A systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines [6]. The search strategy was carried out through the PubMed and ScienceDirect databases using the Medical Subject Heading (MeSH) keywords and relevant keywords in a different order: “breastfeeding”, “women”, “COVID-19”, and synonyms of these keywords. The list of references found in the selected articles was reviewed to find the articles that were not included in the electronic literature search. Boolean operators were used in the search strategy by using conjunctions, namely AND, OR and NOT.

Articles were selected through inclusion and exclusion criteria. The selected articles were researches conducted during the COVID-19 pandemic in 2020-2021, written in English, and provided full text. The author has evaluated the chances of viral transmission and antibody transfer in the first part of the discussion and then described the experience of breastfeeding during the pandemic in the second part. The exclusion criteria for this study included animal studies, letters to editors, study reviews, and abstracts without full text.

All authors performed title and/or abstract screening independently of the included articles using standard Microsoft Excel forms. A third external collaborator was consulted to address disagreements in consensus. The formal assessment of the article quality was carried out with the criteria of having clear objectives, explaining the type of research carried out, writing down the appropriate research methodology according to the objectives, and drawing the right results.

The analysis was based on the results and conclusions of each study. Parameters examined in (Tables 1 and 2) include author, year, purpose, research method, population/sample, and findings. (Table 1) summarizes the presence of virus pathogens and antibodies in breast milk. (Table 2) summarizes the factors influencing the breastfeeding experience during the pandemic.

The systematic review was carried out in several stages. 54 articles on the PubMed database and 134 articles on the ScienceDirect database discuss the presence of the SARS-CoV-2 virus in breast milk. 80 articles on the PubMed database and 86 articles on the ScienceDirect database discuss the presence of antibodies against COVID-19 in breast milk. 51 articles on the PubMed database and 466 articles on the ScienceDirect database discuss the experience of breastfeeding mothers. A total of 14 articles were included in the inclusion criteria covering three main topics from the 254 articles that were screened. The articles were analyzed and examined qualitatively for quality assessment. The types of articles included 2 case reports, 4 cross-sectional studies and 8 prospective cohort studies. The articles have been thoroughly reviewed, and their summary has been presented in (Tables 1 and 2).

Based on various studies that examined the presence of SARS-COV-2 in breastmilk, it was found that most breastmilk samples did not contain the virus. Samples in small quantities were found to contain the virus, but did not permanently harm the baby. Infants, who had ingested breast milk from mothers positive for COVID-19, revealed a negative nasopharyngeal test for SARS-CoV-2 and had a benign clinical course. There was no significant evidence obtained for mother-infant transmission through breast milk, but transmission during breastfeeding needs to be understood, especially with respect to the skin of the breast. Potential antibodies against COVID-19 infection have been found to be present in breastmilk, namely IgA and IgG.

There was a change in breastfeeding patterns during the lockdown observed in breastfeeding mothers. Although most mothers agreed to the importance of breastfeeding, there were differences in opinion regarding breastfeeding practices, such as the use of donor breast milk and relactation, the duration of breastfeeding, and the challenges with respect to a number of children. Anxiety affected mothers in giving breastmilk to their babies. The support required during breastfeeding was also reduced, including the availavility of health workers and families. Mothers had different experiences, such as feeling protected by a lockdown but struggling to find support. The visible impact was that they decided to stop breastfeeding, breastfed irregularly, or used formula milk. Mothers who lived in hospitals had a better chance of exclusively breastfeeding for the first 30 days. After 90 days, they were not affected by the hospital support anymore but may have been influenced in other aspects, such as family support.

Fig. (1). Prisma flowchart.

Based on various studies that examined the content of SARS COV-2 in breastmilk, it was found that most of the breastmilk samples did not contain the virus, and there was potential for antibodies against COVID-19 in the mother's breastmilk. Newborns of mothers infected by SARS-CoV-2 are more likely to receive intensive care that limits direct contact for breastfeeding initiation [21, 22]. So far, breastfeeding is the best feeding for infants and has countless benefits for both mother and infant, including a protective effect on morbidity and mortality [23]. Breast milk protects the infant against several infectious diseases through the transfer of antibodies and stimulates the development of the immune system. In newborns with immature immunity, breast milk is required to protect infants through bioactive factors and secretory IgA antibodies [24]. Breast milk is also rich in immunoglobulin, lactoferrin, and lysozyme, stimulating the innate and adaptive immune response to protect against microorganisms [25]. Previous studies show that preterm birth incidence (12.9%) is higher in women with SARS-CoV-2 infection [26]. Premature infants are much more susceptible to infection, so they need more protection and stimulants for the development of the immune system [27].

Skin-to-skin contact in breastfeeding between mother and infant immediately after the birth provides exposure to the mother's normal flora and stimulates the development of the baby's microbiome. Skin-to-skin contact also increases blood glucose, stabilizes the respiratory system, prevents neurodevelopmental disorders, and also reduces stress for both mother and infant [28, 29]. It has been reported that scaling up breastfeeding to a near-universal level could stop around 823,000 child deaths annually [30]. Breastfeeding also reduces morbidity and mortality in diarrhea by up to 64% and the severity of respiratory syncytial virus (RSV) up to 72% [25]. Therefore, continuing to breastfeed during the COVID-19 pandemic must be considered, especially for women with SARS-CoV-2 infection [31].

During the pandemic, there was a change observed in breastfeeding patterns even though most mothers supported and believed that breastfeeding should be continued during the lockdown. Anxiety and lack of support affect mothers in giving breastmilk to their babies. Mothers reported different experiences, such as feeling protected by the lockdown. Still, mothers had to struggle to get support and experienced many related obstacles, so they decided to stop breastfeeding or breastfeed irregularly. Some even changed it to a combination with formula milk. Apart from mothers, it turned out that most of the staff who participated in providing lactation support to women affected by COVID-19 reported increased stress. Ensuring written or verbal guidance could reduce staff's stressful experience. Efforts to optimize lactation support during COVID-19 involved reduced distraction, physical separation, and logistical challenges [32].

The UNICEF's latest information still recommends exclusive breastfeeding while using necessary precautions for infection prevention and control, even in mothers with suspected or confirmed COVID-19 [33]. CDC indicates that breastfeeding is up to the mother, family members, and health professionals [34]. This recommendation is based on the health benefits of breastfeeding for both the mother and the child. The risk of COVID-19 infection in an infant can be prevented when the mother obeys universal protocols. For a mother with asymptomatic or mildly symptomatic COVID-19, it is highly recommended to wash hands for 20 seconds using running water and soap or hand sanitizer before breastfeeding, touching any pump or bottle parts, and before expressing breast milk. It is also recommended to wear a mask while breastfeeding, expressing breast milk, and whenever within 6 feet distance from the baby [5]. The mother should maintain the breast hygiene with soap and water before breastfeeding the baby. These precautions should be continued until afebrile, the improvement of symptoms, and having two negative tests for SARS-CoV-2 at least 24 hours apart. If there is no source for testing, the mother should continue these precautions until she symptomatically improves and becomes afebrile for at least three days since the onset of symptoms. For moderate to severely symptomatic mothers with COVID-19, the mother must wear a mask, wash her hands, and wash her breast with soap and water. If the mother expresses milk (with a hospital-grade electric breast pump if available), then a healthy family member/nurse shall feed the expressed milk to the baby in a separate room. Breast pump tubing and container should be cleaned after each use. The outside surface of containers must be disinfected after milk expression and before storage [35].

Breastfeeding support is also provided through a private room, which ensures the mother's privacy. Mothers must feel comfortable during breastfeeding, such as the room must have a comfortable chair, electrical outlets, appropriate lighting, and must be kept at a comfortable temperature. There should be a flat surface, such as a table, to place the breast pump and its accessories. Room sanitation must be kept clean. There should be access to hand washing as well as pump supplies. In addition, there must be safe access to breast milk storage and breast pump storage [36].

Various problems have been encountered in terms of breastfeeding during the pandemic, such as the premature termination of the baby. Mothers in this setting have expressed high stress and anxiety levels during their premature infant's NICU admission [37]. It is because postpartum mothers often have unstable emotions, so they have difficulty adapting to changes during the perinatal period that cannot be resolved fundamentally [38]. Support from family and the environment is vital in ensuring that mothers breastfeed well, especially during a pandemic. Mothers with a positive COVID-19 status need to pay attention to the existing symptoms in breastfeeding. Mothers with severe symptoms of COVID-19 can be advised to get a breast milk donor, while mothers with moderate symptoms, if possible, can give expressed breast milk. Mothers who receive proper support will continue breastfeeding well, even during a pandemic.