COVID-19 and pregnancy: Lessons from 2020

Comparing the immunogenicity of COVID-19 infection and vaccination in pregnant women as measured by anti-S IgG

BACKGROUND

Pregnancy is a critical time for women, making them more susceptible to infectious diseases like COVID-19. This study aims to determine the immunogenicity of COVID-19 in pregnant women who have been infected compared to those who have received the inactive COVID-19 vaccine.

MATERIALS AND METHODS

In this retrospective cohort study, pregnant women who received the inactivated COVID-19 vaccine (Sinopharm) and those with a history of COVID-19 infection during pregnancy were studied. Participants who had experienced stillbirth, received different COVID-19 vaccines, or had intrauterine fetal death were excluded from the study. Overall, the study included 140 participants. The participants were divided into two groups of 70 participants - pregnant women who received the Sinopharm vaccine and pregnant women who had COVID-19 infection during pregnancy. Before delivery, blood samples were collected from all mothers to evaluate the maternal immunoglobulin G (IgG) level. Blood samples were also taken from the baby's umbilical cord during delivery to measure the newborn's IgG level. Additionally, blood samples were collected from babies whose mothers showed signs of acute infection to measure their IgM levels and evaluate vertical transmission.

FINDINGS

The study found a significant relationship between the mean level of maternal IgG and umbilical cord IgG within the groups (P < 0.001). The highest levels of maternal IgG (2.50 ± 2.17) and umbilical cord IgG (2.43 ± 2.09) were observed in pregnant women with a previous COVID-19 infection and no history of vaccination (P < 0.001). Only one baby was born with a positive IgM, and this baby was born to a mother who showed signs of COVID-19 infection in the last five days of pregnancy. The mother was 28 years old, with a BMI of 33; it was her first pregnancy, and she gave birth to a male newborn at term.

CONCLUSION

Administering an inactivated vaccine during pregnancy can generate immunity in both the mother and the child. However, the vaccine's immunity level may not be as potent as that conferred by COVID-19 infection during pregnancy. Nonetheless, the risk of vertical transmission of COVID-19 is considered minimal and can be classified as negligible.

Analysis of the transplacental transmission of SARS CoV-2 virus and antibody transfer according to the gestational age at maternal infection

To quantify transplacental transmission of SARS-CoV-2 virus and antibody transfer in pregnant women and their newborns according to the gestational age at maternal infection. A prospective observational multicenter study including pregnant women with a positive RT-PCR or a positive serology for SARS-CoV-2 and compatible symptoms, from April to December 2020, in 11 French maternities. The study was designed to obtain a systematic collection of mother-infant dyad's samples at birth. SARS-CoV-2 viral load was measured by RT-PCR. IgG and IgM antibodies against the SARS-CoV-2 spike protein were measured by enzyme-linked immunosorbent assay. Antibody concentrations and transplacental transfer ratios were analyzed according to the gestational age at maternal infection. The primary outcome was the rate of SARS CoV-2 materno-fetal transmission at birth. The secondary outcome was the quantification of materno-fetal antibody transfer. Maternal and neonatal outcomes at birth were additionally assessed. Among 165 dyads enrolled, one congenital infection was confirmed {n = 1 (0.63%) IC95% [0.02%; 3.48%]}. The average placental IgG antibody transfer ratio was 1.27 (IC 95% [0.69-2.89]). The transfer ratio increased with increasing time between the onset of maternal infection and delivery (P Value = 0.0001). Maternal and neonatal outcomes were reassuring. We confirmed the very low rate of SARS-CoV-2 transplacental transmission (< 1%). Maternal antibody transfer to the fetus was more efficient when the infection occurred during the first and second trimester of pregnancy.

The impact of COVID-19 on maternal death and fetal death, a cohort study in Brazil

OBJECTIVE

The study aimed to evaluate the risk of maternal death and fetal death among pregnant women infected with SARS-CoV-2.

METHODS

This is a retrospective cohort study among pregnant women with secondary data from the National Live Births System (Sistema Nacional de Nascidos Vivos), National Mortality System (Sistema Nacional de Mortalidade), and e-SUS Health Surveillance System (Sistema e-SUS Vigilância em Saúde). Pregnant women confirmed for COVID-19 had positive RT-PCR between March 2020 and May 2021, pregnant women without COVID-19 were those without notification for disease. Maternal death, fetal death, and stillbirth were assessed as primary outcomes.

RESULTS

We included 68,673 pregnant women not notified as suspected of COVID-19 and 1,386 with a confirmed diagnosis of COVID-19. Among pregnant women with COVID-19, 1013 (73.0%) were aged 20 to 34 years, 655 (47.2%) were brown, 907 (65.4%) had ≥ 8 years of education, in the third trimester of pregnancy (41.5%), undergoing cesarean section (64.5%). In adjusted analyses, COVID-19 in pregnancy had a higher risk of maternal death (relative risk [RR] 18.73-95% confidence interval [95%CI] 11.07-31.69), fetal death/stillbirth (RR 1.96-95%CI 1.18-3.25), preterm birth [RR 1.18-95%CI 1.01-1.39], cesarean delivery (RR 1.07-95%CI 1.02-1.11), and cesarean delivery occurring before the onset of labor (RR 1.33-95%CI 1.23-1.44).

CONCLUSION

COVID-19 may contribute to unfavorable pregnancy outcomes. Results showed that pregnant women infected with SARS-CoV-2 had a higher risk of maternal death, fetal death/stillbirth, preterm birth, cesarean delivery, and cesarean section occurring before the onset of labor.

COVID-19 Vaccine Hesitancy among Pregnant Women Attending Antenatal Clinics in Pakistan: A Multicentric, Prospective, Survey-Based Study

This study aimed to assess the vaccination status and factors contributing to vaccine hesitancy among pregnant women in the largest province of Pakistan. A multicentric, prospective, survey-based study using an interviewer-administered tool was conducted among pregnant women attending antenatal clinics between 1 December 2021 through 30 January 2022 across seven hospitals in Pakistan. The healthcare professionals providing care at the participating hospitals administered the survey. Four hundred and five pregnant women fully consented and completed the study. The majority of the study participants (70.6%, n = 286) were aged between 25 and 34 and had a previous successful pregnancy history. More than half of the study participants (56.0%, n = 227) did not receive COVID-19 vaccination at the time of data collection despite their family members (93.9%, n = 372) had already received at least one dose of COVID-19 vaccine. Among those who received COVID-19 vaccination (n = 173), vaccine efficacy, protection for the foetus, and risk of COVID-19-associated hospitalisation were the main driving factors for vaccine hesitancy. The majority of the unvaccinated women (77.8%, n = 182) had no intention of receiving the vaccine. However, more than two-thirds (85.7%, n = 342) consulted the doctor about COVID-19 vaccines, and most were recommended to receive COVID-19 vaccines by the doctors (80.7%, n = 280). Women were significantly more likely to be vaccinated if they had employment (odds ratio [OR] 4.47, 95% confidence interval [CI]: 2.31-8.64) compared with their counterparts who were homemakers, consulted their doctors (OR 0.12, 95% CI: 0.04-0.35), and if they did not have pregnancy-related issues (OR 6.02, 95% CI: 2.36-15.33). In this study, vaccine hesitancy was prevalent, and vaccine uptake was low among pregnant women. Education and employment did impact COVID vaccination uptake, emphasising the need for more targeted efforts to enhance the trust in vaccines.

Mild or Moderate COVID-19 during Pregnancy Does Not Affect the Content of CD34+ Hematopoietic Stem Cells in Umbilical Cord Blood of Newborns

The study included umbilical cord blood samples (n=64) intended for cryogenic storage of hematopoietic stem cells and obtained from patients with a history of mild and moderate forms of COVID-19 during pregnancy. The control group was composed of samples (n=746) obtained from healthy women in labor. A comparative analysis of the volume of cord blood collected, the total leukocyte count, the relative and absolute content of cells with the CD34⁺/CD45⁺ phenotype revealed no significant differences between the groups.

Assessment of Oral Microbiome Changes in Healthy and COVID-19-Affected Pregnant Women: A Narrative Review

During pregnancy, there are several metabolic changes and an alteration in the composition of microorganisms that inhabit the oral cavity, with an increase in pathogenic bacteria that promote the onset of gingival diseases. This review is based on research in reference to the PICO model (Problem/Intervention/Comparison/Outcome), related to changes in the oral microbiome of pregnant women and possible oral consequences in patients with COVID-19. The results showed a growth of some pathogenic bacteria in pregnant women, including Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum, and the selective growth of the Prevotella intermedia, Porphyromonas gingivalis and Tannerella species, probably due to the fact that these bacteria use progesterone as a source of nutrition. These same bacteria are implicated in the development of periodontal disease. Periodontal pockets have bidirectional interactions between the oral cavity and the systemic circulatory system through the peripheral gingival blood vessels. The affinity of the SARS-CoV-2 virus to specific membrane receptors is now clear, and could involve the internal and external epithelial lining or the fibroblasts of the periodontal ligament. According to the results of the present review, the control of oral microbiome changes during pregnancy would be welcomed. The use of probiotics could help clinicians manage pregnant patients, reducing inflammatory indexes. Future studies should focus not only on changes in the level of the oral microbiome in pregnancy or the correlation between periodontal disease and COVID-19, but also on oral changes induced by both clinical situations.