In December 2019, the first cases of pneumonia due to a new coronavirus, SARS-CoV-2 were described in China . In early March 2020, the disease, now known as COVID-19, was declared a pandemic by the World Health Organisation (WHO). To date, the world has nearly 13,616,593 cases and approximately 585,727 deaths  among which 16,057 cases and 369 deaths have been recorded in Cameroon as of July 17, 2020 . COVID-19 is now known to portray a vast array of clinical manifestations ranging from asymptomatic individuals to overt respiratory distress . The disease is thought to be severe in the elderly and patients with chronic debilitating conditions such as hypertension, heart failure and diabetes and other immune-compromised states.
Pregnancy is generally known to be an immune-compromised condition, so pregnant women may be at risk of severe COVID-19 given that back in 2003 and 2012 fatal forms of coronavirus pneumopathy were identified with SARS-CoV-1 and MERS-CoV infections in pregnancy  . However, to date, the available data related to SARS-CoV-2 infection do not indicate a higher infection rate or increased risk of severity in pregnant women compared to the general population  . There are few descriptions of maternal-fetal transmission of COVID-19 and their corresponding outcomes in the literature at the moment and none has otherwise been described in sub-Saharan Africa. We therefore aimed to describe the outcomes of maternal and fetal transmission of COIVD-19 in a group of women followed up at the Yaounde Central Hospital in Cameroon.
2.1. Study Design and Setting
This was a prospective observational study which lasted for 3 months (April 1 to June 30, 2020) at the Obstetric and Gynecological Unit of the Yaounde Central Hospital in Cameroon. This unit provides tertiary care to pregnant women and serves as a referral unit for over 40 district hospitals in the centre region of Cameroon. The unit is served by 14 physicians and 20 non-physician staff. Mask wearing was compulsory for all staff and patients in the unit with staff using additional prescribed protective gears.
2.2. Study Participants
All COVID-19 positive pregnant symptomatic women who were screened-diagnosed [via the Real-Time Polymerase Chain Technique (RT-PCR) or Rapid Diagnostic Test (RDT)] during the time of the study were included after a signed written informed consent was provided. All data provided by the participants were recorded in anonymised forms which were available only to the clinical and research team.
2.3. Data Collection
Data was collected from the participants’ prenatal consultation and pregnancy monitoring record as well as their referral sheet (if they were referred for care with a positive COVID-19 test). Data was recorded onto a pre-structured data collection form designed for the study. We interviewed the participants or their accompanying family carer to complete their socio-demographic characteristics, medical and pregnancy history, presenting complaints, treatment received, and the pregnancy outcomes. A complete physical examination was performed by the attending physician or nurse and obstetric parameters were also recorded.
2.4. Data Management
Data was entered into a prepared Microsoft Excel 2010 Spreadsheet by a non-clinical staff. The data was then double-checked item by item to ensure accuracy and completeness. The data was later exported to SPSS version 23 for analysis. Data was expressed in frequency, percentage and median (interquartile range) were necessary.
3.1. Baseline Characteristics of the Study Participants
Over the 3 months period, a total of 1197 pre-natal consultations were registered with 83 pregnant women tested for SARS-CoV-2 based on their presenting symptoms, of whom 25 had a positive COVID-19 test. Of the 25 pregnant women, 23 were PCR-confirmed cases while 2 were positive on a serologic test. Table 1 shows the baseline characteristics of the study participants. The majority (64%) of women were aged between 25 to 35 years. Most patients came to consult within at least 6 days after the onset of initial symptoms (76%), and more than half of them having a gestational age greater than 28 weeks of amenorrhea (68%).
3.2. Presenting Symptoms of COVID-19 Positive Pregnant Women
Twenty-two patients (88%) had fever (≥39˚C), eighteen (80%) presented with cough. Nineteen (76%) reported intense fatigue. Symptoms of respiratory involvement were seen as follows: Ten (40%) had respiratory distress, eight (32%) had a rhinorrhoea, 7 (28%) had anosmia and six (24%) had ageusia; Three patients (8%) had diarrhoea. Ten (40%) of our patients developed severe respiratory distress requiring admission to the intensive care unit. Figure 1 shows the presenting complaints.
Table 1. Socio-demographic characteristics of the study population.
Median age (IQR) = 31 (27 - 35) years; Min - Max = 18 - 43 years.
Figure 1. Presenting symptoms of the study participants presenting with COVID-19.
3.3. Treatment Received for COVID-19
Antibiotic (96%) and anti-parasitic (88%) treatment had been initiated in the majority of patients. Ten (40%) patients received oxygen therapy and seven (28%) were treated with anti-coagulant therapy (see Table 2).
3.4. Maternal and Fetal Outcomes and Prognosis
Obstetrically, four (16%) patients had their pregnancies terminated, two (8%) had notified the occurrence of uterine contractions and one (4%) had per vaginal bleeding (Figure 2). All the pregnant women were alive by the end of the study. Regarding the outcome of pregnancy, we noted that fourteen (56%) women have a current pregnancy. Among the nine (36%) women who gave birth, four (44.4%) had a cesarean section. Acute fetal distress was the indication for cesarean section in three cases. Among the nine births, there were seven live births. All seven neonates were tested negative for COVID-19 via RT-PCR after birth (see Table 3).
Table 2. Treatment received during follow-up.
*Others: Antitussive agents, Progesterone tablets.
Figure 2. Description of study procedure and number of women and neonates followed-up.
Table 3. Table showing maternal and foetal outcomes.
Our study found out that, all seven babies born of COVID-19 positive pregnant women tested negative for the SARS-CoV-2 infection and showed no signs of abnormality. The median age of the pregnant women was 31 years. Most of them (76%), consulted within 6 days of onset of symptoms suspicious of having COVID-19 after failure of the traditional herbal medicines to reduce their symptoms. This delay in consultation could be explained by the use of the traditional pharmacopoeia for symptoms initially considered mild .
During our study, we recorded ten cases (40%) of Severe Acute Respiratory Distress Syndrome linked to COVID-19 pneumonia requiring transfer to intensive care. Due to physiological and immunological changes, pregnant women are more susceptible to severe pneumonia  . This was noticed during the influenza pandemic in 1918 which caused a mortality rate among pregnant women of 37% against 2.6% in the general population . Our findings are similar to those of Wong et al.  who found 33% of severe forms in pregnant women with SARS and there are studies which have shown up to 79% sequence similarity between SARS-CoV-2 and SARS  . We did not register any death in our series; but we remain vigilant because the evolution and prognosis of COVID-19 pneumonia could follow the same profile as SARS-CoV-1 and MERS-CoV.
In general, the clinical characteristics are similar in pregnant or non-pregnant women . The most frequent symptoms at the start of COVID-19 pneumonia in our series were fever, cough, and asthenia which have been found in similar proportions in other published studies  ; while the least common symptoms were diarrhea, dizziness, anorexia, and chest pain.
All of our study participants received an anti-parasitic/antibiotic association treatment in accordance with the directives of the scientific council of the Ministry of Public Health of Cameroon . Only ten women benefited from oxygen therapy who presented with severe respiratory distress (temperature ≥ 38˚C, respiratory rate > 30 cycles/minute, respiratory distress, SpO2 < 90% in ambient air, cyanosis) requiring permanent oxygen therapy to maintain their SpO2 > 92%.
Five (55.6%) women delivered vaginally, four underwent an emergency cesarean and two had an abortion. The indications for cesarean sections were fetal distress and cervical dystocia in a patient with a past history of cesarean section. Two Chinese studies show that their route of delivery was caesarean in 100% and 76.9% respectively  . Two (22.24%) of the five vaginal deliveries occurred while the patients were under investigation for their pneumonia; the other deliveries were performed after the patients were cured of their pneumonia with COVID-19. We do not have the data necessary to assess the risks to the newborn from per vaginal delivery to those of cesarean section. Seven (77.8%) fetuses were alive with an APGAR score greater than 7 in the first minute and we have two neonatal deaths. It was difficult to formally incriminate the SARS-CoV-2 virus, but it is possible that these complications reflect poor tolerance to hypoxia . Nasopharyngeal swabs were taken from newborns no later than 48 hours after birth and all were negative; no newborn presented with symptoms during admission and required pediatric care. Huijun et al.  did not find neonatal complications in his series of nine births, all performed by cesarean section.
We did not find any association between the occurrence of severe COVID-19 pneumonia and the unfavorable prognosis of pregnancy in our series. This could be justified by the limited sample size and also by the fact that the majority of pregnancies are in progress. The patients were recruited every trimester of pregnancy and the causal relationship of COVID-19 on the unfavorable outcome of the pregnancy seems difficult to establish.
The small size of our sample does not allow definitive conclusions to be drawn. The follow-up of the remaining pregnant women will allow us to propose new results for the next work.
The maternal-fetal consequences of COVID-19 are not very frequent if we have a close follow-up. The data of our series follows the international pattern, so we recommend to the practitioners, to continue screening on a large scale and in a systematic way.
The authors would like to thank the patients for having given their consent to participate in the study carried out as well as the administration of the central hospital and its staff who mobilized in the care of these patients.
Ethics Approval and Consent to Participate
The ethical approval has been obtained from the ethics committee of the Central Hospital of Yaounde. We didn’t need to obtain informed consent from a parent or guardian as our patients were all over the age of 18.
Availability of Data and Materials
The datasets generated and/or analyzed during the current study are not accessible to the public because they are the subject of ongoing research, but are available from the corresponding author on reasonable request.
These patients have not been reported in any other submission by me or anyone else.
MN Dingom and ES originated and designed the study.
MN, AA, YW contributed to data collection and clean. AN and JK conducted data analysis. MD, ES, GN, AN interpreted the findings and drafted the manuscript.
MN, ES, FE, AA, YW, JN, PS, CS, BW, GL, JB, FE, FF, GN, JF, RT, PO, PF, RM took care of the patients during their hospitalization.
All authors have read and approved the manuscript.
 Zhu, N., Zhang, D., Wang, W., Li, X., Yang, B., Song, J., et al. (2020) A Novel Coronavirus from Patients with Pneumonia in China, 2019. New England Journal of Medicine, 382, 727-733.
 Ksiazek, T.G., Erdman, D., Goldsmith, C.S., Zaki, S.R., Peret, T., Emery, S., et al. (2003) A Novel Coronavirus Associated with Severe Acute Respiratory Syndrome. New England Journal of Medicine, 348, 1953-1966.
 Zaki, A.M., van Boheemen, S., et al. (2012) Isolation of a Novel Coronavirus from a Man with Pneumonia in Saudi Arabia. New England Journal of Medicine, 367, 1814-1820.
 Lescure, F.-X., et al. (2020) Clinical and Virological Data of the First Cases of COVID-19 in Europe: A Case Series. The Lancet Infectious Diseases, 20, 697-706.
 Yu, N., Li, W., Kang, Q., Xiong, Z., Wang, S., Lin, X., et al. (2020) Clinical Features and Obstetric and Neonatal Outcomes of Pregnant Patients with COVID-19 in Wuhan, China: A Retrospective, Single-Centre, Descriptive Study. The Lancet Infectious Diseases, 20, 559-564.
 Chen, H., Guo, J., Wang, C., Luo, F., Yu, X., Zhang, W., et al. (2020) Clinical Characteristics and Intrauterine Vertical Transmission Potential of COVID-19 Infection in Nine Pregnant Women: A Retrospective Review of Medical Records. The Lancet (London, England), 395, 809-815.
 Warning, J.C., McCracken, S.A. and Morris, J.M. (2011) A Balancing Act: Mechanisms by Which the Fetus Avoids Rejection by the Maternal Immune System. Reproduction (Cambridge, England), 141, 715-724.
 Wong, G., Liu, W., Liu, Y., Zhou, B., Bi, Y. and Gao, G.F. (2015) MERS, SARS, and Ebola: The Role of Super-Spreaders in Infectious Disease. Cell Host Microbe, 18, 398-401.
 Huang, C., Wang, Y., Li, X., Ren, L., Zhao, J., Hu, Y., et al. (2020) Clinical Features of Patients Infected with 2019 Novel Coronavirus in Wuhan, China. The Lancet, 395, 497-506.
 Wu, C., Chen, X., Cai, Y., Xia, J., Zhou, X., Xu, S., et al. (2020) Risk Factors Associated with Acute Respiratory Distress Syndrome and Death in Patients with Coronavirus Disease 2019 Pneumonia in Wuhan, China. JAMA Internal Medicine, 180, 934-943.
 Zhou, F., Yu, T., Du, R., Fan, G., Liu, Y., Liu, Z., et al. (2020) Clinical Course and Risk Factors for Mortality of Adult Inpatients with COVID-19 in Wuhan, China: A Retrospective Cohort Study. The Lancet (London, England), 395, 1054-1062.
 Gautret, P., et al. (2020) Clinical and Microbiological Effect of a Combination of Hydroxychloroquine and Azithromycin in 80 COVID-19 Patients with at Least a Six-Day Follow Up: A Pilot Observational Study. Travel Medicine and Infectious Disease, 34, Article ID: 101663.