Relationship between fetal biophysical activities and umbilical cord blood gas values

Midwives' and obstetricians' practice, perspectives and experiences in relation to altered fetal movement: A focused ethnographic study

BACKGROUND

Reducing avoidable stillbirth is a global priority. The stillbirth rate in England compares unfavourably to that of some other high-income countries. Poorly-managed episodes of altered fetal movement have been highlighted as a key contributor to avoidable stillbirth, and strategies introduced in England in 2016 to reduce perinatal mortality included recommendations for the management of reduced fetal movement. Despite a downward trend in stillbirth rates across the UK, the effects of policies promoting awareness of fetal movement remain uncertain.

OBJECTIVE

To provide in-depth knowledge of how practice and clinical guidance relating to altered fetal movement are perceived, enacted and experienced by midwives and obstetricians, and explore the relationship between recommended fetal movement care and actual fetal movement care.

DESIGN

A focused ethnographic approach comprising over 180 h of observation, 15 interviews, and document analysis was used to explore practice at two contrasting UK maternity units.

SETTINGS

Antenatal services at two UK maternity units, one in the Midlands and one in the North of England.

PARTICIPANTS

Thirty-six midwives, obstetricians and sonographers and 40 pregnant women participated in the study across 52 observed care episodes and relevant unit activity. Twelve midwives and three obstetricians additionally participated in formal semi-structured interviews.

METHODS

Fieldnotes, interview transcripts, policy documents, maternity notes and clinical guidelines were analysed using a modified constant comparison method to identify important themes.

RESULTS

fetal movement practice was mostly consistent and in line with guideline recommendations. Notwithstanding, most midwives and obstetricians had concerns about this area of care, including challenges in diagnosis, conflicting evidence about activity, heightened maternal anxiety, and high rates of monitoring and intervention in otherwise low-risk pregnancies. To address these issues, midwives spent considerable time reassuring women through information and regular monitoring, and coaching them to perceive fetal movement more accurately.

CONCLUSIONS

Practice relating to altered fetal movement might be more uniform than in the past. However, a heightened focus on fetal movement is associated by some midwives and obstetricians with potential harms, including increased anxiety in pregnancy, and high rates of monitoring and intervention in pregnancies where there are no 'objective concerns'. Challenges in diagnosing a significant change in fetal movement with accuracy might mean that interventions and resources are not being directed towards those pregnancies most at risk. More research is needed to determine how healthcare professionals can engage in conversations about fetal movement and stillbirth to support safe outcomes and positive experiences in pregnancy and birth.

REGISTRATION

Not registered.

TWEETABLE ABSTRACT

Midwives and obstetricians take #reducedfetalmovement seriously but worry this 'unreliable' symptom increases anxiety, monitoring and intervention in many 'low risk' pregnancies.

The role of the fetal biophysical profile in the management of fetal growth restriction

Growth-restricted fetuses are at risk of hypoxemia, acidemia, and stillbirth because of progressive placental dysfunction. Current fetal well-being, neonatal risks following delivery, and the anticipated rate of fetal deterioration are the major management considerations in fetal growth restriction. Surveillance has to quantify the fetal risks accurately to determine the delivery threshold and identify the testing frequency most likely to capture future deterioration and prevent stillbirth. From the second trimester onward, the biophysical profile score correlates over 90% with the current fetal pH, and a normal score predicts a pH >7.25 with a 100% positive predictive value; an abnormal score on the other hand predicts current fetal acidemia with similar certainty. Between 30% and 70% of growth-restricted fetuses with a nonreactive heart rate require biophysical profile scoring to verify fetal well-being, and an abnormal score in 8% to 27% identifies the need for delivery, which is not suspected by Doppler findings. Future fetal well-being is not predicted by the biophysical profile score, which emphasizes the importance of umbilical artery Doppler and amniotic fluid volume to determine surveillance frequency. Studies with integrated surveillance strategies that combine frequent heart rate monitoring with biophysical profile scoring and Doppler report better outcomes and stillbirth rates of between 0% and 4%, compared with those between 8% and 11% with empirically determined surveillance frequency. The variations in clinical behavior and management challenges across gestational age are better addressed when biophysical profile scoring is integrated into the surveillance of fetal growth restriction. This review aims to provide guidance on biophysical profile scoring in the in- and outpatient management of fetal growth restriction.

Clinical Opinion: The diagnosis and management of suspected fetal growth restriction: an evidence-based approach

This study reviewed the literature about the diagnosis, antepartum surveillance, and time of delivery of fetuses suspected to be small for gestational age or growth restricted. Several guidelines have been issued by major professional organizations, including the International Society of Ultrasound in Obstetrics and Gynecology and the Society for Maternal-Fetal Medicine. The differences in recommendations, in particular about Doppler velocimetry of the ductus venosus and middle cerebral artery, have created confusion among clinicians, and this review has intended to clarify and highlight the available evidence that is pertinent to clinical management. A fetus who is small for gestational age is frequently defined as one with an estimated fetal weight of <10th percentile. This condition has been considered syndromic and has been frequently attributed to fetal growth restriction, a constitutionally small fetus, congenital infections, chromosomal abnormalities, or genetic conditions. Small for gestational age is not synonymous with fetal growth restriction, which is defined by deceleration of fetal growth determined by a change in fetal growth velocity. An abnormal umbilical artery Doppler pulsatility index reflects an increased impedance to flow in the umbilical circulation and is considered to be an indicator of placental disease. The combined finding of an estimated fetal weight of <10th percentile and abnormal umbilical artery Doppler velocimetry has been widely accepted as indicative of fetal growth restriction. Clinical studies have shown that the gestational age at diagnosis can be used to subclassify suspected fetal growth restriction into early and late, depending on whether the condition is diagnosed before or after 32 weeks of gestation. The early type is associated with umbilical artery Doppler abnormalities, whereas the late type is often associated with a low pulsatility index in the middle cerebral artery. A large randomized clinical trial indicated that in the context of early suspected fetal growth restriction, the combination of computerized cardiotocography and fetal ductus venosus Doppler improves outcomes, such that 95% of surviving infants have a normal neurodevelopmental outcome at 2 years of age. A low middle cerebral artery pulsatility index is associated with an adverse perinatal outcome in late fetal growth restriction; however, there is no evidence supporting its use to determine the time of delivery. Nonetheless, an abnormality in middle cerebral artery Doppler could be valuable to increase the surveillance of the fetus at risk. We propose that fetal size, growth rate, uteroplacental Doppler indices, cardiotocography, and maternal conditions (ie, hypertension) according to gestational age are important factors in optimizing the outcome of suspected fetal growth restriction.

An integrated approach based on advanced CTG parameters and Doppler measurements for late growth restriction management

Background

The clinical diagnosis of late Fetal Growth Restriction (FGR) involves the integration of Doppler ultrasound data and Fetal Heart Rate (FHR) monitoring through computer assisted computerized cardiotocography (cCTG). The aim of the study was to evaluate the diagnostic power of combined Doppler and cCTG parameters by contrasting late FGR –and healthy controls.

Methods

The study was conducted from January 2018 to May 2020. Only pregnant women who had the last Doppler measurement obtained within 1 week before delivery and cCTG performed within 24 h before delivery were included in the study. Two hundred forty-nine pregnant women fulfilling the inclusion criteria were enrolled in the study; 95 were confirmed as late FGR and 154 were included in the control group.

Results

Among the extracted cCTG parameters, Delta Index, Short Term Variability (STV), Long Term Variability (LTV), Acceleration and Deceleration Phase Rectified Slope (APRS, DPRS) values were lower in the late FGR participants compared to the control group. In the FGR cohort, Delta, STV, APRS, and DPRS were found different when stratifying by MCA_PI (MCA_PI <5th centile or > 5th centile). STV and DPRS were the only parameters to be found different when stratifying by (UA_PI >95th centile or UA_PI <95th centile). Additionally, we measured the predictive power of cCTG parameters toward the identification of associated Doppler measures using figures of merit extracted from ROC curves.

The AUC of ROC curves were accurate for STV (0,70), Delta (0,68), APRS (0,65) and DPRS (0,71) when UA_PI values were > 95th centile while, the accuracy attributable to the prediction of MCA_PI was 0.76, 0.77, 0.73, and 0.76 for STV, Delta, APRS, and DPRS, respectively.

An association of UA_PI>95th centile and MCA_PI<5th centile with higher risk for NICU admission, was observed, while CPR < 5th centile resulted not associated with any perinatal outcome. Values of STV, Delta, APRS, DPRS were significantly lower for FGR neonates admitted to NICU, compared with the uncomplicated FGR cohort.

Conclusions

The results of this study show the contribution of advanced cCTG parameters and fetal Doppler to the identification of late FGR and the association of those parameters with the risk for NICU admission.

Trial registration

Retrospectively registered.

Indications for Outpatient Antenatal Fetal Surveillance: ACOG Committee Opinion, Number 828

ABSTRACT

The purpose of this Committee Opinion is to offer guidance about indications for and timing and frequency of antenatal fetal surveillance in the outpatient setting. Antenatal fetal surveillance is performed to reduce the risk of stillbirth. However, because the pathway that results in increased risk of stillbirth for a given condition may not be known and antenatal fetal surveillance has not been shown to improve perinatal outcomes for all conditions associated with stillbirth, it is challenging to create a prescriptive list of all indications for which antenatal fetal surveillance should be considered. This Committee Opinion provides guidance on and suggests surveillance for conditions for which stillbirth is reported to occur more frequently than 0.8 per 1,000 (the false-negative rate of a biophysical profile) and which are associated with a relative risk or odds ratio for stillbirth of more than 2.0 compared with pregnancies without the condition. Table 1 presents suggestions for the timing and frequency of testing for specific conditions. As with all testing and interventions, shared decision making between the pregnant individual and the clinician is critically important when considering or offering antenatal fetal surveillance for individuals with pregnancies at high risk for stillbirth or with multiple comorbidities that increase the risk of stillbirth. It is important to emphasize that the guidance offered in this Committee Opinion should be construed only as suggestions; this guidance should not be construed as mandates or as all encompassing. Ultimately, individualization about if and when to offer antenatal fetal surveillance is advised.

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.

No. 197a-Fetal Health Surveillance: Antepartum Consensus Guideline

OBJECTIVE

This guideline provides new recommendations pertaining to the application and documentation of fetal surveillance in the antepartum period that will decrease the incidence of birth asphyxia while maintaining the lowest possible rate of obstetrical intervention. Pregnancies with and without risk factors for adverse perinatal outcomes are considered. This guideline presents an alternative classification system for antenatal fetal non-stress testing to what has been used previously. This guideline is intended for use by all health professionals who provide antepartum care in Canada.

OPTIONS

Consideration has been given to all methods of fetal surveillance currently available in Canada.

OUTCOMES

Short- and long-term outcomes that may indicate the presence of birth asphyxia were considered. The associated rates of operative and other labour interventions were also considered.

EVIDENCE

A comprehensive review of randomized controlled trials published between January 1996 and March 2007 was undertaken, and MEDLINE and the Cochrane Database were used to search the literature for all new studies on fetal surveillance antepartum. The level of evidence has been determined using the criteria and classifications of the Canadian Task Force on Preventive Health Care (Table 1).

SPONSOR

This consensus guideline was jointly developed by the Society of Obstetricians and Gynaecologists of Canada and the British Columbia Perinatal Health Program (formerly the British Columbia Reproductive Care Program or BCRCP) and was partly supported by an unrestricted educational grant from the British Columbia Perinatal Health Program. RECOMMENDATION 1: FETAL MOVEMENT COUNTING: RECOMMENDATION 2: NON-STRESS TEST: RECOMMENDATION 3: CONTRACTION STRESS TEST: RECOMMENDATION 4: BIOPHYSICAL PROFILE: RECOMMENDATION 5: UTERINE ARTERY DOPPLER: RECOMMENDATION 6: UMBILICAL ARTERY DOPPLER.

Reduced fetal movement intervention Trial-2 (ReMIT-2): protocol for a pilot randomised controlled trial of standard care informed by the result of a placental growth factor (PlGF) blood test versus standard care alone in women presenting with reduced fetal movement at or after 36+ 0 weeks gestation

BACKGROUND

Forty percent of babies who are stillborn born die after 36 weeks gestation and have no lethal structural abnormality. Maternal perception of reduced fetal movement (RFM) is associated with stillbirth and is related to abnormal placental structure and function. The ultimate objective of this trial is to assess whether for women with RFM, intervention directed by measurement of placental biochemical factors in addition to standard care improves pregnancy outcome compared with standard care alone. This is the protocol for a pilot trial to determine the feasibility of a definitive trial and also provide proof of concept that informing care by measurement of placental factors improves neonatal outcomes.

METHODS

ReMIT-2 is a multicentre, pilot randomised controlled trial of care informed by results of an additional placental factor blood test versus standard care alone for women presenting with RFM at or after 36+ 0 weeks gestation. Participants will be randomised 1:1 to the intervention arm where the blood test result is revealed and acted on, or to the control arm where the blood sample is not tested immediately and therefore the result cannot be acted on. All participants will be followed up six weeks after delivery to assess their health status and views of the trial, along with healthcare costs. A sub-group will be interviewed within 16 weeks after delivery to further explore their views of the trial. Outcomes to determine feasibility of a definitive trial include number of potentially eligible women, proportion lost to follow-up, clinical characteristics at randomisation, reasons for non-recruitment, compliance with the trial intervention and views of participants and clinicians about the trial. Proof of concept outcomes include: rates of induction of labour; Caesarean birth; and a composite neonatal outcome of stillbirths and deaths before discharge, 5-min Apgar score < 7, umbilical artery pH < 7.05 and admission to neonatal unit for > 48 h.

DISCUSSION

Results from this pilot trial will help determine whether a large definitive trial is feasible. Such a study would provide evidence to guide management of women with RFM and reduce stillbirths.

TRIAL REGISTRATION

ISRCTN Registry, ISRCTN12067514 . Registered on 8 September 2017.

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.

Can promoting awareness of fetal movements and focusing interventions reduce fetal mortality? A stepped-wedge cluster randomised trial (AFFIRM)

BACKGROUND

In 2013, the stillbirth rate in the UK was 4.2 per 1000 live births, ranking 24th out of 49 high-income countries, with an annual rate of reduction of only 1.4% per year. The majority of stillbirths occur in normally formed infants, with (retrospective) evidence of placental insufficiency the most common clinical finding. Maternal perception of reduced fetal movements (RFM) is associated with placental insufficiency and increased risk of subsequent stillbirth.This study will test the hypothesis that the introduction of a package of care to increase women's awareness of the need for prompt reporting of RFM and standardised management to identify fetal compromise with timely delivery in confirmed cases, will reduce the rate of stillbirth. Following the introduction of a similar intervention in Norway the odds of stillbirth fell by 30%, but the efficacy of this intervention (and possible adverse effects and implications for service delivery) has not been tested in a randomised trial.

METHODS

We describe a stepped-wedge cluster trial design, in which participating hospitals in the UK and Ireland will be randomised to the timing of introduction of the care package. Outcomes (including the primary outcome of stillbirth) will be derived from detailed routinely collected maternity data, allowing us to robustly test our hypothesis. The degree of implementation of the intervention will be assessed in each site. A nested qualitative study will examine the acceptability of the intervention to women and healthcare providers and identify process issues including barriers to implementation.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Scotland A Research Ethics Committee (Ref 13/SS/0001) and from Research and Development offices in participating maternity units. The study started in February 2014 and delivery of the intervention completed in December 2016. Results of the study will be submitted for publication in peer-reviewed journals and disseminated to local investigating sites to inform education and care of women presenting with RFM.

TRIAL REGISTRATION NUMBER

www.clinicaltrials.gov NCT01777022.

VERSION

Protocol Version 4.2, 3 February 2017.

Maternal-Fetal Monitoring of Opioid-Exposed Pregnancies: Analysis of a Pilot Community-Based Protocol and Review of the Literature

OBJECTIVES

To describe/analyse a novel, community-based prenatal monitoring protocol for opioid-exposed pregnancies developed by our centre in 2014 to optimize prenatal care for this population. A literature review of published monitoring protocols for this population is also presented.

METHODS

Retrospective comparison of pre-protocol (n = 215) and post-protocol (n = 251) cohorts. Medline and Embase were searched between 2000-2016 using MeSH terms: [fetal monitoring OR prenatal care] AND [opioid-related disorders OR substance-related disorders] in Medline and [fetal monitoring OR prenatal care] AND [opiate addiction OR substance abuse] in Embase, producing 518 results. Thirteen studies included protocols for monitoring opioid-exposed pregnancies. No comprehensive monitoring protocols with high-quality supporting evidence were found.

RESULTS

We evaluated 466 opioid-exposed pregnancies, 215 before and 251 after introduction of the protocol. Since implementation, there was a significant increase in the number of opioid-exposed patients who have underwent urine drug screening (72.6% to 89.2%, P < 0.0001); a significant reduction in the number of urine drug screenings positive for illicit opioids (50.2% to 29.1%, P < 0.0001); and a significant increase in the number of patients who discontinued illicit opioid use by the time of delivery (24.7% to 39.4%, P < 0.01). There was no difference in the CS rate (27.4% vs. 26.3%, P > 0.05). There were no observed differences in the rate of preterm birth, birth weight <2500 g, or Apgar score <7 (P > 0.05).

CONCLUSIONS

Care of women with increased opioid use during pregnancy is an important but under-studied health issue. A novel protocol for focused antenatal care provision for women with opioid-exposed pregnancies improves standard of care and maternal/fetal outcomes.

Vascular Endothelial Growth Factor Activation of Intramembranous Absorption: A Critical Pathway for Amniotic Fluid Volume Regulation

OBJECTIVE

The purpose of this review is to propose a critical role for vascular endothelial growth factor (VEGF) in mediating the transfer of amniotic fluid from the amniotic compartment through the fetal membranes and fetal surface of the placenta into fetal blood.

METHODS

Experimental findings in humans and animal models on the action of VEGF in mediating fluid transfer are reviewed and interpreted in order to postulate a proposed mechanism for VEGF regulation of amniotic fluid absorption through the fetal membranes and placenta.

RESULTS

Recent scientific advances suggest that up-regulation of VEGF gene expression in the amnion and chorion is associated with increased transfer of amniotic fluid into fetal blood. The possible mechanisms of action for VEGF appear to involve regulation of intramembranous blood vessel proliferation and membrane transport via passive permeation as well as nonpassive transcytotic vesicular movement of fluid.

CONCLUSION

Currently evolving concepts suggest that amniotic fluid volume is regulated through modulation of the rate of intramembranous absorption of amniotic fluid by both passive and nonpassive mechanisms. The permeability factor VEGF appears to be a critical regulator of amniotic fluid transport in the fetal membranes.

Antenatal Surveillance in Twin Pregnancies Using the Biophysical Profile

Objectives-The nonstress test is currently the most widely used modality for antenatal surveillance in twin pregnancies, with a quoted false-positive rate of 11%-12%. Our objective was to report our experience with the sonographic portion of the biophysical profile in twin pregnancies as the primary screening modality.Methods-Women with twin pregnancies delivered by a single maternal-fetal medicine practice from 2005 to 2013 were included. We excluded monoamniotic twins. Twin pregnancies began weekly sonography for the biophysical profile starting at 32 to 33 weeks, or earlier if indicated. The nonstress test was performed if the sonographic biophysical profile score was less than 8 of 8. We reviewed biophysical profile scores and outcomes for all patients who delivered at 33 weeks or later to assess the false-positive rate for the biophysical profile, as well as the incidence of intrauterine fetal death (IUFD) after initiation of antenatal surveillance.Results-A total of 539 twin pregnancies were included. The incidence of IUFD per patient was 2 per 539 (0.4%; 95% confidence interval [CI], 0.1%-1.3%), and the incidence of IUFD per fetus was 2 per 1078 (0.19%; 95% CI, 0.05%-0.7%). The overall positive screen rate was 24 per 539 (4.45%; 95% CI, 3.0%-6.5%). The false-positive screen rate, defined as an abnormal biophysical profile that did not diagnose an IUFD or lead to delivery, was 10 per 539 (1.9%; 95% CI, 1.0%-3.4%).Conclusions-In twin pregnancies the use of the sonographic biophysical profile for routine antenatal surveillance has a low false-positive rate, with a very low incidence of IUFD. The sonographic biophysical profile should be considered as a primary mode for antenatal surveillance in twin pregnancies, with a reflex nonstress test for an abnormal score.

Evaluation of an optimal gestational age cut-off for the definition of early- and late-onset fetal growth restriction

OBJECTIVE

The terms early- and late-onset fetal growth restriction (FGR) are commonly used to distinguish two phenotypes characterized by differences in onset, fetoplacental Doppler, association with preeclampsia (PE) and severity. We evaluated the optimal gestational age (GA) cut-off maximizing differences among these two forms.

PATIENTS AND METHODS

A cohort of 656 consecutive singleton pregnancies with FGR was created. We used the decision tree analysis to evaluate the GA cut-off that best discriminated perinatal mortality, association with PE and adverse perinatal outcome (fetal demise, early neonatal death, neonatal acidosis at birth, and 5-min Apgar score <7).

RESULTS

We identified 32 weeks at diagnosis as the optimal cut-off, resulting in two groups with 7.1 and 0%, p < 0.001 perinatal mortality, 35.1 and 12.1%, p < 0.001 association with PE, and 13.4 and 4.6%, p < 0.001 composite adverse perinatal outcome. Abnormal versus normal umbilical artery (UA) Doppler classified two groups with 10.6 and 0.2%, p < 0.001 perinatal mortality, 50.0 and 11.8%, p < 0.001 association with PE, and 18.2 and 4.2%, p < 0.001 composite adverse perinatal outcome.

CONCLUSIONS

UA Doppler discriminated better the two forms of FGR with average early- and late-onset presentation, higher association with PE and poorer outcome. In the absence of UA information, a GA cut-off of 32 weeks at diagnosis maximizes differences between early- and late-onset FGR.

Maternal perception of reduced fetal movements is associated with altered placental structure and function

Background

Maternal perception of reduced fetal movement (RFM) is associated with increased risk of stillbirth and fetal growth restriction (FGR). DFM is thought to represent fetal compensation to conserve energy due to insufficient oxygen and nutrient transfer resulting from placental insufficiency. To date there have been no studies of placental structure in cases of DFM.

Objective

To determine whether maternal perception of reduced fetal movements (RFM) is associated with abnormalities in placental structure and function.

Design

Placentas were collected from women with RFM after 28 weeks gestation if delivery occurred within 1 week. Women with normal movements served as a control group. Placentas were weighed and photographs taken. Microscopic structure was evaluated by immunohistochemical staining and image analysis. System A amino acid transporter activity was measured as a marker of placental function.

Placentas from all pregnancies with RFM (irrespective of outcome) had greater area with signs of infarction (3.5% vs. 0.6%; p<0.01), a higher density of syncytial knots (p<0.001) and greater proliferation index (p<0.01). Villous vascularity (p<0.001), trophoblast area (p<0.01) and system A activity (p<0.01) were decreased in placentas from RFM compared to controls irrespective of outcome of pregnancy.

Conclusions

This study provides evidence of abnormal placental morphology and function in women with RFM and supports the proposition of a causal association between placental insufficiency and RFM. This suggests that women presenting with RFM require further investigation to identify those with placental insufficiency.

Predicting pH at birth in pregnancies with abnormal pulsatility index and positive end-diastolic velocity in the umbilical artery

OBJECTIVES

To identify potential associations between fetal surveillance tests and acidosis at birth in pregnancies with abnormal but positive end-diastolic velocity in the umbilical artery.

METHODS

A prospective case-control study [group 1: pH < 7.2; group 2: pH ≥ 7.2] including 46 fetuses with abnormal but positive end-diastolic velocity in the umbilical artery was conducted between February 2007 and March 2009. Outcome variables were evaluated by univariate analysis and compared between the two groups. Clinically relevant and statistically significant variables were analyzed by logistic regression.

RESULTS

Abnormal nonstress test, presence of deceleration, and absent fetal breathing movements were statistically significant. Logistic regression analysis revealed that fetal heart rate (FHR) deceleration in the nonstress test is the only predictor of fetal acidosis at birth (p = 0.024; OR = 8.2; 95%CI: 1.2-52).

CONCLUSIONS

In fetuses with positive end-diastolic flow velocity, acute variables of the antenatal surveillance tests are correlated with acidosis at birth and FHR deceleration in the nonstress test is the only predictor of fetal acidosis.

Timing delivery of the growth-restricted fetus

Intrauterine growth restriction (IUGR) is commonly defined as an estimated fetal weight of less than the 10th percentile. While 70% of these are small for normal reasons and not at risk, 30% are pathologically small at risk for numerous complications including fetal death. In the late preterm IUGR fetus (>34 weeks), prematurity risks less and the risk of fetal demise becomes the primary concern. Pulsed-wave Doppler interrogation of the umbilical and middle cerebral artery is useful in reducing perinatal mortality, however, Doppler changes in these vessels of the IUGR fetus may not occur after 34 weeks gestation. There are no randomized trials addressing the timing of delivery of the IUGR fetus in the late preterm or early-term period. However, retrospective reports show an increase risk of fetal demise. While timing the delivery of the late preterm/early-term IUGR fetus requires consideration of multiple factors (e.g. degree of growth restriction, etiology, amniotic fluid volume, and biophysical and Doppler testing), available data suggests that delivery should occur by 37 to 38 weeks for singleton IUGR fetuses. In twin pregnancies with a co-twin IUGR fetus, chorionicity also impacts timing of delivery, but delivery should occur by 34-36 weeks.

Neurodevelopment following fetal growth restriction and its relationship with antepartum parameters of placental dysfunction

Placental dysfunction leading to fetal growth restriction (FGR) is an important risk factor for neurodevelopmental delay. Recent observations clarify that FGR evolves prenatally from a preclinical phase of abnormal nutrient and endocrine milieu to a clinical phase that differs in characteristics in preterm and term pregnancies. Relating childhood neurodevelopment to these prenatal characteristics offers potential advantages in identifying mechanisms and timing of critical insults. Based on available studies, lagging head circumference, overall degree of FGR, gestational age, and umbilical artery (UA), aortic and cerebral Doppler parameters are the independent prenatal determinants of infant and childhood neurodevelopment. While head circumference is important independent of gestational age, overall growth delay has the greatest impact in early onset FGR. Gestational age has an overriding negative effect on neurodevelopment until 32-34 weeks' gestation. Accordingly, the importance of Doppler status is demonstrated from 27 weeks onward and is greatest when there is reversed end-diastolic velocity in the UA or aorta. While these findings predominate in early-onset FGR, cerebral vascular impedance changes become important in late onset FGR. Abnormal motor and neurological delay occur in preterm FGR, while cognitive effects and abnormalities that can be related to specific brain areas increase in frequency as gestation advances, suggesting different pathophysiology and evolving vulnerability of the fetal brain. Observational and management studies do not suggest that fetal deterioration has an independent impact on neurodevelopment in early-onset FGR. In late-onset FGR further research needs to establish benefits of perinatal intervention, as the pattern of vulnerability and effects of fetal deterioration appear to differ in the third trimester.

The uses and limitations of the fetal biophysical profile

In the second half of the twentieth century, true antepartum fetal assessment became possible, mainly due to the advent of real-time ultrasound. Initially, the most widely used form of antepartum fetal assessment was electronic fetal heart rate monitoring, through the nonstress test or the oxytocin-induced contraction stress test. It was soon realized, however, that these forms of monitoring had significant limitations. The biophysical profile allows a more thorough evaluation of fetal well-being and has the potential to significantly reduce the false-positive rate of the nonstress test/contraction stress test.

Identifying placental dysfunction in women with reduced fetal movements can be used to predict patients at increased risk of pregnancy complications

Maternal perception of fetal movements has historically been used to indicate fetal wellbeing, and has been used with varying success in recent years to identify those pregnancies at increased risk of stillbirth, and other placental pathologies. We present a hypothesis that links reduced fetal movements (RFM) to fetal growth restriction (FGR) and stillbirth through placental dysfunction, and suggests the possibility that this can allow development of a reliable method to identify those women experiencing RFM who are at increased risk of adverse outcome. Reduced fetal movement is thought to represent fetal compensation in a chronic hypoxic environment due to inadequacies in the placental supply of oxygen and nutrients. Placental analysis in FGR and in stillbirth has revealed a number of structural abnormalities and an imbalance in cell turnover, and in terms of function, FGR is also associated with reduced nutrient transport. Both FGR and stillbirth are linked to changes in maternal levels of placental hormones. However, no such studies have been performed in samples from pregnancies affected by RFM. Currently, there are no formal guidelines to direct the management of such women, although it is recommended they undergo measurement of symphysis-fundal height and cardiotocography, and possibly Doppler ultrasound and biophysical profiling. Novel tests could involve the measurement of placental-derived hormones in maternal serum. To address this hypothesis, macroscopic and microscopic analysis of placental samples from both normal pregnancies and those affected by RFM is needed to detect any changes in structure. Placental function could be evaluated by levels of placental hormones in maternal blood. If placental dysfunction can be linked to RFM, and a robust method of identifying those women with placental insufficiency can be developed; screening patients with RFM could lead to a reduction in perinatal morbidity and mortality.

Fetal growth restriction - from observation to intervention

Fetal growth restriction (FGR) due to placental dysfunction has important short- and long-term impacts that may reach into adulthood. Early-onset FGR before 34 weeks' gestation shows a characteristic sequence of responses to placental dysfunction that evolves from the arterial circulation to the venous system and finally to biophysical abnormalities. In this form of FGR safe prolongation of pregnancy is a primary management goal, as gestational age at delivery, birth weight and iatrogenic premature delivery have an important impact on short-term outcome and neurodevelopment. Surveillance intervals should be adjusted based on umbilical artery and venous Doppler studies. Intervention thresholds need to be based on the balance of fetal vs. neonatal risks and therefore critically depend on gestational age. Late-onset FGR presents with subtle Doppler and biophysical abnormalities and therefore poses a diagnostic dilemma. Often unrecognized, term FGR contributes to a large proportion of adverse perinatal outcome. Monitoring intervals should be adjusted based on middle cerebral artery Doppler and fetal heart rate parameters. Delivery timing thresholds can be low. In both forms of FGR neurodevelopmental impacts of placental disease occur before clinical decisions regarding delivery timing arise. This places special emphasis on future preventative studies.

Fetal growth restriction

Normal fetal growth is determined by the genetically predetermined growth potential and further modulated by maternal, fetal, placental, and external factors. Fetal growth restriction (FGR) is a failure to reach this potential and is clinically suspected if sonographic estimates of fetal weight, size, or symmetry are abnormal. Integration of fetal anatomy assessment, amniotic fluid dynamics, uterine, umbilical, and fetal middle cerebral artery Doppler is the most effective approach to differentiate potentially manageable placenta-based FGR from aneuploidy, nonaneuploid syndromes, and viral infection. Although placental dysfunction results in a multisystem fetal syndrome with impacts on short- and long-term outcome, only cardiovascular and behavioral responses are helpful to guide surveillance and intervention. Early-onset FGR before 34 weeks gestation is readily recognized but challenging to manage as questions about optimal delivery timing remain unanswered. In contrast, near-term FGR provides less of a management challenge but is often missed as clinical findings are more subtle. Once placenta-based FGR is diagnosed, integrating multivessel Doppler and biophysical profile score provides information on longitudinal progression of placental dysfunction and degree of fetal acidemia, respectively. Choosing appropriate monitoring intervals based on anticipated disease acceleration and intervention when fetal risks exceed neonatal risks are the prevailing current management approaches.

Integrated testing and management in fetal growth restriction

Growth-restricted fetuses are at higher risk for poor perinatal and long-term outcome than those who are appropriately grown. Multiple antenatal testing modalities can help document the sequence of fetal deterioration. The full extent of this compromise is best identified by a combination of fetal biometry, biophysical profile scoring, and arterial and venous Doppler. In the preterm growth-restricted fetus, timing of delivery is critically determined by the balance of fetal versus neonatal risks. In the near-term fetus, accurate diagnosis continues to be a challenge as unrecognized growth restriction contributes to a significant proportion of unexplained stillbirths. In this review, we present an integrated diagnostic and surveillance approach that accounts for these factors.

Doppler and biophysical assessment in growth restricted fetuses: distribution of test results

OBJECTIVE

Multi-vessel Doppler ultrasonography and biophysical profile scoring (BPS) are used in the surveillance of growth restricted fetuses (IUGR). The interpretation of both tests performed concurrently may be complex. This study examines the relationship between Doppler ultrasonography and biophysical test results in IUGR fetuses.

METHODS

Three hundred and twenty-eight IUGR fetuses (abdominal circumference < 5th percentile, elevated umbilical artery (UA) pulsatility index (PI)) had concurrent surveillance with UA, middle cerebral artery (MCA) and ductus venosus (DV) Doppler ultrasonography and BPS (fetal tone, movement, breathing, maximal amniotic fluid pocket and fetal heart rate). Patients were stratified into three groups according to their Doppler examination: (1) abnormal UA alone; (2) brain sparing (MCA-PI > 2 SD below mean for gestational age); and (3) abnormal DV (PI > 2 SD above the mean for gestational age) and BPS groups: (1) normal (> 6/10); (2) equivocal (6/10); and (3) abnormal (< 6/10). Predictions of short-term perinatal outcomes by both modalities were compared for stratification. The distribution and concordance of Doppler and BPS test results were examined for the whole patient group and based on delivery prior to 32 weeks' gestation.

RESULTS

Abnormal UA Doppler results alone were observed in 109 fetuses (33.2%), brain sparing in 87 (26.5%) and an abnormal DV in 132 (40.2%). The BPS was normal in 158 (48.2%), equivocal in 68 (20.7%) and abnormal in 102 (31.1%). Both testing modalities stratified patients into groups with comparable acid-base disturbance and perinatal outcome. Of the nine possible test combinations the largest subgroups were: abnormal UA alone/normal BPS (n = 69; 21%) and abnormal DV Doppler/abnormal BPS (n = 62; 18.9%). Assessment of compromise by both testing modalities was concordant in 146 (44.5%) cases. In 182 fetuses with discordant results the BPS grade was better in 115 (63.2%, P < 0.0001). Marked disagreement of test abnormality was present in 57 (17.4%) fetuses. Of these, abnormal venous Doppler in the presence of a normal BPS constituted the largest group (Chi-square P < 0.002). Stratification was not significantly different in patients delivered prior to 32 weeks' gestation.

CONCLUSION

Doppler ultrasonography and BPS effectively stratify IUGR fetuses into risk categories, but Doppler and BPS results do not show a consistent relationship with each other. Since fetal deterioration appears to be independently reflected in these two testing modalities further research is warranted to investigate how they are best combined.

Using fetal acoustic stimulation to shorten the biophysical profile

PURPOSE

To determine whether fetal acoustic stimulation can decrease the time required to achieve a reassuring biophysical profile.

METHODS

Patients scheduled for a biophysical profile were prospectively assigned to study and control groups. The study group received 3 seconds of acoustic stimulation if fetal breathing, tone, or movement were not present during the first 5 minutes of the study. The biophysical profile was completed in the standard fashion, for both groups.

RESULTS

A total of 870 patients were enrolled (458 control, 412 with stimulation). The fetal acoustic stimulation group had decreased testing time (3 minutes) and fewer non-reassuring tests (5%). The fetal acoustic stimulation group had fewer studies without breathing, potentially reducing the need for further testing or intervention.

CONCLUSIONS

Fetal acoustic stimulation can be used to decrease the biophysical profile testing time and to reduce the number of non-reassuring tests.

Middle cerebral artery Doppler indices at different sites: prediction of umbilical cord gases in prolonged pregnancies

OBJECTIVES

To assess the value of middle cerebral artery Doppler indices obtained from different sampling sites in predicting umbilical cord gases at delivery in prolonged pregnancies.

METHODS

This was a prospective study of consecutive pregnant women referred for prolonged-pregnancy surveillance. The predictive value of distal and proximal middle cerebral artery Doppler indices for cord blood gases was evaluated in women who delivered within 48 h of their last antenatal test using stepwise multiple regression.

RESULTS

There was a significant linear correlation between proximal and distal middle cerebral artery pulsatility indices (R = 0.777; P < 0.0001), the mean values being 1.49 (SD, 0.45) and 1.56 (SD, 0.47), respectively. There was also a linear correlation between proximal and distal cerebroplacental ratios (R = 0.68; P < 0.0001), the mean values being 1.85 (SD, 1.96) and 1.92 (SD, 1.89), respectively. The stepwise multiple regression analysis for umbilical artery pH showed that once the distal middle cerebral artery pulsatility index was introduced into the model, the addition of any variable did not result in a significant improvement of the predictive capacity. The model showed a coefficient of determination (R(2)) of 0.079. There was a significant correlation between umbilical artery pO(2) and both proximal middle cerebral artery pulsatility index (positive) and the occurrence of elective Cesarean section (negative). This model accounted for 21% of the variance (R(2) = 0.21). No other variables added any significant prediction for pO(2).

CONCLUSIONS

In post-term pregnancies the proximal middle cerebral artery pulsatility index significantly predicts umbilical artery pO(2) at delivery but does not predict pH. There is a weak association between distal middle cerebral artery pulsatility index and pH but, as this only explains 8% of the variance, it is of little clinical value.

Pathophysiology of Fetal Growth Restriction: Implications for Diagnosis and Surveillance

Normal fetal growth depends on the genetically predetermined growth potential and is modulated by fetal, placental, maternal, and external factors. Fetuses with intrauterine growth restriction (IUGR) are at high risk for poor short- and long-term outcome. Although there are many underlying etiologies, IUGR resulting from placental insufficiency is most relevant clinically because outcome could be altered by appropriate diagnosis and timely delivery. A diagnostic approach that aims to separate IUGR resulting from placental disease from constitutionally small fetuses and those with other underlying etiologies (e.g., aneuploidy, viral infection, nonaneuploid syndromes) needs to integrate multiple imaging modalities. In placental-based IUGR, cardiovascular and behavioral responses are interrelated with the disease severity. Ultrasound assessment of fetal anatomy, amniotic fluid volume, and growth is complementary to the Doppler investigation of fetoplacental blood flow dynamics. A diagnostic approach to IUGR combining these modalities is presented in this review.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to describe the development of the placental interface, to outline the mechanisms of placental insufficiency, and to list the manifestations of placental insufficiency and the tests that can be used to diagnose fetal growth restriction.

Fetal growth restriction due to placental disease

Normal fetal growth depends on the genetically predetermined growth potential and its modulation by the health of the fetus, placenta and the mother. Fetuses that are small because of intrauterine growth restriction (IUGR) are at higher risk for poor perinatal and long-term outcome than those who are appropriately grown. Of the many potential underlying processes that may result in IUGR, placental disease is clinically the most relevant. Fetal cardiovascular and behavioral responses to placental insufficiency and the metabolic status are interrelated. The concurrent evaluation of fetal biometry, amniotic fluid volume, heart rate patterns, arterial and venous Doppler, and biophysical variables therefore allow the most comprehensive fetal evaluation in IUGR. In the absence of successful intrauterine therapy, the timing of delivery is perhaps the most critical aspect of the antenatal management. A discussion of the fetal responses to placental insufficiency and a management protocol that accounts for multiple Doppler and biophysical parameters as well as gestational age is provided in this review.

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.

Fetal biophysical profile

This article begins with an outline of the theoretic basis of the fetal biophysical profile, the method for the biophysical profile score (BPS), and the timing and frequency of testing. The article further discusses the clinical management based on test scores; modified methods of the BPS; and clinical application, predictive accuracy, and impact on outcome of BPS. The authors specifically examine the relationship between BPS and cerebral palsy. They conclude with a discussion of adult sequelae and fetal adaptation to asphyxia.

Fetal death after normal biophysical profile score: An eighteen-year experience

OBJECTIVE

It was our goal to determine the false-negative rate of the biophysical profile, characterize an 18-year variation in the false-negative rate, examine the relationship between the last normal biophysical profile score and death, and compare the false-negative rate of 2 disparate populations.

STUDY DESIGN

Biophysical profile scores of 86,955 patients at 2 medical centers were collected and recorded prospectively. All perinatal deaths occurring within 1 week of a normal score were similarly recorded. The annual false-negative rate, the cumulative false-negative rate, and the ratio of false-negative results in cases of subsequent fetal death to the perinatal mortality rate were calculated.

RESULTS

There were 65 fetal deaths among 86,955 fetuses. Over an 18-year study period at one institution, the false-negative rate varied but not significantly. The cumulative false-negative rate was 0.708 per 1000 at one medical center studied and 2.289 per 1000 at the other center. The average interval between last normal score and fetal death was 3.62 days and did not vary significantly between the medical centers.

CONCLUSIONS

False-negative results in cases of subsequent fetal death reflect events that are subsequent to the last normal test result. Fetomaternal hemorrhage was the single most identifiable fetal cause of false-negative results in cases of subsequent fetal death. The ratio of the false-negative rate in cases of subsequent fetal death to the perinatal mortality rate should be used as a more objective approach to reporting this value, because the false-negative rate likely reflects the underlying perinatal mortality.

Intrapartum fetal hypoxia and biochemical markers: a review

Intrapartum fetal hypoxia is a rare event, although fetal intrapartum surveillance is discussed as a subject of major importance. This is mainly because of consequences of fetal hypoxia that may lead to cerebral palsy. A fetus suffering from hypoxia initially compensates by producing energy through anaerobic metabolism. At some stage, the fetus becomes decompensated and basic cellular functions fail, with risks of permanent morbidity or mortality. How long a fetus can survive on anaerobic metabolism differs because metabolic reserves differ, i.e., growth-restricted fetuses might deteriorate at an earlier stage. An increasing body of evidence has clarified brain-damaging mechanisms. Neuronal loss occurs in two phases: during the primary hypoxic event and later during the reperfusion/reoxygenation phase. Animal studies have suggested the possibility of prophylactic treatment to prevent neuronal loss after the hypoxic event. Intrapartum diagnostic tools should aim for detecting fetal hypoxemia/hypoxia when the fetus is still compensated. This may be achieved by assessment of biochemical data such as pH, lactate, and oxygen saturation, with the aim of prophylactic intervention before the fetus becomes decompensated. The measurement of cord blood levels of oxygen free radicals and excitatory amino acids at the time of birth may prove to be helpful in determining the risk of brain damage and evaluating the effect of prophylactic treatments to prevent or ameliorate brain injury from hypoxia.

Fetal assessment based on fetal biophysical profile scoring. VIII. The incidence of cerebral palsy in tested and untested perinates

OBJECTIVE

The intent of this comparative clinical study was fourfold: (1) to determine the incidence of cerebral palsy in a large obstetric population, (2) to compare the incidence of cerebral palsy in patients at high risk referred for and managed according to the fetal biophysical profile score result with the incidence among unreferred and untested patients, (3) to determine the relationship, if any, between the last fetal biophysical profile score and the incidence of cerebral palsy, and (4) to categorize cases of cerebral palsy according to the clinical parameters and the probable time and nature of the damaging insult.

STUDY DESIGN

In this retrospective 5-year comparative study (1987 to 1991) the incidence of cerebral palsy was determined by analysis of International Classification of Diseases, Ninth Revision, -coded related medical services. The clinical records were then sought and reviewed in index cases and obstetric, neonatal, and postnatal clinical data were abstracted. Cross-correlation with partial registries was done to confirm completeness of capture of index cases. The population of referred high-risk patients who received serial fetal biophysical profile scoring and were managed according to test results was determined by review of a prospective computer-stored database and by review of patient log books. The population of untested patients was calculated as the residual of total cases minus tested cases. The rate of cerebral palsy for all patients and for the tested and untested population was calculated and compared. The tested and untested perinates were compared for birth age, weight, and assigned timing or etiology of cerebral palsy. In the tested population the distribution of test results by last recorded biophysical profile score was determined and the relationship between the last test result and cerebral palsy and predictive accuracy parameters of the fetal biophysical profile score were calculated.

RESULTS

The incidence of cerebral palsy among the 84,947 live births was 3.68 per 1000 live births (313 cases). The rate of cerebral palsy in the 26,290 referred high-risk tested patients was 1.33 per 1000 (35 cases) compared with a rate of 4.74 per 1000 live births in the 58,657 untested mixed low-risk/high-risk patients (278 cases). These differences were highly significant. A significant declining trend in the annual incidence of cerebral palsy was observed in the total population and the untested population, whereas the rate in the tested population remained relatively constant over the 5-year study interval. The differences in the cerebral palsy rate between the tested and untested population were not related to differences in gestational age, birth weight, or assigned timing or etiology category. In the tested population the relationship between the incidence of cerebral palsy and the last test fetal biophysical profile score was inverse, exponential, and highly significant.

CONCLUSIONS

Antepartum assessment by fetal biophysical profile scoring is associated with a significant reduction in the incidence of cerebral palsy compared with untested patients. The relationship between the last test score and the incidence of cerebral palsy is inverse and exponential, suggesting that antenatal asphyxia is an important and potentially avoidable cause of cerebral palsy.

Biophysical testing in premature rupture of the membranes

The management of pregnancies complicated by premature rupture of the membranes (PROM) should include some type of surveillance for the development of infectious complications. This is a necessity because neonatal sepsis is not heralded by maternal chorioamnionitis in the majority of cases. Fetal biophysical assessment holds promise as a method to assess fetal well-being and predict the development of infectious complications. The frequent use of fetal biophysical profiles in patients with PROM helps to distinguish healthy fetuses from those infected or at high risk of infection. This distinction enables the physician to intervene appropriately and in a timely manner. The recognition of the healthy fetus allows for safe prolongation of pregnancy. This article reviews the published experience using antepartum fetal biophysical monitoring in patients with PROM.