Effect of ejaculatory abstinence period on fertilization and clinical outcomes in ICSI cycles: a retrospective analysis.

RESEARCH QUESTION: Does ejaculatory abstinence impact fertilization outcomes in intracytoplasmic sperm injection (ICSI) cycles in infertile couples? DESIGN: This single-centre retrospective observational study included 6919 ICSI cycles from 2013 to 2022. The primary outcome was the assessment of oocyte fertilization, measured in terms of the rate of formation of two-pronuclear (2PN), 3PN and 1PN zygotes. Secondary outcomes were blastulation, cumulative positive ß-human chorionic gonadotrophin test and clinical pregnancy rates. Relationships between ejaculatory abstinence and fertilization outcomes, and ejaculatory abstinence and clinical outcomes were evaluated with multivariable analysis, including possible confounders. RESULTS: A positive association was observed between ejaculatory abstinence and semen sample volume (P < 0.001), sperm concentration (P < 0.001) and total motile sperm count (P < 0.001). No association was found between the 1PN zygote rate and ejaculatory abstinence (P = 0.97). Conversely, for each additional day of ejaculatory abstinence, the likelihood of obtaining 2PN zygotes from all inseminated oocytes decreased by 3% [adjusted odds ratio (aOR) 0.97, 95% CI 0.94-0.99], whilst the likelihood of obtaining 3PN zygotes from all inseminated oocytes increased significantly by 14% (aOR 1.14, 95% CI 1.07-1.22). No significant associations were found between ejaculatory abstinence and blastulation, cumulative pregnancy or miscarriage rates. CONCLUSIONS: A longer ejaculatory abstinence period significantly decreases the rate of 2PN zygotes, and increases the rate of 3PN zygotes without directly affect blastulation and pregnancy rates.

Greater estimated fetal weight and birth weight in IVF/ICSI pregnancy after frozen-thawed vs fresh blastocyst transfer: prospective cohort study with novel unified modeling methodology.

OBJECTIVE: To compare, using a unified approach, standardized estimated fetal weight (EFW) trajectories from the second trimester to birth and birth-weight (BW) measurements in in-vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) pregnancies obtained after frozen-thawed vs fresh blastocyst transfer (BT). METHODS: This was a secondary analysis of a prospective longitudinal cohort study performed at the Fetal Medicine and Obstetric Departments of San Raffaele Hospital in Milan, Italy, from January 2016 to December 2020. Eligible for inclusion were singleton viable gestations conceived by autologous IVF/ICSI conception after fresh or frozen-thawed BT that underwent standard fetal biometry assessment at 19-41 weeks and had BW measurements available. All ultrasound assessments were performed by operators blinded to the employment of cryopreservation. Patients with twin gestation, significant pregestational disease, miscarriage, major fetal abnormalities and use of other types of medically assisted reproduction techniques were excluded. EFW and BW Z-scores and their trajectories were analyzed using general linear models (GLM) and logistic regression with a unified modeling methodology based on the Fetal Medicine Foundation fetal and neonatal population weight charts, adjusting for major confounders. Differences between prenatal EFW and postnatal BW centiles in the two groups were assessed and compared using contingency tables, χ2 test and conversion of prenatal to postnatal centiles. RESULTS: A total of 631 IVF/ICSI pregnancies were considered, comprising 263 conceived following fresh BT and 368 after frozen-thawed BT. A total of 1795 EFW observations were available (n = 715 in fresh BT group and n = 1080 in frozen-thawed BT group; median of three observations per patient). EFW and BW < 10th centile were significantly more frequent in the fresh than in the frozen-thawed BT group (P = 0.003 and P < 0.001, respectively). EFW and BW > 90th centile were significantly more frequent in the frozen-thawed vs fresh BT group (P = 0.034 and P = 0.002, respectively). GLM showed significantly decreasing EFW Z-scores with advancing gestational age (GA) in both groups. The effect of GA was assumed to be equal in the two study groups, as no significant interaction effect was found. Smoothed mean EFW Z-scores from 19 weeks of gestation to term and smoothed mean BW Z-scores were both significantly higher in the frozen-thawed compared with the fresh BT group (EFW Z-score, 0.70 ± 1.29 vs 0.28 ± 1.43; P < 0.001; BW Z-score, 0.04 ± 1.08 vs -0.31 ± 1.28; P < 0.001). Mean smoothed EFW Z-score values in the frozen-thawed vs fresh BT groups were 1.01 ± 0.12 vs 0.60 ± 0.08 at 19-27 weeks, 0.36 ± 0.07 vs -0.06 ± 0.04 at 28-35 weeks and -0.66 ± 0.01 vs -0.88 ± 0.02 at 36-41 weeks. Mean smoothed BW Z-score values in the frozen-thawed vs fresh BT groups were -0.80 ± 0.14 vs -1.20 ± 0.10 at 28-35 weeks and 0.22 ± 0.16 vs -0.24 ± 0.14 at 36-41 weeks. Assessment of EFW and BW concordance showed a significantly greater rate of postnatal confirmation of prenatally predicted small-for-gestational age (SGA) < 10th centile in the fresh compared with the frozen-thawed BT group (P < 0.001), whereas the rate of postnatal confirmation of large-for-gestational age (LGA) > 90th centile was significantly higher in the frozen-thawed vs the fresh BT group (P < 0.001). Logistic regression analysis showed that the smoothed rate of EFW < 3rd centile was about 6-fold higher in the fresh vs frozen-thawed BT group (P < 0.001), whereas the smoothed rates of EFW 90th -97th centile and > 97th centile were nearly double in the frozen-thawed compared with the fresh BT group (P < 0.05 and P < 0.001, respectively). CONCLUSIONS: Robust novel unified prenatal-postnatal modeling in IVF/ICSI pregnancies after frozen-thawed or fresh BT from 19 weeks of gestation to birth showed non-divergent growth trajectories, with higher EFW and BW Z-scores in the frozen-thawed vs fresh BT group. The mean EFW Z-scores in both IVF/ICSI groups were greater than those expected for natural conceptions, being highest in the midtrimester and decreasing with advancing gestation in both groups, becoming negative after 32 weeks in the fresh and after 35 weeks in the frozen-thawed BT group. Mean BW Z-scores were negative in both groups, with lower values in preterm fetuses, and increased with advancing gestation, becoming positive at term in the frozen-thawed BT group. IVF/ICSI conceptions from frozen-thawed as compared to fresh BT presented increased rate of LGA and reduced rate of SGA both prenatally and postnatally. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Dietary habits and semen parameters: a systematic narrative review.

Semen quality and male fertility are declining worldwide. As it was observed that physiologic and pathologic processes of spermatogenesis can be influenced by diet, the relation between dietary habits and semen parameters has been the focus of much interest. To review the human observational studies on this issue, we performed a systematic literature search, up to November 2016 (MEDLINE and EMBASE). We included all observational full-text papers reporting the relation between dietary habits and semen parameters. Article selection was carried out in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Twenty-three observational studies were included. Overall, 8477 healthy men and 1204 men presenting at Fertility Clinics were included in the selected studies. Even if some inconsistencies are present, possibly due to the different effect of nutrients in fertile and infertile men, results support the hypothesis that diets including fruit and vegetables, for their contents in vitamins, and fish or low-fat dairy products as the main source of proteins, are associated with better semen quality. Recommendations may be confidently provided because of the many beneficial effects of a healthy diet, although further studies are needed to clarify the currently inconsistent findings and to shed light on the underlying mechanisms.