COVID-19 and Pregnancy

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Information regarding COVID-19 and pregnancy is limited. Given the newness of the disease, there isn’t yet much information on how COVID-19 affects fetal development and preterm birth. Other severe coronaviruses, MERS-CoV and SARS-CoV, are more problematic in those who are pregnant.

Here is what we do we know so far:

COVID-19-associated pneumonia does not seem to worsen during pregnancy beyond the risk of a non-pregnant cohort. However, the reported numbers are small and other coronaviruses (MERS-CoV, SARS-CoV) are more virulent in gravid women. Pregnancy is characterized by a reduction in T and B cells as well as a reduction in CD4+ cell activity. For this reason, many bacterial infectious diseases are more dangerous in those who are pregnant. We are awaiting more epidemiologic data about pregnancy and COVID-19-related pneumonia.

Vertical transmission does occur but not readily. A Chinese study of nine infants demonstrated no transmission of COVID-19 from the mother to the fetus in the 3rd trimester. However, all of the children were delivered by Cesarean. The same study found no virus in cord blood, amniotic fluid, breast milk or infants’ throats. A second study in China found about a 10% transmission rate from mother to infant (3 of 33 births).  All of the infants did well clinically ( JAMA Pediatr. March 26, 2020. doi:10.1001/jamapediatrics.2020.0878)

There is no good data on fetal demise or preterm labor in direct relation to COVID-19.  It is known, however, from other illnesses, that a high fever in the first trimester is associated with birth defects. There are case reports of preterm birth in patients with COVID-19 but at this point there are no prospective studies.

As expected, some pregnant women are COVID-19 positive and asymptomatic.  A letter in the New England Journal reports that of 211 asymptomatic pregnant women being delivered in New York, 1 in 8 (13.7%) were COVID-19 positive and of these 90% were asymptomatic. (April 13, 2020 DOI: 10.1056/NEJMc2009316)

This is not unexpected given the degree of disease in New York and the fact that we know a significant portion of patients with COVID-19 are asymptomatic.
The testing of women who go into labor should be individualized to each community and should follow the local testing practice pattern

Women scheduled for induction or Cesarean section 24-28 hours before admission and again on presentation.  If screening is positive, the induction or operative delivery should be delayed if medically possible. All patients (obstetrical or not, in labor or not) should be screened for symptoms.  A summary of these recommendations can be found here.  

General CDC guidelines for infection control can be found here.

Inpatient Obstetrics: The CDC has issued specific guidelines regarding mother/infant contact in the post-partum period if the mother is COVID-19 positive or is a person under investigation (PUI). 

  • Determination of when to reunite mother and baby is on a case-by-case basis, based on disease severity, etc.  This is a judgment call to be made by the provider, parent, public health officials and infection prevention and control personnel. Per the CDC, “Considerations to discontinue temporary separation are the same as those to discontinue transmission-based precautions for hospitalized patients with COVID-19.”  These criteria are:
    • Resolution of fever, without use of antipyretic medication
    • Improvement in illness signs and symptoms
    • Negative results of an FDA Emergency Use Authorized molecular assay for COVID-19 from at least two consecutive sets of paired nasopharyngeal and throat swabs specimens collected ≥24 hours apart (total of four negative specimens—two nasopharyngeal and two throat).

New Guidelines on Breast Feeding
The CDC has issued new guidelines which can be found here:

  • Breast feeding is generally the best nutrition for an infant and COVID-19 does not SEEM to be a source of transmission of COVID-19 (though it can’t be entirely excluded yet).
  • Whether to breast feed or not should be a shared decision between the mother/parents and provider.
  • Hand washing and wearing a cloth facemask are critical. Note that the guideline makes no mention of N95 or surgical masks.
  • Assume that the infant of a COVID-19 positive mother who is breast feeding is itself COVID-19 positive for purposes of isolation.
  • Newborn and young child wellness visits (through 24 months) and vaccination should be prioritized.
  • Telemedicine can provide lactation support for mothers breast feeding.

Comment:  These are simplified but essentially the same as the prior breast-feeding guidelines for COVID-19 positive mothers.

New CDC guidelines for when it is safe to leave isolation after being diagnosed with COVID-19
New guidelines for when it is safe to leave home isolation has extended the period of isolation. The new guidelines can be found here. 
Briefly: "For persons recovered from COVID-19 illness, CDC recommends that isolation be maintained for at least 10 days after illness onset and at least 3 days (72 hours) after recovery. Illness onset is defined as the date symptoms begin. Recovery is defined as resolution of fever without the use of fever-reducing medications with progressive improvement or resolution of other symptoms. Ideally, isolation should be maintained for this full period to the extent that it is practicable under rapidly changing circumstances (verbatim from CDC)."


Aghaeepour, E. A. Ganio, D. Mcilwain, et al. An immune clock of human pregnancy. Sci. Immunol 2017 2, eaan2946CDC. Inpatient Obstetric Healthcare Guidance. accessed 20 March 2020

CDC. Pregnant Women FAQ.

Chen H et al. Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: A retrospective review of medical records. Lancet 2020; 395: 809–15 Feb 12; [e-pub]. (

Schwartz, D.A.; Graham, A.L. Potential Maternal and Infant Outcomes from Coronavirus 2019-nCoV (SARS-CoV-2) Infecting Pregnant Women: Lessons from SARS, MERS, and Other Human Coronavirus Infections. Viruses 2020, 12, 194.