Screening and management of the small for gestational age fetus in the UK: A survey of practice

Clinical utility of maternal TORCH screening in fetal growth restriction: A retrospective two-centre study

OBJECTIVE

The aim of this study was to evaluate the indications for maternal TORCH (Toxoplasma gondii, rubella, cytomegalovirus (CMV), and herpes simplex virus (HSV)) serology, with a focus on the yield in isolated fetal growth restriction (FGR).

MATERIALS AND METHODS

A retrospective review of antenatal TORCH testing between January 2014 and December 2018 was carried out at two hospitals in Melbourne, Australia. TORCH testing ordered for pregnancy losses and stillbirth was excluded.

RESULTS

Medical records of 718 pregnancies were reviewed, representing 760 fetuses. Isolated FGR was the indication for TORCH screening in 71.2% of pregnancies. Screens ordered for isolated FGR were positive in 7.4% (95% CI 5.5-10.0%). There were 49 positive maternal immunoglobulin M (CMV = 34, Toxoplasma = 15). Two acute maternal infections during pregnancy were diagnosed (CMV = 1, Toxoplasma = 1), with both screens ordered to assess symptomatic maternal illness. There was one neonatal CMV infection, born to a woman with symptomatic primary CMV. No maternal or neonatal rubella or HSV infections were identified. We found a diagnostic yield of TORCH screening for isolated FGR of 0.0% (95% CI 0.00-0.8%). An estimated AUD$64 269.75 was expended on maternal TORCH screens in this study.

CONCLUSION

Maternal TORCH testing for isolated FGR is of no diagnostic yield and should be abandoned.

Preventing Stillbirth: A Review of Screening and Prevention Strategies

Stillbirth is a devastating pregnancy complication that still affects many women, particularly from low and middle-income countries. It is often labeled as "unexplained" and therefore unpreventable, despite the knowledge that placental dysfunction has been identified as a leading cause of antepartum stillbirth. Currently, screening for pregnancies at high-risk for placental dysfunction relies on checklists of maternal risk factors and serial measurement of symphyseal-fundal height to identify small for gestational age fetuses. More recently, the first-trimester combined screening algorithm developed by the Fetal Medicine Foundation has emerged as a better tool to predict and prevent early-onset placental dysfunction and its main outcomes of preterm preeclampsia, fetal growth restriction and stillbirth by the appropriate use of Aspirin therapy, serial growth scans and induction of labour from 40 weeks for women identified at high-risk by such screening. There is currently no equivalent to predict and prevent late-onset placental dysfunction, although algorithms combining an ultrasound-based estimation of fetal weight, assessment of maternal and fetal Doppler indices, and maternal serum biomarkers show promise as emerging new screening tools to optimize pregnancy monitoring and timing of delivery to prevent stillbirth. In this review we discuss the strategies to predict and prevent stillbirths based on first-trimester screening as well as fetal growth and wellbeing assessment in the second and third trimesters.

Sonographic growth curves versus neonatal birthweight growth curves for the identification of fetal growth restriction

OBJECTIVE

Fetal growth restriction is suspected when the estimated fetal weight is <10th percentile for gestational age. Using a regional sonographic estimated fetal weight growth curve to diagnose fetal growth restriction has no known benefits; however, the traditional approach of using birthweight curves is misleading, since a large proportion of preterm births arise from pathological pregnancies. Our aim was to compare the diagnostic accuracies of sonographic versus birthweight curves in diagnosing fetal growth restriction. Our secondary aim was to compare maternal, fetal and neonatal outcome based on these two approaches.

METHODS

Retrospective study based on computerized medical records. Included were women with a singleton pregnancy, that underwent fetal biometry between 24 and 36.6 weeks' gestation (January 2010-February 2016) and delivered in our center. Each pregnancy was assigned to one of three groups based on the earliest sonographic estimated fetal weight performed: G1-Appropriate for gestational age, G2-fetal growth restriction based on sonographic but not birthweight curves; or G3-fetal growth restriction based on birthweight growth curves. Demographics, obstetric characteristics, ultrasound data, and neonatal data were retrieved and compared between groups. Primary outcome: rate of small for gestational age neonates in each group. Secondary outcomes were various adverse maternal and neonatal outcomes.

RESULTS

Six thousand and five pregnancies met inclusion criteria. Of these 5386 (89.6%) were categorized as G1, 300 (5%) as G2 and 319 (5.3%) as G3. The rate of small for gestational age neonates differed significantly between groups: G1 9.2%, G2 39.7% and G3 70%. Multivariable logistic regression modeling reiterated these rates: the odds ratios for small for gestational age were 6.47 [95% CI 4.99-8.40] and 23.99 [95% CI 18.26-31.51] for G2 and G3 respectively. Prediction of small for gestational age based on sonographic EFW curves increased the sensitivity for detection of SGA from 26% to 41% with a slight decrease in specificity from 98% to 95%, and a decrease of the positive likelihood ratio from 18.4 to 7.7, however there was no significant change in the overall test accurcy; 88.5% to 87.1%. Secondary outcomes also differed between groups: G2 and G3 had similar rates of maternal and neonatal morbidities and most parameters were higher than G1. G2 and G3 showed lower mean gestational age at delivery (36.2 weeks and 35.9 weeks vs.37.8; p < .0001), and higher rates of preterm delivery (40% and 51.7% vs. 21.5%; p < .001), as well as higher rates of intrauterine fetal demise 3% in G2, 6.9% in G3 and 0.9% in G1, p < .0001.

CONCLUSION

Pregnancies that are currently managed as appropriate for gestational age based on birthweight curves, but classified as growth restricted when prenatal sonographic curves are used, are associated with higher rates of small for gestational age and poor perinatal outcomes, at rates comparable to pregnancies that are classified as growth restricted based on birthweight curves. Furthermore, applying sonographic curves increases the sensitivity for detection of small for gestational age neonates. Consequently, consideration should be given to the use of sonographic biometry curves for defining fetal growth restriction.

The PLANES study: a protocol for a randomised controlled feasibility study of the placental growth factor (PlGF) blood test-informed care versus standard care alone for women with a small for gestational age fetus at or after 32 + 0 weeks' gestation

Background

Stillbirth remains a major concern across the globe and in some high-resource countries, such as the UK; efforts to reduce the rate have achieved only modest reductions. One third of stillborn babies are small for gestational age (SGA), and these pregnancies are also at risk of neonatal adverse outcomes and lifelong health problems, especially when delivered preterm. Current UK clinical guidance advocates regular monitoring and early term delivery of the SGA fetus; however, the most appropriate regimen for surveillance of these babies remains unclear and often leads to increased intervention for a large number of these women. This pilot trial will determine the feasibility of a large-scale trial refining the risk of adverse pregnancy outcome in SGA pregnancies using biomarkers of placental function sFlt-1/PlGF, identifying and intervening in only those deemed at highest risk of stillbirth.

Methods

PLANES is a randomised controlled feasibility study of women with an SGA fetus that will be conducted at two tertiary care hospitals in the UK. Once identified on ultrasound, women will be randomised into two groups in a 3:1 ratio in favour of sFlt-1/PlGF ratio led management vs standard care. Women with an SGA fetus and a normal sFlt-1/PlGF ratio will have a repeat ultrasound and sFlt-1/PlGF ratio every 2 weeks with planned birth delayed until 40 weeks. In those women with an SGA fetus and an abnormal sFlt-1/PlGF ratio, we will offer birth from 37 weeks or sooner if there are other concerning features on ultrasound. Women assigned to standard care will have an sFlt-1/PlGF ratio taken, but the results will be concealed from the clinical team, and the woman’s pregnancy will be managed as per the local NHS hospital policy. This integrated mixed method study will also involve a health economic analysis and a perspective work package exploring trial feasibility through interviews and questionnaires with participants, their partners, and clinicians.

Discussion

Our aim is to determine feasibility through the assessment of our ability to recruit and retain participants to the study. Results from this pilot study will inform the design of a future large randomised controlled trial that will be adequately powered for adverse pregnancy outcome. Such a study would provide the evidence needed to guide future management of the SGA fetus.

Trial registration

ISRCTN58254381. Registered on 4 July 2019

Antenatal management of multiple pregnancies within the UK: A survey of practice

OBJECTIVES

To identify variation in the antenatal management of multiple pregnancy. The UK has 10,000 twin pregnancies per year. There is established guidance on the management of dichorionic (DC) and monochorionic (MC) twin pregnancy from both the RCOG and NICE, however it is likely that the provision and practice of multiple pregnancy management varies amongst units.

DESIGN

Questionnaires were posted to 151 UK maternity units in 3 rounds from May to November 2019.

RESULTS

60 responses were received (range 11,500 to 501 deliveries), with annual multiple pregnancy rates of 190 to 4. 25 % of units did not offer a dedicated twin clinic and less than 15 % of units provided dedicated multiple pregnancy midwifery staff for intrapartum and postnatal care. Cervical length screening was performed in 24 % of units with 84 % of units offering treatment for a short cervix. 15 % of units prescribed Aspirin to all multiples, 47 % prescribing 75 mg and 43 % 150 mg. Monitoring of MC pregnancies varied with 18 % of units not measuring Middle Cerebral Artery and 29 % Ductus Venosus Dopplers. Mean caesarean section rate was 61.7 %. Delivery was offered from 37 weeks in 93 % of DC twins and from 36 weeks in 90 % MC twins. 5% of MC twins were given non labouring prophylactic antenatal steroids.

CONCLUSION

Despite well-established national guidance for twin pregnancy management there remains a wide variation in practice among units in the provision and antenatal management of multiple pregnancies throughout the UK. The exact reasons for this variation require further exploration.

Stillbirth at term: Does size really matter?

Placental dysfunction has a deleterious influence on fetal size and is associated with higher rates of perinatal morbidity and mortality. This association underpins the strategy of fetal size evaluation as a mechanism to identify placental dysfunction and prevent stillbirth. The optimal method of routine detection of small for gestational age (SGA) remains to be clarified with choices between estimation of symphyseal-fundal height versus routine third-trimester ultrasound, various formulae for fetal weight estimation by ultrasound, and the variable use of national, customized, or international fetal growth references. In addition to these controversies, the strategy for detecting SGA is further undermined by data demonstrating that the relationship between fetal size and adverse outcome weakens significantly with advancing gestation such that near term, the majority of stillbirths and adverse perinatal outcomes occur in normally sized fetuses. The use of maternal serum biochemical and Doppler parameters near term appears to be superior to fetal size in the identification of fetuses compromised by placental dysfunction and at increased risk of damage or demise. Multiparameter models and predictive algorithms using maternal risk factors, and biochemical and Doppler parameters have been developed, but need to be prospectively validated to demonstrate their effectiveness.

Antenatal detection of fetal growth restriction and risk of stillbirth: population-based case-control study

OBJECTIVES

Antenatal surveillance of intrauterine growth aims to detect growth-restricted fetuses (FGR), which face increased risk of stillbirth. Improving their detection could be an effective strategy for prevention of stillbirth. The French REPERE study was conducted to estimate the association between antenatal detection of FGR and risk of stillbirth.

METHODS

REPERE is a case-control study performed in three French districts with a combined total of approximately 30 000 births annually. Cases were singleton small-for-gestational-age (SGA) stillbirths ≥ 24 weeks' gestation and without severe congenital anomaly, between 2012 and 2014, identified using a population-based stillbirth registry; controls were live births fulfilling the same inclusion criteria over a 9-week period from 7 April to 8 June 2014. Data were extracted by trained investigators from medical records and ultrasound reports. SGA was defined as birth weight < 10^th percentile of French customized standards. FGR was defined by the presence of at least one of seven predefined parameters (suspected FGR mentioned in medical records or in ultrasound report, suspected faltering growth mentioned in an ultrasound report, documented abdominal circumference or estimated fetal weight < 10^th percentile, referral for additional ultrasound examination to monitor growth or abnormal umbilical artery Doppler). We used logistic regression to estimate crude and adjusted odds ratios (ORs) for the association between detection of FGR and risk of stillbirth. Included covariables were parity, maternal medical history, vascular complications during pregnancy and birth-weight percentile, which are known to be associated with risk of detection of FGR and of stillbirth.

RESULTS

During the study period, there were 92 182 births ≥ 22 weeks' gestation, including 669 stillbirths, of which 79 were singleton SGA stillbirths ≥ 24 weeks and without severe congenital anomaly. Of these cases, 44.3% (35/79) had FGR detected, compared with a detection rate of 36.2% in controls (154/426). The crude OR expressing the association between detection of FGR and risk of stillbirth was 1.4 (95% CI, 0.9-2.3) and the OR adjusted for parity, presence of risk factors for FGR, presence of vascular disorder and birth-weight percentile was 0.6 (95% CI, 0.3-1.0). Among deliveries ≥ 28 weeks, detection rates were 38.3% vs 36.0% for cases and controls, with an adjusted OR of 0.5 (95% CI, 0.2-1.0).

CONCLUSION

Antenatal detection of FGR was protective against stillbirth, but over 40% of stillbirths among SGA fetuses occurred despite detection of FGR, pointing to the need to improve management following detection. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Misoprostol vaginal insert (Mysodelle) versus Dinoprostone intravaginal gel (Prostin) for induction of labour

OBJECTIVE

The aim of this study is the compare the effectiveness and safety of Misoprostol Vaginal Insert (Mysodelle) versus Dinoprostone intravaginal gel (Prostin) for induction of labour.

STUDY DESIGN

We performed a prospective cohort study of the use of misoprostol vaginal inserts (Mysodelle) in the induction of pregnancy and compared it to a historical cohort of women induced with the Dinoprostone intravaginal gel (Prostin) at the Liverpool Women's Hospital, a large UK teaching hospital.

RESULTS

A total of 4102 women were induced between December 2016 and September 2018 of whom 2540 were induced with dinoprostone gel until September 2017. Since October 2017 1562 were induced using misoprostol vaginal inserts (MVI). The MVI demonstrated a significantly quicker median time to delivery compared with dinoprostone gel (18.2 h versus 21.8 h; p < 0.0001). There was a 32% reduced risk of Caesarean section with MVI (7.5% vs 10.9%; RR 0.62 95%CI 0.56-0.84) There was no significant difference in any of the key maternal or neonatal adverse outcomes.

CONCLUSIONS

The results of this study suggest that misoprostol vaginal inserts, compared with dinoprostone intravaginal gel, achieve quicker delivery times, and a reduction in caesarean sections with no increased rate of adverse maternal or neonatal outcomes.