key: cord-1021267-rddq89gy
authors: Hwang, Sunah S.; Weikel, Blair W.; Hannan, Kathleen E.; Bourque, Stephanie L.
title: Impact of COVID-19 “Stay-At-Home” Orders on Preterm Birth in Colorado
date: 2021-10-28
journal: J Pediatr
DOI: 10.1016/j.jpeds.2021.10.046
sha: 8371857c5cfc2767a3cd7f51d3547bef6ada24d4
doc_id: 1021267
cord_uid: rddq89gy

nan

In March 2020, Colorado Governor Jared Polis issued stay-at-home orders to curb transmission of the Coronavirus-19 (COVID-19), limiting the mobility of Colorado residents, including the birthing population. 1 The impact of such statewide mandates on birth outcomes has been investigated in Tennessee where researchers found that the preterm birth rate during the 2020 stay-at-home order was lower than rates in previous years (10.2% vs 11.3%; P = .003). 2 Data on the effect of stay-at-home orders on the health of pregnant individuals and their newborns at population-based state-levels are limited. Moreover, significant racial/ethnic disparities exist in U.S. birth outcomes and data on the differential impact of COVID-19 restrictions on birth outcomes for diverse racial/ethnic groups are also lacking. To provide a larger evidence base for if and how COVID-19 restrictions affected the birthing population at a population-based state-level, we sought to) compare preterm birth rates during the periods before and after COVID-19 stay-at-home orders were issued and assess whether change in preterm birth rates varied across racial/ethnic groups in Colorado.

We analyzed Colorado birth certificate records from April to December 2015 through 2020 to account for seasonality in the pre-and post-COVID-19 stay-at-home orders. The pre-period was defined as April-December 2015-2019 and the post-period was defined as April-December 2020.

We excluded records with missing or unreasonable values for birth weight (<300g), gestational age (<20 or >44 weeks), infant sex, delivery method, insurance type, maternal race/ethnicity, age, highest education, or marital status.

The primary outcome was preterm birth, defined as gestational age <37 weeks. Gestational age on birth certificates is typically calculated from clinical estimates by first trimester ultrasound and when missing, the estimated date of last menstrual period.

We compared maternal and infant characteristics for all and preterm births separately for pre and post COVID-19 stay-at-home orders using χ 2 tests with significance at P < .05. Using logistic regression models, we explored the outcome of preterm birth comparing the 2015-2019 birth cohort to that of 2020. All variables significant in the bivariate analysis were considered for model inclusion along with birth year. We compared the difference in mean preterm birth rates between non-Hispanic White (NHW) and each racial/ethnic group using an interaction term between maternal race/ethnicity and pre-/post-COVID-19 in the logistic regression model. We explored the crude difference in preterm birth by maternal race/ethnicity between 2015-2019 and 2020 using χ 2 tests and calculated adjusted odds ratios for preterm birth in the post-period with logistic regression models for each race/ethnicity adjusting for the same covariates as in the overall model. SAS 9.4 (Cary, North Carolina) was used for all analyses.

There were 296,934 live births captured by Colorado birth certificates during the study period. After exclusion of 5,569 (1.9%) for missing or unreasonable demographic variables (Table I) .

The 2020 overall, early (< 34 weeks), and late (34-36 weeks) preterm birth rates were not significantly different than in previous years (8.9% vs 9.05%, P = 0.3095, 2.40% vs 2.41%, p = 0.8383,6.50% vs 6.63%, p = 0.2956) ( Figure; available at www.jpeds.com). NHB mothers experienced a noticeable, though not statistically significant, increase in preterm birth from 11.3% to 12.6%. The difference in preterm birth rates between NHW and NHB mothers widened after COVID-19 stay-at-home orders by 30%, albeit without statistical significance (p = 0.563).

After controlling for covariates, including maternal age, education, race/ethnicity, marital status, insurance, previous preterm birth, 1 st trimester prenatal care, diabetes and hypertension, which may reduce our power to detect a statistically significant pre/post preterm birth rate change. Though the increase in the preterm birth rate for NHB women from 11.3% to 12.6%

was not statistically significant in our analyses, a larger NHB cohort would have potentially had greater power to detect a significant change. In Colorado, Hispanic and NHB residents are over-represented in COVID-19 infections, hospitalizations, and deaths. 6 For Hispanic mothers, despite higher COVID-19 infection rates in their communities, preterm birth rates declined, suggesting that as demonstrated by Son et al, infection alone does not explain the association of birth outcomes and COVID-19 positivity. We hypothesize that potentially broader family and/or community supports could allow some pregnant individuals to better weather the enormous stress caused by the pandemic and maintain perinatal health. NHB and AI/AN women have the highest maternal and infant mortality rates in the U.S. [7] [8] [9] We hypothesize that the broad array of factors related to health status, healthcare access, social determinants of health as well as racism likely persisted in the post-restriction period and thus these groups experienced no decline in their preterm birth rates. The Black-White disparity in preterm birth increased during our study period, highlighting the urgent need to disaggregate perinatal health data to fully understand differential impacts of both negative and positive exposures on our birthing population.

There are limitations to this study, namely the focus on births from one state, limiting potential generalizability beyond Colorado. In addition, although the primary exposure of this analysis was defined as the timing of the stay-at-home order, we recognize that much broader social, economic, and health exposures associated with COVID-19 lockdown orders were likely driving the association between stay-at-home orders and preterm birth rates. Also, our analysis was limited to maternal race/ethnicity as captured by the birth certificates and did not account for J o u r n a l P r e -p r o o f country of origin or immigrant status. We also recognize the heterogeneity within each racial/ethnic group and that each subgroup may have been impacted by the COVID-19 restrictions in different ways. Despite these limitations, this analysis contributes to the literature on how COVID-19 stay-at-home orders affected birth outcomes at a statewide population level. 

Association of Preterm Birth Rate With COVID-19 Statewide Stay-at-Home Orders in Tennessee

Changes in obstetric interventions and preterm birth during COVID-19: A nationwide study from Iceland

COVID-19) Pandemic and Pregnancy Outcomes in a U.S. Population

Preterm birth and stillbirth rates during the COVID-19 pandemic: a population-based cohort study

Racial and ethnic disparities in severe maternal morbidity prevalence and trends

Data From the Period Linked Birth/Infant Death File

9% 10%

34 weeks) and Late Preterm (34-36 weeks) Births Apr-Dec by birth year