Oxytocin challenge test and intrauterine growth retardation

Directive clinique no 442 : Retard de croissance intra-utérin : Dépistage, diagnostic et prise en charge en contexte de grossesse monofœtale

OBJECTIF

Le retard de croissance intra-utérin est une complication obstétricale fréquente qui touche jusqu'à 10 % des grossesses dans la population générale et qui est le plus souvent due à une pathologie placentaire sous-jacente. L'objectif de la présente directive clinique est de fournir des déclarations sommaires et des recommandations pour appuyer un protocole clinique de dépistage, diagnostic et prise en charge du retard de croissance intra-utérin pour les grossesses à risque ou atteintes.

POPULATION CIBLE

Toutes les patientes enceintes menant une grossesse monofœtale. BéNéFICES, RISQUES ET COûTS: La mise en application des recommandations de la présente directive devrait améliorer la compétence des cliniciens quant à la détection du retard de croissance intra-utérin et à la réalisation des interventions indiquées. DONNéES PROBANTES: La littérature publiée a été colligée par des recherches effectuées jusqu'en septembre 2022 dans les bases de données PubMed, Medline, CINAHL et Cochrane Library en utilisant un vocabulaire contrôlé au moyen de termes MeSH pertinents (fetal growth retardation and small for gestational age) et de mots-clés (fetal growth, restriction, growth retardation, IUGR, FGR, low birth weight, small for gestational age, Doppler, placenta, pathology). Seuls les résultats de revues systématiques, d'essais cliniques randomisés ou comparatifs et d'études observationnelles ont été retenus. La littérature grise a été obtenue par des recherches menées dans des sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, des registres d'essais cliniques et des sites Web de sociétés de spécialité médicale nationales et internationales. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations Assessment, Development and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Obstétriciens, médecins de famille, infirmières, sages-femmes, spécialistes en médecine fœto-maternelle, radiologistes et autres professionnels de la santé qui prodiguent des soins aux patientes enceintes. RéSUMé POUR TWITTER: Mise à jour de la directive sur le dépistage, le diagnostic et la prise en charge du retard de croissance intra-utérin pour les grossesses à risque ou atteintes. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS: Prédiction du retard de croissance intra-utérin Prévention du retard de croissance intra-utérin Détection du retard de croissance intra-utérin Examens en cas de retard de croissance intra-utérin soupçonné Prise en charge du retard de croissance intra-utérin précoce Prise en charge du retard de croissance intra-utérin tardif Prise en charge du post-partum et consultations préconception.

Guideline No. 442: Fetal Growth Restriction: Screening, Diagnosis, and Management in Singleton Pregnancies

OBJECTIVE

Fetal growth restriction is a common obstetrical complication that affects up to 10% of pregnancies in the general population and is most commonly due to underlying placental diseases. The purpose of this guideline is to provide summary statements and recommendations to support a clinical framework for effective screening, diagnosis, and management of pregnancies that are either at risk of or affected by fetal growth restriction.

TARGET POPULATION

All pregnant patients with a singleton pregnancy.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline should increase clinician competency to detect fetal growth restriction and provide appropriate interventions.

EVIDENCE

Published literature in English was retrieved through searches of PubMed or MEDLINE, CINAHL, and The Cochrane Library through to September 2022 using appropriate controlled vocabulary via MeSH terms (fetal growth retardation and small for gestational age) and key words (fetal growth, restriction, growth retardation, IUGR, FGR, low birth weight, small for gestational age, Doppler, placenta, pathology). Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Grey 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.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Table A1 for definitions and Table A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

Obstetricians, family physicians, nurses, midwives, maternal-fetal medicine specialists, radiologists, and other health care providers who care for pregnant patients.

TWEETABLE ABSTRACT

Updated guidelines on screening, diagnosis, and management of pregnancies at risk of or affected by FGR.

SUMMARY STATEMENTS

RECOMMENDATIONS: Prediction of FGR Prevention of FGR Detection of FGR Investigations in Pregnancies with Suspected Fetal Growth Restriction Management of Early-Onset Fetal Growth Restriction Management of Late-Onset FGR Postpartum management and preconception counselling.

Antenatal glucocorticoids, magnesium sulfate, and mode of birth in preterm fetal small for gestational age

A diagnosis of fetal growth restriction and subsequent preterm birth is associated with increased risks of adverse perinatal and neurodevelopmental outcomes and potentially long-lasting effects to adulthood. Most such cases are associated with placental insufficiency and the fetal response to chronic intrauterine hypoxemia and nutrient deprivation leads to substantial physiological and metabolic adaptations. The management of such pregnancies, especially with respect to perinatal interventions and birth mode, remains an unresolved dilemma. The benefits from standard interventions for threatened preterm birth may not be necessarily translated to pregnancies with small-for-gestational-age fetuses. Clinical trials or retrospective studies on outcomes following administration of antenatal glucocorticoids and magnesium sulfate for neuroprotection when preterm birth is imminent either have yielded conflicting results for small-for-gestational-age fetuses, or did not include this subgroup of patients. Experimental models highlight potential harmful effects of administration of antenatal glucocorticoids and magnesium sulfate in the pregnancies with fetal small for gestational age although clinical data do not substantiate these concerns. In addition, heterogeneity in definitions of fetal small for gestational age, variations in the inclusion criteria, and the glucocorticoid regime contribute to inconsistent results. In this review, we discuss the physiologic adaptions of the small-for-gestational-age fetus to its abnormal in utero environment in relation to antenatal glucocorticoids; the impact of antenatal glucocorticoids and intrapartum magnesium sulfate in pregnancies with fetal small for gestational age; the current literature on birth mode for pregnancies with fetal small for gestational age; and the knowledge gaps in the existing literature.

Outcome of induced deliveries in growth-restricted fetuses: second thoughts about the vaginal option

OBJECTIVE

To assess the outcome of induced deliveries with IUGR.

STUDY DESIGN

We reviewed the computerized files of parturients who underwent inducted labor because of IUGR (<5th percentile). Outcome assessment included mode of delivery, indication for CS, NICU admissions and 5 min Apgar score. We compared these parameters to a control group of women whose deliveries were induced for other indications.

RESULTS

A total of 836 women with IUGR were included. Mean gestational age and birth weight were 38.2 weeks and 2,114 g, respectively. Overall, 43% of women delivered by non-elective C/S. The rate of non-elective CS for other indications was 12.3% (P < 0.0001) for all deliveries and 23.6% (P < 0.001) for induced deliveries. CS was performed due to non-reassuring FHR in 63% of IUGR fetuses, compared with 27% of all induced deliveries. There were 160 women with IUGR who preferred elective CS. Their newborns' NICU admission and 5 min Apgar score <7 rates were lower than those for induced deliveries (NICU 43.1 and 29.4%, P < 0.05, 5 min Apgar <7 5 and 1%, P < 0.05).

CONCLUSION

Growth-restricted neonates born after labor induction had higher rates of low Apgar scores and NICU admissions compared to growth restricted neonates delivered by elective C/S. Inductions of labor for IUGR were associated with higher rates of non-elective C/S due to non-reassuring fetal heart rate compared with inductions performed for other indications.

Contraction stress test versus ductus venosus Doppler evaluation for the prediction of adverse perinatal outcome in growth-restricted fetuses with non-reassuring non-stress test

OBJECTIVE

To compare Doppler evaluation of the ductus venosus and contraction stress test (CST) in the prediction of adverse perinatal outcome in growth-restricted fetuses with evidence of hemodynamic redistribution and a non-reactive non-stress test (NST).

METHODS

Data were collected from all singleton pregnancies seen in our Fetal Surveillance Unit who underwent antenatal monitoring for fetal growth restriction, non-reactive NST and arterial redistribution beyond 26 weeks of pregnancy. Patients were divided into four groups based on their CST and ductus venosus waveform results. Perinatal outcome was evaluated by means of four variables: the need for admission to the neonatal intensive care unit (NICU), need for neonatal intubation, an umbilical artery pH < 7.10 and significant neonatal morbidity. Outcome was compared among fetuses delivered within 3 days of their antenatal test. Logistic regression analysis was used to analyze the relation between predictive and outcome variables.

RESULTS

Sixty-eight women met the inclusion criteria for the study. The positive predictive value of the CST was 45% for admission to the NICU, 13% for significant neonatal morbidity, 26% for need of neonatal intubation and 29% for umbilical artery pH < 7.10. The positive predictive values of abnormal ductus venosus waveform (ADVW) were 81.5%, 26%, 48% and 55%. Groups with ADVW showed significantly poorer neonatal outcome. No significant differences were observed when CST results were compared. Logistic regression analysis showed that both gestational age at delivery and ADVW significantly predict the occurrence of adverse perinatal outcome.

CONCLUSION

In growth-restricted fetuses with hemodynamic redistribution and a non-reassuring NST, Doppler assessment of the ductus venosus correlates with adverse perinatal outcome. In this clinical situation there is no benefit of CST in terms of prediction.

Nonstress testing and contraction stress testing

Antepartum fetal heart rate (FHR) testing, including the nonstress test and contraction stress test, has evolved in clinical usage over the past 3 decades. Although the nonstress test has become a standard of care in high-risk pregnancy, it has been modified by the use of fetal stimulation (vibroacoustic stimulation) and the addition of automated fetal movement recording (actocardiotocography). In all of its formats, antepartum FHR testing has been associated with reduction of preventable fetal loss. More recently, there have been attempts to improve test efficacy by computer-enhanced approaches.

Comparison of associated high-risk factors and perinatal outcome between symmetric and asymmetric fetal intrauterine growth retardation

This study compares associated high-risk factors and perinatal outcome between 273 symmetric and 445 asymmetric infants with intrauterine growth retardation. No differences were seen in 17 obstetric, medical, and environmental-behavioral high-risk factors between symmetric and asymmetric intrauterine growth retardation. In preeclampsia, the incidence of symmetric intrauterine growth retardation is higher than that of asymmetric intrauterine growth retardation. The timing of the interaction between the high-risk factor and the stage of gestation is more important than the specific high-risk factor in determining whether symmetric or asymmetric intrauterine growth retardation is produced. On comparison of perinatal outcome between the two groups, we concluded: (1) that the onset of symmetric intrauterine growth retardation occurs much earlier in the course of pregnancy than does asymmetric intrauterine growth retardation, (2) that more symmetric than asymmetric pregnancies with intrauterine growth retardation result in preterm delivery, (3) that the neonatal morbidity rate for symmetric intrauterine growth retardation is higher than that for asymmetric intrauterine growth retardation, and (4) that term symmetric infants with intrauterine growth retardation tend to have a lower mean birth weight and a higher incidence of small placentas than term infants with asymmetric intrauterine growth retardation.

Effects of maternal hyperoxia on the biophysical assessment of fetuses with suspected intrauterine growth retardation

Fifty-two third-trimester fetuses with suspected intrauterine growth retardation were studied by means of a computer-assisted biophysical assessment scheme, which used maternal hyperoxia as a diagnostic probe. Biophysical data examined included percentage of time spent in breathing, mean breath rate, and percentage of time spent in body movement during a 90-minute observation: 30-minute baseline, 15-minute hyperoxia, and 45-minute posthyperoxia. Mean baseline movement in fetuses found as neonates to have intrauterine growth retardation (N = 18) was significantly lower than that of normal fetuses (N = 34). Fetal body movements and breathing movements increased significantly after hyperoxia in the intrauterine growth retardation group but not in the normal group. Increases of more than 75% over baseline for fetal breathing and more than 250% over baseline for fetal body movements yielded a sensitivity of 56%, specificity of 94%, positive predicative value of 83%, and negative predicative value of 80%. Maternal hyperoxia during biophysical testing may improve the accuracy of detecting intrauterine growth retardation.