Investigation on silent bacterial infections in specimens from pregnant women affected by spontaneous miscarriage

Area of Science:

• Reproductive Medicine
• Microbiology
• Genetics

Background:

• Miscarriage is a significant pregnancy complication.
• The role of subclinical bacterial infections in adverse pregnancy outcomes remains under-investigated.
• Ureaplasma, Mycoplasma, and Chlamydia are potential pathogens in reproductive health.

Purpose of the Study:

• To investigate the presence and load of Ureaplasma parvum, Ureaplasma urealiticum, Mycoplasma hominis, and Chlamydia trachomatis DNA in women experiencing spontaneous abortion (SA) versus voluntary interruption (VI).
• To explore the association between these bacterial infections and spontaneous abortion.
• To establish a baseline for understanding silent infections in pregnancy complications.

Main Methods:

• Polymerase chain reaction (PCR) methods were used to detect bacterial DNA sequences.
• Quantitative real-time PCR (qPCR) was employed for the first time to measure bacterial DNA load.
• Samples were analyzed from chorionic villi tissues and peripheral blood mononuclear cells (PBMCs) of 100 SA and 100 VI cases.

Main Results:

• Ureaplasma parvum DNA was detected in 14% of SA and 15% of VI cases, with higher DNA load in SA.
• Ureaplasma urealiticum, Mycoplasma hominis, and Chlamydia trachomatis DNA were detected at lower percentages (2-6%) in both SA and VI groups.
• Bacterial DNA prevalence in PBMCs was low (1-3%) across both groups.

Conclusions:

• The study detected specific bacterial DNA in both spontaneous abortion and voluntary interruption cases, suggesting a potential role for these infections in pregnancy complications.
• Quantitative analysis revealed differences in bacterial DNA loads, particularly for Ureaplasma parvum, between SA and VI groups.
• Further research is warranted to elucidate the precise mechanisms by which these 'silent' infections contribute to adverse pregnancy outcomes like miscarriage.