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Effect of Maternal Aging on Fertility Outcomes in Assisted
Reproductive Technology: A Study of Autologous and Donor Oocyte
Cycles
Ibinabo Fubara Bob-Manuel, Henry Ajulor Amadi-Ikpa, Gospel Uchechukwu Collins
Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of
Port Harcourt, Rivers State, Nigeria.
DOI: https://dx.doi.org/10.51244/IJRSI.2025.12110092
Received: 21 November 2025; Accepted: 27 November 2025; Published: 10 December 2025
ABSTRACT
With increasing numbers of women delaying childbearing, age-related declines in fertility have become a
significant concern, often necessitating the use of assisted reproductive technologies (ART). Although ART has
enabled many individuals and couples to achieve pregnancy, evidence shows that conceptions through ART carry
higher risks of adverse outcomes. This study aimed to investigate the impact of female aging on reproductive
outcomes in ART cycles, comparing outcomes between autologous and donor oocytes across different age
groups. A retrospective design was employed, using medical records from two fertility clinics in Port Harcourt,
Nigeria. Data on age, weight, number of oocytes retrieved, embryo quality, and IVF cycle outcomes were
analyzed, and the Chi-square test was used to examine associations between variables. Among 120 donor oocyte
cycles, the highest positive IVF outcomes were observed in women aged 36–39 years (n = 11, 52.38%), followed
by those aged 31–35 years (n = 10, 50%), 40–44 years (n = 11, 31.43%), ≤30 years (n = 9, 39.13%), and ≥45
years (n = 5, 23.81%). In the 120 autologous cycles, success rates declined progressively with age: ≤30 years (n
= 15, 55.56%), 31–35 years (n = 10, 42.67%), 36–39 years (n = 6, 25%), 40–44 years (n = 2, 8.33%), and ≥45
years (n = 0, 0%). Chi-square analysis demonstrated a significant association between age and IVF outcome in
autologous cycles, whereas no significant association was observed in donor cycles. These findings highlight
the influence of maternal age on IVF success when using autologous oocytes and underscore the ability of donor
oocytes to mitigate age-related declines in reproductive potential.
Keywords: Female Ageing, Assisted Reproduction Technology, Donor Oocytes, Autologous Oocytes
INTRODUCTION
Reproduction is essential to species survival, and female ageing remains one of the most significant factors
influencing human fertility. As women age, particularly beyond 35 years, fertility declines due to reductions in
oocyte quantity and quality, leading to diminished ovarian reserve, increased aneuploidy, and lower success rates
in assisted reproductive technologies (ART) such as in vitro fertilization (IVF) (1, 2). Oocytes from older women
exhibit higher rates of chromosomal abnormalities, resulting in implantation failure, miscarriage, and increased
risk of chromosomally abnormal offspring (3). These changes are largely linked to age-related alterations in the
ovarian microenvironment and mitochondrial dysfunction.
To address age-related infertility, assisted reproductive technologies, including IVF and intracytoplasmic sperm
injection (ICSI), increasingly rely on donor oocytes, which are typically sourced from younger, fertile women.
Donor oocytes offer significantly higher success rates than autologous oocytes in older women, with evidence
showing that women aged 40–44 achieve live birth rates similar to younger women when donor oocytes are used
(4). However, the choice between donor and autologous oocytes is complex and shaped by psychological, ethical,
and emotional considerations, including concerns about genetic relatedness and parent– child bonding (5, 6).
Despite extensive global research on ART outcomes, there is limited evidence from Port Harcourt, Nigeria, on
how female aging influences reproductive success, particularly regarding differences between autologous and
donor oocyte cycles. With increasing trends of delayed childbearing in the region, this knowledge gap contributes
to uncertainty in managing age-related infertility. Therefore, this study aims to address this gap by evaluating
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the impact of female aging on reproductive outcomes in Port Harcourt, comparing success rates between cycles
using autologous and donor oocytes.
Objectives of the Study
The objectives of the study include to:
i. Characterise and evaluate the descriptive attributes and clinical success rates of oocytes utilised in
assisted reproductive procedures among women across different age groups in Port Harcourt.
ii. Determine the association between oocyte age groups and in vitro fertilization (IVF) cycle outcomes.
iii. Compare the success rates of IVF cycles employing autologous oocytes versus donor oocytes in order
to elucidate differences in reproductive performance.
Justification
This study seeks to make a meaningful difference in the lives of women and families grappling with agerelated
infertility by clarifying how maternal age affects oocyte quality and ART outcomes. By directly comparing IVF
success with autologous versus donor oocytes across age groups, the research gives clinicians clearer guidance
and patients better, more compassionate counselling so difficult choices are met with solid evidence rather than
uncertainty. Beyond improving clinical decision-making and resource use, the study is intended to reassure and
empower couples and individuals pursuing parenthood later in life, helping them navigate treatment options with
dignity, hope, and realistic expectations.
Research Questions
1. How do the descriptive characteristics and clinical success rates of oocytes used in assisted reproductive
technology vary across different maternal age groups in Port Harcourt?
2. What is the relationship between the age group of the oocytes and the resulting in vitro fertilization (IVF)
cycle outcomes?
3. How do IVF success rates differ between cycles utilizing autologous oocytes and those utilizing donor
oocytes among women of varying age groups?
Research Hypothesis
H1₀: Oocyte age has no significant association with in vitro fertilization outcomes
H1: Oocyte age is significantly associated with in vitro fertilization outcomes.
H2₀: There is no significant difference in reproductive success rates between IVF cycles using donor oocytes
and those using autologous oocytes, regardless of maternal age group.
H2: In vitro fertilization cycles utilizing donor oocytes achieve significantly higher reproductive success rates
than cycles utilizing autologous oocytes across all maternal age groups.
Definition of Key TermsIn Vitro Fertilization (IVF): In vitro fertilization is an assisted reproductive
technology in which oocytes are retrieved from a woman’s ovaries and fertilized with sperm outside the body,
typically in a controlled laboratory environment. The resulting embryos are cultured and subsequently
transferred into the uterus to achieve pregnancy.
Donor Oocytes: These are mature oocytes obtained from a different woman.
Autologous Oocytes: Autologous oocytes are a woman’s own oocytes retrieved from her ovaries and used in
her assisted reproductive treatment (7, 8)
LITERATURE REVIEW
The global rise in maternal age at first birth has coincided with an increasing reliance on assisted reproductive
technologies (ARTs) (9). ). Although ART has enabled many individuals and couples to achieve pregnancy,
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evidence shows that conceptions through ART carry higher risks of adverse outcomes such as stillbirth,
preeclampsia, preterm delivery, low birth weight, and congenital anomalies. These risks persist even among
singleton pregnancies and are not fully explained by unmeasured confounding, suggesting that both ARTrelated
factors and underlying infertility may contribute (10, 11, 12). At the same time, infertility affects approximately
8–10% of people of reproductive age globally, reinforcing the importance of ART as a vital option for families
experiencing reproductive challenges (13). With ART now accounting for an estimated 8% of births in some
regions, though influenced by national regulations, its relevance in modern fertility care continues to expand
(14, 15).
Shifts in demographic patterns have also contributed to delayed childbearing, with many women postponing
pregnancy into their mid-thirties and beyond. This trend is driven by widespread contraceptive use and broader
socioeconomic changes, including women’s increasing educational and professional opportunities, economic
instability, and evolving family structures (16, 17). The biological decline in female fertility typically begins
around age thirty and becomes more pronounced between thirty-five and forty (18, 19). Both ovarian and
endometrial aging are recognized contributors to reduced pregnancy success. Endometrial alterations related to
age may account for a large proportion of implantation failures, and premature endometrial aging has been linked
to recurrent implantation failure (20, 19) Concurrently, ovarian aging leads to fewer available oocytes and
increased aneuploidy, further compromising embryo viability (21, 22, 19). Tinelli et al., 2023; To counter these
challenges, strategies such as early oocyte cryopreservation, preimplantation genetic testing for aneuploidy, and
the use of donor oocytes have been adopted to improve the likelihood of transferring chromosomally healthy
embryos (23, 18,19).
Advancing maternal age also directly affects the biological quality of oocytes, with reductions in both quantity
and functional competence becoming more evident after the age of thirty-five (17) Age-related declines in
ovarian reserve, increased chromosomal abnormalities, and mitochondrial dysfunction contribute to lower
fertilization rates, higher miscarriage rates, and decreased success in ART cycles. Conversely, oocytes obtained
from younger donors generally exhibit superior developmental potential, which is reflected in higher pregnancy
and live birth rates among older recipients. Previous studies have demonstrated that donor oocytes substantially
improve outcomes compared to autologous oocytes in older women. Despite this, the use of donor oocytes may
influence the emotional and psychological experience of pregnancy and parenting, highlighting the multifaceted
nature of ART decisions. Overall, ART remains a critical medical intervention for addressing infertility across
diverse clinical contexts (17, 24, 19).
METHODOLOGY
Study Design
This was a retrospective, cross-sectional comparative study, designed to investigate the influence of maternal
age on reproductive outcomes in assisted reproductive technology (ART) cycles in Port Harcourt. Women were
stratified by age and by oocyte type (autologous or donor) to examine outcomes.
Study Area
The study was carried out in two purposively selected assisted reproductive technology (ART) clinics in Port
Harcourt, Nigeria, recognized for their comprehensive in vitro fertilization (IVF) programs and diverse patient
populations. These clinics provide a representative setting for evaluating reproductive outcomes across different
maternal age groups and oocyte sources.
Methods of Data Collection
Data were retrospectively extracted from patient records and systematically organized according to relevant
clinical and laboratory variables. Patients and donor were health individuals.
1. Patient age
2. Donor age
3. Patient weight (reported as mean ± standard deviation for each age group)
4. Embryo quality score
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Number of oocytes retrieved
1. Positive outcome: Defined as a clinical pregnancy confirmed by ultrasound
2. Negative outcome: Defined as failure to achieve clinical pregnancy
Outcome rates were summarized as frequency counts and percentages for each maternal age group and oocyte
type (autologous or donor)
Sampling Technique
A purposive sampling technique was employed. A total of 240 in vitro fertilization cycles were included,
comprising 120 cycles using autologous oocytes and 120 cycles using donor oocytes. Patients were stratified by
maternal age into five groups: ≤30, 31–35, 36–39, 40–44, and ≥45 years. Inclusion criteria were availability of
complete medical records and at least one completed in vitro fertilization cycle. Only healthy patients and donors
were used. Records that lacked essential information required for analysis were excluded.
Data Analysis
Descriptive statistics were used to summarize the sample: means and standard deviations for continuous
variables, and frequencies and percentages for categorical variables. To evaluate the association between
maternal age group and in vitro fertilization outcome, the Chi-square test of independence was performed. An
alpha level of 0.05 was set a priori; p-values less than 0.05 were considered statistically significant. All analyses
were conducted using standard statistical software.
Ethical Consideration
The study protocol was approved by the Ethics Committee of the University of Port Harcourt. To protect
participant privacy, all data were anonymized prior to analysis and handled in accordance with ethical standards
for retrospective research.
RESULT
The results of the study were presented in tables, as follows;
Table 1: Descriptive statistics of IVF outcome using donor eggs
Age
Groups
N
Mean ± SD
IVF cycle outcome
Weight (kg)
NRO
Positive [N (%)]
Negative [N(%)]
≤30
23
74.74 ± 17.79
17.30 ± 10.19
9 (39.13)
14 (60.87)
31 -35
20
73.20 ± 13.70
15.70 ± 4.72
10 (50)
10 (50)
36 -39
21
77.00 ± 11.75
17.00 ± 12.08
11 (52.38)
10 (47.62)
40- 44
35
84.14 ± 15.19
17.00 ± 8.29
11 (31.43)
24 (68.57)
≥45
21
78.52 ± 11.47
14.52 ± 5.75
5 (23.81)
16 (76.19)
N= Sample Size; kg= Kilogram; SD= Standard Deviation; NRO= Number of Retrieved Oocyte; QE= Quality of
Embryo; IVF= In vitro Fertilization; %= Percentage
Table 2: Descriptive statistics of IVF outcome using autologous eggs
Age
Groups
N
Mean ± SD
IVF cycle outcome
Weight (kg)
NRO
QE
Positive [N(%)]
Negative [N(%)]
≤30
27
81.67 ± 12.90
16.33 ± 6.23
3.22 ± 0.42
15 (55.56)
12 (44.44)
31 -35
24
81.00 ± 4.15
9.00 ± 7.47
4.25 ± 3.34
10 (42.67)
14 (58.33)
36 - 39
24
79.17 ± 10.15
18.17 ± 13.38
4.50 ± 2.58
6 (25)
18 (75)
40- 44
24
96.50 ± 15.87
13.75 ± 5.51
4.50 ± 0.51
2 (8.33)
22 (91.67)
≥45
21
98.33 ± 12.08
23.33 ± u.50
3.67 ± 0.48
0 (0)
21 (100)
N= Sample Size; kg= Kilogram; SD= Standard Deviation; NRO= Number of Retrieved Oocyte; QE= Quality of
Embryo; IVF= In vitro Fertilization; %= Percentage
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Table 3. Test for association between IVFoutcomes and age groups using donor oocytes
Age
Groups
IVF Cycle Outcome
Calculated X
2
df
Critical X
2
at α=0.05
Inference
Positive
[frequency]
Negative
[Frequency]
p-value
≤30
9
14
4.96
4
9.49
p>0.05
NS
31 -35
10
10
36 - 39
11
10
40- 44
11
24
≥45
5
16
X
2
= Chi-Square value; df= Degree of Freedom; NS= Not Significant
Table 4. Test for association betweenIVF outcomes and age groups using autologous oocytes
Age
Groups
IVF Cycle Outcome
Calculated X
2
p-value
Inference
Positive
[frequency]
Negative
[Frequency]
df
Critical X
2
at
α=0.05
≤30
15
12
27.27
4
9.49
P<0.05
S
31 -35
10
14
36 - 39
6
18
40- 44
2
22
≥45
0
21
X
2
= Chi-Square value; df= Degree of Freedom; S= Significant
Table 5: Comparison between autologous and donor oocytes positive outcomes.
Age Group
Positive Outcome of Autologous Oocytes (%)
Positive Outcome of Donor Oocytes (%)
≤30
55.6
39.1
31–35
42.7
50.0
36–39
25.0
52.4
40–44
8.3
31.4
≥45
0
23.8
Autologous oocyte cycles exhibited a statistically significant age-related decline in IVF success (p < 0.05). In
contrast, donor oocyte cycles showed no significant association between age group and treatment outcome (p >
0.05). Across all age categories, donor cycles also yielded higher numbers of retrieved oocytes and superior
embryo quality scores compared with autologous cycles.
DISCUSSION
The present study evaluated the impact of female age on reproductive outcomes in assisted reproduction cycles
using both donor and autologous oocytes. Across donor oocyte cycles, pregnancy rates varied by age group, with
women aged 36–39 years achieving the highest positive outcome (52.38%), followed closely by the 31– 35 year
group (50%). Conversely, women aged ≥45 years exhibited the lowest success rate (23.81%), highlighting a
decline in outcomes even when high-quality donor oocytes were used (Table 1). The relative consistency in
embryo quality scores across donor oocyte groups suggests that the observed reduction in pregnancy rates among
older recipients may be influenced more by uterine or systemic factors associated with maternal age rather than
by oocyte quality.
In autologous cycles, a clear age-dependent decline in IVF success was observed, with women ≤30 years
demonstrating the highest pregnancy rate (55.56%). Pregnancy rates decreased progressively with advancing
age, dropping to 25% in the 36–39 year group, 8.33% in the 40–44 group, and 0% in women aged ≥45 years
(Table 2). These findings are consistent with previous literature demonstrating the effect of maternal aging on
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ovarian reserve and oocyte competence (17, 24, 19). The absence of positive outcomes among women ≥45 years,
despite relatively high oocyte retrieval numbers, underscores that oocyte quantity alone cannot compensate for
the decline in oocyte quality associated with advanced maternal age.
The Chi-square analysis revealed no statistically significant association between age and pregnancy outcome in
donor oocyte cycles (χ² = 4.96, p > 0.05), indicating that donor eggs mitigate the effects of maternal age on
reproductive outcomes (Table 3). In contrast, autologous cycles showed a strong age-related association (χ² =
27.27, p < 0.05), reflecting the significant influence of maternal age on IVF success when women use their own
oocytes (Table 4). Comparative analysis further revealed that donor cycles outperformed autologous cycles in
nearly all age categories, particularly in women aged ≥36 years (Table 5). These results support the use of donor
oocytes as an effective strategy to overcome age-related declines in ovarian reserve and oocyte competence,
particularly in women of advanced reproductive age.
The observed decline in autologous IVF outcomes aligns with findings by Sebastian-Leon et al. (19), ), who
reported that live birth rates decreased from 45.8% to 32.7% between ages 40 and 50, while implantation failure
and pregnancy loss rates increased significantly after age 40. Their analysis, accounting for patient baseline
characteristics such as BMI and IVF cycle variables, confirmed that these declines were largely attributable to
maternal age rather than other confounding factors. Similarly, Pathare et al. (17) ) highlighted that aging
negatively affects endometrial biology at molecular, cellular, and histological levels, impairing receptivity and
increasing the risk of implantation failure and pregnancy loss. These age-related changes include cellular
senescence, chronic low-grade inflammation, tissue fibrosis, and epigenetic modifications, all of which may
contribute to reduced success in autologous cycles.
Further support for the observed patterns comes from Yurchuk et al. (25) , who emphasized that reproductive
decline in advanced maternal age is driven by both ovarian and systemic factors, including reduced sensitivity
to gonadotropins, accumulated negative changes in the oocyte genome, and mitochondrial dysfunction. These
alterations compromise oocyte quality, fertilization potential, and embryo development, thereby reducing the
likelihood of successful implantation and healthy live birth. Taken together, these findings underscore the
multifactorial nature of age-related infertility, highlighting that both gamete quality and endometrial environment
contribute to reduced ART success in older women.
CONCLUSION
This study demonstrates that female age has a significant impact on reproductive outcomes in assisted
reproductive technology (ART) cycles, particularly when autologous oocytes are used, with pregnancy rates
declining sharply in women over 35 years and reaching zero in those aged ≥45 years. In contrast, donor oocyte
cycles largely mitigate the effects of maternal age, producing higher and more consistent pregnancy rates across
all age groups, especially in women over 36 years. These findings highlight the critical role of oocyte quality in
determining IVF success and indicate that age-related declines in fertility are influenced not only by ovarian
reserve but also by uterine and systemic factors. Clinically, the results support the use of donor oocytes as an
effective strategy to improve reproductive outcomes in older women and underscore the importance of
incorporating maternal age and oocyte source into personalized ART planning to optimize the likelihood of
conception and live birth.
RECOMMENDATIONS
For women of advanced maternal age or with low ovarian reserve, fertility clinics should offer donor oocyte IVF
as the preferred option, while also providing personalized protocols for those using their own eggs.
Comprehensive counselling should be included to help women understand their options, the likely outcomes,
and any emotional or ethical considerations, ensuring informed decisions and the best possible chances of
success.
ACKNOWLEDGEMENTS
The authors sincerely acknowledge the management and staff of the participating fertility clinics in Port
Harcourt, Nigeria, for granting access to their facilities and providing the necessary support for this study. We
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also extend our gratitude to colleagues who provided valuable insights and guidance throughout the research
process.
Data Availability
The data supporting the findings of this study are available from the corresponding author upon reasonable
request. All relevant datasets were generated and analyzed during the current research and can be provided for
academic or research purposes.
Conflict Of Interest
The authors declare no conflicts of interest related to this study.
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