Interpretation
Common symptoms at onset of COVID-19 of pregnant women were fever, cough
and abdominal pain, and the less common symptoms were chills, dyspnoea,
chest pain and pharyngalgia. However, some patients presented initially
with atypical symptoms, such as diarrhea and rhinobyon. The most
significant laboratory abnormalities observed in pregnant group were
depressed lymphocytes counts, increased leucocytes and neutrophil
counts, and elevated C-reactive protein level compared with those in
non-pregnant group (all P < 0.001, Table 2). These
abnormalities suggest that SARS-CoV-19 infection in pregnant women may
be associated with cellular immune deficiency and inflammation response
(may resulted in cytokine storm) induced by virus. Meanwhile,
physiological haemodilution in pregnancy lowers the hemoglobin level of
pregnant women, as reflected in the difference of hemoglobin level
between the two groups. A further drop in hemoglobin level might
jeopardise the stressed oxygen carrying capacity of mother, adding
further risk to pregnant COVID-19 patients. Additionally, a higher level
of lactate dehydrogenase at presentation had been associated with
potential severity among pneumonia patients in
most7, but not all, case
series8. Likewise, a
higher lactate dehydrogenase level was found in our pregnant group,
reflecting tissue necrosis related to immune hyperactivity in COVID-19.
The presence of such adverse outcome predictor may reflect the severity
of the disease course in pregnancy.
Currently, the approach to this disease is to control the source of
infection; use of personal protection precaution to reduce the risk of
transmission; and early diagnosis, isolation, and supportive treatments
for affected patients. Until now, no specific treatment has been proven
to be effective for coronavirus infection except for meticulous
supportive care9. In our
study, most pregnant patients were treated with arbidol and oseltamivir
(24 of 31 patients, 77.4%). Although arbidol and other antiviral drugs
have been used in the clinical treatment of patients with COVID-19, no
data of their safety and efficacy as COVID-19 treatments have been
published. The experience gained from previous antiviral pneumonia (eg.
SARS and MERS) is also
limited10-12. More
pregnant patients received antibacterial agents and corticosteroids in
this study, as compared with non-pregnant patients (all P ≤ 0.001; Table
3 and online supplement, Table S1). Timely use of antibiotics to prevent
secondary bacterial infections and strengthen immune support treatment
can reduce complications and mortality, so antibiotics were used
routinely after
operation13.
Corticosteroids should not be routinely given systemically, unless for
possible benefit by reducing inflammatory-induced lung injury, according
to WHO interim
guidance14.
Additionally, the use of large doses of corticosteroids during pregnancy
might lead to fetal malformation in previous
study15. Among our two
groups of 155 laboratory-confirmed patients with SARS-CoV-19 infection,
corticosteroids were given to very few non-pregnant women (16.1%), and
low dose of corticosteroids were given to 23 pregnant patients (74.2%,
Table 3 and online supplement, Table S1). Thus far, no complications
related to the steroids have been recorded in the pregnant women,
mothers and neonates in our study. Further evidence is urgently needed
to assess their safety.
As
is known to us, total lung capacity of pregnant women decreases towards
term. There is also a decrease in both residual volume and expiratory
volume in pregnant women, resulting in a 9.5% to 25% drop in
functional residual capacity. Moreover, there is a 20% increase in
oxygen demand in
pregnancy16. This might
explain why more pregnant patients required oxygen support in this study
(Table 3).
Because of alterations in hormone levels and decreased lung volumes
caused by increases in uterus size during pregnancy, patients might have
a more rapid clinical deterioration. In this study, we have presented 31
cases of COVID-19 in pregnancy and 124 control cases with similar
outcomes, including 17 newborns with negative COVID-19. There were no
ICU admissions and no complications of ARDS, acute renal injury and
acute liver injury for all the pregnant throughout the study period. All
of the 155 patients have been discharged as of Jul 8, 2020, the hospital
stay of pregnant patients was 13 days (IQR, 9.0-24.0). These results are
different from those former pneumonias (eg. SARS, MERS, H1N1, et
al)17,
18, which stated that infected pregnant
patients had wore outcomes. This might be associated with: First,
different pathogenicity among these human coronaviruses. For example,
the mortality rate of SARS infection is
10%19, and the
mortality rate of SARS in pregnant women was
25%20, while the
mortality rate of patients with COVID-19 is about
1.4%21. Second,
COVID-19 pneumonia in pregnancy is a complicated clinical scenario, a
multidisciplinary team of medical personnel from Renmin Hospital of
Wuhan University participated in the whole procedure of caring these
patients comprehensively and timely (the median durations of pregnant
women from illness onset to hospital admission were 5 days). This team,
including obstetrics, internal medicine, paediatrics, infectious
diseases, anaesthesia, psychology, and infection control, has played a
positive role.