 2.30; 95% CI: 1.00–5.29). Meta-analysis did not show differences with regard to meconium, Apgar, pH, SGA, NICU and perinatal death.

Conclusion

In term or post-term pregnancies, IO is associated with increased risk of obstetric interventions but outcomes are similar to those of pregnancies with normal AF.     

Fetal pulse oximetry and wavelet analysis of the fetal heart rate in the evaluation of abnormal cardiotocography tracings

AIM: Previous studies indicate that the addition of wavelet analysis of the fetal pulse oximetry tracings (FSPO2) and fetal heart rate (FHR) variability to cardiotocography (CTG), for intrapartum fetal monitoring, provides useful information on the fetal response to hypoxia. We applied the new procedure in non-reassuring CTG patterns, in which cesarean section was performed, and tested its accuracy in the diagnosis of the intrapartum fetal compromise. METHODS: At the 'Aretaieion' University Hospital labor ward, 318 women with term fetuses in the cephalic presentation entered the trial during labor. They all were monitored with external CTG and fetal pulse oximetry. In the cases that cesarean section was applied, because of abnormal CTG tracings, we applied a method based on the multiresolution wavelet analysis and a self-organized map neural network on the first and second stage of labor. The main outcome parameter was the rate of cord metabolic acidosis at birth (pH < 7.05). Secondary outcomes included Apgar scores at 5 min, fetal transmission to neonatal intensive care unit (NICU) and neonatal encephalopathy. RESULTS: Fifty out of 318 cases delivered operatively because of abnormal CTG patterns (rate 15.72%). In 30 cases, cord pH was >7.05, while in 11 Apgar scores at 5 min were <7, while none of those neonates were transferred to NICU. In the rest 20 cases cord pH was <7.05; in all of these cases Apgar scores at 5 min were <7, while four neonates were transferred to NICU. In one of them, neonatal encephalopathy was diagnosed. After the offline application of wavelet analysis and neural networks to the pulse oximetry and FHR variability readings of the 50 cases, statistics calculated that the system showed a sensitivity of 85% and a specificity of 93%, while false negative and false positive rates were 15% and 7%, respectively. CONCLUSION: Computerized FHR and FSPO2 monitoring shows an excellent efficacy and reliability in interpreting non-reassuring FHR recordings.     

Suspected versus non-suspected small-for-gestational age fetuses at term: perinatal outcomes

Objective: To compare perinatal outcomes of suspected versus non-suspected small-for-gestational age fetuses (SGA) at term. Methods: Retrospective cohort study among all term singleton neonates with a birth weight <10th percentile born in the Parkstad region between 1 January 2006 and 3 March 2008. The subjects were assigned to a prenatally suspected or non-suspected SGA group. Primary outcome was adverse neonatal outcome at birth, defined as a composite of intrauterine fetal death, Apgar <7 at 5?min, or pH umbilical artery <7.05. Secondary outcome included neonatal medium care unit (NMCU) admission ≥7 days. Results: 430 subjects were included in the study; 36.7% was suspected of SGA. In the suspected SGA group mean gestational age at birth and birth weight were significantly lower, whereas maternal morbidity was significantly higher. The incidence of labor induction and elective cesarean section were also significantly higher in the suspected SGA group. Total perinatal mortality was 2.1%. Identification of SGA and subsequent management led to a significant decrease of adverse neonatal outcome at birth, but did not lead to a significant decrease in NMCU admission ≥7 days. Conclusions: Suspicion of SGA was associated with a more active management of labor and delivery, resulting in a better neonatal outcome at birth.     

To ignore or not to ignore placental calcifications on prenatal ultrasound: a systematic review and meta-analysis

Objective: The human placenta is known to calcify with advancing gestational age, and, in fact, the presence of significant calcifications is one of the components of grade III placenta, typical of late gestation. As such, the presence of significant placental calcifications often prompts obstetric providers to expedite delivery. This practice has been attributed, in part, to the presumed association between grade III placenta and adverse pregnancy outcomes. Such approach, however, can be the source of major anxiety and may lead to unnecessary induction of labor, with its associated predisposition to cesarean delivery as well as a myriad of maternal and neonatal morbidities. The objective of this study was to examine the association between grade III placental calcifications and pregnancy outcomes.

Materials and methods: A systematic review of the literature was performed for studies evaluating the association between grade III placenta and a number of pregnancy outcomes, including labor induction, fetal distress (abnormal fetal heart tracing), low Apgar score (less than 7 at 5?min), need for neonatal resuscitation, admission to the Neonatal Intensive Care Unit, perinatal death, meconium liquor, and low birth weight.

Results: There was a five-fold increase in risk of labor induction with the presence of grade III placenta (OR 5.41; 95% CI 2.98–9.82). There was no association between grade III placenta and the incidence of abnormal fetal heart tracing (OR 1.62; 95% CI 0.94–2.78), low Apgar score of less than 7 at 5?min (OR 1.68; 95% CI 0.84–3.36), need for neonatal resuscitation (OR 1.08; 95% CI 0.67–1.75), and admission to the Neonatal Intensive Care Unit (OR 0.90; 95% CI 0.21–3.74). In turn, the incidence of meconium liquor was higher in the setting of grade III placentae (OR 1.68; 95% CI 1.17–2.39). Similarly, a positive association between grade III placental calcifications and low birth weight (OR 1.63; 95% CI 1.19–2.22) and perinatal death (OR 7.41; 95% CI 4.94–11.09) was identified.

Conclusion: The study alerts us to a significant association between grade 3 placental calcifications and labor induction, although it demonstrates that these sonographic findings do not appear to predispose to fetal distress, low Apgar score, need for neonatal resuscitation, or admission to the NICU.     

Is the fetal cerebroplacental ratio better that the estimated fetal weight in predicting adverse perinatal outcomes in a low risk cohort?

Objective: In high-risk pregnancies combining the cerebro–placental ratio (CPR) with the estimated fetal weight (EFW) improves the identification of vulnerable fetuses. The purpose of this study was to assess the CPR and EFW’s ability to predict adverse obstetric and perinatal outcomes in a low-risk pregnancy, when measured late in gestation.

Methods: This was a retrospective study of women who birthed at Mater Mothers Hospitals, Brisbane, Australia between 2010 and 2015. We included all nonanomalous singleton pregnancies that had an ultrasound scan performed between 36 and 38 weeks gestation. Excluded was any major congenital abnormality, aneuploidy, multiple pregnancy, preterm birth, maternal hypertension, or diabetes. The primary outcome was a severe composite neonatal outcome (SCNO) defined as severe acidosis (umbilical cord artery pH <7.0, cord lactate ≥6?mmol/L, cord base excess ≤-12?mmol/L) Apgar score ≤3 at 5 minutes, admission to the neonatal intensive care unit (NICU), and death. A low CPR was defined as <10th centile for gestation and small for gestational age (SGA) was defined as an EFW <10th centile and appropriate for gestational age (AGA) was defined as EFW ≥10th centile.

Results: Of 2425 pregnancies, 13.2% (321/2425) had a fetus with a CPR <10th centile and 13.7% (332/2425) with an EFW <10th centile. Both a low CPR and SGA predicted the SCNO. Individually a low CPR and SGA had sensitivity for detection of SCNO of 23.3% and 24.7%, respectively which increased to 36.7% when combined. Both were associated with emergency caesarean for nonreassuring fetal status (NRFS), as well as early-term birth and admission to NICU. Stratifying the population into EFW <10th centile and EFW ≥10th centile, a low CPR maintained its association with the SCNO, early-term birth and emergency caesarean for NRFS in the cohort with an EFW <10th centile but SCNO lost its association with a low CPR in the EFW >10th cohort. Stratifying the population into CPR <10th centile and CPR >10th centile, a low EFW was associated with early-term birth, induction of labor, admission to NICU, and the SCNO.

Conclusions: In a low-risk cohort both the CPR and EFW individually and in combination predicts adverse obstetric and perinatal outcomes when measured late in pregnancy. However, the predictive value was enhanced when both were used in combination.     

Perinatal outcome in pregnancy with polyhydramnios in comparison with normal pregnancy in department of obstetrics at Shiraz University of Medical Sciences

Objective: Polyhydramnios can lead to maternal and fetal complication during pregnancy, so diagnosis and management can decrease some perinatal complications.

Study design: One hundred and fourteen singleton pregnancies were diagnosed with idiopathic polyhydramnios in the department of obstetrics at Shiraz University of Medical Sciences between January 2000 and January 2011 and were compared with 114 normal pregnancies for their perinatal outcome. Variables include birth weight, admission to neonatal intensive care unit (NICU), meconium staining, respiratory distress, fetal death, neonatal death, low 1-min and 5-min APGAR score, primary cesarean section (C/S), preterm delivery (<37?weeks), postpartum bleeding, and placental abruption.

Results: Low birth weight (<2500?g), macrosoma (>4000?g), NICU admission, fetal distress, fetal death, lower 1-min and 5-min APGAR score, preterm delivery, and neonatal death were higher in the case group. However, meconium staining and malpresentation were equal between the two groups. Except for prematurity and 1-min and 5-min APGAR scores, there were no significant differences in other maternal or fetal outcomes considering the severity of polyhydramnios.

Conclusion: Idiopathic polyhydramnios should be considered as a high-risk pregnancy that warrants close surveillance. More studies should be done to detect the best time and interval of fetal surveillance in these patients. Chromosomal and torch studies can determine the definite cause of polyhydramnios.     

Umbilical cord pH and base excess values in relation to adverse outcome events for infants delivering at term

OBJECTIVE: This study was undertaken to determine the relationship of umbilical cord pH and base excess (BE) values to adverse neonatal outcomes for a large tertiary hospital population delivering at term.Study design The perinatal/neonatal database of St. Joseph's Health Care, London, Canada, was used to obtain the umbilical cord pH and BE values, incidence of adverse neonatal outcomes, and patient demographics for all term (>/=37 weeks' gestation), singleton, liveborn infants with no major anomalies delivering between November 1995 and March 2002 (n=20,456). Statistical analyses included chi(2) analysis, logistic regression models to develop odds ratios and creation of receiver operating characteristic (ROC) curves with area under curve (AUC) calculations. RESULTS: Umbilical vein and artery pH and BE values for this tertiary care population averaged 7.33 +/- 0.06 and 7.24 +/- 0.07, and -4.5 +/- 2.4 and -5.6 +/- 3.0 mmol/L, respectively. Apgar less than 7 at 5 minutes, neonatal intensive care unit (NICU) admission, and assisted neonatal ventilation had significant inverse relationships with both umbilical artery and umbilical vein pH and BE (all P < .0001), with marginal increases in the incidences of these outcomes beginning with cord blood values close to the mean, and more substantial increases with cord values less than 1 or 2 SD below the mean, depending on the outcome studied. The ROC AUC for all these relationships were significant (P < .001) ranging from 0.76 to 0.79 when predicting Apgar less than 7 at 5 minutes to 0.68 to 0.70 when predicting NICU admission, and with cutoff cord blood values at which sensitivity and specificity were maximized again close to mean values. For each of these neonatal outcomes, the relation to cord blood values was similar with little difference in the data analysis whether using pH or BE values, and whether from the umbilical artery or vein. CONCLUSION: There is a progression of risk in term infants for Apgar less than 7 at 5 minutes, NICU admission, and need for assisted ventilation with worsening acidosis at birth, which begins with cord blood values close to mean values indicating a higher threshold for associated acidemia with these outcomes than is seen for more severe neonatal outcomes.     

Significance of meconium during labor.

Continuous fetal heart rate (FHR) monitoring and routine fetal scalp blood sampling was utilized in the evaluations of 366 fetuses during labor. One hundred and six patients had meconium in the amniotic fluid at some time during labor. A total of 26,110 uterine contractions were monitored during these 366 labors. The incidence of FHR patterns as a percentage of uterine contractions was calculated for the meconium and nonmeconium groups. Although there was a 3 1/2-fold increase in the incidence of low five-minute Apgar scores (less than 7) in the meconium group, signs of fetal distress were, with rare esception, not significantly different from those in the nonmeconium group. The presence of meconium in the amniotic fluid without signs of fetal asphyxia (late decelerations and acidosis) is not a sign of fetal distress and need not be an indication for active intervention. The combination of fetal asphyxia and meconium staining of the amniotic fluid, however, does enhance the potential for meconium aspiration and a poor neonatal outcome. Universal fetal heart rate monitoring and appropriate fetal acid-base evaluation is recommended for following patients with meconium in the amniotic fluid during labor.     

Screening of foetal distress by assessment of umbilical cord lactate

PURPOSE OF INVESTIGATION: Studies on umbilical cord blood for determination of lactate indicate that high levels seem to be correlated to foetal metabolism for anaerobic glycolysis taking place in oxygen-deprived tissues of the foetus. These findings may be of particular-deprived clinical importance when foetal distress or foetal hypoxemia is caused by perinatal events. METHODS: The maternal and foetal heart rates, acid-base values measured and the outcome of 94 pregnancies complicated by intrapartum foetal asphyxia have been reviewed, and the maternal and foetal acid-base and lactate levels during the course of labour and at delivery were studied in patients with evidence of metabolic acidosis. Lactate concentrations were measured during labour and at delivery in blood samples obtained from the foetal presenting part and from the umbilical cord with the use of a rapid electrochemical technique. The foetuses were evaluated by means of the Apgar score, intrapartum cardiotocography, observation of the presence of meconium stained amniotic fluid, and clinical features of distress at birth. RESULTS: Evidence of clinical foetal distress was not related to the severity of the asphyxia. An increased lactate level was found in asphyctic infants and a clear correlation between lactic acidosis and foetal distress was documented. Low Apgar scores were observed in infants with moderate or severe asphyxia at delivery. Scalp lactate correlated significantly with umbilical artery lactate, but not with 1-min or 5-min Apgar scores. The lactate concentration was higher in cases of instrumental delivery compared to spontaneous delivery. No perfect correlation was found between lactate level and neonatal outcome but there were not a significant number of neonates with immediate complications. The rate of forceps delivery in the distress group was significantly higher than that of the healthy foetuses, so spontaneous labour was less frequently associated with foetal distress than instrumental delivery. In the distress group, severe variable decelerations were generally recorded in the second stage of labour. The incidence of neonatal Apgar score < or = 7 in neonates with abnormal baseline foetal heart rate (FHR) was higher than in those with severe variable decelerations, mild variable decelerations, and transient tachycardia. Duration of the active second stage of labour was significantly with the presence of foetal lactate at the time of crowning of the foetal head and the presence of lactate in umbilical arterial and vein blood at delivery. Expulsion time > or = 45 minutes, compared with shorter active second stage, and acidaemia at birth implied larger arterial-venous lactate differences. The presence of foetal lactate at crowning was also significantly associated with the level of umbilical arterial-venous lactate difference. CONCLUSION: Lactate and pH values provide the best parameters to distinguish between asphyctic and normal newborns, with lactate having the most discriminating power. The prospective value of the discrimination functions derived from lactate and pH data is good when the foetuses are allocated into normal parameters but poor when an attempt is made to allocate the foetuses into pathologic ones, with a high false-negative rate. However, the discriminating ability is improved when pathologic foetuses are included into one single abnormal group. These results confirm the potential use of rapid foetal blood lactate measurements for the early diagnosis of intrapartum foetal distress.