reSeArcH Article
Extended Data Fig. 1 | Two cohorts of placental samples were analysed.
Cohort 1 (n = 80) contained only samples from pre-labour Caesarean
section (CS) deliveries and S. bongori was added to the samples before
DNA isolation as a positive control. Samples in cohort 1 were analysed
by both metagenomics and16S rRNA amplicon sequencing. Cohort
2 (n = 498) contained placental samples from Caesarean section and
vaginal deliveries. DNA was isolated twice from each placental sample
with two different DNA extraction kits. Samples were analysed by 16S
rRNA amplicon sequencing. Pre-eclampsia (PE) was defined using The
American College of Obstetricians and Gynaecologists (ACOG) 2013
definition. Small for gestational age (SGA) was defined as a birth weight
less than the fifth percentile using a customized reference. Preterm denotes
birth before 37 weeks gestation.