Strengths and Limitations
The main strength of the study is the number of registered cases (403
deliveries from 70 centers across Spain), being one of the largest
cohorts described. Furthermore, it represents a novel topic because, to
our knowledge, there are no studies that have analyzed perinatal
outcomes in neonates born to mothers with COVID-19 regarding the timing
of cordon clamping, or that have evaluated the safety of DCC,
skin-to-skin contact, and breastfeeding practices in these neonates.
On the other hand, our study has several limitations. Routine serology
tests (for determining the immunological state after delivery) were not
performed in neonates born to mothers with confirmed COVID-19 due to the
lack of availability at the beginning of the pandemic in Spain, and
later, once they were available, due to the diversity of tests and
protocols in the distinct centers. Furthermore, the clinical
questionnaire (for evaluating the neonatal symptoms) was not normalized
and homogeneous in all the centers. The determination of parts of the
virus in the neonate with ultrasensitive tests does not mean the
existence of the complete virus with infective capacity. We did not know
if the healthcare professionals who assisted the deliveries or the
relatives who visited the neonates were SARS-CoV-2 positive or not. We
were able to trace this association in one of the positive PCR cases;
nevertheless, in a pandemic like this, we do believe that the present
results are unique and relevant because of the difficult circumstances
in which they were obtained. In the future, once serologic diagnostic
methods improve and become more available, there will be a need to
determine the presence and evolution of immunoglobulins against
SARS-CoV-2 in order to clarify whether transplacental transmission does
exist. Further long-term, prospective studies with neonates are thus
required.