The current situation and future directions for the study on time-to-pregnancy: a scoping review

Abstract

Introduction As problems associated with infertility and population aging increase, there is a growing interest in the factors that cause a decline in human fertility. Time-to-pregnancy (TTP) is a good indicator with which to reflect human fecundability. Here, we present a comprehensive overview of this topic. Methods Relevant qualitative and quantitative studies were identified by searching the Web of science and PubMed electronic databases. We included all literature, written in English, from inception to the 10th April 2021 providing the focus was on TTP. We conducted a narrative synthesis using thematic analysis. Results Traditional TTP-related study protocols include prospective and retrospective cohorts that provide a wealth of data to reveal potential influences on TTP. Thus far, a variety of factors have been shown to be associated with TTP in couples preparing for pregnancy, including basic demographic characteristics, menstrual status, chronic disease status, environmental endocrine disruptor exposure, and lifestyles. However, there are inevitable epidemiological bias in the existing studies, including recall bias, selection bias and measurement bias. Some methodological advances have brought new opportunities to TTP research, which make it possible to develop precision interventions for population fertility. Future TTP studies should take advantage of artificial intelligence, machine learning, and high-throughput sequencing technologies, and apply medical big data to fully consider and avoid possible bias in the design. Conclusion There are many opportunities and future challenges for TTP related studies which would provide a scientific basis for the “precise health management” of the population preparing for pregnancy.

Plasma Proteomics Analysis of Early Biomarkers for Predicting Female Fecundability: A Nested Case-Control Study

“…Based on the results of MS-based proteomics analysis and determination of pyruvate levels, this study confirmed that plasma proteins are beneficial in predicting low fecundability. According to previous studies, women with longer time-to-pregnancy (TTP) have difficulty in conceiving . Our study revealed that the plasma expression levels of PKM, ALDH2, ALDOC, IDH3A, DLST, ER, GAPDH, and pyruvate were significantly lower in infertile women than in women with a shorter TTP who have a greater likelihood of conceiving.…”

“…According to previous studies, women with longer time-to-pregnancy (TTP) have difficulty in conceiving. 15 Our study revealed that the plasma expression levels of PKM, ALDH2, ALDOC, IDH3A, DLST, ER, GAPDH, and pyruvate were significantly lower in infertile women than in women with a shorter TTP who have a greater likelihood of conceiving. Thus, the downregulation of these proteins indicates a poor pregnancy potential.…”

Female fecundability is associated with pre‐pregnancy allostatic load: Analysis of a Chinese cohort

“…All of the women reported they did not smoke. This information was potentially associated with female fecundability 19 and were therefore selected as confounding factors in our study.…”

Subjective biology: how perceived fecundity influences relationship satisfaction and stability

“…Male fecundity can be assessed based on semen quality, testicular volume, and hormonal profiles (Olsen & Ramlau-Hansen, 2014). One measure of couple fecundability is the number of calendar months or menstrual cycles required to conceive, with a longer time-to-pregnancy (TTP) indicating lower fecundity (Hong et al, 2022).…”