Risk Factors for Infertility in Korean Women.

BACKGROUND: Female infertility is a crucial problem with significant implications for individuals and society. In this study, we explore risk factors for infertility in Korean women. METHODS: A total of 986 female patients who visited six major infertility clinics in Korea were recruited from April to December 2014. Fertile age-matched controls were selected from two nationwide survey study participants. Conditional logistic regression after age-matching was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of each risk factor for infertility. RESULTS: Women with a body mass index (BMI) < 18.5 kg/m² had 1.35 times higher odds of infertility (OR, 1.35; 95% CI, 1.03-1.77), while those with a BMI ≥ 25.0 kg/m² had even higher odds (OR, 2.06; 95% CI, 1.61-2.64) compared to women with a normal BMI (18.5 kg/m² ≤ BMI < 25 kg/m²). Ever-smokers exhibited 4.94 times higher odds of infertility compared to never-smokers (95% CI, 3.45-8.85). Concerning alcohol consumption, women who consumed ≥ 7 glasses at a time showed 3.13 times significantly higher odds of infertility than those who consumed ≤ 4 glasses at a time (95% CI, 1.79-5.48). Lastly, women with thyroid disease demonstrated 1.44 times higher odds of infertility compared to women without thyroid disease (95% CI, 1.00-2.08). CONCLUSION: Female infertility in Korea was associated with underweight, obesity, smoking, alcohol consumption, and thyroid disease.

Effect of insemination timing on pregnancy outcome in association with female age, sperm motility, sperm morphology and sperm concentration in intrauterine insemination.

AIM: We investigated the effect of insemination timing on pregnancy outcomes in intrauterine insemination (IUI) cycles. METHODS: This is a retrospective study of 411 IUI cycles performed with a diagnosis of unexplained infertility and male factor infertility. The cycles were divided according to the interval between insemination and ovulation: ≤36 h, 36-37 h, 37-38 h and >38 h. The overall pregnancy rate, chemical pregnancy rate and clinical pregnancy rate were compared. We also analyzed the association between pregnancy outcomes and clinical characteristics, including age, duration of infertility, sperm concentration, body mass index (BMI), anti-Müllerian hormone (AMH) and number of mature follicles at ovulation. RESULTS: There were no differences regarding age, duration of infertility, BMI, AMH, sperm concentration and number of mature follicles between different IUI timing groups. Sperm morphology was significantly lower in ≤36 h group (5.3 ± 1.4) compared to 36-37 h, 37-38 h and >38 h (6.3 ± 2.5 vs 6.5 ± 2.7 vs 6.5 ± 3.5, P = 0.004) groups. The ≤36 h group showed lowest total pregnancy rate (5.0%) compared to other IUI timings (21.8% vs 24.8% vs 20.0%, P = 0.05). Multivariate analysis showed that sperm morphology was associated with pregnancy in 36-37 h (odd ratio 1.42, 95% confidence interval 1.03-1.95, P = 0.02). CONCLUSION: Insemination at least 36 h after ovulation is associated with increased pregnancy rate compared to IUIs performed ≤36 h following ovulation.