To breastfeed or not to breastfeed? Lack of evidence on the presence of SARS-CoV-2 in breastmilk of pregnant women with COVID-19.

A rapid systematic review was carried out to evaluate the current evidence related to the presence of SARS-CoV-2 in breast milk from pregnant women with COVID-19. Eight studies analyzing the presence of SARS-CoV-2 RNA in the breast milk of 24 pregnant women with COVID-19 during the third trimester of pregnancy were found. All patients had fever and/or symptoms of acute respiratory illness and chest computed tomography images indicative of COVID-19 pneumonia. Most pregnant women had cesarean delivery (91.7%) and two neonates had low birthweight (< 2 500 g). Biological samples collected immediately after birth from upper respiratory tract (throat or nasopharyngeal) of neonates and placental tissues showed negative results for the presence SARS-CoV-2 by RT-PCR test. No breast milk samples were positive for SARS-CoV-2 and, to date, there is no evidence on the presence of SARS-CoV-2 in breast milk of pregnant women with COVID-19. However, data are still limited and breastfeeding of women with COVID-19 remains a controversial issue. There are no restrictions on the use of milk from a human breast milk bank.

SARS-CoV-2 is a novel emerged positive-strand RNA virus associated with an acute respiratory distress disease known as COVID-19. Studies have suggested that transmission of SARS-CoV-2 is primarily from person to person through respiratory droplets (1,2). In addition, there is emergent evidence that the virus could be detected in biological fluids including bronchoalveolar lavage fluid specimens (3), blood (3,4) and saliva (5), but substantial knowledge gaps remain regarding the presence of SARS-CoV-2 in the breast milk. Recently, a report in Science discussed the wrenching choices of pregnant women with COVID-19 after childbirth including whether or not they should breastfeed their children (6).

METHODS

We performed a rapid systematic review to evaluate the current evidence related to the presence of SARS-CoV-2 in breast milk from pregnant women with COVID-19. The study was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines (7), but given emergency-need for this review, PROSPERO registration was not sought. Using terms related to coronavirus, we searched in PubMed, Web of Science, Scopus, China National Knowledge Infrastructure database, and grey literature (Google Scholar and preprint repositories) to identify studies reporting results of RT-PCR tests on breast milk in pregnant women with laboratory-confirmed SARS-CoV-2 infection. Searches were performed up to March 30, 2020 and updated on April 21, 2020.

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RESULTS AND DISCUSSION

We found eight studies (8–15) analyzing the presence of SARS-CoV-2 RNA in the breast milk of 24 pregnant women with COVID-19 during the third trimester of pregnancy (Table 1). All patients had fever and/or symptoms of acute respiratory illness and chest computed tomography (CT) images indicative of COVID-19 pneumonia. Most pregnant women had cesarean delivery (91.7%) and two neonates had low birthweight (< 2,500 g). Biological samples collected immediately after birth from upper respiratory tract (throat or nasopharyngeal) of neonates and placental tissues showed negative results for the presence SARS-CoV-2 by RT-PCR test. In addition, no breast milk samples were positive for SARS-CoV-2. In three studies (10,12,13) there was a clear recommendation for mother’s to not breastfeed their children despite the lack of evidence on the potential viral transmission via breast milk.

TABLE 1.

Sample characteristics and RT-PCR results for SARS-CoV-2 in breast milk

Author	N	Maternal				Delivery		Neonate				Breast milk
		Age (years)	Presentation at admission	Chest imaging	Outcome	Gestational age at delivery (weeks)	Type of delivery	Gender	Birth weight (g)	Major complications	RT-PCR	Analysis	RT-PCR
Chen, 2020 [8]	1 -6	Minimum 26, maximum 34	Fever (6/6), cough (2/6), dyspnea (1/6), and diarrhea (1/6)	Evidence of pneumonia	Survived	Minimum 36, maximum 39	Cesarean section	?	Minimum 1880, maximum 3730	No	Negative (URT and placental tissues)	DO	Negative
Dong, 2020 [9]	7	29	Fever, nasal congestion, and shortness of breath	Evidence of pneumonia	Survived	34	Cesarean section	Female	3120	No	Negative (URT)	Day 6 after delivery	Negative
Fan, 2020 [10]	8	34	Fever and nasal congestion	Evidence of pneumonia	Survived	37	Cesarean section	Female	3400	No	Negative (URT and placental tissues)	DO	Negative
	9	29	Fever, cough, and nasal congestion	Evidence of pneumonia	Survived	36	Cesarean section	Female	2890	No	Negative (URT and placental tissues)	DO	Negative
Li, 2020 [11]	10	30	Cough and shortness of breath	Evidence of pneumonia	Survived	35	Cesarean section	Male	?	No	Negative (URT and placental tissues)	DO	Negative
Liu, 2020 [12]	11	34	Fever	Evidence of pneumonia	Survived	40	Cesarean section	Male	3250	MSAF	Negative (URT and placental tissues)	DO and days 1 and 10 after delivery	Negative
	12	30	Cough	Evidence of pneumonia	Survived	39	Vaginal	Male	3670	No	Negative (URT)	Day 2 after delivery	Negative
Wang, 2020 [13]	13	34	Fever	Evidence of pneumonia	Survived	40	Cesarean section	Male	3205	MSAF	Negative (URT and placental tissues)	Days 1 and 3 after delivery	Negative
Xiong, 2020 [14]	14	25	Fever and cough	Evidence of pneumonia	Survived	38	Vaginal	Male	3070	No	Negative (URT and placental tissues)	DO	Negative
Liu, 2020 [15]	15-24	Minimum 26, maximum 38	Fever (7/10), cough (4/10), and diarrhea (1/10)	Evidence of pneumonia	Survived	Minimum 35, maximum 41	Cesarean section	?	Minimum 2500, maximum 3670	No	Negative (URT and placental tissues)	DO	Negative

As the coronavirus pandemic takes hold, pregnant women infected with SARS-CoV-2 experience fear and uncertainties regarding the care of their child. Making decisions without a robust evidence base may influence mother-child interactions and lead to poor outcomes. Furthermore, there is a lack of consensus among health agencies regarding breastfeeding for women with COVID-19. In February 2020, the National Health Commission of China recommended that neonates of pregnant women with suspected or confirmed COVID-19 should be isolated in a designated unit for at least 14 days and should not be breastfeed due to the high risk of infection (16). Although this expert working group has suggested breastfeeding only in cases of negative tests for SARS-CoV-2, this warning may contribute to reducing breastfeeding by women with no exposure to the virus which may lead to infant poor health outcomes. On the other hand, interim guidance provided by the Centers for Disease Control and Prevention (CDC) (17) and the World Health Organization (WHO) (18) advises that breastfeeding should be determined by the mother in coordination with her family and healthcare providers, and all possible prevention measures to avoid spreading the virus to the infant must be taken including wearing a mask and washing hands and breasts with soap and water before breastfeeding. If the woman opts to express breast milk, all recommendations for cleaning the breast pumps and utensils after each use must be rigorously followed. Consideration should be given to the possibility of someone healthy providing breast milk to the infant using a cup or spoon. This person must receive training from a qualified professional before starting procedures. If there is no production of breast milk by the mother, a human milk bank should be contacted. There are no restrictions on the use of milk from a human breast milk bank (19,20). The possibility of drug excretion into breast milk with potential adverse effects in breastfeed neonates should also be analyzed (21). To date, there is no evidence on the presence of SARS-CoV-2 in breast milk of pregnant women with COVID-19. Data provided on current literature are still limited and breastfeeding of women with COVID-19 remains a controversial issue. Further studies with large samples are needed to confirm these results particularly given the importance of breastfeeding in preventing other childhood illnesses.

Author contributions.

All authors conceived the original idea and contributed to the analysis and interpretation of the results. All authors reviewed and approved the final version.

Disclaimer.

Authors hold sole responsibility for the views expressed in the manuscript, which may not necessarily reflect the opinion or policy of the RPSP/PAJPH or the Pan American Health Organization (PAHO).