Results
From April 19 to June 27, 2020, 1,838 women were referred to the
delivery unit, compared to 88,973 women between March 21, 2011 and April
18, 2020. A comparison of clinical parameters, delivery data and
neonatal outcomes between the mask-wearing period and pre-pandemic
periods is presented in Table 1. Compared with the 2011 to 2020
pre-pandemic period, the mean hemoglobin levels and the proportion of
women with hemoglobin>13 (g/dL) were significantly higher
during the mask-wearing period [12.15±1.1 vs. 11.96±1.2,
p<0.001; 21.5% vs. 16%, OR-1.43 (95% CI, 1.28-1.61),
p<0.001 respectively], while the proportion of women with
hemoglobin <11 g/dL was lower [13.5% vs. 16.5%, OR-0.79
(0.69-0.91), p=0.01]. Platelets levels were lower during the pandemic
period compared to the pre-pandemic period [200±56.0 vs. 206±57.5
(K/microL), p<0.001], while fibrinogen levels were higher
[472±103.6 vs. 448±85.1 (mg/dL), p<0.001]. Cesarean
delivery rates were higher during the mask-wearing period compared to
the pre-pandemic period [26.7% vs. 24.4%, OR- 1.13 (95% CI,
1.02-1.25), p=0.022], while rates of delivery<34 weeks of
gestation were lower [1.1% vs. 2%, OR-0.57 (95% CI, 0.37-0.88),
p=0.010]. The rate of post-partum hemorrhage and the composite
bleeding rate were higher during the mask-wearing period [4.1% vs.
2.8%, OR- 1.5 (1.2-1.8), p=0.01 and 5.1% vs. 3.8%, OR- 1.3
(1.07-1.60), p=0.07, respectively].
A comparison between the mask-wearing period and the parallel period in
2019 demonstrated the same hematologic findings, preterm delivery
<34 weeks of gestation and post-partum hemorrhage rates.
Neonatal outcomes are presented in Table 2. Birthweights were higher
during the mask-wearing period compared to the 2011-2020 pre-pandemic
period (3,232 vs. 3,200 grams, p=0.009). Neonatal Apgar score
<5 one minute after delivery was lower during the mask-wearing
period as well as NICU admissions [0.2% vs. 0.6%, OR- 0.36
(0.13-0.97), p=0.03; 2.8% vs. 3.7%, OR- 0.75 (0.56-0.99), p=0.046,
respectively]. Compared with the parallel period in 2019, the rate of
composite neonatal outcome was lower during the mask-wearing period
[3.8% vs. 5.8%, OR- 0.64 (0.47-0.87), p=0.004]. The same trend of
higher birthweight and NICU admission during the mask-wearing period
compared to the parallel period in 2019 was observed (p=0.015 and
p<0.001 respectively).
Further dividing the whole study cohort into two groups; a group with
hemoglobin <11g/dL and the other ≥11g/dL, we performed a
multivariate regression analysis, which has identified that pre-pandemic
period is independently associated with hemoglobin level <11.0
g/dL (Table 3).