Vaginal, Placental and Neonatal Buccal Mycobiota and Microbiome in Preterm Birth

Summary

Participation Requirements

Description

Preterm birth is responsible for more than 70% of all neonatal and infant deaths. In addition, the risk of cerebral palsy among children born preterm is 10 times than those born at term. The risk of preterm birth is inversely related to cervical length at midgestation. Randomized-controlled trials i...

Preterm birth is responsible for more than 70% of all neonatal and infant deaths. In addition, the risk of cerebral palsy among children born preterm is 10 times than those born at term. The risk of preterm birth is inversely related to cervical length at midgestation. Randomized-controlled trials involving singleton pregnancies with a short cervical length ( less than 25 mm) have shown that the prophylactic use of progesterone significantly decrease the rate of preterm delivery and neonatal death. The relation of vaginal micobiota with preterm birth has been documented. Yet, impact of short cervical lenght and progesteron treatment on vaginal, neonatal and placental microbiota and mycobiota has not been evaluated. The objectives of present study are to adress the following points; Longitudinal maternal (vaginal), fetal (oral) and placental (basal plate and parenchyma) 16S-based and 18S-based metagenomic profiling with inferred metagenomics will reveal distinct microbial communities in association with preterm birth. Comparison of vaginal, neonatal (buccal) and placental (basal plate and parenchyma) 16s rRNA with bacteria and 18s rRNA with fungi in pregnant women with a short cervical length with those with normal cervical length; 2. Comparison of maternal (vaginal), neonatal(oral) and placental (basal plate and parenchyma)16s rRNA with bacteria and 18s rRNA with fungi in pregnant women with short cervical length who gave a preterm birth with those who gave birth at term; 3. The effect of progesterone on maternal (vaginal), neonatal (buccal) and placental (basal plate and parenchyma)16s rRNA with bacteria and 18s rRNA with fungi. The measurements of cervical length will be performed in two different periods of pregnancy (11-14 and 18-22 weeks of gestation) in singleton pregnancies. Firstly, the vaginal swabs will be collected from women who accept to participate in the study at 11-14th weeks of gestation just before the measurement of cervical length. Also, the vaginal swabs will be done again at 18-22 weeks of gestation as explained above. Micronized progesterone will be started in women with a cervical length equal or less than 25 mm (smaller than 3rd percentile) at 18-22 weeks of gestation. The medication (progesterone 200mg) will be administered intravaginally every night before bedtime and will continue until 36th gestational week unless the patient gives birth. Measurement of cervical length will be repeated transvaginally at 28th and 32nd gestational weeks, and samples will be obtained with a cervical swab before these measurements. In order to evaluate the presence of placental mycobiota and microbiota, 1 cm x 1 cm x 1 cm of the tissue sample from the placenta that is 3 cm lateral of the cord insertion will be taken under sterile conditions after birth. In order to evaluate the amniotic compartment, a buccal mucosal swab will be collected from the neonates immediately after birth. All samples will be delivered to our Research Laboratory immediately and stored in -80 ? cabinet until the evaluation. The V3-V4 regions by the 16s ribosomal RNA sequencing method will be sequenced with the Illumina MiSeq device and the data will be analyzed according to the protocols standardized in the Human Microbiome Project. DNA samples that will be ranked from the data to be sequenced in accordance with the ITS1 region metabiota protocol will be evaluated within the Human Microbiome Project. Pseudomonas, Escherichia, Neisseria, Streptococcus, Lactobacillus, Candida, Actinomyces will be used as positive controls and, V3-V4 and ITS regions will be matched for bacterial microbiota and Fungal microbiota. After the "Operational taxonomic units" of the amplicons are configured with the VSEARCH program, the analyzes will be carried out with GENBANK microbiota and micobiota data.

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