Characteristics of preterm births during COVID-19 mitigation measures.

BACKGROUND: During the COVID-19 pandemic, mitigation measures were associated with a reduction in preterm birth rates; while not clearly proven, this observation has sparked significant interest. AIM: To understand the cause of this reduction by exploring the characteristics of preterm birth cohorts. MATERIAL AND METHODS: We performed a retrospective cohort study where we compared women who delivered preterm in three Melbourne maternity hospitals and conceived between November 2019 and February 2020 (mitigation measures-exposed cohort) to women who delivered preterm and conceived between November 2018 and February 2019 (non-exposed cohort). We compared maternal characteristics, pregnancy complications, antenatal interventions, intrapartum care, and indications for delivery. RESULTS: In the exposed cohort, 252/3129 women delivered preterm (8.1%), vs 298/3154 (9.4%) in the non-exposed cohort (odds ratio (OR) 0.84, 95% CI 0.70-1.00, P = 0.051). The baseline characteristic of two cohorts were comparable. Rates of spontaneous preterm labour (sPTL) without preterm pre-labour rupture of membranes (PPROM) were lower in the exposed cohort (13.1% vs 24.2%, OR 0.47, P = 0.001) while PPROM occurred more often (48.0% vs 35.6%, OR 1.67, P = 0.003). With a non-statistically significant prolongation of pregnancy in the cohort exposed to mitigation measures for both sPTL without PPROM (35.4 vs 34.9 weeks, P = 0.703) and PPROM (35.6 vs 34.9 weeks, P = 0.184). The rate of spontaneous labour after PPROM was higher in the exposed cohort compared to the non-exposed cohort (40.1% vs 24.1%, OR 2.09, P < 0.001). CONCLUSION: The reduction in preterm delivery during mitigation measures may have been driven by a reduction in spontaneous labour without PPROM, which seemed to result in more PPROM later in pregnancy.

The use of intrapartum ultrasound in operative vaginal birth: a retrospective cohort study.

BACKGROUND: Poor outcomes from operative vaginal birth have been associated with failure to recognize malposition, breakdown in interdisciplinary communication, and deviation from accepted guidelines. We recently implemented a safety bundle including routine intrapartum ultrasound and a structured time-out and procedural checklist aiming to reduce maternal and perinatal morbidity from operative vaginal birth. OBJECTIVE: This study aimed to compare births where intrapartum ultrasound was used and those where it was not used during a safety bundle implementation period at Monash Health. STUDY DESIGN: We performed a retrospective cohort study at Monash Health during the transitional phase of implementing an operative vaginal birth safety bundle. We studied all women with operative vaginal birth and fully dilated cesarean delivery with a singleton cephalic term fetus. We compared births for which intrapartum ultrasound was used and those for which it was not. The primary outcome was neonates delivered in an unexpected position. Neonatal and maternal morbidity were also assessed, including a neonatal composite of Apgar score <7 at 5 minutes, cord lactate >8 mmol/L, need for resuscitation, significant birth trauma, or neonatal intensive care unit admission. To control for confounding by indication, we estimated propensity scores for the probability of using intrapartum ultrasound for each case based on maternal and labor characteristics, and adjusted the effect estimates for the propensity scores using multivariable logistic regression models. RESULTS: From August 2022 to July 2023, there were 1205 operative vaginal births or fully dilated cesarean deliveries at Monash Health, including 743 (61.7%) forceps, 346 (28.7%) vacuum, and 116 (9.6%) fully dilated cesarean deliveries. Over this time, we observed increased uptake of intrapartum ultrasound from 26% in August 2022 to 60% (P<.001) in July 2023, of the time-out from 21% to 58% (P<.001), and the checklist from 33% to 80% (P<.001) of operative second-stage births. Among the births where intrapartum ultrasound was used (n=509), compared with those where it was not (n=696), there were significantly more forceps births (67% vs 58%; adjusted odds ratio, 1.35; 95% confidence interval, 1.05-1.74; P=.021) and a reduction in vacuum births (24% vs 32%; adjusted odds ratio, 0.77; 95% confidence interval, 0.58-1.01; P=.059). There were no significant differences in fully dilated cesarean delivery or maternal morbidity. Intrapartum ultrasound use was associated with significantly fewer infants being delivered in an unexpected position (0.2% vs 2.2%; adjusted odds ratio, 0.08; 95% confidence interval, 0.00-0.44; P=.019) and a significant reduction in composite neonatal morbidity (22% vs 25%; adjusted odds ratio, 0.73; 95% confidence interval, 0.54-0.97; P=.031). CONCLUSION: During the implementation of a safety bundle, the use of ultrasound before operative vaginal birth was associated with fewer infants delivered in an unexpected position and reduced neonatal morbidity.

Feasibility of a pregnancy intervention mimicking viral transmission mitigation measures on the incidence of preterm birth in high-risk pregnant women enrolled in antenatal clinics in Melbourne, Australia: protocol for a pilot, randomised trial.

INTRODUCTION: Preterm birth is a leading cause of perinatal morbidity and mortality. During the COVID-19 pandemic, reduction in rates of preterm birth in women exposed to viral mitigation measures was reported by multiple studies. In addition, others and we observed a more pronounced reduction of preterm birth in women who had previously experienced a preterm birth. The aim of this pilot study is to establish the feasibility of a lifestyle intervention based on viral mitigation measures in high-risk pregnancies, with the ultimate aim to reduce the incidence of preterm birth. METHODS AND ANALYSIS: One hundred pregnant women, enrolled in antenatal clinics at two tertiary maternity centres in Melbourne, Australia, who have had a previous preterm birth between 22 and 34 weeks gestation will be recruited. This is a two-arm, parallel group, open-label randomised controlled feasibility trial: 50 women will be randomised to the intervention group, where they will be requested to comply with a set of lifestyle changes (similar to the viral mitigation measures observed during the pandemic). Another 50 women will be randomised to the control group, where they will undergo standard pregnancy care. The primary outcome of this trial is feasibility, which will be assessed by measuring patient eligibility rate, recruitment rate, compliance rate and data completion rate. Secondary outcomes include incidence of preterm birth, maternal satisfaction, maternal quality of life and other pregnancy outcomes. Standard methods in statistical analysis for randomised controlled trials on an intention to treat basis will be followed. ETHICS AND DISSEMINATION: This trial has been approved by the Monash Human Research Ethics Committee; approval reference number RES-22-0000-122A. Study findings will be reported and submitted to peer-reviewed journals for publication, and presentation at conferences. TRIAL REGISTRATION NUMBER: ACTRN12622000753752; Pre-results.

Uterine artery doppler in screening for preeclampsia and fetal growth restriction / Doppler das artérias uterinas no rastreamento para pré-eclâmpsia e restrição do crescimento fetal

Abstract Objective To perform a comprehensive review of the current evidence on the role of uterine artery Doppler, isolated or in combination with other markers, in screening for preeclampsia (PE) and fetal growth restriction (FGR) in the general population. The review included recently published large cohort studies and randomized trials. Methods A search of the literature was conducted usingMedline, PubMed, MeSH and ScienceDirect. Combinations of the search terms "preeclampsia," "screening," "prediction," "Doppler," "Doppler velocimetry," "fetal growth restriction," "small for gestational age" and "uterine artery" were used. Articles in English (excluding reviews) reporting the use of uterine artery Doppler in screening for PE and FGR were included. Results Thirty articles were included. As a single predictor, uterine artery Doppler detects less than 50% of the cases of PE and no more than 40% of the pregnancies affected by FGR. Logistic regression-based models that allow calculation of individual risk based on the combination of multiple markers, in turn, is able to detect ~ 75% of the cases of preterm PE and 55% of the pregnancies resulting in small for gestational age infants. Conclusion The use of uterine artery Doppler as a single predictive test for PE and FGR has poor accuracy. However, its combined use in predictive models is promising, being more accurate in detecting preterm PE than FGR.

Resumo Objetivo Realizar revisão da literatura científica acerca do uso do Doppler das artérias uterinas, de forma isolada ou em combinação com outros marcadores, no rastreamento para pré-eclâmpsia (PE) e restrição do crescimento fetal (RCF) na população geral. A revisão incluiu estudos de coorte e ensaios clínicos randomizados recentemente publicados. Métodos Realizou-se uma pesquisa da literatura nas bases de dados Medline, PubMed, MeSH e ScienceDirect. Diferentes combinações dos termos "preeclampsia," "screening," "prediction," "Doppler," "Doppler velocimetry," "fetal growth restriction," "small for gestational age" e "uterine artery" foram utilizadas. Artigos eminglês, (excluindo-se artigos de revisão) em que o Doppler das artérias uterinas é reportado como ferramenta no rastreamento para PE e RCF foram incluídos. Resultados Trinta artigos foram incluídos. Como teste preditivo isolado, o Doppler das artérias uterinas tem sensibilidade inferior a 50% na detecção de casos de PE e inferior a 40% para identificação de gestações afetadas por RCF. Modelos matemáticos preditivos baseados em equações de regressão logística que permitem o cálculo de risco individual, por sua vez, são mais promissores, permitindo a detecção de 75% dos casos de PE pré-termo, e 55% das gestações que resultarão emparto de recém-nascidos pequenos para a idade gestacional. Conclusão O uso do Doppler das artérias uterinas tem baixa acurácia na identificação de gestações afetadas por PE e RCF. No entanto, seu uso combinado com outros marcadores é mais promissor, apresentando maior acurácia para detecção de PE do que para RCF.