Symphysial fundal height (SFH) measurement in pregnancy for detecting abnormal fetal growth

Screening for fetal growth restriction and placental insufficiency

Fetal growth restriction (FGR) continues to be a leading cause of preventable stillbirth and poor neurodevelopmental outcomes in offspring, and furthermore is strongly associated with the obstetrical complications of iatrogenic preterm birth and pre-eclampsia. The terms small for gestational age (SGA) and FGR have, for too long, been considered equivalent and therefore used interchangeably. However, the delivery of improved clinical outcomes requires that clinicians effectively distinguish fetuses that are pathologically growth-restricted from those that are constitutively small. A greater understanding of the multifactorial pathogenesis of both early- and late-onset FGR, especially the role of underlying placental pathologies, may offer insight into targeted treatment strategies that preserve placental function. The new maternal blood biomarker placenta growth factor offers much potential in this context. This review highlights new approaches to effective screening for FGR based on a comprehensive review of: etiology, diagnosis, antenatal surveillance and management. Recent advances in novel imaging methods provide the basis for stepwise multi-parametric testing that may deliver cost-effective screening within existing antenatal care systems.

Regimens of fetal surveillance of suspected large-for-gestational-age fetuses for improving health outcomes

BACKGROUND

Policies and protocols vary widely for fetal surveillance in a pregnancy where the fetus is suspected to be large-for-gestational-age (LGA). All ultimately culminate in decisions about the mode and timing of birth. LGA is known to be associated with increased risks to both the mother and baby. Interventions based on surveillance regimen findings may be associated with risks to the mother and baby.

OBJECTIVES

To assess the effectiveness or efficacy of different antenatal surveillance methods for the suspected LGA fetus on important health outcomes for the mother and baby.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 August 2015), ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (21 August 2015).

SELECTION CRITERIA

Published and unpublished randomised, quasi-randomised and cluster-randomised trials comparing the effects of described antenatal fetal surveillance regimens for women with suspected LGA infants.

DATA COLLECTION AND ANALYSIS

We identified no studies that met the inclusion criteria for this review.

MAIN RESULTS

There are no included trials.

AUTHORS' CONCLUSIONS

We found no randomised controlled trials that assessed the effect of antenatal fetal surveillance regimens of a suspected LGA fetus on important health outcomes for the mother and baby.There has been a rise in the prevalence of LGA babies over the past few decades in many countries. Research is therefore required on regimens of antenatal surveillance of suspected LGA infants, in order to guide practice and improve the health outcomes for the mother and infant. In particular, randomised control trials to investigate whether serial antenatal clinic and ultrasound assessments of suspected LGA infants (including liquor volume and markers of fetal adiposity) would be useful, to assess whether surveillance methods improve health outcomes. In addition, as there are concerns that identifying suspected LGA fetuses may lead to unnecessary maternal anxiety, investigations and interventions, any such trial would need to assess the risks as well as benefits of regimens of fetal surveillance for suspected LGA fetuses.

Does the Presence of Risk Factors for Fetal Growth Restriction Increase the Probability of Antenatal Detection? A French National Study

BACKGROUND

Screening for fetal growth restriction (FGR) is a major component of prenatal care. We investigated whether the presence of maternal and pregnancy risk factors for FGR improves the antenatal suspicion of FGR for infants born small-for-gestational age (SGA) as well as their impact on screening specificity.

METHODS

Data are from a representative sample of births from the 2010 French National Perinatal Survey (n = 14 100). Detection of FGR was determined by a suspicion of FGR noted in medical charts. Analyses were performed for singleton infants with birthweight under the 10th percentile (SGA), under the 3rd percentile (severely SGA), and above the 10th percentile (false positives) of French references. We studied risk factors for FGR (medical and obstetric conditions, advanced maternal age, nulliparity, body mass index and smoking) using multivariable Poisson regression to derive adjusted risk ratios (aRR).

RESULTS

Of SGA infants, 21.7% were suspected of FGR. The presence of obstetric and medical risk factors for FGR was associated with higher suspicion among SGA infants [RR 2.1, 95% confidence interval (CI) 1.7, 2.7]. However, despite the presence of these factors, 60% and 40% of SGA and severely SGA infants, respectively, were not suspected of FGR. Two per cent of normal birthweight infants were suspected of FGR, increasing to 5% when obstetric and medical risk factors were present. Smoking and older maternal age were unrelated to suspicion while females were more likely to be suspected of FGR.

CONCLUSION

Our results suggest that better risk assessment could improve antenatal identification of FGR. Sex-specific fetal growth references should be used to avoid systematic bias linked to sex.

Symphysial fundal height (SFH) measurement in pregnancy for detecting abnormal fetal growth

BACKGROUND

Symphysis fundal height (SFH) measurement is commonly practiced primarily to detect fetal intrauterine growth restriction (IUGR). Undiagnosed IUGR may lead to fetal death as well as increase perinatal mortality and morbidity.

OBJECTIVES

The objective of this review is to compare SFH measurement with serial ultrasound measurement of fetal parameters or clinical palpation to detect abnormal fetal growth (IUGR and large-for-gestational age), and improving perinatal outcome.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (14 July 2015) and reference lists of retrieved articles.

SELECTION CRITERIA

Randomised controlled trials including quasi-randomised and cluster-randomised trials involving pregnant women with singleton fetuses at 20 weeks' gestation and above comparing tape measurement of SFH with serial ultrasound measurement of fetal parameters or clinical palpation using anatomical landmarks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

One trial involving 1639 women was included. It compared SFH measurement with clinical abdominal palpation.There was no difference in the two reported primary outcomes of incidence of small-for-gestational age (risk ratio (RR) 1.32; 95% confidence interval (CI) 0.92 to 1.90, low quality evidence) or perinatal death.(RR 1.25, 95% CI 0.38 to 4.07; participants = 1639, low quality evidence). There were no data on the neonatal detection of large-for-gestational age (variously defined by authors). There was no difference in the reported secondary outcomes of neonatal hypoglycaemia, admission to neonatal nursery, admission to the neonatal nursery for IUGR (low quality evidence), induction of labour and caesarean section (very low quality evidence). The trial did not address the other outcomes specified in the 'Summary of findings' table (intrauterine death; neurodevelopmental outcome in childhood). GRADEpro software was used to assess the quality of evidence, downgrading of evidence was based on including a small single study with unclear risk of bias and a wide confidence interval crossing the line of no effect.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine whether SFH measurement is effective in detecting IUGR. We cannot therefore recommended any change of current practice. Further trials are needed.

Diagnostic accuracy of fundal height and handheld ultrasound-measured abdominal circumference to screen for fetal growth abnormalities

OBJECTIVE

We sought to compare fundal height and handheld ultrasound-measured fetal abdominal circumference (HHAC) for the prediction of fetal growth restriction (FGR) or large for gestational age.

STUDY DESIGN

This was a diagnostic accuracy study in nonanomalous singleton pregnancies between 24 and 40 weeks' gestation. Patients underwent HHAC and fundal height measurement prior to formal growth ultrasound. FGR was defined as estimated fetal weight less than 10%, whereas large for gestational age was defined as estimated fetal weight greater than 90%. Sensitivity and specificity were calculated and compared using methods described elsewhere.

RESULTS

There were 251 patients included in this study. HHAC had superior sensitivity and specificity for the detection of FGR (sensitivity, 100% vs 42.86%) and (specificity, 92.62% vs 85.24%). HHAC had higher specificity but lower sensitivity when screening for LGA (specificity, 85.66% vs 66.39%) and (sensitivity, 57.14% vs 71.43%).

CONCLUSION

HHAC could prove to be a valuable screening tool in the detection of FGR. Further studies are needed in a larger population.

Causes of perinatal mortality and associated maternal complications in a South African province: challenges in predicting poor outcomes

Background

Reviews of perinatal deaths are mostly facility based. Given the number of women who, globally, deliver outside of facilities, this data may be biased against total population data. We aimed to analyse population based perinatal mortality data from a LMIC setting (Mpumalanga, South Africa) to determine the causes of perinatal death and the rate of maternal complications in the setting of a perinatal death.

Methods

A secondary analysis of the South African Perinatal Problems Identification Program (PPIP) database for the Province of Mpumalanga was undertaken for the period October 2013 to January 2014, inclusive. Data on each individual late perinatal death was reviewed. We examined the frequencies of maternal and fetal or neonatal characteristics in late fetal deaths and analysed the relationships between maternal condition and fetal and/or neonatal outcomes. IBM SPSS Statistics 22.0 was used for data analysis.

Results

There were 23503 births and 687 late perinatal deaths (stillbirths of ≥ 1000gr or ≥ 28 weeks gestation and early neonatal deaths up to day 7 of neonatal life) in the study period. The rate of maternal complication in macerated stillbirths, fresh stillbirths and early neonatal deaths was 50.4%, 50.7% and 25.8% respectively. Mothers in the other late perinatal deaths were healthy. Maternal hypertension and obstetric haemorrhage were more likely in stillbirths (p = <0.01 for both conditions), whereas ENNDs were more likely to have a healthy mother (p < 0.01). The main causes of neonatal death were related to immaturity (48.7%) and hypoxia (40.6%). 173 (25.2%) of all late perinatal deaths had a birth weight less than the 10^th centile for gestational age.

Conclusion

A significant proportion of women have no recognisable obstetric or medical condition at the time of a late perinatal death; we may be limited in our ability to predict poor perinatal outcome if emphasis is put on detecting maternal complications prior to a perinatal death. Intrapartum care and hypertensive disease remain high priority areas for addressing perinatal mortality. Consideration needs to be given to novel ways of detecting growth restriction in a LMIC setting.

Symphysis-fundus height measurement to predict small-for-gestational-age status at birth: a systematic review

BACKGROUND

Fetal growth restriction is among the most common and complex problems in modern obstetrics. Symphysis-fundus (SF) height measurement is a non-invasive test that may help determine which women are at risk. This study is a systematic review of the literature on the accuracy of SF height measurement for the prediction of small-for-gestational-age (SGA) status at birth in unselected and low-risk pregnancies.

METHODS

The Medline, Embase, Cinahl, SweMed, and Cochrane Library databases were searched with no limitation on publication date (through September 2014), which returned 722 citations. Two reviewers then developed a short list of 51 publications of possible relevance and assessed them using the following inclusion criteria: cohort study of test accuracy performed in a routine prenatal care setting; SF height measurement for all participants; classification of SGA, defined as birth weight (BW) < 10th, 5th, or 3rd percentile or ≥ one or two standard deviations below the mean; study conducted in Northern, Western, or Central Europe; USA; Canada; Australia; or New Zealand; and sufficient data for 2 × 2 table construction. Quality of the included studies was assessed in duplicate using criteria suggested by the Cochrane Collaboration. Review Manager 5.3 software was used to analyze the data, including plotting of summary receiver operating curve spaces.

RESULTS

Eight studies were included in the final dataset and seven were included in summary analyses. The sensitivity of SF height measurement for SGA (BW < 10(th) percentile) prediction ranged from 0.27 to 0.76 and specificity ranged from 0.79 to 0.92. Positive and negative likelihood ratios ranged from 1.91 to 9.09 and from 0.29 to 0.83, respectively.

CONCLUSIONS

SF height can serve as a clinical indicator along with other clinical findings, information about medical conditions, and previous obstetric history. However, SF height has high false-negative rates for SGA. Clinicians must understand the limitations of this test. The protocol has been registered in the international prospective register of systematic reviews, PROSPERO (Registration No. CRD42014008928, http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42014008928 ).

[Fetus, small for gestational age]

A small for gestational age foetus is defined by the foetal weight below the 10th centile for the corresponding gestational age. However, the vast majority of these cases has no apparent underlying abnormality, while in other cases a serious causative pathological condition can be identified. The detection, follow-up and treatment of an intrauterine growth retarded, compromised foetus has great obstetric and neonatologic relevance. In this review, the causes, clinical aspects and screening methods of intrauterine growth retardation are summarized based on the most recent international guidelines. Furthermore, recommendations regarding the monitoring and the optimal timing of the labour induction of pregnancies complicated with intrauterine growth retardation are discussed.

Maternal KIR in combination with paternal HLA-C2 regulate human birth weight

Human birth weight is subject to stabilizing selection; babies born too small or too large are less likely to survive. Particular combinations of maternal/fetal immune system genes are associated with pregnancies where the babies are ≤ 5th birth weight centile, specifically an inhibitory maternal KIR AA genotype with a paternally derived fetal HLA-C2 ligand. We have now analyzed maternal KIR and fetal HLA-C combinations at the opposite end of the birth weight spectrum. Mother/baby pairs (n = 1316) were genotyped for maternal KIR as well as fetal and maternal HLA-C. Presence of a maternal-activating KIR2DS1 gene was associated with increased birth weight in linear or logistic regression analyses of all pregnancies >5th centile (p = 0.005, n = 1316). Effect of KIR2DS1 was most significant in pregnancies where its ligand, HLA-C2, was paternally but not maternally inherited by a fetus (p = 0.005, odds ratio = 2.65). Thus, maternal KIR are more frequently inhibitory with small babies but activating with big babies. At both extremes of birth weight, the KIR associations occur when their HLA-C2 ligand is paternally inherited by a fetus. We conclude that the two polymorphic immune gene systems, KIR and HLA-C, contribute to successful reproduction by maintaining birth weight between two extremes with a clear role for paternal HLA.

Fundal height growth curve for underweight and overweight and obese pregnant women in Thai population

Objectives. To develop fundal height growth curves for underweight and overweight and obese pregnant women based on gestational age from last menstrual period and/or ultrasound. Methods. A retrospective study was conducted at four hospitals in the northern part of Thailand between January 2009 and March 2011. Fundal height, gestational age, height, and prepregnancy weight were extracted from antenatal care and delivery records. Fundal height growth curves were presented as smoothed function of the 10th, 50th, and 90th percentiles between 20 and 40 weeks of gestation, derived from multilevel models. Results. Fundal height growth curve of the underweight was derived from 1,486 measurements (208 women) and the overweight and obese curve was derived from 1,281 measurements (169 women). The 50th percentile line of the underweight was 0.1-0.4 cm below the normal weight at weeks 23-31 and 0.5-0.8 cm at weeks 32-40. The overweight and obese line was 0.1-0.4 cm above the normal weight at weeks 22-29 and 0.6-0.8 cm at weeks 30-40. Conclusions. Fundal height growth curves of the underweight and overweight and obese pregnant women were different from the normal weight. In monitoring or screening for abnormal intrauterine growth in these women, fundal height growth curves specifically developed for such women should be applied.

Intrauterine growth restriction: screening, diagnosis, and management

BACKGROUND

Intrauterine growth restriction (IUGR) is an obstetrical complication, which by definition would screen in 10% of fetuses in the general population. The challenge is to identify the subset of pregnancies affected with pathological growth restriction in order to allow intervention that would decrease morbidity and mortality.

OBJECTIVE

The purpose of this guideline is to provide summary statements and recommendations and to establish a framework for screening, diagnosis, and management of pregnancies affected with IUGR.

METHODS

Affected pregnancies are compared with pregnancies in which the fetus is at an appropriate weight for its gestational age. History, physical examination, and laboratory investigations including biochemical markers and ultrasound characteristics of IUGR are reviewed, and a management strategy is suggested.

EVIDENCE

Published literature in English was retrieved through searches of PubMed or MEDLINE, CINAHL, and The Cochrane Library in January 2013 using appropriate controlled vocabulary via MeSH terms (fetal growth restriction and small for gestational age) and key words (fetal growth, restriction, growth retardation, IUGR, low birth weight, small for gestational age). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table).

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline should increase clinician recognition of IUGR and guide intervention where appropriate. Optimal long-term follow-up of neonates diagnosed as IUGR may improve their long-term health.

Fundal height growth curve for thai women

Objectives. To develop fundal height (FH) growth curve from normal singleton pregnancy based on last menstrual period (LMP) and/or ultrasound dating for women in the northern part of Thailand. Methods. A retrospective time-series study was conducted at four hospitals in the upper northern part of Thailand between January 2009 and March 2011. FH from 20 to 40 weeks was measured in centimeters. The FH growth curve was presented as smoothed function of the 10th, 50th, and 90th percentiles, which were derived from a regression model fitted by a multilevel model for continuous data. Results. FH growth curve was derived from 7,523 measurements of 1,038 women. Gestational age was calculated from LMP in 648 women and ultrasound in 390 women. The FH increased from 19.1 cm at 20 weeks to 35.4 cm at 40 weeks. The maximum increase of 1.0 cm/wk was observed between 20 and 32 weeks, declining to 0.7 cm/wk between 33 and 36 weeks and 0.3 cm/wk between 37 and 40 weeks. A quadratic regression equation was FH (cm) = -19.7882 + 2.438157 GA (wk) - 0.0262178 GA(2) (wk) (R-squared = 0.85). Conclusions. A demographically specific FH growth curve may be an appropriate tool for monitoring and screening abnormal intrauterine growth.