Pregnancy microbiome

Also see separate pages with papers on infant colonization and human breast milk microbiome. Updated December, 2015.

Research papers

From our lab: Temporal and spatial variation of the human microbiota during pregnancy – Daniel B. DiGiulio et al. – PNAS – 2015

Using a case-control cohort of 40 women, we characterized weekly variation in the vaginal, gut, and oral microbiota during and after pregnancy.

Significant increase of oral bacteria in the early pregnancy period in Japanese women – Natsumi Fujiwara et al.– Journal of Investigative and Clinical Dentistry – 2015

The study was performed using 132 healthy pregnant women enrolled from Hiroshima City Asa Citizens Hospital and 51 healthy nonpregnant women as control. During pregnancy, 132 subjects were assessed for seven microbial species by the cultured method and polymerase chain reaction at the early (7–16 weeks gestation), the middle (17–28 weeks), and the late (29–39 weeks) pregnancy periods.

Diversity of the vaginal microbiome correlates with preterm birth – Richard W. Hyman et al. – Reproductive Sciences – 2014

The objective of this prospective cohort study of 88 participants was to determine whether PTB correlates with the vaginal microbiome during pregnancy. Total DNA was purified from posterior vaginal fornix swabs during gestation. The 16S ribosomal RNA gene was amplified using polymerase chain reaction primers, followed by chain-termination sequencing.

The Placenta Harbors a Unique Microbiome – Kjersti Aagaard – Science Translational Medicine – May 2014

A population-based cohort of placental specimens collected under sterile conditions from 320 subjects with extensive clinical data was established for comparative 16S ribosomal DNA–based and whole-genome shotgun (WGS) metagenomic studies.


A Metagenomic Approach to Characterization of the Vaginal Microbiome Signature in Pregnancy – Kjersti Aagaard- PLOS ONE – 2012

DNA was isolated from the vagina (introitus, posterior fornix, midvagina) and the V5V3 region of bacterial 16S rRNA genes were sequenced (454FLX Titanium platform). Sixty-eight samples from 24 healthy gravidae (18 to 40 confirmed weeks) were compared with 301 non-pregnant controls (60 subjects).

Host Remodeling of the Gut Microbiome and Metabolic Changes during Pregnancy – Omry Koren, Julia K. Goodrich, Tyler C. Cullender, Aymé Spor, Kirsi Laitinen, Helene Kling Bäckhed, Antonio Gonzalez, Jeffrey J. Werner, Largus T. Angenent, Rob Knight, Fredrik Bäckhed, Erika Isolauri, Seppo Salminen, Ruth E. Ley – Cell – 2012

Here, to explore their role in pregnancy, we characterized fecal bacteria of 91 pregnant women of varying prepregnancy BMIs and gestational diabetes status and their infants.

Vaginal microbiota of healthy pregnant Mexican women is constituted by four Lactobacillus species and several vaginosis-associated bacteria – Hernández-Rodríguez C, et al – Infect Dis Obstet Gynecol – 2011

Vaginal swabs were obtained during the prenatal visit of women from all trimesters () of healthy pregnant women of Mexico City. DNA was isolated from each sample, and PCR-DGGE and sequencing of 16S rRNA gene fragments were used to identify the bacterial communities.

The vaginal microbiota of pregnant women who subsequently have spontaneous preterm labor and delivery and those with a normal delivery at term – Roberto Romero et al. – Microbiome – 2014

This was a nested case–control study of pregnant women who had a term delivery (controls) and those who had a spontaneous preterm delivery before 34 weeks of gestation (cases). Samples of vaginal fluid were collected longitudinally and stored at −70°C until assayed. A microbial survey using pyrosequencing of V1-V3 regions of 16S rRNA genes was performed.

The composition and stability of the vaginal microbiota of normal pregnant women is different from that of non-pregnant women – Roberto Romero et al. – Microbiome – 2014

A retrospective case–control longitudinal study was designed and included non-pregnant women (n = 32) and pregnant women who delivered at term (38 to 42 weeks) without complications (n = 22). Serial samples of vaginal fluid were collected from both non-pregnant and pregnant patients. A 16S rRNA gene sequence-based survey was conducted using pyrosequencing to characterize the structure and stability of the vaginal microbiota.

Longitudinal analysis of the vaginal microflora in pregnancy suggests that L. crispatus promotes the stability of the normal vaginal microflora and that L. gasseri and/or L. iners are more conducive to the occurrence of abnormal vaginal microflora – Hans Verstraelen, et al. – BMC Microbiology 2009

From 100 consecutive Caucasian women vaginal swabs were obtained at mean gestational ages of 8.6 (SD 1.4), 21.2 (SD 1.3), and 32.4 (SD 1.7) weeks, respectively.

Review papers

Potential NICU Environmental Influences on the Neonate’s Microbiome: A Systematic Review – Hartz, Lacey E.; Bradshaw, Wanda; Brandon, Debra H. – Advances in Neonatal Care – 2015