P-087 Obstetrical and perinatal outcomes from intracytoplasmic sperm injection couples with oocyte donation are not affected by advanced paternal age measured as a continuous variable
Authors: Navarro Gomez-Lechon A , Gil Juliá M , Hervás I , Mossetti L , Pacheco-Rendón R  M , Rivera-Egea R , Garrido N 
Published: July 2024

Abstract

Study question
Does paternal age (PA), considered a continuous variable, have any effect on obstetrical and perinatal outcomes in intracytoplasmic sperm injection (ICSI) with donated oocytes?

Summary answer
PA does not affect clinically relevant obstetrical and perinatal outcomes, but it significantly increases the pregnancy’s duration in ICSI with autologous sperm and donated oocytes.

What is known already
Currently there has been an evident delay in childbearing, therefore studies relating advanced PA with reproductive risks are increasing and results are controversial. These studies frequently study PA by dividing it in groups arbitrarily constructed, but probably a more precise evaluation is obtained using PA as a continuous variable. Furthermore, oocyte donation standardizes female factor, to some extent, allowing a more realistic male factor evaluation. In this regard, we aimed to evaluate the effect of PA at conception (continuous variable) on obstetrical and perinatal outcomes in ICSI couples with autologous sperm and donated oocytes in a large population of patients.

Study design, size, duration
This retrospective observational multicentric cohort study evaluated data from couples that performed an ICSI between January 2008 and March 2020 using autologous sperm and donated oocytes. We included only singleton deliveries and the first delivery of each couple. PA was analysed as a continuous variable, considered more informative in comparison to its analysis as categorical. Data available and included consisted of 15,696 patients who had a delivery with or without a live birth.

Participants/materials, setting, methods
PA ranged from 21-54 years. Clinical database was constructed with reproductive outcomes from electronic medical records. Erroneous or incomplete data were removed. Statistical analysis included a descriptive analysis, followed by univariate and multivariate models using binary logistic regression or linear regression. We adjusted for maternal age and body mass index, PA, fresh sperm concentration and progressive motility, cycle type, gestational age, transfer on day 5 and delivery type (when appropriate). P &lt; 0.05 was considered statistically significant.

Main results and the role of chance
Mean PA was 41.45 (41.38-41.51). We included a total of 15,696 deliveries and 15,673 live births. Results from multivariate models are presented as adjusted odd ratio or regression coefficient with 95% confidence intervals and adjusted p. In terms of obstetrical outcomes, PA results were 1.086 (0.959-1.229) p = 0.194 for gestational diabetes, 0.963 (0.849-1.093) p = 0.561 for anemia, 0.947 (0.837-1.072) p = 0.388 for hypertension, 0.959 (0.878-1.048) p = 0.356 for preterm birth and 0.986 (0.929-1.046) p = 0.641 for caesarean delivery. Regarding perinatal outcomes, PA results were 0.442 (0.005-0.879) p = 0.047 for gestational age, -0.216 (-15.559-15.126) p = 0.978 for infant weight, 1.101 (0.941-1.288) p = 0.231 for low birth weight (&lt;2,500 g), 0.710 (0.463-1.088) p = 0.116 for very low birth weight (&lt;1,500g), 0.988 (0.933-1.047) p = 0.684 for female sex, 0.002 (-0.076-0.08) p = 0.96 for length, -0.012 (-0.088-0.064) p = 0.763 for cranial perimeter, 0.991 (0.876-1.12) p = 0.88 for NICU admission, and 0.027 (-0.028-0.083) p = 0.337, 0.025 (-0.012-0.061) p = 0.18 and -0.045 (-0.096-0.007) p = 0.089 for Apgar 1, 5 and 10 minutes, respectively. According to our results, PA does not affect clinically relevant outcomes for the health during pregnancy and of the infant. However, PA significantly increases the duration of the pregnancy in ICSI with autologous sperm and donated oocytes.

Limitations, reasons for caution
The study’s major strengths are the consideration of PA as a continuous variable, the use of oocyte donation (controlling female factors) and the inclusion of a huge sample size. However, due to its retrospective nature there are some biases derived from the clinical practice and the presence of missing data.

Wider implications of the findings
Current evident delay in childbearing merits further research on the effect of PA on reproductive outcomes, addressed in this study. Our study suggests that PA is not associated with obstetrical and perinatal outcomes, except for gestational age, which sends a hopeful message to fathers of advanced paternal age.

Trial registration number
not applicable