key: cord-0866997-rf743esc
authors: Roberts, Nicole F.; Sprague, Ann E.; Taljaard, Monica; Fell, Deshayne B.; Ray, Joel G.
title: Maternal-Newborn Health System Changes and Outcomes in Ontario Canada during Wave 1 of the COVID-19 Pandemic – A Retrospective Study
date: 2021-12-29
journal: J Obstet Gynaecol Can
DOI: 10.1016/j.jogc.2021.12.006
sha: b96ef09c6cc9ae1d6f3d34452e98e6dc976584cd
doc_id: 866997
cord_uid: rf743esc

OBJECTIVE: To determine the population-level impact of COVID-19 pandemic–related obstetric practice changes on maternal and newborn outcomes. METHODS: Segmented regression analysis examined changes that occurred 240 weeks pre-pandemic through the first 32 weeks of the pandemic using data from Ontario’s Better Outcomes Registry & Network. Outcomes included birth location, length of stay, labour analgesia, mode of delivery, preterm birth, and stillbirth. Immediate and gradual effects were modelled with terms representing changes in intercepts and slopes, corresponding to the start of the pandemic. RESULTS: There were 799 893 eligible pregnant individuals included in the analysis; 705 767 delivered in the pre-pandemic period and 94,126 during the pandemic wave 1 period. Significant immediate decreases were observed for hospital births (relative risk [RR] 0.99; 95% CI 0.98–0.99), length of stay (median change –3.29 h; 95% CI –3.81 to –2.77), use of nitrous oxide (RR 0.11; 95% CI 0.09–0.13) and general anesthesia (RR 0.69; 95% CI 0.58– 0.81), and trial of labour after cesarean (RR 0.89; 95% CI 0.83–0.96). Conversely, there were significant immediate increases in home births (RR 1.35; 95% CI 1.21–1.51), and use of epidural (RR 1.02; 95% CI 1.01–1.04) and regional anesthesia (RR 1.01; 95% CI 1.01–1.02). There were no significant immediate changes for any other outcomes, including preterm birth (RR 0.99; 95% CI 0.93–1.05) and stillbirth (RR 1.11; 95% CI 0.87–1.42). CONCLUSION: Provincial health system changes implemented at the start of the pandemic resulted in immediate clinical practice changes but no significant increases in adverse outcomes.

Objectif: Déterminer les effets des changements dans la pratique de l'obstétrique apportés par la pandémie de COVID-19 sur les issues maternelles et néonatales dans la population obstétricale.

Méthodologie : Une analyse de régression segmentée a été effectuée pour connaître les changements qui ont eu lieu pendant les 240 semaines avant la pandémie jusqu'à 32 semaines après le début de la pandémie au moyen des données du Registre et réseau des bons résultats dès la naissance de l'Ontario. Les critères de jugement étaient le lieu de naissance, la durée du séjour, l'analgésie pendant le travail, le mode d'accouchement, l'accouchement prématuré et la mortinaissance. Les effets immédiats et graduels, correspondants au début de la pandémie, ont été modélisés au moyen de termes qui représentaient des changements dans les points d'intersection et les courbes. As SARS-COV-2 testing was not universally used in hospitals, preventive measures for care around birth included restriction of hospital visitors, changes to induction and emergency vaginal and cesarean delivery protocols, reduced options for trial of labour after cesarean (TOLAC), changes in anesthesia/analgesia, practice changes around breastfeeding and other newborn care, and time spent in hospital following birth. These changes were informed by the limited evidence available that that time: early case reports from China, 1,2 Italy 3 and Spain, 4 previous experience with respiratory viral outbreaks such as H1N1 influenza 5 and SARS, 6 as well as early expert clinical opinions from the Society of Obstetricians and Gynaecologists of Canada (SOGC) 7 and other professional organizations. There was some evidence from international studies about possible increases in rates of cesarean birth, preterm birth, and potential fetal growth issues, 2, 8 but robust evidence on which to guide practice was lacking. While it was expected from the H1N1 and SARS pandemics that respiratory function could be compromised in pregnant women 9 , it wasn't until the fall of 2020 and into 2021 that stronger evidence emerged showing that pregnant people infected with SARS-CoV-2 were at higher risk of hospitalization and intensive care unit (ICU) admission compared with non-pregnant infected individuals. 10 While provincial and national-level guidance on practice changes for maternal-newborn care during the COVID-19 pandemic was being developed and finalized, 11, 12 hospitals and regions J o u r n a l P r e -p r o o f immediately responded by implementing local guidelines, which varied across Canada.

Contemporaneously, the media was reporting hesitancy of individuals to seek routine or urgent care, 13 which led to concerns about possible unintended consequences of these changes in care delivery. We carried out this study to examine the impact of the early COVID-19 pandemic time period on obstetric practices and pregnancy and birth outcomes at a provincial level in Ontario.

We focused on clinical practices and maternal-newborn outcomes that we hypothesized could be most impacted by the acute 'shock' on the health system and care-seeking behaviour, and also evaluated corresponding rates of preterm birth and stillbirth.

We conducted an interrupted time series (ITS) analysis using a province-wide birth registry to examine changes in outcomes from the pre-pandemic baseline period (March 1, 2015-February 29, 2020) through wave 1 of the COVID-19 pandemic (March 1, 2020-October 31, 2020; hereafter referred to as COVID-19 Wave 1) in Ontario, Canada. An ITS study is a robust quasiexperimental approach that can be used to evaluate immediate and gradual impacts of interventions/exposures when random allocation is not possible. 14 Although the World Health Organization declared the pandemic on March 11, 2020, we chose March 1, 2020 as the start of the COVID-19 Wave 1 period because clinical practice was already changing in care settings and the SARS-CoV-2 virus was circulating in Ontario. 15 Since public health measures for the COVID-19 pandemic were implemented almost simultaneously across Ontario, the ITS was an ideal approach for evaluating the impact of the pandemic at a population level, while accounting J o u r n a l P r e -p r o o f for any ongoing secular trends in obstetric care practices and maternal-newborn outcomes in the five years predating the pandemic. 14 The study included records of all pregnancies in Ontario resulting in a live birth or stillbirth delivery at ≥20 weeks of gestation. Pregnant individuals choose their healthcare providers (family physicians, obstetricians or midwives), and care is publicly funded by the provincial health insurance plan. Ontario has approximately 140,000 births per year, which represents around 40% of all births in Canada. 16 

Since 2012, Better Outcomes Registry & Network (BORN) Ontario has collected pregnancy, birth, and newborn information from all of Ontario's hospitals and midwifery practice groups for the purposes of facilitating and improving maternal-newborn care. 16 Data are collected in near real-time either by point-of-care manual data entry into a secure portal, direct feeds from hospital systems, or by automated extraction and batch uploads from electronic health record systems. A robust linking and matching algorithm ensures data sources are appropriately aggregated to individual records. The routine data collected include socio-demographic information, health behaviours, prenatal screening, pregnancy interventions and complications, intrapartum events, peripartum outcomes, intensive care, and newborn screening information. Data quality assessments have concluded that these data are highly reliable. 17, 18 Outcomes J o u r n a l P r e -p r o o f Detailed definitions of all study outcomes are provided in Table S1. We examined system level, clinical practices and birth outcomes that we anticipated might be affected by changes in maternal-newborn care delivery, and for which we had reliable data.

We described the study population using frequency distributions, and computed cumulative incidence rates of all outcomes, stratified by the two time periods: pre-pandemic and COVID-19

Robust statistical analysis of ITS data requires between 40 and 50 intervals, or a minimum of at least 12 pre-and post-intervention/exposure intervals. To avoid instability of interval estimates, denominator sizes of at least 50-100 per interval are preferred. 19 We used weekly intervals, providing 240 intervals in the pre-pandemic and 32 in COVID-19 Wave 1 time periods. Data were aggregated to a provincial level and binary outcomes were expressed as weekly percentages, while the continuous outcome (length of stay) was expressed as the median value for each week. We generated descriptive time-series plots of temporal patterns in study outcomes across the full time period to visually inspect the temporal trends.

The provincially aggregated numerator/denominator data were analyzed using segmented logistic regression. The model included terms for continuous time (week interval), a binary variable indicating whether the time interval was before or after the start of COVID-19 Wave 1 on March 1, 2020, and continuous time post-onset of COVID-19 Wave 1 (number of weeks after pandemic onset). Additionally, due to regular seasonal fluctuations found in many perinatal J o u r n a l P r e -p r o o f outcomes, we included a categorical term for month. 20 The distribution was binomial and log or identity link functions were used to produce estimates as relative risk (RR) or risk difference (RD). Each model was estimated using restricted pseudo-likelihood accounting for first-order autoregression. The findings were expressed as immediate and gradual effects (intercept and slope changes, respectively), together with 95% confidence intervals (CI).Visual inspection of residual plots against time was used to assess goodness of fit. To improve the model fit for length of stay and nitrous oxide, the first three weekly intervals in the pandemic period were censored from the analysis. Due to the low rate of missing data, records with missing data on the outcome variables were excluded for the specified outcome.

All analyses were conducted using SAS Version 9.4 (Cary, NC) and the study was reported according to STROBE guidance. 21 We additionally followed guidance by Ramsay et al. 22 Figure S1 presents the study flow diagram. The distributions of characteristics of the population were similar during the pre-pandemic period and COVID-19

Wave 1, although on average, pregnant individuals in COVID-19 Wave 1 period were slightly J o u r n a l P r e -p r o o f older, had a higher prevalence of overweight/obesity and comorbidities, and a higher percentage started prenatal care in the first trimester ( Table 1) .

The denominator sizes in each weekly interval varied by outcome, ranging from 58 records in the smallest week interval (VBAC) to 3,520 records in the largest week interval (preterm birth and stillbirth). The prevalence of missing data ranged from 0% to 6.4%, depending on the outcome. Figure S2 depicts timeseries plots for all other outcomes. Cumulative incidence rates and denominators for each outcome, stratified by the two time periods, are provided in Table 2 and corresponding relative risks and risk differences from segmented regression analyses are provided in Table 3 and Table   S2 . Overall, statistically significant decreases (immediate effects) were observed for rates of hospital birth (RR 0.99, 95% CI 0.98 to 0.99), length of stay for mother-infant dyads discharged together (median difference -3.29 hours, 95% CI -3.81 to -2.77), nitrous oxide use (RR 0.11, 95% CI 0.09 to 0.13), general anesthesia (RR 0.69, 95% CI 0.58 to 0.81), and TOLAC (RR 0.89, 95% CI 0.83 to 0.96). Conversely, statistically significant immediate increases were found in rates of home birth (RR 1.35, 95% CI 1.21 to 1.51), epidural use (RR 1.02, 95% CI 1.01 to 1.04), and regional anesthesia (RR 1.01, 95% CI 1.01 to 1.02). There were no statistically significant immediate changes for any adverse perinatal outcomes including NICU admission (RR 1.01, J o u r n a l P r e -p r o o f 95% CI 0.97 to 1.05), preterm birth (RR 0.99, 95% CI 0.93 to 1.05), stillbirth (RR 1.11, 95% CI 0.87 to 1.42) and 5-minute Apgar <4 or Arterial cord blood pH <7.0 (RR 1.09, 95% CI 0.93 to 1.27). Risk differences showed similar patterns. There was virtually no change in the rate of general anesthesia use per week prior to the pandemic (RD 0.0002%, 95% CI -0.002 to 0.002); after the start of the pandemic there was an absolute immediate decrease of 1.57% (95% CI -2.23 to -0.91), followed by a gradual return to baseline (0.022%, 95% CI (-0.011 to 0.055) per week.

There were no statistically significant immediate or gradual effects of COVID-19 Wave 1 on labour induction, opioids for labour analgesia, VBAC, cesarean birth, medically-indicated preterm birth or spontaneous preterm birth.

This study examined population-level effects of COVID-19 Wave 1 on obstetric practices and outcomes in Ontario. The start of the pandemic resulted in an immediate decrease in hospital births, length of hospital stay, nitrous oxide use for labour analgesia, general anesthesia for cesarean birth, and TOLAC. There were no statistically significant increases in adverse outcomes such as preterm birth and stillbirth. After the immediate effect of the pandemic, the majority of outcomes demonstrated a trend returning toward pre-pandemic levels.

J o u r n a l P r e -p r o o f Two meta-analyses examining the effects of the pandemic time period on maternal and perinatal outcomes have been published. 24,25 . Similar to our findings, Chmielewska et al. 24 found no significant differences between pandemic and pre-pandemic periods in pooled analyses of labour induction, cesarean birth, NICU admission or 5-minute Apgar. While these outcomes are important, our major concern was whether changes in clinical care were temporally associated with any changes in adverse perinatal outcomes such as rates of preterm birth or stillbirth. While in eight studies originating from high-income country settings, the overall pooled OR for stillbirth across 12 studies was 1.28 (95% CI 1.07 to 1.54) indicating a significant increase during the pandemic period. Differences in pooled estimates from these systematic reviews and our study may be due to differences in study time period, study populations and the study design and analytical approaches used. A strength of our study was the use of an ITS analysis which allowed us to account for baseline temporal patterns and seasonality when examining immediate and gradual effects over many time intervals; in contrast, the majority of studies published todate have used a before-and-after comparison.

For the purposes of comparison, we were unable to find other studies examining the impact of the COVID-19 pandemic on health system or clinical practice outcomes such as birth location, length of stay, labour analgesia, anesthesia method for cesarean or TOLAC.

Most of the significant changes identified occurred immediately after the pandemic started when healthcare providers, clinical committees and policymakers were rapidly deciding which practice changes were needed based on limited and constantly shifting evidence. The media reports about people avoiding hospitals, overwhelmed hospitals and special COVID-19 units being set up within hospitals 13, 26 were likely associated with our findings of an initial decrease in hospital births and increase in home births, as well as a decrease in length of hospital stay regardless of mode of delivery.

J o u r n a l P r e -p r o o f Some practice changes occurred quickly, in alignment with recommendations. Nitrous oxide use showed the most dramatic decrease; recommendations against the use of nitrous oxide were largely due to the potential for aerosolization of the SARS-CoV-2 virus and thus risk of infection for others in the room. 27 The same rationale applied to general anesthetics. It is not surprising that epidural use for labour analgesia and regional anesthesia for cesarean increased in line with provincial and national guidelines, 11, 12 .

TOLAC decreased dramatically after the pandemic onset because of the unpredictability for emergency cesarean birth during a TOLAC. In September 2020, the SOGC issued a statement recommending that TOLAC continue to be offered during the pandemic versus routinely resorting to elective repeat cesarean birth. 28 It is a sign of progress that we found TOLAC rising towards pre-pandemic levels since this statement and indeed many of our study outcomes were trending towards pre-pandemic levels by the end of the study time period. It is apparent that the first few months led to the most upheaval as healthcare providers and hospitals were trying to adapt in accordance with emerging research and experience.

It is reassuring that we did not find significant increases in adverse outcomes such as preterm birth, stillbirth, NICU admissions, low Apgar scores and abnormal arterial cord blood pH as these could have been unintended consequences of avoiding hospitals or ultrasounds when care was necessary or of time delays for cesarean births in labour due to the need to properly don personal protective equipment. Ontario from the onset of the pandemic to the end of September 2020. 29 Given that our study included 94,126 pregnant individuals in the COVID-19 Wave 1 period it is extremely unlikely that the study outcomes were influenced by the virus itself instead of pandemic countermeasures.

We used a robust quasi-experimental design allowing an assessment of the impact of the COVID-19 Wave 1 across the entire obstetric population, while accounting for any prepandemic secular trends. 14,30 Additionally, the time series design uses population-level data which should eliminate concern about individual-level confounders, unless these changed concurrently with the pandemic. 30 We had the availability of a birth registry with near-complete and timely capture of all provincial births in hospitals, at home, or in a birth centre.

Hospital-level summary data using random effects segmented regression analyses would have been beneficial to examine variation across sites, and account for characteristics such as birth volume, level of care, and region of the province. However, given the small birth volume of some sites, as well as the criteria for certain study outcomes, the denominators at the hospital level were too small, which would have led to instability in the analysis. One approach to increase denominators is to choose a wider time interval (e.g., monthly); however, this would have led to too few time intervals in the COVID-19 Wave 1 period. Although we were unable to specifically explore variation across the province, hospitals, clinicians and maternal-newborn networks in Ontario ultimately collaborated to implement system-level changes, which would have diluted any initial variability in maternal-newborn care.

We were unable to examine longer term maternal-newborn outcomes as the majority of the registry data are collected up until discharge from hospital or midwifery care. Examining outcomes past the hospital stay (such as breastfeeding) would be helpful in evaluating pandemic effects once mother and baby are at home. Finally, we cannot rule out the possibility of a type I error due to the many outcomes we examined.

Wave 1 of the COVID-19 pandemic led to system level and clinical practice changes in Ontario maternal-newborn settings. Importantly, there is no evidence that these changes resulted in any contemporaneous increase in adverse perinatal outcomes including stillbirth and preterm birth. Among all pregnant individuals in labour at a hospital, the rate of nitrous oxide use for labour analgesia. Epidural use for labour analgesia Among all pregnant individuals in labour at a hospital, the rate of epidural use for labour analgesia. Opioid use for labour analgesia Among all pregnant individuals in labour at a hospital, the rate of opioid use for labour analgesia. General anesthesia for cesarean birth Among all pregnant individuals who deliver by cesarean in a hospital, the rate of general anesthesia for cesarean birth. Regional anesthesia for cesarean birth Among all pregnant individuals who deliver by cesarean in a hospital, the rate of regional anesthesia for cesarean birth. TOLAC Among all pregnant individuals eligible for a VBAC, the rate of pregnant individuals doing a TOLAC. Criteria for eligibility was established by a provincial Maternal Neonatal Committee 1 and includes multiparity, live hospital births, singleton gestation with cephalic presentation, gestational age ≥37 weeks, one previous cesarean birth. Exclusion criteria include: previous uterine rupture, placental anomalies (accreta /increata /percreta/previa), previous T incision/classical incision/uterine surgery, any other maternal or fetal complication that is a contraindication to vaginal birth such as a prenatally diagnosed major fetal anomaly, malposition/malpresentation, or other obstetrical complication). VBAC Among eligible pregnant individuals who did a TOLAC, the rate of VBAC. Cesarean births Among all pregnant individuals who have a hospital birth, the rate of cesarean deliveries.

Among live births, any admission to a NICU or special care nursery.

-Further subgroup analysis restricted to term infants. Breastfeeding during hospital stay Among live births in hospitals, the rate of breastfeeding from birth to discharge home on the postpartum unit. This includes breast milk only or a combination of breast milk and a breast milk substitute.

Live or stillbirth occurring after ≥20 weeks but prior to 37 completed weeks of gestation.

-Further subdivided into gestational age categories of <24 weeks, 24 to 27+ 6 weeks, 28 to 31+ 6 weeks, 32 to 33+ 6 weeks and 34 to 36+ 6 weeks. Medically-indicated preterm birth Among live or stillbirths less than 37 weeks of gestation, preterm birth following labour induction or cesarean delivery (initiated by medical treatment) without PPROM or conditions indicating prior onset of labour. 2 Spontaneous preterm birth Among live or stillbirths less than 37 weeks of gestation, preterm birth following spontaneous onset of labour without PPROM. 2 

Birth with no signs of life at ≥ 20 weeks or ≥500g occurring in the antepartum or intrapartum period. 5-minute Apgar score < 4 or Arterial cord blood pH < 7.0 

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Figure 1. Time series plots of length of stay, nitrous oxide use, preterm birth and stillbirth

Plots include terms for continuous time (week interval), a binary indicator for whether the time interval was before or after the start of the COVID-19 pandemic on March 1, 2020, and continuous time post onset of COVID-19 Wave 1

Among live births in hospitals, and as a proxy for compromised infants, the rate of 5-minute Apgar score <4 or an arterial cord blood pH <7.0. -Further subgroup analysis restricted to term infants

VBAC, vaginal birth after cesarean

PPROM, preterm premature rupture of membranes 1. Health Quality Ontario. Vaginal Birth After Caesarean: Care for People Who Have Had a Caesarean Birth and Are Planning Their Next Birth

Temporal trends in neonatal outcomes following iatrogenic preterm delivery

Models included terms for continuous time (week interval), a binary indicator for whether the time interval was before or after the start of the COVID-19 pandemic on March 1, 2020, continuous time post onset of COVID-19 Wave 1 and seasonality (month). Intercept and seasonality parameter estimates not shown. All models accounted for first-order autocorrelation

05 for immediate effects (change in level after onset of COVID-19 Wave 1) and gradual effects (change in slope after onset of COVID-19