An exploration of opinion and practice patterns affecting low use of antenatal corticosteroids☆

We investigated how the Antenatal Late Preterm Steroids (ALPS) trial findings have been translated into clinical practice in Canada and the United States (U.S.).

The study included all live births in Nova Scotia, Canada, and the U.S. from 2007 to 2020. Antenatal corticosteroids (ACS) administration within specific categories of gestational age was assessed by calculating rates per 100 live births, and temporal changes were quantified using odds ratio (OR) and 95% confidence intervals (CI). Temporal trends in optimal and suboptimal ACS use were also assessed.

In Nova Scotia, the rate of any ACS administration increased significantly among women delivering at 35⁰ to 36⁶ weeks, from 15.2% in 2007–2016 to 19.6% in 2017–2020 (OR 1.36, 95% CI 1.14–1.62). Overall, the U.S. rates were lower than the rates in Nova Scotia. In the U.S., rates of any ACS administration increased significantly across all gestational age categories: among live births at 35⁰ to 36⁶ weeks gestation, any ACS use increased from 4.1% in 2007–2016 to 18.5% in 2017–2020 (OR 5.33, 95% CI 5.28–5.38). Among infants between 24⁰ and 34⁶ weeks gestation in Nova Scotia, 32% received optimally timed ACS, while 47% received ACS with suboptimal timing. Of the women who received ACS in 2020, 34% in Canada and 20% in the U.S. delivered at ≥37 weeks.

Publication of the ALPS trial resulted in increased ACS administration at late preterm gestation in Nova Scotia, Canada, and the U.S. However, a significant fraction of women receiving ACS prophylaxis delivered at term gestation.

Les auteurs ont étudié la manière dont les résultats de l’essai Antenatal Late Preterm Steroids (ALPS) ont été transposés dans la pratique clinique au Canada et aux États-Unis (É.-U.).

L’étude portait sur toutes les naissances vivantes enregistrées en Nouvelle-Écosse, au Canada et aux États-Unis entre 2007 et 2020. L’administration d’une corticothérapie prénatale (CTP) dans des catégories précises d’âge gestationnel a été évaluée par le calcul du taux par 100 naissances vivantes, et les changements temporels ont été quantifiés au moyen du rapport de cotes (RC) et d’un intervalle de confiance (IC) à 95 %. L’étude a également évalué les tendances temporelles pour l’utilisation optimale et sous-optimale de la CTP.

En Nouvelle-Écosse, le taux d’administration de toute CTP a considérablement augmenté chez les femmes ayant accouché entre 35 semaines d’aménorrhée (SA) + 0 j et 36 SA + 6 j, passant de 15.2 % entre 2007 et 2016 à 19.6 % entre 2017 et 2020 (RC : 1.36; IC à 95 % : 1.14-1.62). En général, les taux étaient plus faibles aux États-Unis qu’en Nouvelle-Écosse. Aux États-Unis, le taux d’administration de toute CTP a considérablement augmenté dans toutes les catégories d’âge gestationnel. Dans le groupe de naissances vivantes entre 35 SA + 0 j et 36 SA + 6 j, l’utilisation de toute CTP a augmenté de 4.1 % entre 2007 et 2016 à 18.5 % dans la période de 2017 à 2020 (RC : 5.33; IC à 95 % : 5.28-5.38). Dans le groupe des naissances vivantes entre 24 SA + 0 j et 34 SA + 6 j en Nouvelle-Écosse, 32 % des patientes ont reçu une CTP au moment optimal, alors que 47 % ont reçu la CTP à un moment sous-optimal. Au final, 34 % (Canada) et 20 % (É.-U.) des femmes ayant reçu une CTP en 2020 ont accouché à 37 SA ou plus.

La publication de l’essai ALPS a entraîné une augmentation de l’administration d’une CTP en période de prématurité tardive en Nouvelle-Écosse, au Canada et aux États-Unis. Néanmoins, une proportion importante des femmes ayant reçu une CTP en prophylaxie ont accouché à terme.

Preterm birth is a leading cause of perinatal morbidity and mortality. Antenatal corticosteroid administration before preterm birth reduces the risks of perinatal death, respiratory morbidity, necrotizing enterocolitis, and intraventricular hemorrhage and reduces the costs of perinatal care. Antenatal corticosteroids are optimally effective when administered within 7 days before preterm birth. However, only 20% to 40% of early preterm infants receive antenatal corticosteroids within 7 days before birth, in part because it is difficult to predict the precise timing of preterm birth. Until 2020, The Joint Commission had a Perinatal Care quality metric measuring the rate of antenatal corticosteroid administration at any time before early preterm birth. This metric incentivized providers to use antenatal corticosteroids liberally. The Joint Commission retired the metric in 2020 after the rate reached more than 97% in The Joint Commission–accredited hospitals. However, the metric did not evaluate whether the timing of antenatal corticosteroid administration was optimal, that is, within 7 days of birth. A 2016 multistakeholder Cooperative Workshop recommended the development of a new quality metric to assess the rate of optimally timed antenatal corticosteroids among early preterm births. In this statement, we outline proposed specifications for such a metric and discuss potential uses, advantages, limitations, and barriers. Furthermore, we propose a balancing metric that tracks the percentage of patients treated with antenatal corticosteroids who ultimately give birth at term. We suggest that the use of these new metrics may incentivize more conservative antenatal corticosteroid timing, which could, in turn, lead to meaningfully improved outcomes for preterm neonates.

Administration of antenatal corticosteroids has been standard of care for women between 24 and 34 weeks of gestation who are at risk for preterm delivery for more than 20 years longer in other parts of the world. Although the benefit of steroids in this population has been confirmed, there remain many questions including the frequency of dosing and whether it is possible to expand the gestational age criteria to women likely to deliver before 24 weeks or after 34 weeks. The MFMU Network has played a major role in answering some of these questions.

To assess the impact of cervical length (CL) measurement and fetal fibronectin testing (fFN) on the clinicians’ decision to prescribe antenatal corticosteroids (ACS) to women with symptoms of preterm labor.

This is a secondary analysis of a prospective cohort study including women with symptoms of preterm labor and intact membranes between 24 and 34 weeks’ gestation. We compared the proportion prescribed and completed ACS courses, preterm delivery within seven days and median intervals from ACS to delivery in four groups: group 1 CL < 10 mm, group 2 CL 10–30 mm and positive fFN, group 3 CL 10–30 mm and negative fFN, group 4 CL > 30 mm.

ACS were prescribed to 63/65 (97%) women in group 1, 176/192 (91%) in group 2, 111/172 women (65%) in group 3 and 55/242 (23%) in group 4. In group 1, 42 (65%) women delivered within seven days, compared to 34 (18%) in group 2, 6 (3%) in group 3 and 3 (1%) in group 4. Median intervals between ACS and delivery were 6 days (IQR 3–61 days), 44 days (IQR 17–69 days), 53 days (IQR 37–77 days) and 66 days (IQR 43–78 days) in group 1, 2, 3 and 4 respectively.

ACS were prescribed frequently to women with a CL of 10–30 mm and a negative fFN test or a CL > 30 mm. There is room for improvement in the prescription of ACS in these low risk women.