Vaccination for SARS-COV-2 in pregnancy in a referral center in Italy

Objective

The aim of the study was to investigate uptake of COVID-19 vaccination among pregnant women in a referral center in Italy.

Methods

This was an observational retrospective study conducted at ASL NA1 Centro, and at University of Naples Federico II, Italy, among pregnant women. The primary outcome was uptake of COVID-19 vaccination and its determinants.

Results

Data were available for 1,478 pregnant women who were offered COVID-19 vaccination during pregnancy. Of them, 498 (33.7%) rejected the vaccine, while 980 (66.3%) received at least 1 dose of the vaccine before delivery. Out of the 980 women who received vaccination, 357 (36.4%) were vaccinated in the second trimester, 497 (50.7%) in the third trimester, and 126 (12.9%) in the first trimester of pregnancy. 327 (33.3%) women received one dose of the vaccine in pregnancy, and 653 (66.6%) received two doses. 

Conclusion

Of pregnant women eligible for COVID-19 vaccination, more than two-third cases accepted COVID-19 vaccination during pregnancy.

Keywords

COVID-19, SARS-COV-2, vaccination, epidemiology

Introduction

Coronaviruses are enveloped, non-segmented positive-sense RNA belonging to the Nidovirales order [1]. In December 2019, a novel Coronavirus spread in China and identified as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) was responsible of a cluster of respiratory disorders, the COVID-19 disease [2]. Pregnant women are at increased risk for severe illness from influenza virus and other respiratory infections due to cardiopulmonary adaptive changes occurring during pregnancy, such as increased heart rate and stroke volume and reduced pulmonary residual capacity, that can increase the risk of hypoxemia and contribute to the increased severity. As well, COVID-19 in pregnancy, is associated with increased risk of maternal and perinatal outcomes [2-5]. Mass vaccination is the best method by which all countries are aiming to control the COVID-19 pandemic [6]; and COVID-19 vaccines are safe for use in pregnancy [7]. Despite this, there is paucity of data regarding the willingness to accept vaccination during pregnancy among pregnant women [8].
This may question whether the course of COVID-19 in pregnant women can be associated with a higher burden of maternal mortality and morbidity compared to the general population.
Objective
The aim of this study was to investigate uptake of COVID-19 vaccination among pregnant women in a referral center in Italy.

Methods

This was an observational retrospective study conducted at ASL NA1 Centro, and at University of Naples Federico II, Italy, among pregnant women. The primary outcome was uptake of COVID-19 vaccination and its determinants. The secondary outcomes were perinatal safety outcomes. Data were collected on COVID-19 vaccination uptake, vaccination type, gestational age at vaccination, maternal characteristics, and perinatal outcomes.
Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) v. 19.0 (IBM Inc., Armonk, NY, USA). Data were shown as means± standard deviation or as number (percentage). Dichotomous data were compared using the chi-square. Comparisons between groups were performed with the use of the T-test to test group means by assuming equal within-group variances. A sample size of 200 women for each group was planned

Results

Data were available for 1,478 pregnant women who were offered COVID-19 vaccination during pregnancy (Table 1). Of them, 498 (33.7%) rejected the vaccine, while 980 (66.3%) received at least 1 dose of the vaccine before delivery. Out of the 980 women who received vaccination, 357 (36.4%) were vaccinated in the second trimester, 497 (50.7%) in the third trimester, and 126 (12.9%) in the first trimester of pregnancy. 327 (33.3%) women received one dose of the vaccine in pregnancy, and 653 (66.6%) received two doses. There was evidence of reduced vaccine uptake in women younger than 30 years old (<0.01), in smokers (0.02), and in those at risk of preterm birth (<0.01). Women with high-risk pregnancy, including pregnancy-induced hypertension, had increased vaccine uptake (0.02). The rate of adverse pregnancy outcomes in women who received at least one does of the COVID-19 during pregnancy, were similar to those who did not in terms of stillbirth, fetal abnormalities, intrauterine growth restriction, and admission to neonatal intensive care unit. Rate of preterm birth was significantly higher in unvaccinated compared to vaccinated women (0.02) (Table 2).

Discussion

Theoretically, COVID-19 vaccines are safe for use in pregnancy, as they do not contain a live attenuated virus. Safety and efficacy have been also shown by data collected by the Centers for Disease Control and Prevention (CDC) V-safe pregnancy registry, and by national and international data [7]. However, pregnant women were excluded from randomized controlled trials (RCTs) testing the safety and efficacy of COVID-19 vaccines, and this have caused debate between patients and providers [10]. In this paper we aimed to investigate the uptake and safety of COVID-19 vaccination among pregnant women. Data from our study shown that of pregnant women eligible for COVID-19 vaccination, more than two-third accepted COVID-19 vaccination during pregnancy. The acceptance rate was lower in younger women, in smokers, and in those with increased risk of preterm delivery, while was higher in patients with pregnancy-induced hypertension.

Conclusion

Of pregnant women eligible for COVID-19 vaccination, more than two-third accepted COVID-19 vaccination during pregnancy, and they experienced similar perinatal outcomes compared with unvaccinated pregnant women

References

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2. Di Mascio D, Khalil A, Saccone G, Rizzo G, Buca D, Liberati M, Vecchiet J, Nappi L, Scambia G, Berghella V, D’Antonio F. Outcome of coronavirus spectrum infections (SARS, MERS, COVID-19) during pregnancy: a systematic review and meta-analysis. Am J Obstet Gynecol MFM  2020 May;2(2):100107. [PubMed] [CrossRef]
3. Di Mascio D, Buca D, Berghella V, Khalil A, Rizzo G, Odibo A, Saccone G, Galindo A, Liberati M, D’Antonio F. Counseling in maternal-fetal medicine: SARS-CoV-2 infection in pregnancy. Ultrasound Obstet Gynecol  . 2021 May;57(5):687-697. [PubMed] [CrossRef]
4. WAPM (World Association of Perinatal Medicine) Working Group on COVID-19. Maternal and perinatal outcomes of pregnant women with SARS-CoV-2 infection. Ultrasound Obstet Gynecol  . 2021 Feb;57(2):232-241.
5. Saccone G. Get your obstetric inpatient and outpatient units ready for COVID-19. Minerva Ginecol  . 2020 Aug;72(4):185-186. [CrossRef]
6. Blakeway H, Prasad S, Kalafat E et al. COVID-19 vaccination during pregnancy: coverage and safety. Am J Obstet Gynecol. 2022 Feb; 226(2): 236.e1–236.e14. [PubMed] [CrossRef]
7. Carbone L, Trinchillo MG, Di Girolamo R et al. COVID-19 vaccine and pregnancy outcomes: A systematic review and meta-analysis. Int J Gynaecol Obstet  . 2022 Dec;159(3):651-661. [PubMed] [CrossRef]
8. Carbone L, Di Girolamo R, Mappa I et al. Worldwide beliefs among pregnant women on SARS-CoV-2 vaccine: a systematic review. Eur J Obstet Gynecol Reprod Biol  . 2022 Jan;268:144-164. [PubMed] [CrossRef]
9. Carbone L, Meppa I, Sirico A et al. Pregnant women’s perspectives on severe acute respiratory syndrome coronavirus 2 vaccine. Am J Obstet Gynecol MFM  . 2021 Jul;3(4):100352. [PubMed] [CrossRef]
10. Saccone G, Zullo F, Di Mascio D. Coronavirus disease 2019 vaccine in pregnant women: not so far! The importance of counseling and the need for evidence-based data. Am J Obstet Gynecol MFM 2021 May;3(3):100324. [PubMed] [CrossRef]

	File/Dsecription
	Table-1 Data on pregnant women who were offered COVID-19 vaccination
	Table-2 Pregnancy outcomes in vaccinated and unvacinated patients