Background Infertility is a reproductive health problem which affects not only individuals, families and social populations. Recently, the infertility rate in China has a trend of increase year by year, and few studies have reported the infertility rate in Henan Province, China. The aim of this study was to investigate the current prevalence and associated factors of infertility among women of childbearing age in Henan Province, China. Methods This cross-sectional study was conducted from March 2019 to October 2019. We sampled 765 women who were 20–49 years old in eight hospitals of four cities in Henan Province, China. This survey included a questionnaire, physical examination, vaginal ultrasound examinations, and serum anti-Mullerian hormone (AMH) assessment, all of which were conducted under uniform standards by trained personnel. According to the data collected from questionnaire, participants were divided into infertile and fertile groups and analyzed associated factors. Results Among all the 765 participants in this study, the prevalence of infertility was 24.58%. The prevalence of primary infertility was 6.54%, and the prevalence of secondary infertility was 18.04%. In logistic multivariate regression analyses, infertility was associated with age (p < 0.001), history of gynecological surgery (p < 0.001), sweet food (p = 0.003) and decreased ovarian reserve (DOR) (p < 0.001). After further analyses, factors associated with primary infertility were age of marriage (p = 0.006), age of first sexual intercourse (p = 0.003), long-term air-conditioning environment (p < 0.001), decreased ovarian reserve (p = 0.005) and age (p = 0.002). And factors associated with secondary infertility were history of gynecological surgery (p < 0.001), decreased ovarian reserve (p = 0.002), waist-to-hip ratio (WHR) above 0.85 (p = 0.043), delivery times (p = 0.001) and ages (p < 0.001). Conclusion The prevalence of infertility among women aged 20–49 was 24.58% and only 61.17% infertile women sought medical help in Henan Province, China. Age, history of gynecological surgeries and DOR may increase the risk of infertility. Local public health departments and medical professionals need to discharge their duty of reducing the high incidence of infertility and protecting women’s reproductive health.

Cow dung (CD) is a waste product of livestock production. Improper disposal of a large amount of CD will cause environmental pollution. In this work, three biochar materials based on CD (BMCD) were prepared by using three types of base, including KOH, NaOH, and mixed base (MB, a mixture of equal mass NaOH and KOH) as activators to investigate the different physicochemical properties of BMCDs (BMCD-K, BMCD-Na, and BMCD-MB). The objective was to verify the effectiveness of MB activation in the preparation of biochar materials. The results show that MB has an effect on the structural characteristics of BMCDs. In particular, the surface area and total pore volume, the specific surface area, and the total pore volume of BMCD-MB (4081.1 m2 g−1 and 3.0118 cm3 g−1) are significantly larger than those of BMCD-K (1784.6 m2 g−1 and 1.1142 cm3 g−1) and BMCD-Na (1446.1 m2 g−1 and 1.0788 cm3 g−1). While synthetic dye rhodamine B (RhB) and antibiotic tetracycline hydrochloride (TH) were selected as organic pollutant models to explore the adsorption performances, the maximum adsorption capacities of BMCD-K, BMCD-NA and BMCD-MB were 951, 770, and 1241 mg g−1 for RhB, 975, 1051, and 1105 mg g−1 for TH, respectively, which were higher than those of most adsorbents. This study demonstrated that MB can be used as an effective activator for the preparation of biochar materials with enhanced performance.

For young women with normal ovarian reserve, retrieving 10∼12 oocytes might result in optimized pregnancy outcomes in a fresh cycle with low OHSS risk and would not compromise cumulative outcomes. When ≥16 oocytes were retrieved, a "freeze-all" embryo strategy might be preferable.