Routine third-trimester ultrasound in low-risk pregnancies and perinatal death: a systematic review and meta-analysis

Long-term neurological outcomes of offspring misdiagnosed with fetal growth restriction

OBJECTIVE

Fetal growth restriction (FGR) is a major determinant of adverse short- and long-term perinatal outcomes. The current definition of FGR (estimated fetal weight measurement < 10th percentile) may lead, at times, to a false diagnosis of fetuses that are eventually born appropriate for gestational age (AGA). Our objective was to investigate the potential association between a misdiagnosis of antepartum fetal growth restriction and long-term neurological outcomes in offspring.

STUDY DESIGN

A population-based cohort analysis was performed including deliveries between the years 1991-2020 in a tertiary medical center. We compared neurological hospitalization during childhood among AGA infants falsely diagnosed as FGR versus AGA infants without a false FGR diagnosis. A Kaplan-Meier survival curve was used to assess cumulative morbidity and a Cox proportional hazards model was employed to control for confounders.

RESULTS

During the study period, 324,620 AGA infants met the inclusion criteria; 3249 of them were falsely classified as FGR. These offspring had higher rates of hospitalizations due to various neurological conditions, as compared to those without an FGR diagnosis (OR 1.431, 95% CI 1.278-1.608; P < 0.001). In addition, cumulative hospitalization incidence was elevated in the FGR group (log-rank P-value < 0.001). When controlling for confounders, a false FGR diagnosis remained independently associated with long-term neurological morbidities (adjusted HR 1.086, 95% CI 1.003-1.177, P = 0.043).

CONCLUSION

Misdiagnosis of FGR in the antepartum period is associated with an increased risk for offspring long-term neurological morbidities.

Routine third-trimester ultrasound assessment for intrauterine growth restriction

Intrauterine growth restriction significantly impacts perinatal outcomes. Undetected IUGR escalates the risk of adverse outcomes. Serial symphysis-fundal height measurement, a recommended strategy, is insufficient in detecting abnormal fetal growth. Routine third-trimester ultrasounds significantly improve detection rates compared with this approach, but direct high-quality evidence supporting enhanced perinatal outcomes from routine scanning is lacking. In assessing fetal growth, abdominal circumference alone performs comparably to estimated fetal weight. Hadlock formulas demonstrate accurate fetal weight estimation across diverse gestational ages and settings. When choosing growth charts, prescriptive standards (encompassing healthy pregnancies) should be prioritized over descriptive ones. Customized fetal standards may enhance antenatal IUGR detection, but conclusive high-quality evidence is elusive. Emerging observational data suggest that longitudinal fetal growth assessment could predict adverse outcomes better. However, direct randomized trial evidence supporting this remains insufficient.

Ultrasound imaging and the culture of pregnancy management in low-and middle-income countries: A systematic review

BACKGROUND

Obstetric ultrasound imaging is a relatively new, but rapidly expanding, technology in low- and middle-income countries (LMICs). Given that new technologies modify practices, the influence of ultrasound on pregnancy management in LMICs is not comprehensively understood.

OBJECTIVES

To map how ultrasound technology may be modulating the culture of pregnancy management in LMICs.

SEARCH STRATEGY

A search of five databases up to November 18, 2022.

SELECTION CRITERIA

Original, peer-reviewed articles from LMICs, published in English from 2000 to 2022.

DATA COLLECTION AND ANALYSIS

All articles were assessed for quality using the GRADE approach. Data were analyzed thematically to generate new interpretive constructs and explanations.

RESULTS

Forty articles involving 113 000 respondents suggests that obstetric ultrasound is becoming the preferred method of pregnancy surveillance, replacing clinically important components of prenatal care. Mothers overestimate ultrasound as an all-powerful diagnostic and "therapeutic" tool that can deliver the perfect baby. For-profit providers are driving medically unnecessary scans while the poor do not receive the recommended scans.

CONCLUSION

Ultrasound technology has modified the culture of pregnancy management in LMICs in unintended and possibly harmful ways. Private health services are pushing the detrimental trends. Limitations include generalizability of qualitative studies and insufficient attention to inequities.

The impact of a universal late third-trimester scan for fetal growth restriction on perinatal outcomes in term singleton births: A prospective cohort study

OBJECTIVE

To investigate perinatal mortality, morbidity and obstetric intervention following the introduction of a universal late third-trimester ultrasound scan for growth restriction.

DESIGN

Prospective cohort study.

SETTING

Oxfordshire (OUH), UK.

POPULATION

Women with a non-anomalous singleton pregnancy undergoing pregnancy care and term delivery at OUH with an estimated due date (EDD) of birth between 1 January 2014 and 30 September 2019.

METHODS

Universal ultrasound for fetal growth restriction between 35⁺⁰ and 36⁺⁶ weeks was introduced in 2016. The outcomes of the next 18 631 eligible term pregnancies were compared, adjusting for covariates and time, with the previous 18 636 who had clinically indicated ultrasounds only. 'Screen-positives' for growth restriction were managed according to a pre-determined protocol which included non-intervention for some small-for-gestational-age babies.

MAIN OUTCOME MEASURES

Extended perinatal mortality, a composite of mortality or encephalopathy Grade II-III, and expedited birth. Other outcomes included composite adverse outcomes used elsewhere, detection of low birthweight and birth from 37⁺⁰ to 38⁺⁶ weeks.

RESULTS

Extended perinatal deaths decreased 27% and severe morbidity decreased 33% but neither change was statistically significant (adjusted odd ratio [aOR] 0.53, 95% confidence interval [C1] 00.18-1.56 and aOR 0.71, 95% CI 0.31-1.63). Expedited births changed from 35.2% to 37.7% (aOR 0.99, 95% CI 0.92-1.06). Birthweight (<10th centile) detection using fetal biometry alone was 31.4% and rose to 40.5% if all abnormal scan parameters were used.

CONCLUSION

Improvements in mortality and severe morbidity subsequent to introducing a universal ultrasound for growth restriction are encouraging but remain unclear. Little change in intervention is possible. The antenatal detection of low birthweight remains poor but improves where markers of growth restriction are used.

Late pregnancy ultrasound parameters identifying fetuses at risk of adverse perinatal outcomes: a protocol for a systematic review of systematic reviews

INTRODUCTION

Stillbirths and neonatal deaths are leading contributors to the global burden of disease and pregnancy ultrasound has the potential to help decrease this burden. In the absence of high-Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence on universal obstetric ultrasound screening at or close to term, many different screening strategies have been proposed. Systematic reviews have rapidly increased over the past decade owing to the diverse nature of ultrasound parameters and the wide range of possible adverse perinatal outcomes. This systematic review will summarise the evidence on key ultrasound parameters in the published literature to help develop an obstetric ultrasound protocol that identifies pregnancies at risk of adverse perinatal outcomes at or close to term.

METHODS

This study will follow the recent Cochrane guidelines for a systematic review of systematic reviews. A comprehensive literature search will be conducted using Embase (OvidSP), Medline (OvidSP), CDSR, CINAHL (EBSCOhost) and Scopus. Systematic reviews evaluating at least one ultrasound parameter in late pregnancy to detect pregnancies at risk of adverse perinatal outcomes will be included. Two independent reviewers will screen, assess the quality including the risk of bias using the ROBIS tool, and extract data from eligible systematic reviews that meet the study inclusion criteria. Overlapping data will be assessed and managed with decision rules, and study evidence including the GRADE assessment of the certainty of results will be presented as a narrative synthesis as described in the Cochrane guidelines for an overview of reviews.

ETHICS AND DISSEMINATION

This research uses publicly available published data; thus, an ethics committee review is not required. The findings will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42021266108.

Routine Third Trimester Sonogram: Friend or Foe

Several risk factors for adverse pregnancy outcomes can be identified by a routine third trimester ultrasound scan. However, there is also potential for harm, anxiety, and additional health care costs through unnecessary intervention due to false positive results. The evidence base informing the balance of risks and benefits of universal screening is inadequate to fully inform decision making. However, data on the diagnostic effectiveness of universal ultrasound suggest that better methods are required to result in net benefit, with the exception of screening for presentation near term, where a clinical and economic case can be made for its implementation.