The influence of male age on treatment outcomes and neonatal birthweight following assisted reproduction technology involving intracytoplasmic sperm injection (ICSI) cycles

Indications affect neonatal outcomes following early rescue ICSI: a retrospective study

PURPOSE

To investigate the impact of heterogeneity in patient indications or insemination protocols on neonatal outcomes of singletons following early rescue ICSI (rICSI) treatments.

METHODS

A retrospective study was conducted. Propensity score matching and multivariable logistic regression were used to adjust for confounders and biases.

RESULTS

A total of 9095 IVF patients, 2063 ICSI patients, and 642 early rICSI patients were included in the study. No differences were detected in neonatal outcomes except small for gestational age (SGA) which increased in early rICSI patients compared with both unmatched and matched IVF groups with the risk ratio (RR) of 1.31 (95% CI: 1.05, 1.64) and 1.49 (95% CI: 1.05, 2.12). Further analysis showed that SGA increased significantly in partial fertilization failure (PFF) cycles with RRs of 1.56 (95% CI: 1.08, 2.27) and 1.78 (95% CI: 1.22, 2.59) compared with both unmatched and matched IVF patients but not in TFF patients. A positive association between fertilization rate via IVF and birth weight z-score was revealed in the PFF patients.

CONCLUSION

Early rICSI in patients with total fertilization failure (TFF) appeared to be safe in terms of neonatal outcomes. However, when expanding the indications of rICSI to PFF patients, the SGA in the offspring increased, suggesting a potential effect on long-term health. Since other treatment options, such as using only the IVF-origin embryos still exist for these patients, further studies were needed to confirm the optimal decision for these patients.

Impact of paternal age on assisted reproductive technology outcomes and offspring health: a systematic review

BACKGROUND

The increase in paternal age and the percentage of births after assisted reproductive technologies (ART) may have consequences on offspring and society's position regarding access to ART must be questioned. Most countries recommend limiting ART to men under 60 years. What is the rationale for this threshold?

OBJECTIVE

This systematic review assesses scientific arguments to establish links between paternal age, male fertility, and offspring health.

MATERIAL AND METHODS

Using the PRISMA guidelines, this systematic review of the literature analyzed 111 articles selected after screening PubMed, ScienceDirect, and Web of Science for articles published between January 1, 1995 and December 31, 2021.

RESULTS

A strong correlation was highlighted between advanced paternal age and a decrease of some sperm parameters (semen volume and sperm motility) and infant morbidity (exponentially increased incidence of achondroplasia and Apert syndrome, and more moderately increased incidence of autism and schizophrenia). The impact of paternal age on pregnancy and fetal aneuploidy rates is more controversial. No association was found with spontaneous abortion rates.

DISCUSSION AND CONCLUSION

The scientific parameters should be explained to older parents undergoing ART. And for countries that discuss a limit on paternal age for access to ART, the debate requires consideration of social and ethical arguments.

Association between paternal age and singleton birthweight in frozen embryo transfer cycles

BACKGROUND

Many studies have considered maternal age as a determinant factor for success in assisted reproductive technologies (ART), but the potential role of paternal age on neonatal outcomes has been overlooked. This study aimed to explore the association between paternal age and birthweight in frozen embryo transfer (FET) cycles.

METHODS

This retrospective study involved singleton live births born to women undergoing frozen embryo transfer from January 2013 to December 2017 at a tertiary care center in Shanghai, China. The paternal age was classified into four categories: ≤ 30, 31-35, 36-40, and ≥ 41 years. The group consisting of respondents with paternal age of 31-35 was set as the reference group. Singleton birthweight was the primary outcome measure. Z-scores were calculated according to gestational age and newborn gender on birthweight based on the national birthweight reference. Multivariable linear regression analysis was performed to reveal the relationship between paternal age and newborns' birthweight after considering several potential confounders.

RESULTS

Exactly 9765 women who fulfilled the inclusion criteria were enrolled. No significant difference was found on mean birthweight (P = 0.082) and gestation-adjusted Z-scores (P = 0.569) among paternal age categories. The reference group and the group with aged 36-40 years had the highest mean birthweight and Z-scores, respectively (3350.2 ± 467.8 g, 0.36 ± 1.00). A decline in mean birthweight with paternal age was observed, and the group over 40 years had the lowest value of 3309.4 ± 474.3 g, but the difference was not statistically significant. In multivariate analyses, the adjusted odds of very low birthweight (LBW), LBW, and high birthweight in the reference group did not significantly differ with the three other groups. After correcting several potential confounders, no significant correlation was observed between paternal age and neonatal birthweight (P = 0.289).

CONCLUSION

Paternal age was not associated with mean birthweight and gestational age- and gender-adjusted birthweight (Z-scores) of singletons among women who became pregnant in FET cycles.

Influence of paternal age on assisted reproductive technology cycles and perinatal outcomes

OBJECTIVE

To characterize paternal age among assisted reproductive technology (ART) cycles performed in the United States and to evaluate the influence of paternal age on ART cycles and perinatal outcomes.

DESIGN

Retrospective cohort.

SETTING

Not applicable.

PATIENT(S)

All reported fresh, nondonor, noncancelled in vitro fertilization (IVF) cycles performed in 2017.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

The primary outcomes were intrauterine pregnancy, live birth (≥20 weeks), and miscarriage (<20 weeks) per cycle start and per embryo transfer. The secondary outcomes were full-term live birth (≥37 weeks) among singleton and twin gestations. Modified Poisson regression was performed to estimate associations between paternal age and cycle and perinatal outcomes, overall and stratified by maternal age.

RESULT(S)

Among 77,209 fresh nondonor, noncancelled IVF cycles, the average paternal age was 37.8 ± 6.3 years and the average maternal age was 35.5 ± 4.6 years. Compared with paternal age ≤45 years, paternal age ≥46 years was associated with a lower likelihood of pregnancy per cycle (adjusted risk ratio [aRR] 0.81; 95% confidence interval [CI] 0.76-0.87) and per transfer (aRR 0.85; 95% CI 0.81-0.90), as well as a lower likelihood of live birth per cycle (aRR 0.76; 95% CI 0.72-0.84) and per transfer (aRR 0.82; 95% CI 0.77-0.88) after controlling for maternal age and other confounders. When restricted to women aged <35 years, there were no significant differences in the rates of live birth or miscarriage among couples in which the men were aged ≤45 years compared with those aged ≥46 years.

CONCLUSION(S)

Compared with paternal age ≤45 years, paternal age ≥46 years is associated with a lower likelihood of pregnancy and live birth among couples undergoing IVF. The negative effect of paternal age is most notable among women aged ≥35 years, likely because maternal age is a stronger predictor of ART outcome.

Sperm DNA fragmentation measured by sperm chromatin dispersion impacts morphokinetic parameters, fertilization rate and blastocyst quality in ICSI treatments

To determine the effects of sperm DNA fragmentation (SDF) on embryo morphokinetic parameters, cleavage patterns and embryo quality, this retrospective study analyzed 151 intracytoplasmic sperm injection (ICSI) cycles (1152 embryos collected) between November 2016 and June 2019. SDF was assessed using sperm chromatin dispersion. The cycles were divided into two groups based on the SDF rate: SDF < 15% (n = 114) and SDF ≥ 15% (n = 37). The embryo morphokinetic parameters, cleavage patterns, and embryo quality were compared between the two groups. The morphokinetic parameters tPNf, t2, t3, t4, t5, t6, and t8 were achieved significantly earlier in the SDF < 15% group compared with in the SDF ≥ 15% group. The fertilization and 2PN rates seemed to be significantly higher in the SDF < 15% group compared with in the SDF ≥ 15% group, while the abnormal cleavage rates were similar. However, a significantly higher rate of chaotic cleavage (CC) was observed in the SDF ≥ 15% group. The D3 high-quality embryo and available embryo rates were similar between the two groups. The blastocyst formation, high-quality blastocyst, and available blastocyst rates in the SDF < 15% group were significantly higher than those in the SDF ≥ 15% group. With an increase in SDF level, the chemical pregnancy, clinical pregnancy and implantation rates tended to decrease, while the miscarriage rate increased. This study demonstrated that SDF ≥ 15% reduces the fertilization rate of ICSI cycles and affects certain morphokinetic parameters. A higher SDF level can also induce a higher rate of CC, with subsequent decreases in the blastocyst formation rate and blastocyst quality.

Sperm origins and concentration do not impact the clinical outcomes in intracytoplasmic sperm injection cycles

In the present study, we evaluated the impact of sperm origins and concentration on the clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles. A total of 1201 ICSI cycles were retrospectively analyzed for male azoospermia or oligozoospermia between January 2015 and December 2015 in the Peking University Third Hospital. Patients were divided into three groups (Group 1 vs Group 2/3; surgically extracted sperm vs ejaculated sperms): Group 1 included 343 ICSI cycles and Group 2 analyzed 388 cycles on semen with sperm concentration <5 × 10⁶ ml⁻¹ (severe oligozoospermia group). Group 3 included 470 cycles with sperm concentration between 5 × 10⁶ ml⁻¹ and 15 × 10⁶ ml⁻¹ (mild oligozoospermia group). Fertilization rates, clinical pregnancy rates, and live birth rates were analyzed and compared among groups of different semen origins and concentrations on the oocyte retrieval day. Group 2 showed a lower fertilization rate than Group 3 (62.9% ± 21.6% vs 66.8% ± 22.1%,P < 0.05). There were no statistically significant differences in clinical pregnancy rate per transfer (51.3%, 46.7%, and 50.0%, respectively), live birth rate per transfer (44.4%, 40.9%, and 41.4%, respectively), accumulative live birth rate (58.3%, 51.0%, and 52.1%, respectively), twin birth rate (18.4%, 10.6%, and 12.6%, respectively), and birth defects rate (0, 0.3%, and 0.2%, respectively) among three groups. The results of this study indicated that sperm origins and concentration do not impact the clinical outcomes in ICSI cycles.

Aging and the Male Reproductive System

This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.