Practice variation in timing of antenatal corticosteroid administration in early-onset fetal growth restriction: A secondary analysis of the Dutch STRIDER study

INTRODUCTION

In early-onset fetal growth restriction the fetus fails to thrive in utero due to unmet fetal metabolic demands. This condition is linked to perinatal mortality and severe neonatal morbidity. Maternal administration of corticosteroids in high-risk pregnancies for preterm birth at a gestational age between 24 and 34 weeks has been shown to reduce perinatal mortality and morbidity. Practice variation exists in the timing of the administration of corticosteroids based on umbilical artery monitoring findings in early-onset fetal growth restriction. The aim of this study was to examine differences in neonatal outcomes when comparing different corticosteroid timing strategies.

MATERIAL AND METHODS

This was a post-hoc analysis of the Dutch STRIDER trial. We examined neonatal outcomes when comparing institutional strategies of early (umbilical artery pulsatility index >95th centile) and late (umbilical artery shows absent or reversed end-diastolic flow) administration of corticosteroids. The primary outcomes were neonatal mortality and a composite of neonatal mortality and neonatal morbidity, defined as bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis or retinopathy of prematurity. We also analyzed predictors for adverse neonatal outcomes, including gestational age at delivery, birthweight, maternal hypertensive disorders, and time interval between corticosteroids and birth.

RESULTS

A total of 120 patients matched our inclusion criteria. In 69 (57.5%) the early strategy was applied and in 51 (42.5%) patients the late strategy. Median gestational age at delivery was 28 4/7 (± 3, 3/7) weeks. Median birthweight was 708 (± 304) g. Composite primary outcome was found in 57 (47.5%) neonates. No significant differences were observed in the primary outcome between the two strategies (neonatal mortality adjusted odds ratio [OR] 1.22, 95% CI 0.44-3.38; composite primary outcome adjusted OR 1.05, 95% CI 0.42-2.64). Only gestational age at delivery was a significant predictor for improved neonatal outcome (adjusted OR 0.91, 95% CI 0.86-0.96).

CONCLUSIONS

No significant differences in neonatal outcomes were observed when comparing early and late strategy of antenatal corticosteroid administration on neonatal outcomes in pregnancies complicated by early-onset fetal growth restriction. We found no apparent risk contribution of interval between corticosteroid administration and delivery in multivariate analysis. Gestational age at delivery was found to be an important predictor of neonatal outcome.

The Safe Use of 125I-Seeds as a Localization Technique in Breast Cancer during Pregnancy

INTRODUCTION

Some aspects of the treatment protocol for breast cancer during pregnancy (PrBC) have not been thoroughly studied. This study provides clarity regarding the safety of the use of ¹²⁵I-seeds as a localization technique for breast-conserving surgery in patients with PrBC.

METHODS

To calculate the exposure to the fetus of one ¹²⁵I-seed implanted in a breast tumor, we developed a model accounting for the decaying ¹²⁵I-source, time to surgery, and the declining distance between the ¹²⁵I-seed and the fetus. The primary outcome was the maximum cumulative fetal dose of radiation at consecutive gestational ages (GA).

RESULTS

The cumulative fetal dose remains below 1 mSv if a single ¹²⁵I-seed is implanted at a GA of 26 weeks. After a GA of 26 weeks, the fetal dose can be at a maximum of 11.6 mSv. If surgery takes place within two weeks of implantation from a GA of 26 weeks, and one week above a GA of 32 weeks, the dose remains below 1 mSv.

CONCLUSION

The use of ¹²⁵I-seeds is safe in PrBC. The maximum fetal exposure remains well below the threshold of 100 mSv, and therefore, does not lead to an increased risk of fetal tissue damage. Still, we propose keeping the fetal dose as low as possible, preferably below 1 mSv.

OPtimal TIming of antenatal COrticosteroid administration in pregnancies complicated by early-onset fetal growth REstriction (OPTICORE): study protocol of a multicentre, retrospective cohort study

INTRODUCTION

Early-onset fetal growth restriction (FGR) requires timely, often preterm, delivery to prevent fetal hypoxia causing stillbirth or neurologic impairment. Antenatal corticosteroids (CCS) administration reduces neonatal morbidity and mortality following preterm birth, most effectively when administered within 1 week preceding delivery. Optimal timing of CCS administration is challenging in early-onset FGR, as the exact onset and course of fetal hypoxia are unpredictable. International guidelines do not provide a directive on this topic. In the Netherlands, two timing strategies are commonly practiced: administration of CCS when the umbilical artery shows (A) a pulsatility index above the 95th^h centile and (B) absent or reversed end-diastolic velocity (a more progressed disease state). This study aims to (1) use practice variation to compare CCS timing strategies in early-onset FGR on fetal and neonatal outcomes and (2) develop a dynamic tool to predict the time interval in days until delivery, as a novel timing strategy for antenatal CCS in early-onset FGR.

METHODS AND ANALYSIS

A multicentre, retrospective cohort study will be performed including pregnancies complicated by early-onset FGR in six tertiary hospitals in the Netherlands in the period between 2012 and 2021 (estimated sample size n=1800). Main exclusion criteria are multiple pregnancies and fetal congenital or genetic abnormalities. Routinely collected data will be extracted from medical charts. Primary outcome for the comparison of the two CCS timing strategies is a composite of perinatal, neonatal and in-hospital mortality. Secondary outcomes include the COSGROVE core outcome set for FGR. A multivariable, mixed-effects model will be used to compare timing strategies on study outcomes. Primary outcome for the dynamic prediction tool is 'days until birth'.

ETHICS AND DISSEMINATION

The need for ethical approval was waived by the Ethics Committee (University Medical Center Utrecht). Results will be published in open-access, peer-reviewed journals and disseminated by presentations at scientific conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT05606497.