Factors associated with having COVID-19 among unvaccinated pregnant and non-pregnant women in Metro Manila, Philippines: a multicentre longitudinal cohort study.

OBJECTIVE: To determine the potential risk factors associated with having COVID-19 among unvaccinated pregnant and non-pregnant women. DESIGN: A multicentre prospective cohort study among eligible women in Metro Manila, Philippines, from 2020 to 2022. SETTING: Five national and local hospital research sites altogether recruited and screened 500 consenting eligible individuals. PARTICIPANTS: Pregnant and non-pregnant participants meeting the eligibility criteria were admitted for a reverse-transcription PCR determination of SARS-CoV-2, pregnancy testing and ultrasound, and an interview with an administered questionnaire. EXPOSURES: Primary exposure was pregnancy; secondary exposures involve sociodemographic, lifestyle and obstetric-gynaecologic factors. OUTCOME MEASURE: Outcome being measured was COVID-19 status. RESULTS: The significant COVID-19 risk factors were: pregnancy (PR=1.184, 95% CI 1.096, 1.279), having a white-collar job (PR=1.123, 95% CI 1.02, 1.235), travelling abroad (PR=1.369, 95% CI 1.083, 1.173) and being infected by at least one vaccine-preventable disease (VPD) (PR=1.208, 95% CI 1.113, 1.310). Protective factors included having graduate-level education (PR=0.787, 95% CI 0.649, 0.954), immunisation against a VPD (PR=0.795, 95% CI 0.733, 0.862) and practising contraception (PR=0.889, 95% CI 0.824, 0.960). CONCLUSION: This study is the first in the country to determine the risks influencing COVID-19 infection among unvaccinated pregnant and non-pregnant women. Pregnancy is a significant risk for COVID-19 among women in Metro Manila. Educational attainment and positive health behaviours seem to confer protection. Occupations and activities that increase the frequency of interactions, as well as history of communicable diseases may predispose women to COVID-19. Further studies are needed to elucidate the development of the disease in pregnant women, including the maternal and neonatal effects of COVID-19 via potential vertical mechanisms of transmission.

Risk factors of COVID-19 vertical transmission among pregnant and non-pregnant Filipinos in Metro Manila: a multicentre cohort study protocol.

INTRODUCTION: The novel (COVID-19 was first reported to have originated in Wuhan, China, in December 2019. This new strain, SARS-CoV-2, has spread rapidly worldwide, prompting the WHO to declare the COVID-19 outbreak a global pandemic. The main objective of this cohort study is to determine the risk factors of COVID-19, the modes of COVID-19 vertical transmission, and the maternal and fetal outcomes among non-pregnant and pregnant women and their fetuses. METHODS AND ANALYSIS: This is a multicentre epidemiological study that will involve a prospective cohort. COVID-19 status among consulting non-pregnant and pregnant women in public hospitals in Manila, Philippines, will be determined and monitored for 6-12 months. Swab specimens from the nasopharynx, cervix, rectum, amniotic fluid, placenta, cord blood and breastmilk will be collected during consult and admission for reverse transcription-PCR (RT-PCR) testing. Blood will be collected during the postdelivery period to monitor the women and their neonates for any undue development and determine the antibody development to indicate an infective or non-infective state. Evidence of vertical transmission will be explored with the presence or absence of the virus using the maternal and fetal neonatal RT-PCR and lateral flow antibody status. Descriptive and inferential statistics will be done, including the associations between exposures and risk factors, description of clinical characteristics, and the COVID-19 status of the participants. ETHICS AND DISSEMINATION: The Single Joint Research Ethics Board of the Department of Health has approved this protocol (SJREB 2020-30). The study results will be disseminated through conference presentations, peer-reviewed articles, and various stakeholder public forums and activities.