Maternal SARS-CoV-2 sero-surveillance using newborn dried blood spot (DBS) screening specimens highlights extent of low vaccine uptake in pregnant women.

SARS-CoV-2 vaccine uptake in pregnant women is believed to be low and lags behind the general population contributing to increased hospital admissions, and poor maternal and fetal outcomes. However, there is a paucity of information on the SARS-CoV-2 serostatus of pregnant women to help inform policy planning and assess impact of interventions to improve vaccine uptake in this at-risk group. We analyzed 8,683 residual, anonymized newborn screening dried bloodspot (DBS) specimens during a 15-month period (October 2020 to December 2021) in Wales (UK) for SARS-CoV-2 IgG-antibodies. We compared newborn DBS antibody-positive rates to the percentage number of pregnant women vaccinated and the percentage number of antibody-positive adults. In December 2021, 47.8% of women in Wales had received two doses of the vaccine by their delivery date; however, only 41.1% of DBS specimens had high antibody concentrations. Results indicate that a proportion of pregnant women remain at higher-risk of COVID complications, particularly given the reduction in antibody neutralization of Omicron versus the Delta variant. Our study demonstrates the utility of newborn screening DBS specimens to monitor SARS-CoV-2 serostatus in pregnant women representing maternal vaccination and natural infection in almost real-time, defining the immunity gap and impact of any interventions.

Implementation of non-invasive prenatal testing within a national UK antenatal screening programme: Impact on women's choices.

OBJECTIVE: To evaluate the implementation of non-invasive prenatal testing (NIPT) on pregnant women's choices in a national NHS antenatal screening programme for Down's syndrome, Edwards' syndrome and Patau's syndrome. METHOD: An observational study of all pregnant women with a singleton pregnancy and higher chance (≤1:150) combined or quadruple screening result from 30 April 2018 to 25 September 2020 in Wales, UK. Pregnant women's journey through the pathway was determined including uptake of NIPT, performance of NIPT in a non-research setting and invasive procedures performed. RESULTS: Of the 1273 women with a higher chance initial screening, 1073 (84%) chose NIPT contingent test, 174 (14%) no further testing and 26 (2%) invasive procedure. There were 1001 (93%) low chance NIPT results; 11 (1%) failed results and 61 (6%) high chance results. Average annual incidence of 27 invasive procedures undertaken compared to 229 pre-NIPT implementation, a nearly ninefold reduction. Down's syndrome annual live birth rate remained unchanged across the implementation period. DISCUSSION: This study demonstrates that NIPT contingent screening was highly acceptable to women with a resulting reduction in invasive procedures performed. CONCLUSION: The high uptake of NIPT in NHS antenatal screening pathway conditions should inform planning for other national screening programmes.