INTRODUCTION

Coronavirus disease 2019 (COVID-19) is a new pathology with a rapid increase of infections and deaths since it was first identified in Wuhan (China) in December 2019¹. Available data on its effects on pregnant women and offspring are still sparse. Nevertheless, information regarding its detrimental consequences on the respiratory tract may help discover how it may affect pregnant women and their developing fetuses¹.

Coronavirus is a virus that causes infections in humans and animals. More specifically, it is a zoonotic pathology, that is, it can be transmitted from animals to humans². They can cause several diseases from a common cold to Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS-CoV)². As a result of COVID-19 disease, the World Health Organization (WHO) stated in late January 2020 that we were (and are) facing a pandemic and an international public health emergency³.

During pregnancy, a variety of environmental circumstances can affect maternal and newborn health^4,5,6. Taking this into consideration, it is known how the environment a pregnant woman is exposed to can create a permanent imprint on fetal physiology, which will last a lifetime. Thus, as stated from the Developmental Origin of Health and Disease (DOHaD) theory promulgated by epidemiologist David Barker, fetal programming that occurs during prenatal development will determine the health and illness of that individual throughout his extrauterine life⁷. Exposure to viruses has been described among the prenatal events that may affect the health of the developing fetus⁸.

Due to the special care we must give to pregnant women and their newborns⁹, and the information provided before, the aim of this study was to explore the available knowledge on the consequences of developing COVID-19 in pregnant women and newborns during pregnancy.

MATERIAL AND METHODS

In order to perform an initial mapping of the literature, the methodology referring to a scoping review was used^10,11. The characteristics of a scoping review are that it is systematic and rigorous. In addition, it allows the possibility of generating hypotheses, as well as proposing which areas of study are partially developed¹².

Thus, the search for articles was carried out using the DeCS (“pregnancy”, “coronavirus”, “health”) and MeSH (“pregnan*”, “pregnant women”, “coronavirus”) directories, linking the terms with the Boolean operator AND. The inclusion criteria were: articles in Spanish or English language, published in the last 2 years (due to the novelty of the subject), that included the full text, including pregnant women, and that addressed the maternal and/or neonatal infections consequences of coronavirus infection during pregnancy. In addition, other sources of information were used such as the Spanish Society of Gynecology and Obstetrics (SEGO), the Royal College of Obstetricians and Gynaecologists (UK), The Royal College of Midwives (UK), Royal College of Paediatrics and Child Care (UK) and the WHO final report on the China-WHO joint mission on COVID-19. Exclusion criteria were opinion articles and animal studies.

The databases in which the search was performed were Web of Science, Scopus, BVS, Scielo and CUIDEN. In addition, Google Scholar was used to identify potential articles not indexed in the databases used. The search was carried out between February-March 2020. Figure 1 shows the PRISMA flow diagram¹³, reflecting the search and selection process for articles according to the inclusion criteria. Finally, 10 studies were selected for further analysis.

Figure 1.  PRISMA flow diagram reflecting the search and selection process. 

RESULTS

The novelty of this topic helped that 10 studies met the inclusion criteria and were included in this scoping review^{14,15,16,17,18,19,20,21,22,23}. Table 1 shows the main results of the included empirical studies (n=5)^{14,15,16,17,18}. All empirical studies (n=5) were observational, either single case or case series. The total sample of the 5 empirical studies was 64 pregnant women and 65 neonates (one pregnancy was twin). The 100% (n=5) of empirical studies were conducted in China^{14,15,16,17,18}. A study on recommendations for obstetricians based on the SARS-CoV coronavirus and on the Middle East Respiratory Syndrome (MERS) was included¹⁹. In addition, a consensus of experts from China for perinatal and neonatal management in the prevention and control of COVID-19 was added in the review²⁰. Furthermore, among the documents included in this exploratory review were three reports of recommendations for health professionals prepared by the Spanish Society of Gynecology and Obstetrics (SEGO), the Royal College of Obstetricians and Gynaecologists (UK), The Royal College of Midwives (UK), Royal College of Paediatrics and Child Care (UK) and the China-WHO joint mission on COVID-19^21,22,23.

Table 1.  Maternal and neonatal outcomes of the empirical studies included in the scoping review. 

DISCUSSION

The aim of this study was to know the current state regarding the possible negative consequences of maternal COVID-19 infection on the own health of the pregnant woman and the newborn. In addition, it sought to provide clarity on the vertical transmission of COVID-19 from mother to fetus. Studies of COVID-19 during pregnancy are attracting interest, although empirical research has only been conducted in China. This review constitutes the first study in Spain that addressed the health of pregnant women and newborns in relation to COVID-19. The predominant symptom in pregnant women in this review was fever, which did not always appear before birth^14,15,16. It should be noted the absence of seriousness of COVID-19 in pregnant women^{14,15,16,17,18,19,21,23}. This contradicts what was previously reported regarding SARS-CoV in Hong Kong in 2003 and in respect to a study stating that SARS was much more severe in pregnant women than among non-pregnant women¹⁹. Some cases required admission to an intensive care unit. During the SARS in 2003, the death of some pregnant women was reported as a consequence of the coronavirus that infected them at that time¹⁹.

Regarding the neonatal consequences of COVID-19, only one baby was reported to have died possibly due to her/his 2,200 g birth weight and prematurity¹⁸. In respect to the rest of the neonates, apparently no lasting complications were observed^{14,15,16,17,18}. It is important to note that almost all newborns screened for COVID-19 tested negative, except in one case where the test was not performed. It is unknown whether that neonate was the deceased baby¹⁸. Coronavirus SARS-Cov-2 was not found in any of the analyzed amniotic fluid, breast milk, or cord blood samples^{14,15,16,17,18}.

To date and using the information available, there is insufficient evidence to verify that COVID-19 is transmitted vertically from mother to baby^{14,15,16,17,18,21}.

International professional associations, being aware of the public health problem we are facing, have developed some recommendations for professionals dedicated to the health of pregnant women^{19,20,21,22,23}. These recommendations include the management of those pregnant women during pregnancy, childbirth and postpartum at risk or suffering from an infection by COVID-19^19,21,22. In addition, they include a list of recommendations regarding newborns care²⁰. Pregnant women and their neonates health must be a priority^24,25,26.

In conclusion, there is no evidence of greater susceptibility to COVID-19 infection in pregnant women than in non-pregnant women¹⁹. Furthermore, there is no evidence to support the vertical transmission of SARS-CoV-2 from pregnant women to the fetus^{14,15,16,21,22}. This is supported by the absence of SARS-CoV-2 in breast milk, amniotic fluid and umbilical cord blood samples from newborns of mothers with COVID-19^14,15,16. According to the studies included in this review, neonatal infection is quite infrequent. Only one single newborn deceased, possibly due to prematurity and low birth weight¹⁸.

This study may have certain limitations. Studies published in Chinese language were not included in the search. Furthermore, pregnant women with a positive result for SARS-CoV-2 and not those with symptoms but without a diagnosis of COVID-19 were included.