Fetal assessment based on fetal biophysical profile scoring. IV. An analysis of perinatal morbidity and mortality

Integrating technologies to provide comprehensive remote fetal surveillance: A prospective pilot study

OBJECTIVE

To determine the feasibility of extending remote maternal-fetal care to include fetus well-being.

METHODS

The authors performed a prospective pilot study investigating low-risk pregnant participants who were recruited at the time of their first full-term in-person visit and scheduled for a follow-up telemedicine visit. Using novel self-operated fetal monitoring and ultrasound devices, fetal heart monitoring and amniotic fluid volume measurements were obtained to complete a modified biophysical profile (mBPP). Total visit length was measured for both the in-person first visit and the subsequent telemedicine encounter. A patient satisfaction survey form was obtained.

RESULTS

Ten women between 40 + 1 and 40 + 6 weeks of gestation participated in telemedicine encounters. Nine women (90%) were able to complete remote mBPP assessment. For one participant, fetal assessment was not completed due to technically inconclusive fetal monitoring. Another participant was referred for additional assessment in the delivery room. Satisfactory amniotic fluid volume measurements were achieved in 100% of participants. The telemedicine encounter was significantly shorter (93.1 ± 33.1 min) than the in-person visit (247.2 ± 104.7 min; P < 0.001). We observed high patient satisfaction.

CONCLUSION

Remote fetal well-being assessment is feasible and time-saving and results in high patient satisfaction. This novel paradigm of comprehensive remote maternal and fetal assessment is associated with important clinical, socioeconomic, and logistics advantages.

Combining Resampling Strategies and Ensemble Machine Learning Methods to Enhance Prediction of Neonates with a Low Apgar Score After Induction of Labor in Northern Tanzania

Objective

The goal of this study was to establish the most efficient boosting method in predicting neonatal low Apgar scores following labor induction intervention and to assess whether resampling strategies would improve the predictive performance of the selected boosting algorithms.

Methods

A total of 7716 singleton births delivered from 2000 to 2015 were analyzed. Cesarean deliveries following labor induction, deliveries with abnormal presentation, and deliveries with missing Apgar score or delivery mode information were excluded. We examined the effect of resampling approaches or data preprocessing on predicting low Apgar scores, specifically the synthetic minority oversampling technique (SMOTE), borderline-SMOTE, and the random undersampling (RUS) technique. Sensitivity, specificity, precision, area under receiver operating curve (AUROC), F-score, positive predicted values (PPV), negative predicted values (NPV) and accuracy of the three (3) boosting-based ensemble methods were used to evaluate their discriminative ability. The ensemble learning models tested include adoptive boosting (AdaBoost), gradient boosting (GB) and extreme gradient boosting method (XGBoost).

Results

The prevalence of low (<7) Apgar scores was 9.5% (n = 733). The prediction models performed nearly similar in their baseline mode. Following the application of resampling techniques, borderline-SMOTE significantly improved the predictive performance of all the boosting-based ensemble methods under observation in terms of sensitivity, F1-score, AUROC and PPV.

Conclusion

Policymakers, healthcare informaticians and neonatologists should consider implementing data preprocessing strategies when predicting a neonatal outcome with imbalanced data to enhance efficiency. The process may be more effective when borderline-SMOTE technique is deployed on the selected ensemble classifiers. However, future research may focus on testing additional resampling techniques, performing feature engineering, variable selection and optimizing further the ensemble learning hyperparameters.

Antepartum Fetal Surveillance: ACOG Practice Bulletin, Number 229

The goal of antepartum fetal surveillance is to reduce the risk of stillbirth. Antepartum fetal surveillance techniques based on assessment of fetal heart rate (FHR) patterns have been in clinical use for almost four decades and are used along with real-time ultrasonography and umbilical artery Doppler velocimetry to evaluate fetal well-being. Antepartum fetal surveillance techniques are routinely used to assess the risk of fetal death in pregnancies complicated by preexisting maternal conditions (eg, diabetes mellitus) as well as those in which complications have developed (eg, fetal growth restriction). The purpose of this document is to provide a review of the current indications for and techniques of antepartum fetal surveillance and outline management guidelines for antepartum fetal surveillance that are consistent with the best scientific evidence.

FIGO (international Federation of Gynecology and obstetrics) initiative on fetal growth: best practice advice for screening, diagnosis, and management of fetal growth restriction

Fetal growth restriction (FGR) is defined as the failure of the fetus to meet its growth potential due to a pathological factor, most commonly placental dysfunction. Worldwide, FGR is a leading cause of stillbirth, neonatal mortality, and short- and long-term morbidity. Ongoing advances in clinical care, especially in definitions, diagnosis, and management of FGR, require efforts to effectively translate these changes to the wide range of obstetric care providers. This article highlights agreements based on current research in the diagnosis and management of FGR, and the areas that need more research to provide further clarification of recommendations. The purpose of this article is to provide a comprehensive summary of available evidence along with practical recommendations concerning the care of pregnancies at risk of or complicated by FGR, with the overall goal to decrease the risk of stillbirth and neonatal mortality and morbidity associated with this condition. To achieve these goals, FIGO (the International Federation of Gynecology and Obstetrics) brought together international experts to review and summarize current knowledge of FGR. This summary is directed at multiple stakeholders, including healthcare providers, healthcare delivery organizations and providers, FIGO member societies, and professional organizations. Recognizing the variation in the resources and expertise available for the management of FGR in different countries or regions, this article attempts to take into consideration the unique aspects of antenatal care in low-resource settings (labelled “LRS” in the recommendations). This was achieved by collaboration with authors and FIGO member societies from low-resource settings such as India, Sub-Saharan Africa, the Middle East, and Latin America.

Inpatient Biophysical Profiles and the Effect on Clinical Decision Making

Objective  Our primary objective was to determine whether biophysical profiles (BPP) performed on the antepartum unit result in changes in clinical decision making. Study Design  A retrospective cohort chart review was performed among women who had a BPP during hospital admission. BPP status was categorized as normal (8/8 points) and abnormal (6/8 or less points). The primary outcome, clinical decision making, was the need for prolonged external fetal monitoring (defined as > 2 hours) or decision to proceed with delivery. Secondary outcomes included mode of delivery, indicated preterm delivery, birth weight, 5-minute Apgar's score <7, and neonatal intensive care unit (NICU) admission. Results  Among our cohort ( n  = 186), 85.5% ( n  = 159) had a normal BPP. Delivery management was altered in one case (0.54%) by the BPP findings, and there were no BPPs that resulted in need for prolonged monitoring. Compared with women with normal BPP, women with abnormal BPPs were more likely to deliver at <37 weeks, to be admitted to the NICU, or have a 5-minute Apgar's score <7. Conclusion  In-hospital BPPs alter clinical decision making in less than 1% of cases.

Accuracy of the Ultrasound Estimate of the Amniotic Fluid Volume (Amniotic Fluid Index and Single Deepest Pocket) to Identify Actual Low, Normal, and High Amniotic Fluid Volumes as Determined by Quantile Regression

OBJECTIVES

To identify abnormal amniotic fluid volumes (AFVs), normal volumes must be determined. Multiple statistical methods are used to define normal amniotic fluid curves; however, quantile regression (QR) is gaining favor. We reanalyzed ultrasound estimates in identifying oligohydramnios, normal fluid, and polyhydramnios using normal volumes calculated by QR.

METHODS

Data from 506 dye-determined or directly measured AFVs along with ultrasound estimates were analyzed. Each was classified as low, normal, or high for both the single deepest pocket (SDP) and amniotic fluid index (AFI). A weighted κ statistic was used to assess the level of agreement between the AFI and SDP compared to actual AFVs by QR.

RESULTS

The overall level of agreement for the AFI was fair (κ = 0.26), and that for the SDP was slight (κ = 0.19). Although not statistically significant (P = .792), the positive predictive value to classify a low volume using the AFI was lower compared to the SDP (35% vs 43%). The positive predictive value for a high volume was higher using the AFI compared to the SDP (55% versus 31%) but not statistically significant. The missed-call rate for high-volume identification by the SDP versus AFI was statistically significant (odds ratio, 5.5; 95% confidence interval, 2.04-14.97). The missed-call rate for low-volume identification by the AFI versus SDP was not statistically significant (odds ratio, 3.3; 95% confidence interval, 0.96-11.53).

CONCLUSIONS

Both the AFI and SDP identify actual normal AFVs by QR, with sensitivity higher than 90%. The SDP is superior for identification of oligohydramnios, and the AFI superior for identification of polyhydramnios.

Cardiovascular profile and biophysical profile scores predict short-term prognosis in infants with congenital heart defect

AIM

To predict the prognosis of infants with congenital heart disease, accurate prenatal diagnosis of structural abnormality and heart failure are both necessary. The aim of this study was to investigate whether cardiovascular profile (CVP) and biophysical profile (BP) scores are useful for predicting prognosis in infants with congenital heart defect (CHD).

METHODS

A retrospective review of singletons prenatally diagnosed with CHD at a tertiary pediatric cardiac center between 2011 and 2015 was undertaken.

RESULTS

A total of 202 patients with CHD were analyzed. Perinatal and infant deaths occurred in 16 (7.9%) and 10 cases (5.0%), respectively. Infants with the last CVP score ≤ 5 had 18.7-fold higher perinatal mortality than those with a last CVP score > 5 (P < 0.01). Infants with a last BP score ≤ 6 had 18.7-fold higher perinatal mortality than those with a last BP score > 6 (P < 0.01). Infants with a CVP score decrease in utero had 4.5-fold higher infant mortality than those with an increase or no change (P < 0.01). Multivariate analysis showed that single-ventricle physiology, pre-term birth at <37 weeks of gestation, last CVP score ≤ 5, and last BP score ≤ 6 were independent predictors of perinatal mortality. Single-ventricle physiology and a CVP score decrease were independent predictors of infant mortality.

CONCLUSION

CVP and BP scores are useful for predicting perinatal prognosis in infants with CHD. A CVP score decrease in utero is associated with infant mortality, suggesting that serial CVP score assessment may be useful for management planning.

Circulatory Changes and Cerebral Blood Flow and Oxygenation During Transition in Newborns With Congenital Heart Disease

This review aims to describe how the complex events of cardiovascular transition may affect the brain of infants with congenital heart disease (CHD). In particular, we describe the vulnerabilities of the neonatal brain in the transitional period during and immediately after delivery and propose management strategies that can potentially influence neurodevelopmental outcomes in this patient population. Delayed brain development has been identified in the third trimester fetus with certain forms of CHD. Neonates with critical CHD are at risk for brain injury even before their neonatal operation. The transitional period from fetal to neonatal life is marked with hemodynamic changes that can affect cerebral blood flow and oxygenation and may exacerbate injury and influence outcome. We propose specific perinatal management strategies tailored to maternal-fetal pairs aimed at optimizing hemodynamic stability, especially cerebral blood flow and oxygenation, to maximize the neurodevelopmental potential of infants with CHD.

Planning management and delivery of the growth-restricted fetus

A uniform approach to management of fetal growth restriction (FGR) improves outcome, prevents stillbirth, and allows appropriately timed delivery. An estimated fetal weight below the tenth percentile with coexisting abnormal umbilical artery (UA), middle cerebral artery (MCA), or cerebroplacental ratio Doppler index best identifies the small fetus requiring surveillance. Placental perfusion defects are more common earlier in gestation; accordingly, early-onset (≤32 weeks of gestation) and late-onset (>32 weeks) FGR differ in clinical phenotype. In early-onset FGR, progression of UA Doppler abnormality determines clinical acceleration, while abnormal ductus venosus (DV) Doppler precedes deterioration of biophysical variables and stillbirth. Accordingly, late DV Doppler changes, abnormal biophysical variables, or an abnormal cCTG require delivery. In late-onset FGR, MCA Doppler abnormalities precede deterioration and stillbirth. However, from 34 to 38 weeks, randomized evidence on optimal delivery timing is lacking. From 38 weeks onward, the balance of neonatal versus fetal risks favors delivery.

The effect of halogen light stimulation on duration of ultrasound parameters of biophysical profile: a randomized clinical trial

INTRODUCTION

The objective is to assess if fetal halogen light stimulation can reduce the time needed to obtain a normal biophysical profile (BPP).

METHODS

Patients scheduled for a BPP and who satisfied the inclusion criteria were prospectively randomized to halogen light stimulation and no stimulation groups. The study group was exposed to handheld halogen light for 10 s whenever fetal breathing, movement, or tone was absent through the first 5 min of BPP. The time required to achieve complete BPP score was recorded. In patients with complete BPP score who had delivery within 1 week after the test, perinatal morbidity was examined.

RESULTS

A total of 598 patients were randomized (light = 302, no light = 296). There was no difference between the two groups in terms of gestational age, maternal age, body mass index, and indication for BPP except for preterm labor (light: 9%, no light: 4%, p = 0.03). Among the patients who had a normal BPP score (n = 507), the mean (light: 7.1 ± 6 min, no light: 12.3 ± 8 min, p < 0.0001) and median (light: 4.3, no light: 8, p = 0.004) time needed to complete the BPP score was significantly less in the light stimulation group than the no stimulation group. Perinatal outcomes were not different between groups who had delivery during the first week after BPP.

CONCLUSION

Fetal halogen light stimulation can be utilized to reduce the time needed to complete a BPP. However, further studies should be conducted in order to determine the effect of this method on decreasing non-reassuring test results.

CLINICAL TRIAL REGISTRATION

The study was submitted to the Registry of Clinical Trials on 04/20/2017 (IRCT2017041633470N1). After IRCT registration on 06/07/2017, we recruited patients from 06/08/2017 till 10/15/2017.

Addition of Color Doppler Sonography for Detection of Amniotic Fluid Disturbances and Its Implications on Perinatal Outcomes

OBJECTIVES

To determine whether color Doppler sonography increases the detection of pregnancies at risk for adverse outcomes.

METHODS

Participants admitted to labor and delivery with the anticipation of a vaginal delivery underwent measurements of amniotic fluid volume (AFV) using amniotic fluid index (AFI) and single deepest pocket (SDP) techniques by grayscale followed by color Doppler sonography. Oligohydramnios was defined as an AFI of less than 5 cm or an SDP of less than 2 cm. Intrapartum and perinatal outcomes were compared between participants with a diagnosis of a low AFV by grayscale and color Doppler sonography.

RESULTS

Over 42 months, 428 women were enrolled in the study. Color Doppler sonography resulted in lower AFV estimates (mean ± SD by the AFI, 10.7 ± 3.7 cm by grayscale sonography and 8.6 ± 3.6cm by color Doppler sonography; P < .0001). For the SDP, the mean AFVs were 4.6 ± 2.0 cm by grayscale sonography and 3.4 ± 1.4 cm by color Doppler sonography (P < .0001). The level of agreement between grayscale and color Doppler sonography in estimating the AFV was fair, with κ = 0.32 for the AFI and 0.28 for the SDP. Outcome measures of AFVs classified as low based on color Doppler sonography (normal by grayscale sonography) and those classified as low by grayscale sonography (low by color Doppler sonography) were compared. There was no difference in composite perinatal complications, mode of delivery, or composite neonatal complications.

CONCLUSIONS

The use of color Doppler sonography leads to the overdiagnosis of low AFVs and does not appear to increase the detection of pregnancies destined for adverse intrapartum or perinatal outcomes.

Perinatal and Delivery Management of Infants with Congenital Heart Disease

Advances in fetal echocardiography have improved prenatal diagnosis of congenital heart disease (CHD) and allowed better delivery and perinatal management. Some newborns with CHD require urgent intervention after delivery. In these cases, delivery close to a pediatric cardiac center may be considered, and the presence of a specialized cardiac team in the delivery room or urgent transport of the infant should be planned in advance. Delivery planning, monitoring in labor, rapid intervention at birth if needed, and avoidance of iatrogenic preterm delivery have the potential to improve outcomes for infants with prenatally diagnosed CHD.

Polyhydramnios: Causes, Diagnosis and Therapy

Polyhydramnios is defined as a pathological increase of amniotic fluid volume in pregnancy and is associated with increased perinatal morbidity and mortality. Common causes of polyhydramnios include gestational diabetes, fetal anomalies with disturbed fetal swallowing of amniotic fluid, fetal infections and other, rarer causes. The diagnosis is obtained by ultrasound. The prognosis of polyhydramnios depends on its cause and severity. Typical symptoms of polyhydramnios include maternal dyspnea, preterm labor, premature rupture of membranes (PPROM), abnormal fetal presentation, cord prolapse and postpartum hemorrhage. Due to its common etiology with gestational diabetes, polyhydramnios is often associated with fetal macrosomia. To prevent the above complications, there are two methods of prenatal treatment: amnioreduction and pharmacological treatment with non-steroidal anti-inflammatory drugs (NSAIDs). However, prenatal administration of NSAIDs to reduce amniotic fluid volumes has not been approved in Germany. In addition to conventional management, experimental therapies which would alter fetal diuresis are being considered.

Toward consistent terminology: assessment and reporting of amniotic fluid volume

Amniotic fluid is typically measured by ultrasound using the amniotic fluid index (AFI) or the maximum vertical pocket (MVP). Although both parameters correlate poorly with the actual amniotic fluid volume measured with dye-dilution methods, cross-sectional studies have been used to establish gestational norms. The current acceptable definition of polyhydramnios in the late second and the third trimester in both singleton and multiple gestations is a MVP > 8 cm, while the definition of oligohydramnios is a MVP < 2 cm. The pocket to be measured should exclude the umbilical cord or fetal parts. Randomized clinical trials have indicated that defining oligohydramnios as a MVP < 2 cm will result in fewer obstetrical interventions and similar perinatal outcomes when compared to an AFI < 5 cm.

Identification, assessment and management of fetal compromise

The main goals of fetal surveillance are to avoid fetal death and to recognize the fetus that will benefit from early intervention with resuscitation or delivery. Surveillance can occur in the antepartum or intrapartum period. Continuous fetal heart rate monitoring is the most common form of surveillance in the intrapartum period. Several techniques are used in the antepartum period, including nonstress test, biophysical profile, and contraction stress test. Multiple techniques are used once distress is noted in the fetus, with the ultimate resuscitation effort being delivery.

Diagnosis and management of fetal growth restriction

Fetal growth restriction (FGR) remains a leading contributor to perinatal mortality and morbidity and metabolic syndrome in later life. Recent advances in ultrasound and Doppler have elucidated several mechanisms in the evolution of the disease. However, consistent classification and characterization regarding the severity of FGR is lacking. There is no cure, and management is reliant on a structured antenatal surveillance program with timely intervention. Hitherto, the time to deliver is an enigma. In this paper, the challenges in the diagnosis and management of FGR are discussed. The biophysical profile, Doppler, biochemical and molecular technologies that may refine management are reviewed. Finally, a model pathway for the clinical management of pregnancies complicated by FGR is presented.

Antepartum fetal testing: a critical appraisal

PURPOSE OF REVIEW

Recognition of the fetus at risk for death or damage in utero, quantifying the risk, balancing fetal risk against the risk of neonatal complications from immaturity and determining optimal time and mode of intervention, is a cornerstone of modern perinatal medicine. Antepartum fetal testing is essential in making these crucial decisions. The art and science of fetal assessment is fluid. In this treatise, the evolution of testing is reviewed, test accuracy results examined and suggestions for future applications are considered.

RECENT FINDINGS

Composite testing of a range of fetal biophysical variables is an excellent predictor of fetal acidemia and risk of death or damage. Confusion regarding the optimal means of measuring one of these variables, amniotic fluid volume, has been addressed in the literature and contemporary studies from several independent sources indicate that the amniotic fluid index method should be abandoned in favor of the maximal vertical pocket method. It is becoming increasingly more evident that a spectrum of fetal testing modalities based on interrogation of different aspects of fetal adaptive responses to adversity is preferable in fetal testing. Further it is evident that in some fetal diseases, such as intrauterine growth restriction, fetal condition may change acutely and accordingly best outcome is achieved by much more frequent testing. The question of whether intervention for fetal compromise can prevent subsequent neurological sequelae remains open.

SUMMARY

There has been remarkable advancement in identifying the fetus at risk. The concept of multispectral combined fetal testing including acute biophysical variables, amniotic fluid volume and arterial and venous Doppler flow velocity waveforms is established.

Fetal assessment during pregnancy

Fetal monitoring during pregnancy is used to prevent fetal death. This article addresses the goals of fetal monitoring during pregnancy. Methods of fetal surveillance are reviewed, as well as the meaning of abnormal fetal testing and how these results relate to fetal and neonatal outcome. Overall, pediatricians who understand the goals, methods, and interpretation of fetal testing can communicate more effectively with the delivering obstetric team in anticipation of optimizing obstetric and pediatric outcomes.

Antenatal fetal assessment: contraction stress test, nonstress test, vibroacoustic stimulation, amniotic fluid volume, biophysical profile, and modified biophysical profile--an overview

Antenatal fetal assessment was introduced into the United States in the 1970s. The initial antepartum test, the oxytocin challenge test, later renamed as the contraction stress test, became the gold standard for fetal surveillance. Its labor intensive requirements and contraindications made it inapplicable to some high-risk pregnancies. Other testing schemes were developed subsequently, the nonstress test and its alternative, vibroacoustic stimulation, the semiquantitative assessment of amniotic fluid volume, the biophysical profile and its modified version, the modified biophysical profile. This article is a brief critical review of these testing methods and focuses on the following: (1) physiologic bases; (2) testing methodologies; (3) supportive evidence from randomized controlled and observational trials; and (4) areas needing further investigation.

A long-standing incomprehensible matter of obstetrics: meconium-stained amniotic fluid, a new approach to reason

OBJECTIVE

We sought to determine whether meconium-stained amniotic fluid is based on chronic hypoxia or not? In case of chronic hypoxia, higher red blood cell (Rbc) count and/or total hemoglobin levels (Hgb) and/or higher fetal hemoglobin (HbF) and/or lower adult hemoglobin (HbA) levels were expected when compared with controls.

DESIGN

Case-control study.

SETTING

Obstetric unit of a tertiary ministry of health hospital.

SAMPLE

Fifty singleton pregnancies with meconium-stained amniotic fluid and 50 singleton pregnancies with clear amniotic fluid at all stages of labor.

METHODS

Umbilical cord blood samples were collected for determination of total blood parameters and hemoglobin electrophoresis.

MAIN OUTCOME MEASURES

Red blood cell count, total hemoglobin, fetal and adult hemoglobin contents (HbF and HbA).

RESULTS

Red blood cell count, total hemoglobin, fetal hemoglobin (HbF) and adult hemoglobin (HbA) contents were not different between meconium stained and clear amniotic fluid groups.

CONCLUSION

These results suggest that meconium passage may not be associated with chronic fetal hypoxia as demonstrated by similar red blood cell count, total hemoglobin values and fetal hemoglobin (HbF) and adult hemoglobin (HbA) contents.

Prediction of outcome of fetal congenital heart disease using a cardiovascular profile score

OBJECTIVES

Congestive heart failure in fetuses with congenital heart defects (CHD) is associated with high perinatal mortality. The clinical condition can be characterized by five ultrasound markers that comprise the 10-point cardiovascular profile (CVP) score. Our aim was to assess the value of the CVP score in evaluating the condition and in maintaining surveillance of fetuses with CHD.

METHODS

We evaluated retrospectively 131 singleton pregnancies with a diagnosis of fetal CHD, which had been assessed by serial echocardiographic examinations, during which the CVP score was obtained. Fetal and neonatal outcomes, including perinatal mortality and Apgar scores, were assessed.

RESULTS

Fetuses with a final CVP score <or= 7 were statistically significantly more likely to suffer mortality than were fetuses with a final CVP score >or= 8 (87.5% vs. 15.2% mortality; P < 0.0001, chi square = 24.5). Significance was maintained after controlling for birth weight, lag time between the final examination and delivery and the dichotomized 5-min Apgar score (odds ratio, 22.3; P = 0.024). For low Apgar score and mortality, the CVP score had low sensitivity (0.25 and 0.27, respectively) but high specificity (0.98 and 0.99, respectively). The presence of hydrops and severe cardiomegaly were statistically significantly associated with mortality (P < 0.05).

CONCLUSIONS

Fetuses with CHD and a CVP score below 8 are at risk of perinatal death. The CVP score may be used to assess the severity of fetal CHD and to plan perinatal management.

Diagnosis and management of fetal growth restriction: the role of fetal therapy

Fetal growth restriction remains a major cause of perinatal morbidity and mortality in modern obstetric practice. Placental insufficiency is the most common association, but is often a diagnosis of exclusion. Currently, no treatment can ameliorate or reverse established growth restriction: maximising gestational age and judicious timing of steroid administration and delivery are the primary tasks for the obstetrician. Although comprehensive surveillance of the preterm fetus now includes ductus venosus Doppler studies, its effectiveness in timing delivery has yet to be confirmed in randomised controlled trials. More basic research on the regulation of fetal growth is needed before specific therapies for established growth restriction can be developed.

A comparison of 3 criteria of oligohydramnios in identifying peripartum complications: a secondary analysis

OBJECTIVE

The objective of the study was to ascertain the diagnostic accuracy of 3 criteria of oligohydramnios in identifying 4 peripartum complications.

STUDY DESIGN

The 3 definitions of oligohydramnios were amniotic fluid index (AFI) 5.0 cm or less and AFI <5% for gestational age (GA) using nomograms by Moore and Cayle or Magann et al. Likelihood ratio (LR) and guidelines by the Evidence-Based Medicine Working Group were used in the secondary analysis of previously published reports. AFI obtained during antepartum and intrapartum periods were analyzed separately.

RESULTS

The 95% confidence intervals for the prevalence of oligohydramnios using the 3 criteria are significantly different in the antepartum or intrapartum analysis. The LR was <6 for ante- and intrapartum AFI to identify cesarean delivery for nonreassuring fetal heart rate tracing, Apgar score 3 or less at 5 minutes, umbilical arterial pH <7.00, and newborns' weight 5% or less for GA.

CONCLUSION

The 3 criteria for determining the adequacy of amniotic fluid are not fungible, and they are not useful diagnostic tests for identifying peripartum complications because LR is <10.

Obstetric considerations in the management of pregnancy in kidney transplant recipients

Kidney transplant improves reproductive function; planning for pregnancy is crucial. Prenatal management must address potential fetal complications: preterm delivery, intrauterine growth restriction, low birth weight; as well as maternal: hypertension, preeclampsia, gestational diabetes, acute rejection or graft loss. The latter depends upon timing after transplant, prepregnancy kidney function, and continuation of immunosuppressive agents at appropriate levels. Graft function is not adversely affected if preconception kidney function was normal. Acute rejection, 9%-14%, must be immediately addressed, with kidney biopsy if necessary. Blood pressure should be meticulously managed; serious morbidity results from poor control. Blood pressures >130/80 mmHg require acceptable antihypertensives: beta-blockers, alpha-methyldopa, hydralazine, and calcium channel blockers. Preeclampsia requires seizure prophylaxis with magnesium sulfate, with expeditious delivery. Screening for urinary tract infections with aggressive treatment and for opportunistic infections that may affect the fetus is essential. Surveillance for fetal anomalies, growth, and antenatal testing is important. Steroids for fetal lung maturity are indicated for preterm delivery. Vaginal birth is preferred, reserving cesarean for obstetrical indications, with pain management similar to normal laboring patients. Surveillance for infection postpartum is warranted. Conflicting information exists regarding safety of breastfeeding with immunosuppressive drugs; immunosuppressive medication must be adjusted to prepregnancy levels and contraception counseling addressed.

Management of fetal growth restriction

Fetal growth restriction (FGR) is challenging because of the difficulties in reaching a definitive diagnosis of the cause and planning management. FGR is associated not only with a marked increased risk in perinatal mortality and morbidity but also with long-term outcome risks. Combinations of fetal biometry, amniotic fluid volume, heart rate patterns, arterial and venous Doppler, and biophysical variables allow a comprehensive fetal evaluation of FGR. However, no evidence supports that the use of cardiotocography or the biophysical profile improves perinatal outcome. Therefore, obstetricians aim to identify fetuses with early FGR so delivery can be planned according to gestational age and severity of the condition. The balance of risks and the need for the availability of services mean that the involvement of neonatologists in FGR management is vital. In this review, the focus is on the pathophysiology and management of FGR caused by placental diseases.

Fetal congestive heart failure

Fetal echocardiography is used in the diagnosis of many forms of congenital heart disease, and in the assessment of the prognosis of cardiac lesions based on their anatomy and presentation in utero. However, the presence of signs of fetal heart failure such as hydrops or valvular regurgitation makes the assessment of prognosis more difficult. A tool for this assessment is the 'cardiovascular profile score', which combines ultrasonic markers of fetal cardiovascular unwellness based on univariate parameters that have been correlated with perinatal mortality. This profile could become the 'heart failure score' and could potentially be used in much the same way as and in combination with the biophysical profile score. This article will present a straightforward method for rapid evaluation of a fetus that may have congestive heart failure.

Infant and child motor development

Identifying infant and child developmental delay is a skill important for orthopaedic surgeons to master because they often are asked to distinguish between normal and abnormal movement. An emphasis has been placed on early detection and referral for intervention, which has been shown to enhance the lives of the infant or child and his or her family. Appropriate recognition of delay is necessary for referral to early intervention services, which serve to help these children overcome or improve motor dysfunction and to help families grow more confident in caring for children with special needs. We define early intervention, discuss normal and abnormal motor development, and provide useful examination tools to assess motor development.

Meconium passage in utero: mechanisms, consequences, and management

Meconium passage in newborn infants is a developmentally programmed event normally occurring within the first 24 to 48 hours after birth. Intrauterine meconium passage in near-term or term fetuses has been associated with fetomaternal stress factors and/or infection, whereas meconium passage in postterm pregnancies has been attributed to gastrointestinal maturation. Despite these clinical impressions, little information is available on the mechanism(s) underlying the normal meconium passage that occurs immediately after birth or during the intrauterine period of fetal development. Birth itself is a stressful process and it is possible that fetal stress-mediated biochemical events may regulate the meconium passage occurring either during labor or after birth. Aspiration of meconium during intrauterine life may result in or contribute to meconium aspiration syndrome (MAS), representing a continued leading cause of perinatal death. This article reviews aspects of meconium passage in utero, its consequences, and management.

Current concepts in intrauterine growth restriction

Regulation of fetal growth is multifactorial and complex. Diverse factors, including intrinsic fetal conditions as well as maternal and environmental factors, can lead to intrauterine growth restriction (IUGR). The interaction of these factors governs the partitioning of nutrients and rate of fetal cellular proliferation and maturation. Although IUGR is probably a physiologic adaptive response to various stimuli, it is associated with distinct short- and long-term morbidities. Immediate morbidities include those associated with prematurity and inadequate nutrient reserve, while childhood morbidities relate to impaired maturation and disrupted organ development. Potential long-term effects of IUGR are debated and explained by the fetal programming hypothesis. In formulating a comprehensive approach to the management and follow-up of the growth-restricted fetus and infant, physicians should take into consideration the etiology, timing, and severity of IUGR. In addition, they should be cognizant of the immediate perinatal response of the growth-restricted infant as well as the childhood and long-term associated morbidities. A multi disciplinary approach is imperative, including early recognition and obstetrical management of IUGR, assessment of the growth-restricted newborn in the delivery room, possible monitoring in the neonatal intensive care unit, and appropriate pediatric follow-up. Future research is necessary to establish effective preventive, diagnostic, and therapeutic strategies for IUGR, perhaps affecting the health of future generations.

Biophysical profile with amniotic fluid volume assessments

OBJECTIVE

To compare the amniotic fluid index (AFI) with the single deepest pocket technique along with the other components of the biophysical profile (BPP) in predicting an adverse pregnancy outcome.

METHODS

Prospective, randomized trial of amniotic fluid assessment by AFI or single deepest pocket during a BPP. Cesarean delivery for fetal distress was the primary outcome evaluated.

RESULTS

The AFI was used in 273 pregnancies and the single deepest pocket in 264. The AFI significantly increased the number of pregnancies labeled as oligohydramnios, 102 women (38%) compared with 46 women (17%; P <.001), odds ratio (OR) = 2.84, 95% confidence interval 1.90-4.25 in the single deepest pocket group. There was no difference in the number of women with oligohydramnios in the AFI group, 16 of 102 (16%), undergoing a cesarean delivery for fetal intolerance of labor compared with the single deepest pocket group, 6 of 46 (13%; P =.676). More women with normal fluid by the AFI method (AFI > 5), 20 of 170 (12%), underwent a cesarean delivery for fetal distress than the women with normal fluid by the single deepest pocket technique (2 cm x 1 cm pocket present) group, 12 of 218 (6%; P =.037, OR = 2.22, 95% confidence interval 1.05-4.70).

CONCLUSION

The AFI offers no advantage in detecting adverse outcomes compared with the single deepest pocket when performed with the BPP. The AFI may cause more interventions by labeling twice as many at-risk pregnancies as having oligohydramnios than with the single deepest pocket technique.

How well do the amniotic fluid index and single deepest pocket indices (below the 3rd and 5th and above the 95th and 97th percentiles) predict oligohydramnios and hydramnios?

OBJECTIVE

This study was undertaken to determine whether the amniotic fluid index (AFI) and single deepest pocket percentiles can reliably identify a dye-determined amniotic fluid volume.

STUDY DESIGN

Ultrasound measurements and dye-determined volumes were prospectively collected. Oligohydramnios predictors included AFI and single deepest pocket below the 3rd and 5th percentiles, and hydramnios predictors were based on AFI and single deepest pocket above the 95th and 97th percentiles.

RESULTS

Two hundred ninety-one women with singleton pregnancies participated, including 75 pregnancies (26%) with oligohydramnios and 31 pregnancies (10%) with hydramnios. The predictive ability of the AFI and single deepest pocket indices (<3rd and 5th percentiles) to identify oligohydramnios was between 11% and 27% and to identify hydramnios (>95th and 97th percentiles) ranged between 33% and 46%. The best prediction was for normal fluid volume with an accuracy of 83% to 94%.

CONCLUSION

Amniotic fluid indices perform best for the identifying normal AF volumes, whereas the identification of oligohydramnios or hydramnios is poor.

Transabdominal near infrared oximetry of hypoxic stress in fetal sheep brain in utero

The feasibility of transabdominal near-infrared (NIR) spectroscopy for detecting and quantifying fetal hypoxia in utero is demonstrated in a pregnant ewe model. A frequency domain NIR spectroscopy probe, consisting of two detectors and six sources operating at three wavelengths (675, 786, and 830 nm), was placed on the maternal abdomen directly above the fetal head. Fetal hypoxia was indirectly induced through occlusion of uterine blood flow for approximately 3 min. NIR photon diffusion measurements were made during a baseline period, during hypoxia of the fetus, and during recovery. Fetal blood samples were drawn from the fetal brachial artery and jugular veins at several time points during the cycle. Seven hypoxic cycles were induced in a total of five pregnant ewes. The NIR measurements were analyzed by using a two-layer diffusion model to deconvolve the fetal blood saturation from that of the pregnant ewe. Fetal hypoxia was detected. Good agreement was found between fetal blood saturation determined by the transabdominal NIR method and arterial and venous fetal blood saturation quantified from fetal blood samples by using a hemoximeter.

Is amniotic fluid volume status predictive of fetal acidosis at delivery?

OBJECTIVE

To ascertain if dye-determined amniotic fluid volume just prior to delivery correlates with fetal acidosis at delivery.

DESIGN

The present was a prospective observational study.

SETTING

The study took place at the University of Mississippi Medical Center, Jackson MS, USA.

POPULATION

The population included 100 unlaboured women undergoing an amniocentesis for the assessment of fetal lung maturity before an elective Caesarean delivery between January 1997 and December 2000.

MAIN OUTCOMES MEASURED

The amniotic fluid volume was estimated by ultrasound measurement and quantified by dye-determined methodology immediately prior to Caesarean delivery. Umbilical cord artery pH was collected at the time of Caesarean delivery.

RESULTS

The predictive accuracy of an amniotic fluid index < or = versus > 5 to identify an umbilical artery pH of < 7.20 had a sensitivity of 0%, a specificity of 84%, and a likelihood ratio of zero. None of the dye-determined low amniotic fluid volumes were identified using the single deepest pocket technique. Dye-determined low, normal, and high amniotic fluid volume groups contained a similar number of fetuses with umbilical cord arterial pH < 7.20 (P = 0.371), < 7.10 (P = 0.460), and < 7.00 (P = 0.614). Receiver-operating characteristic curves could not identify any amniotic fluid index from 0 to 18, single deepest pocket from 0 to 12, or dye-determined amniotic fluid volume 100-1900 mL to differentiate between the two newborns with an umbilical cord artery pH < 7 from 98 babies with cord pH > or = 7.0.

CONCLUSIONS

Neither ultrasound estimates nor dye-determined amniotic fluid volumes are predictive of a low umbilical artery pH at delivery.

Comparability of the amniotic fluid index and single deepest pocket measurements in clinical practice

Two ultrasound techniques, the amniotic fluid index (AFI) and the single deepest pocket (SDP), are currently used to detect oligohydramnios, predict variable decelerations, risk of Caesarean delivery for fetal distress, Apgar scores, umbilical cord artery pH, perinatal mortality, and cerebral palsy. Both techniques poorly identify oligohydramnios. Both techniques identify pregnancies at risk for variable decelerations, low Apgar scores, and Caesarean delivery for fetal distress. Only the SDP is predictive of a compromised fetus-umbilical artery pH, as a stand-alone test, has been correlated with perinatal mortality, and as part of the biophysical profile has been linked to cerebral palsy. This brief communication reviews the comparability of these two techniques and which method, if either, is superior in the identification of oligohydramnios, the predictability of these techniques to identify an adverse pregnancy outcome, and the ability to predict cerebral palsy and perinatal mortality.

Ultrasound estimation of amniotic fluid volume using the largest vertical pocket containing umbilical cord: measure to or through the cord?

OBJECTIVES

The purpose of this investigation was to determine the preferable method, either measuring to the umbilical cord or through the umbilical cord to the base of the pocket, of ultrasonically estimating amniotic fluid volume.

SUBJECT AND METHODS

This was a prospective study carried out in singleton pregnancies undergoing a third-trimester amniocentesis. The amniotic fluid index (AFI) and single deepest pocket (SDP) were measured prior to amniocentesis. If measured spaces contained umbilical cord, measurements were made to and through the cord. Actual amniotic fluid volume was determined by the dye-dilution technique.

RESULTS

One-hundred pregnancies were evaluated. Low dye-determined volume was identified in a significantly greater number of pregnancies using the AFI to the cord (7/28, 25%) compared to through the cord (2/28, 7%) (P = 0.025). The SDP technique to the cord was superior in low volumes (2/28, 7%) vs. (0/28, 0%) through the cord (although statistical significance could not be determined because there were no low through-the-cord measurements).

CONCLUSIONS

For the detection of low amniotic fluid volumes, the AFI to the cord is better than through the cord. Measurement to the cord and through the cord had similar accuracy for both the AFI and SDP techniques in normal and high dye-determined amniotic fluid volumes.

Fetal congestive heart failure: correlation of Tei-index and Cardiovascular-score

INTRODUCTION

Congestive heart failure (CHF) may be present in fetuses with hydrops fetalis (HF) and the severity is difficult to quantitate. Differential ventricular dysfunction may be present in the fetus with CHF. A non-geometric measure of ventricular function that is not afterload dependent would be useful to measure the severity of myocardial dysfunction.

METHODS

Tei-index (isovolumetric time/ejection time) was measured prenatally in 23 normals (24-34 weeks gestational age-GA) and in 7 with HF (24-34 weeks GA). Prenatal CHF severity was graded by a 10 point cardiovascular (CV) score (2 points each for absence of hydrops, normal venous Doppler, heart function, arterial Doppler, and heart size, and 10/10 = normal). A paired student t-test was used to compare RV and LV and non-paired t-test compared HF and normals. Tei-index and CV score were correlated.

RESULTS

Tei-index normals were 0.38 +/- 0.04 in the right ventricle (RV) and 0.41 +/- 0.05 in the left ventricle (LV) and there were no significant RV-LV or gestational age (GA) differences. Among HF fetuses, RV and LV Tei-indices were both significantly increased (0.54 and 0.92) and not significantly different. CV score ranged from 2 to 8 (mean 5.43 out of 10) and correlated inversely with Tei-index (r = -0.52, r = -0.68).

CONCLUSION

Hydrops fetalis is associated with biventricular dysfunction and congestive heart failure. Tei-index correlates with CV score obtained within two weeks of delivery or intrauterine death. Tei-index may be useful in the serial assessment of myocardial dysfunction in the fetus with hydrops.

The sequence of changes in Doppler and biophysical parameters as severe fetal growth restriction worsens

OBJECTIVE

To test the hypothesis that hemodynamic changes depicted by Doppler precede deteriorating biophysical profile score in severe intrauterine growth restriction.

METHODS

Intrauterine growth-restricted fetuses with elevated umbilical artery Doppler pulsatility index (PI) > 2 standard deviations above mean for gestational age and birth weight < 10th centile for gestational age were examined longitudinally. Fetal well-being was assessed serially with five-component biophysical profile scoring (tone, movement, breathing, amniotic fluid volume and non-stress test) and concurrent Doppler examination of the umbilical artery, middle cerebral artery and ductus venosus, inferior vena cava and free umbilical vein. For fetuses with a final biophysical profile score < 6/10, progression of biophysical profile scoring, arterial PI and venous peak velocity indices were analyzed longitudinally. Gestational age effect was removed by converting indices to Z-scores (deviation from gestational age mean, in standard deviations).

RESULTS

Forty-four of 236 intrauterine growth-restricted fetuses (18.6%) required delivery for abnormal biophysical profile scoring. The median gestational age at entry was 25 weeks and 1 day and at delivery was 29 weeks and 6 days. The median interval between examinations was 1.5 days and the majority had daily testing in the week prior to delivery. Between first examination and delivery, significant deterioration was observed for Doppler criteria (chi-square, P < 0.001) and biophysical parameters (Fisher's exact, P = 0.02) predominantly confined to the week prior to delivery/stillbirth. Doppler variables changed first. In 42 fetuses (95.5%), one or more vascular beds deteriorated, accelerating especially in the umbilical artery and ductus venosus at a median of 4 days before biophysical profile scoring deteriorated. Two to 3 days before delivery, fetal breathing movement began to decline. The next day, amniotic fluid volume began to drop. Composite biophysical profile score dropped abruptly on the day of delivery, with loss of fetal movement and tone. Three principal patterns of Doppler deterioration were observed: (i) worsening umbilical artery PI, advent of brain sparing and venous deterioration (n = 32, 72.7%); (ii) abnormal precordial venous flows, advent of brain sparing (n = 6, 13.6%); and (iii) abnormal ductus venosus only (n = 4, 9.1%). In the majority (31, 70.5%), Doppler deterioration was complete 24 h before biophysical profile score decline. In the remainder (11, 25%), Doppler deterioration and biophysical profile score < 6/10 were simultaneous.

CONCLUSION

In the majority of severely intrauterine growth-restricted fetuses, sequential deterioration of arterial and venous flows precedes biophysical profile score deterioration. Adding serial Doppler evaluation of the umbilical artery, middle cerebral artery and ductus venosus to intrauterine growth restriction surveillance will enhance the performance of the biophysical score in the detection of fetal compromise and therefore optimizing the timing of intervention.