Clinical trial NCT04688866: Investigation Into the Microorganisms in Pregnant Women
Official title: Investigation Into the Fungal Microbiome (Mycobiome) in the Cervices of Cervical Insufficiency Patients Receiving Cerclage Treatment and Resulting in Term or Preterm Birth
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Cervical Insufficiency
Preterm Birth
Keywords: preterm birth
cervical insufficiency
cerclage
pessary
Lead sponsor: Chinese University of Hong Kong
Sponsor class: OTHER
Collaborators: name: Hallym University
name: Health and Medical Research Fund
First posted: 2020-12-30
Enrollment: 200
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Pregnant women who attend preterm clinics or receive antenatal care at the participating hospitals.

Brief summary: Pregnant women with short cervical length (\<25 mm) in second-trimester ultrasonographic assessment are at high risk for preterm birth, a major cause of perinatal mortality and morbidity worldwide. Some of these short-cervix women proceed to a more advanced stage manifested as a painless prematurely dilated cervix in the second trimester. It is not fully understood why some women have short cervical length or prematurely dilated cervix (cervical insufficiency), although evidence is mounting that there is an association between short cervical length and infection by microorganisms. The investigators hypothesize that the cervical microorganisms in pregnant women with a shortened or dilated cervix are different, compared with those in women with normal cervical length and a closed cervix.

Detailed description: Previously, culture-dependent methods were used to detect bacterial or fungal infection, but the sensitivity was low, since not all species grew well in culture. Recently, molecular methods based on PCR amplification of the bacterial 16S ribosomal RNA (rRNA) gene or the fungal internal transcribed spacer (ITS) followed by capillary sequencing has been used to identify bacteria and fungi. However, the resolution of such capillary sequencing-based method (\<100 sequencing reads/sample) is too low to capture the major collection of microorganisms in a sample. Less abundant but possibly pathogenic microorganisms associated with short cervical length remain undetectable. To address the current gap in this field, we propose to more comprehensively survey microbial communities in the cervix of pregnant women by PCR amplification of the 16S rRNA region, ITS or other genomic regions with taxonomic classification potential. This will be followed by next-generation sequencing (\>40,000 sequencing reads/sample), which has been proven to capture the majority of microorganisms in a sample.

Eligibility criteria: Inclusion Criteria:

* Women with or without cervical insufficiency (cervical length \<25 mm or dilated cervix in the second trimester or the late first trimester)

Exclusion Criteria:

* multiple pregnancies and pregnancies associated with fetal chromosomal abnormality

Primary outcomes:
measure: Abundances of microorganisms in the cervix
timeFrame: 1 year
Secondary outcomes:
measure: Gestational age at delivery
timeFrame: 1 year
measure: Mode of delivery
timeFrame: 1 year
measure: Number of participants who received cerclage or ring pessary in the current pregnancy
timeFrame: 1 year
Other outcomes:
Locations:
city: Hong Kong
country: Hong Kong
facility: Research Laboratory, Dept of Obstetrics & Gynaecology, The Chinese University of Hong Kong
Study officials:
affiliation: Chinese University of Hong Kong
name: Stephen S Chim, PhD
role: PRINCIPAL_INVESTIGATOR
References: