Euploid miscarriage is associated with elevated serum C-reactive protein levels in infertile women: a pilot study

Evaluation of Oxidative and Nitrosative Stress Markers Related To Inflammation in The Cumulus Cells and Follicular Fluid of Women Undergoing Intracytoplasmic Sperm Injection: A Prospective Study

BACKGROUND

Oxidative/nitrosative stress in the oocyte microenvironment could have an impact on intracytoplasmic sperm injection (ICSI) outcomes. The presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) can stimulate the secretion of pro-inflammatory cytokines, leading to chronic inflammation and potentially affecting embryo as well as oocyte quality. This study aimed to examine the relationship of lipid peroxidation [measured by the malondialdehyde (MDA) assay] with protein carbonyl [measured by the 2,4 dinitrophenylhydrazine (DNPH) assay] levels in cumulus cells (CCs), as well as nitric oxide (NO), peroxynitrite (ONOO-), and C-reactive protein (CRP) levels in follicular fluid (FF). The potential relationship of these levels with ICSI outcome was also evaluated.

MATERIALS AND METHODS

In this prospective study, 63 FF samples and their corresponding CCs were collected for ICSI procedures. Spectrophotometry was used to assess levels of DNPH, MDA, NO, and ONOO-. CRP levels were evaluated using an immunoturbidimetric assay.

RESULTS

The patients under 37 years with normal ovarian reserve had significantly lower levels of MDA, DNPH, NO, ONOO-, and CRP compared to those over 37 years. Additionally, we observed higher levels of MDA, DNPH, NO, ONOO-, and CRP in the group with an oocyte maturity rate of less than 60%. No significant difference was observed between the DNPH levels and factors such as infertility duration, embryo quality, pregnancy, or the number of retrieved oocytes. A higher level of MDA, NO, ONOO-, and CRP was found to be significantly related to the lower number of retrieved oocytes, longer periods of infertility, poor embryo quality, and negative pregnancy outcomes.

CONCLUSION

Oxidative/nitrosative stress, linking to inflammation in the oocyte microenvironment, can be considered as a potentially useful biomarker for assessing the development and competence of oocytes and embryos and predicting ICSI outcomes.

Low-grade inflammation is negatively associated with live birth in women undergoing IVF

RESEARCH QUESTION

Is low-grade inflammation, detected by C-reactive protein (CRP), a marker of IVF outcome addressing both blastocyst quality and pregnancy outcome?

DESIGN

This sub-study of a multicentre randomized controlled trial included 440 women undergoing IVF treatment with a gonadotrophin-releasing hormone (GnRH) antagonist protocol. Serum CRP was measured on cycle day 2-3 (baseline) and on the day of ovulation triggering. The association between CRP concentrations and reproductive outcomes (number of retrieved oocytes, number of good-quality blastocysts, pregnancy, pregnancy loss and live birth), were analysed, adjusting for relevant confounders.

RESULTS

A negative association was found between higher baseline CRP concentrations and live birth rate (odds ratio [OR] 0.77, 95% confidence interval [CI] 0.62-0.96, P = 0.02) and higher CRP concentrations at baseline were associated with pregnancy loss among women who conceived (OR 1.37, 95% CI 1.07-1.76, P = 0.01). When testing for a specific cut-off, CRP concentrations above 2.34 (the highest quartile) were more likely to be associated with pregnancy loss (P = 0.02) and a lower chance of live birth (P = 0.04) compared with the lowest quartile. No associations were found between CRP concentrations and pregnancy outcomes on the day of ovulation triggering, and there were no associations between CRP concentrations and the number of good-quality blastocysts.

CONCLUSIONS

Higher CRP concentrations at cycle day 2-3, before starting ovarian stimulation, are negatively associated with chance of live birth, possibly because of an increased risk of pregnancy loss. No association was found between the number of good-quality blastocysts and CRP concentration. More studies are needed to investigate the impact of low-grade inflammation.

Female reproductive tract microbiome and early miscarriages

Miscarriage is one of the main causes of reproductive loss, which can lead to a number of physical and psychological complications and other long-term consequences. However, the role of vaginal and uterine microbiome in such complications is poorly understood. To review the published data on the function of the female reproductive tract microbiome in the pathogenesis of early miscarriages. The articles published over the past 20 years and deposited in PubMed, Google Academy, Scopus, Elibrary, ResearchGate, and EBSCO databases were analyzed. The review presents new data on the impact of the vaginal and uterine microbiome on the local immunity, including defense against sexually transmitted infections, and its association with other factors of miscarriages. The studies on the microbiome of non-pregnant women with recurrent miscarriages in the anamnesis, patients undergoing IVF, and pregnant women with miscarriages, as well as new directions in the microbiome research are discussed. The majority of studies have demonstrated that the dominant species of the vaginal and uterine microbiome in patients with early miscarriages are non-Lactobacillus bacteria. As many of these bacteria have not previously been detected by cultural studies and their role in obstetric complications is not well defined, further research on the female reproductive tract microbiome, including the microbiome of the cervix uteri, is needed to develop new approaches for the prognosis and prevention of miscarriages.

High-sensitivity C-reactive protein levels and pregnancy outcomes in women with unexplained infertility after ovarian stimulation with intrauterine insemination in a multicenter trial

Objective

To determine if chronic inflammation, assessed by basal high-sensitivity C-reactive protein (hs-CRP) levels, is associated with pregnancy outcomes in women with unexplained infertility undergoing ovarian stimulation with intrauterine insemination.

Design

Prospective cohort analysis of the Reproductive Medicine Network's Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS) randomized controlled trial.

Setting

Multicenter university-based randomized controlled trial.

Patients

A total of 781 couples with unexplained infertility.

Interventions

Secondary analysis.

Main Outcome Measures

Adjusted risk ratios of live birth, clinical pregnancy, and pregnancy loss rates by hs-CRP levels.

Results

Associations between hs-CRP levels and clinical pregnancy rates were not observed after adjustment for baseline body mass index. There were fewer live births among women with higher hs-CRP levels, although confidence intervals crossed 1.0. The risk of pregnancy loss was greater in women with increased hs-CRP levels (1-3 mg/L: risk ratio [RR], 1.67; 95% confidence interval [CI], 1.00-2.79; >3-10 mg/L: RR, 1.84; 95% CI, 1.06-3.20; and >10 mg/L: RR, 2.14; 95% CI, 1.05-4.36 compared to women with hs-CRP <1 mg/L).

Conclusions

This investigation suggests that chronic inflammation may increase the risk of pregnancy loss but not impact the clinical pregnancy rate in women with unexplained infertility undergoing ovarian stimulation with intrauterine insemination. Associations between inflammation and pregnancy outcomes in women with infertility merit further investigation.

Clinical Trial Registration Number

clinicaltrials.gov NCT01044862.

Inflammation and Conception in a Prospective Time-to-Pregnancy Cohort

BACKGROUND

Inflammation may contribute to subfertility but this has not been well-explored in large prospective cohort studies.

METHODS

We conducted a prospective 12-month cohort study of time to pregnancy in North Carolina, the Time to Conceive study (2010-2016). Participants were 30-44 years old, without a history of infertility (N = 727). We analyzed blood samples with a high sensitivity assay for C-reactive protein (CRP). Women reported their weight, height, and other covariates. We natural log-transformed CRP and examined it (1) linearly, after exploration using restricted cubic splines and (2) in categories based on American Heart Association criteria. We estimated fecundability ratios (FRs) with log-binomial discrete-time-to-pregnancy models. Separate models included an interaction term with body mass index (BMI).

RESULTS

The adjusted estimated FR per natural log-unit increase in CRP level was 0.97 (confidence interval [CI] = 0.91, 1.0). The FR (CI) for high CRP (>10 mg/L) compared with low CRP (<1 mg/L) was 0.78 (0.52, 1.2). Compared with normal-weight women with low CRP, women with obesity and high CRP had lower estimated fecundability, but the confidence interval was wide (FR = 0.63; CI = 0.35, 1.1). There was no pattern in the estimated fecundability across levels of CRP within categories of BMI.

CONCLUSIONS

There was no evidence of an association between CRP and fecundability either alone or within levels of BMI. Further studies of CRP and fecundability should include higher levels of CRP and additional markers of inflammation.