Preterm birth and stillbirth rates during COVID-19 pandemic: differences by socioeconomic status

BACKGROUND: At the onset of the COVID-19 pandemic, there were concerns about maternal and newborn health because of increased stress, economic difficulties and restrictions to healthcare. However, preterm birth (PTB) rates declined in some countries in 2020, while stillbirth (SB) rates remained stable or were slightly elevated. Hypotheses for the PTB result include positive consequences of lockdowns (more rest, less pollution, less exposure to infection) or restricted healthcare, leading to fewer indicated preterm births. These effects have not been examined on a population-level by socioeconomic (SES) group. METHODS: The Euro-Peristat network developed a Common Data Model and R scripts to produce aggregated data tables from vital statistics and birth registers. This analysis uses data from 2015 to 2020 on singleton PTB rates and SB rates as well as on mother's educational level (preferred) or area level deprivation/occupation of mother (if education unavailable). SES measures were harmonised into 3 groups (low, medium, high). We computed observed versus expected risks of the outcomes for the year 2020, given linear trends from 2015 to 2019, overall and by SES group; these estimates were pooled using random effects meta-analysis. RESULTS: 19 countries provided data on perinatal outcomes by SES group. The overall pooled mixed effect measure for PTB was -0.04 (95%CI of -0.06 to -0.02), corresponding to a 4% decline in 2020 over expected levels. This estimate was the same in low and high SES groups (-0.04 (-0.07 to 0.02) versus -0.04 (-0.06 to -0.02)). For stillbirth, the overall pooled measure was 0.02 (-0.03 to 0.07), corresponding to an increase of 2%, with higher estimates in the low SES group 0.05 (-0.02 to 0.11) versus 0.2 (-0.3 to 0.7) in the high group, although confidence limits overlapped. CONCLUSIONS: A small decrease in PTB was observed in all SES groups, while results are suggestive of increases in SB rates among women in lower SES groups. KEY MESSAGES: • Previous results in some countries of decreased preterm birth rates in the general population in 2020 were confirmed in this European study, with similar associations in all socioeconomic groups. • Stillbirth rates were not increased in the overall population, but a 5% increase was observed in lower SES groups.