Main Findings
In this large sample of patients admitted for labor and delivery
undergoing universal SARS-CoV-2 testing during the height of the initial
surge of infections in Massachusetts, we observed an overall 2.8% risk
of infection, with three-quarters of infected patients being
asymptomatic. The risk was largely clustered in patients with distinct
demographic and occupational characteristics.
The risk of infection was 12% for women living in the towns most
heavily affected by COVID-19 based on publicly reported case rates in
the general population, compared to 0.5% for those living in towns with
the lowest infection rates. Approximately 14% of Hispanic women and 5%
of African American women were infected, versus 0.8% of Caucasian and
Asian women. The risk of infection in public health beneficiaries was
more than ten-fold higher than in privately insured women. Essential
workers outside of healthcare had a markedly high risk of infection,
14%. Furthermore, 93.5% of patients with SARS-CoV-2 infection had at
least one of six factors associated with infection; over half had four
or more.
The factors associated with SARS-CoV2 infection may vary between
communities and are likely to evolve as the pandemic progresses in
various settings. Based on Massachusetts data at the peak of the spring
2020 surge, the strong association of infection with particular
demographic characteristics and neighborhoods suggest the need for
public health officials and clinicians to track and use this type of
data as outbreaks occur in order to implement interventions aimed at
decreasing infection rates in particular
communities.18 The high risk of infection in
non-healthcare essential workers suggests that directive work-related
precautions should be offered to women who work in non-healthcare
related high risk settings, if at all possible. As having a household
member with known SARS-CoV-2 infection was also strongly associated with
infection at the time of admission for labor and delivery, all household
members should be counseled to take precautions to avoid infection,
which may prevent transmission of the virus to the parturient. Risk
stratification of patients at risk for SARS-CoV-2 infection is also
instructive at the hospital level. Some hospitals may not have the
capacity to test all parturients or may not have rapid SARS-CoV-2
testing available, leading to a need to prioritize patients at highest
risk for infection for testing.
Our data demonstrate that pregnant women from vulnerable populations
were disproportionately affected by SARS-CoV2 infection during the first
wave of infection in Massachusetts. These trends are in line with the
widespread racial and socioeconomic disparities in COVID-19 seen in the
general population in several geographic areas, and though explanations
for these disparities are multifold, it is likely that residence in
crowded urban settings, poverty and employment in essential occupations,
and decreased access to care play a role.19,20 Thus,
there are profound racial and economic disparities in COVID-19 in
pregnant women in Massachusetts that track racial and economic
disparities in maternal health and obstetrical outcomes observed more
generally.21
Compared to data from our study, the documented rates of new SARS-CoV-2
infection per capita in the state of Massachusetts for the people aged
20-39 was multi-fold lower,1 likely due to a
substantial undercounting of disease burden given widespread
asymptomatic disease and limited testing available for the general
population. Most SARS-CoV-2 testing is performed due to patient
symptoms; there are few settings where ongoing universal screening of
otherwise healthy patients is conducted. Thus, such universal testing
can provide valuable insight into the disease dynamics in the community
and can be used to monitor the burden of disease.3-6