Patterns of Preimplantation Genetic Testing Utilization During In Vitro Fertilization in a Nigerian Fertility Centre: Sociodemographic Characteristics and Clinical Indications

Abstract

Background:

Preimplantation genetic testing (PGT) is increasingly integrated into in-vitro fertilization (IVF) to detect chromosomal abnormalities and monogenic disorders before embryo transfer. Although its use is primarily intended to prevent genetic disease and improve reproductive outcomes, PGT is also applied for non-medical indications such as elective sex selection in some settings. The objective of this study is to characterize the sociodemographic profile of couples undergoing PGT, the clinical indications for testing, and patterns of maternal and paternal age, parity, and geographic distribution in a Nigerian fertility centre.

Methodology:

A Retrospective study conducted at a tertiary fertility and preimplantation genetic testing centre in Lagos, Nigeria, between January 2018 and December 2024 was reviewed. Sociodemographic characteristics, reproductive history, type of PGT performed (PGT-A, PGT-M, or combined), and clinical indications for testing were extracted from anonymized medical records. Descriptive statistics were used to summarize participant characteristics and indications for PGT.

Results:

The mean maternal age was 39.7 ± 6.1 years, while the mean paternal age was 46.3 ± 6.9 years. Most women had parity 2–3 (51.6%), and 86.3% had 1–4 living children. Participants resided predominantly in Nigeria (61.5%), with a substantial proportion from the United Kingdom (17.3%) and Canada (8.8%), reflecting cross-border utilization of fertility services. The most common indication for PGT was elective sex selection/family balancing (89.7%). Among clinical indications, PGT-M for haemoglobin S (HBS) genotype screening accounted for 5.4%. A small proportion of cycles involved combined PGT-A/PGT-M, mainly for women with previous children with oculocutaneous albinism (1.0%, n = 4) and Duchenne Muscular Dystrophy (0.5%, n = 2) and severe male-factor infertility (0.5%).

Conclusions:

In this cohort of Nigerian couples undergoing IVF with PGT, elective sex selection was the predominant indication, highlighting the influence of sociocultural factors on the use of reproductive genetic technologies.

Introduction

Preimplantation genetic testing (PGT) refers to a group of laboratory techniques used during in-vitro fertilization (IVF) to analyze the genetic material of embryos prior to uterine transfer, with the aim of identifying genetic or chromosomal abnormalities and facilitating embryo selection based on defined genetic criteria. [1, 2, 3] The term PGT is an umbrella concept that encompasses techniques previously described as preimplantation genetic screening (PGS) and preimplantation genetic diagnosis (PGD), now more precisely referred to as preimplantation genetic testing for aneuploidy (PGT-A) and preimplantation genetic testing for monogenic or single-gene disorders (PGT-M), respectively. [2,4,5]. PGT involves embryo biopsy followed by genetic analysis and has become increasingly integrated into contemporary gynaecological and assisted reproductive practice. [1,2,6,7]. Clinically, it is used for the detection of single-gene disorders such as sickle cell disease and cystic fibrosis. [3,8,9] In addition, PGT has been employed in a range of other clinical contexts, including recurrent implantation failure, repeated IVF failure, recurrent early pregnancy loss, poor obstetric history, advanced maternal or paternal age, severe male-factor infertility, detecting embryos prone to developing breast cancer, unexplained infertility, and in couples with known or suspected genetic abnormalities, including structural chromosomal rearrangements. [8, 9, 10, 11, 12, 13

Collectively, these applications underscore the primary objective of PGT, which is to optimize IVF outcomes and reduce the likelihood of transmitting genetic or chromosomal abnormalities to offspring. [11, 12, 13] By enabling the selection of embryos with a higher probability of implantation and normal development, PGT has been positioned as a strategy to improve reproductive success while mitigating genetic risk. [10, 11, 12, 13] Notwithstanding these established medical indications, the use of PGT has extended beyond disease prevention in some settings. In several developing countries, PGT has been utilized for non-medical purposes, including family balancing through sex selection of embryos. Couples requesting non-medical sex selection cite diverse motivations, including the desire to have a child of a different sex from existing offspring (“family balancing”), personal preference or curiosity for a particular gender (“elective sex selection”), or the intention to recreate or honor the memory of a deceased loved one of a specific sex. [13, 14, 15]

Although preimplantation genetic testing (PGT) has been applied for non-medical sex selection in some settings, such practices are prohibited in most developed countries. In Canada, the Assisted Human Reproduction Act expressly forbids any procedure or intervention intended to ensure or increase the likelihood of creating a child of a particular sex, or to identify the sex of an embryo, when undertaken for non-medical reasons. [16] The sole exception permitted under the Act is where sex selection is necessary to prevent the transmission of a serious sex-linked genetic disorder, such as certain X-linked conditions. [16] Similarly, in the United Kingdom, the Human Fertilisation and Embryology Act (as amended) prohibit licensed fertility clinics from offering or authorizing sex selection except for the purpose of avoiding serious inherited medical conditions. [17] This prohibition extends to all relevant technologies, including sperm sorting and preimplantation genetic testing, when used for social or elective sex selection. [17] The critics of the use of preimplantation genetic testing (PGT) for non-medical sex selection argue that widespread application of this practice could alter the secondary sex ratio of a population, which under natural conditions is expected to approximate an equal distribution of males and females (50:50). [18, 19]

Beyond clinical considerations, the expanding use of preimplantation genetic testing (PGT) for non-medical purposes has raised significant ethical concerns. [20] Professional bodies in reproductive medicine have expressed reservations regarding elective PGT for social sex selection. [21,22] In particular, the American Society for Reproductive Medicine has issued guidance discouraging the use of PGT for non-medical sex selection, a position that aligns with those of the Human Fertilisation and Embryology Authority and the American College of Obstetricians and Gynecologists. [21,22] Despite these positions, the moral perspectives and sociocultural beliefs of couples seeking sex selection remain an important consideration, especially in African settings. [23, 24, 25] In many such contexts, a strong preference for male offspring persists, driven by factors such as lineage continuation, patriarchal inheritance structures, and perceived family or personal interests, including expectations regarding parenting roles and family composition. [23,24]

Nigeria currently lacks a comprehensive national legal framework specifically regulating assisted reproductive technologies (ART), including in vitro fertilization (IVF), preimplantation genetic testing (PGT), embryo cryopreservation, and non-medical sex selection.[26-28] In the absence of dedicated legislation or a national regulatory authority, many fertility centers operate according to institutional protocols and internationally recognized clinical guidelines. [26] This regulatory gap has prompted calls from scholars and professional bodies for the establishment of a national oversight mechanism, such as a Nigerian Assisted Reproductive Technology Authority, to standardize clinical practice, strengthen patient protection, and ensure ethical governance of ART services. [26-28] Although legislative efforts have been initiated, including proposals such as the Assisted Reproductive Technology Regulation Bill (2016) and earlier attempts to incorporate ART oversight within amendments to the National Health Act, these initiatives have not yet been enacted into law. [26-28] Consequently, ART practice in Nigeria remains largely guided by institutional policies, professional ethical standards, and general national research ethics frameworks rather than by a comprehensive statutory regulatory system. [25-27]

This study, therefore, aimed to determine the pattern of PGT for non-medical Sex selection during in vitro Fertilization and the sociodemographic profile of the Patients in a Nigerian fertility center.

Materials and Methods

Ethical approval for this study was obtained from the Health Research Ethics Committee of the 68 Nigerian Army Reference Hospital, Yaba (NARHY) (Reference number: 68NARHY/ECA/231). This was a retrospective study of all preimplantation genetic testing (PGT) treatment cycles conducted over a 7-year period, from January 1, 2018, to December 31, 2024, at a regional PGT center in Lagos, Nigeria. Anonymized data were extracted from the medical records of all women who attended the facility during the study period. The study protocol adhered to principles of confidentiality and data protection, and no identifiable patient information was collected or analyzed.

Inclusion and Exclusion Criteria: All women who attended the facility for IVF/PGT treatment during the study period, provided consent for the procedure, and agreed to the use of their anonymized data for research purposes, and whose medical records were complete, were included in the study. Women who did not provide consent or whose records were incomplete were excluded.

Outcome Measures: The primary outcome was the clinical indication for PGT. Secondary outcomes included fetal sex and the specific subtype of PGT performed (e.g., PGT-A or PGT-M).

Pre and Post Test Counseling

Prior to initiation of treatment, each couple underwent a multidisciplinary team (MDT) consultation involving fertility gynaecologists, embryologists, andrologists, fertility nurses, a clinical psychologist, and a geneticist. During these individualized MDT consultations, details of the proposed treatment were discussed, including the IVF process, embryo biopsy, preimplantation genetic testing, anticipated success rates, potential risks, and possible complications. Participants were provided with the opportunity to raise questions and express concerns. Following completion of genetic testing, post-test counselling was conducted to communicate treatment outcomes and further address participant questions and decision-making needs.

Ovarian Stimulation Protocol

Controlled ovarian stimulation was performed using either the long protocol or the antagonist protocol. Stimulation dosing was individualized based on patient age, body mass index, and ovarian reserve parameters, with subsequent dose adjustments made according to ovarian response. Follicular development was monitored using serial transvaginal ultrasonography. Ovulation was triggered when a cohort of three or more follicles with an average diameter of 18–20 mm. Oocyte retrieval was carried out under conscious sedation. For patients scheduled for fresh embryo transfer, luteal phase support was commenced immediately following oocyte retrieval.

Oocyte Retrieval Procedure:

Oocyte retrieval was performed 34–36 hours after ovulation trigger using transvaginal ultrasound-guided follicular aspiration. Retrieved oocytes were fertilized 3–6 hours later via intracytoplasmic sperm injection (ICSI).

Embryo Biopsy:

Embryos generated through IVF-ICSI underwent trophectoderm biopsy at the blastocyst stage, followed by cryopreservation. Genetic analysis was performed on the biopsied blastomere(s) or trophectoderm cells, depending on the stage of the embryo. To minimize inter-operator variability, all embryo biopsies were conducted by a single researcher, with a trained geneticist and a clinical embryologist.

Brief Description of Genetic Analysis for PGT-M/PGT-A

Preimplantation genetic testing for monogenic disorders (PGT-M) and aneuploidy (PGT-A) was performed using a validated next-generation sequencing (NGS)–based platform. DNA was obtained from biopsied embryonic cells and subjected to whole-genome amplification (WGA), followed by library preparation and sample barcoding using the Ion Single Seq Kit. Template preparation, including automated clonal amplification, was performed on the Ion Chef System using Ion S5 ExT Chef reagents. Sequencing was conducted on the Ion GeneStudio S5 platform using Ion S5 ExT sequencing reagents. Data processing, copy number analysis, and reporting were carried out using Ion Reporter software (Thermo Fisher Scientific).

Embryos classified as euploid or those demonstrating low-level mosaicism (≤40%) with the desired sex chromosome constitution were considered eligible for frozen embryo transfer (FET) in subsequent cycles. Endometrial preparation and embryo transfer were performed according to standard clinical protocols. Embryos not selected for transfer were either cryopreserved for potential future use or discarded, based on patient preference.

Data Management

Anonymized participant data were initially entered into a Microsoft Excel spreadsheet and subsequently imported into the Statistical Package for the Social Sciences (SPSS), version 29 (IBM Corp., Armonk, NY, USA), for analysis. Sociodemographic characteristics were summarized using descriptive statistics and presented as frequencies and percentages. Clinical variables, including indications for IVF, type of PGT performed, and the use of autologous versus donor oocytes, were similarly summarized. Associations between categorical variables were assessed using the chi-square test. A two-sided p-value of <0.05 was considered statistically significant.

Results

Three hundred and eighty-seven couples who met the inclusion criteria were enrolled in the study. The mean maternal age was 39.67 ± 6.1 years, with women aged 35–39 years (29.5%) and 30–34 years (27.6%) constituting the largest proportions, compared with much smaller proportions aged 25–29 years (3.6%) and ≥45 years (5.7%). The mean paternal age was higher at 46.31 ± 6.9 years, with most partners aged 40–49 years (53.0%), compared with 16.5% aged 30–39 years and 4.4% aged ≥60 years. As regards parity, over half of the women have had 2–3 deliveries (51.6%), compared with 20.6% with 0–1 and 6.4% with parity greater than five. Similarly, most participants had 3–4 living children (50.6%), compared with 35.7% with 1–2, while relatively few had no living children (7.8%) or five or more (5.9%). Table -1

Table 1:

Baseline socio-demographic characteristics of the study population

Variables	Frequency (n=387)	Percentage
Maternal age
25-29	14	3.6
30-34	64	16.5
35-39	107	27.6
40-44	114	29.5
45-49	66	17.1
≥50	22	5.7
Mean±SD	39.67±6.1
Paternal age
30-39	64	16.5
40-49	205	53.0
50-59	101	26.1
≥60	17	4.4
Parity
0-1	80	20.6
2-3	200	51.6
4-5	82	21.2
>5	25	6.4
Number of children living
None	30	7.8
1-2	138	35.7
3-4	196	50.6
≥5	23	5.9

Figure 1 shows the geographic distribution of the study population by country of residence. The majority of participants resided in Nigeria (61.5%), followed by the United Kingdom (17.3%) and Canada (8.8%). Smaller but similar proportions of participants were resident in Europe and the United States (4.7% each), while 3.6% resided in other countries.

Figure 1.

Geographic distribution of the study population by country of residence.

Figure 2. Distribution of Women Undergoing Preimplantation Genetic Testing for Non-Medical Sex Selection by Geopolitical Zone of Residence in Nigeria, with southeastern women contributing the highest proportion of 88.1%, while women from the Northwest Geopolitical zone accounted for 0.5%, and none from the Northeast.

Figure 2.

Distribution of Women Undergoing Preimplantation Genetic Testing for Non-Medical Sex Selection by Geopolitical Zone of Residence in Nigeria

PGT-A was predominantly performed for fetal gender balancing, which accounted for 89.7% (n = 347) of cases. Other indications for PGT-A included recurrent pregnancy loss (2.1%, n = 8), previous IVF failure (1.3%, n = 5), bad obstetric history (1.0%, n = 4), and severe male factor infertility (0.5%, n = 2). PGT-M was primarily undertaken for HBS genotype screening, representing 5.4% (n = 21) of cases. A small proportion of cycles involved combined PGT-A/PGT-M, mainly for women with previous children with oculocutaneous albinism (1.0%, n = 4) and Duchene Muscular Dystrophy (0.5%, n = 2). They needed a male child and wanted to prevent the genetic disease in the offspring. Table 2

Table 2:

Clinical indications for preimplantation genetic testing (PGT-A, PGT-M, PGT-A/PGT-M

Indication	PGT-A(n/%)	PGT-M (n/%)	Both	PGT-A/M (n/%)
Bad obstetrics history	4(1.0)
HBS genotype		21(5.4)
Previous IVF failure	5(1.3)
Recurrent pregnancy loss	8(2.1)
Fetal gender balancing	347 (89.7)
Severe male infertility	2 (0.5)
Albinism	4(1.0)		4(1.0)
Duchene Muscular dystrophy	2(0.5)		2(0.5)

Figure 2 illustrates the distribution of women undergoing PGT for non-medical sex selection by geopolitical zone of origin within Nigeria. The majority of participants were from the South-Eastern geopolitical zone (88.1%, n = 341). Smaller proportions were from the South-South (5.2%, n = 20) and South-West (5.2%, n = 20) zones. A limited number of participants were from the North-Central region (1.0%, n = 4), while only 0.5% (n = 1) originated from the North-West. No participants were recorded from the North-Eastern geopolitical zone. These distributions may partly reflect the geographic location of the study centre.

Table 3:

Distribution of IVF/PGT cycles using autologous versus donor oocytes

Age group (Years)	AO-IVF/PGT N	DO-IVF/PGT N
25-29	14	2
30-34	63	6
35-39	102	13
40-44	4	106
45-49	0	63
≥50	0	22

AO-IVF- Autologous Oocyte IVF

DO- Donor oocyte IVF.

Discussion

The desire to influence the sex of an anticipated offspring has existed across cultures and historical periods. Prior to the advent of preimplantation genetic testing (PGT), various methods of sex selection were employed with limited effectiveness and variable scientific validity[21, 22, 25]. These included pre-fertilization approaches such as sperm sorting techniques aimed at enriching semen samples with spermatozoa carrying a desired sex chromosome, as well as behavioral strategies such as timing of intercourse or insemination in relation to ovulation. Post-conception methods, including elective termination of pregnancy following antenatal sex determination, have also been reported in some settings, alongside more extreme and ethically unacceptable practices such as infanticide of infants of an undesired sex. [22, 29] In many rural and traditional African communities, non-scientific and culturally driven practices persist, including attempts at conception with different partners based on beliefs that offspring sex is influenced by parental fortune or lineage, sometimes resulting in polygamy or extramarital conceptions, as well as the pursuit of spiritual or traditional interventions. [25, 29, 30] Collectively, these practices highlight the long-standing sociocultural importance attached to offspring sex and underscore the need for scientifically sound, ethically regulated approaches to sex selection. [25, 30, 31]

This longstanding sociocultural desire to influence offspring sex has, in recent decades, shifted toward scientifically guided methods with the advent of assisted reproductive technologies (ART). [5,6] Preimplantation genetic testing (PGT), performed in conjunction with in vitro fertilization (IVF), now allows for accurate determination of embryo sex prior to transfer, providing a safe and effective alternative to traditional or post-conception methods of sex selection. [6,7] PGT encompasses preimplantation genetic testing for aneuploidy (PGT-A), monogenic disorders (PGT-M), or a combination of both (PGT-A/M), enabling both the prevention of genetic diseases and elective sex selection under ethically regulated frameworks. [5,7] By facilitating embryo selection before implantation, PGT reduces the need for post-conception interventions and aligns sex selection practices with established clinical, ethical, and legal standards in reproductive medicine. [6]

Our data showed that more than one‑third of patients in this cohort (38.5%) resided outside Nigeria, indicating a notable international utilization of PGT services. This pattern likely reflects both increased acceptance of IVF among Nigerian couples and the expanding availability of trained embryologists and fertility centers domestically. [15] Nevertheless, the preference for treatment for foreign patients may be influenced by restrictive policies on non‑medical use of PGT, such as elective sex selection, prompting some patients to seek services in jurisdictions with more permissive regulatory environments. [16,17,21] Similar cross‑border reproductive care trends have been documented in other settings, where legal limitations on assisted reproductive technologies and sex‑selection practices have led to increased medical tourism for fertility services. [16, 17] These findings highlight the impact of regulatory and sociocultural factors on access to PGT and suggest a need for policy frameworks that balance ethical considerations with equitable access to reproductive care.

Elective sex selection was the predominant indication for PGT in our cohort, accounting for 88.7% of cases, consistent with reports from Northern Nigeria, where 62.7% of couples sought gender balancing.14 Despite ongoing ethical, legal, and social debates surrounding non-medical PGT, its continued utilization in many African contexts likely reflects culturally driven preferences for offspring sex. [14, 16, 17, 18] This trend underscores the challenges of reconciling reproductive autonomy with ethical and demographic considerations, highlighting the need for context-specific policy frameworks that address both societal values and equitable access to assisted reproductive technologies. [18] In contrast, a study from South Africa reported that the most common indication for PGT was the prevention of genetic disease, accounting for 59.1% (13/22) of cases. [32] It is noteworthy that the South African cohort consisted exclusively of Caucasian (European ancestry), Indian, and Ashkenazi Jewish couples, with no Black or mixed-ancestry participants. [32] These contrasts sharply with our study, which was conducted among a homogeneous Black population, highlighting the influence of population demographics, cultural context, and disease prevalence on the patterns of PGT utilization. There is also a consanguineous couple in their study, which is not found among our cohorts. [32]

The geographic distribution of participants demonstrated notable regional variation, with a higher proportion of women undergoing PGT for non-medical sex selection originating from the South-Eastern geopolitical zone of Nigeria. As this region is predominantly inhabited by individuals of Igbo ethnicity, the observed distribution may reflect underlying sociocultural factors influencing reproductive decision-making. Previous Nigerian studies conducted among Igbo populations have reported a higher stated preference for male children among pregnant women. [33, 34] However, the present study did not collect direct data on patient motivations, gender preference direction, or sociocultural determinants of treatment decisions. [33, 34] Consequently, while these prior findings provide contextual background, our results cannot establish that male child preference or patriarchal inheritance practices were definitive drivers of PGT utilization in this cohort. These interpretations should therefore be considered cautiously and viewed primarily as contextual explanations rather than causal conclusions.

An age-related increase in the use of donor oocytes was observed in this cohort, particularly among women aged ≥40 years, with all women aged ≥45 years undergoing donor-oocyte IVF/PGT cycles. While this finding reflects established clinical practice in assisted reproductive technology [35], a detailed analysis of donor oocyte utilization across maternal age groups was beyond the scope of the present study and will be explored in future work.

Strength of the Study

This study provides a comprehensive analysis of PGT utilization in a relatively large cohort of 387 Nigerian couples, offering novel insights into socio-demographic characteristics, clinical indications, and geographic distribution within a homogeneous Black population. The inclusion of both maternal and paternal factors, as well as parity and number of living children, allows for a detailed characterization of the study population. Additionally, the study contextualizes findings with regional and international data, highlighting cultural and regulatory influences on PGT use. By focusing on real-world clinical practice, these results contribute valuable evidence to guide policy development, ethical deliberations, and the management of elective and medically indicated PGT in low-resource settings.

Limitations

This study has several limitations. First, it was conducted at a single tertiary fertility center, which may limit the generalizability of the findings to other regions or populations, particularly rural settings. Second, the cross-sectional design precludes assessment of causal relationships between socio-demographic factors and PGT utilization or outcomes. Third, data were derived from medical records, which may be subject to incomplete documentation or reporting bias. Fourth, the study did not assess the long-term clinical or psychosocial outcomes of PGT, including pregnancy success rates or offspring health. Finally, the predominance of elective sex selection in our cohort limits comparisons with populations where medical indications for PGT are more common, potentially reflecting cultural or regulatory influences rather than biological factors. Despite these limitations, the study provides valuable insights into the demographic and clinical patterns of PGT utilization in a homogeneous Black Nigerian population.

Conclusion

In this cohort of Nigerian couples, elective sex selection is the primary driver of PGT utilization, reflecting the influence of cultural and demographic factors. The findings highlight the growing transnational demand for fertility services and underscore the need for context-specific policies that balance ethical considerations, reproductive autonomy, and equitable access to assisted reproductive technologies.

Ethical Approval

Ethical approval for this study was obtained from the Health Research Ethics Committee of the 68 Nigerian Army Reference Hospital, Yaba (NARHY) (Reference number: 68NARHY/ECA/231). The study was conducted in accordance with the principles of the Declaration of Helsinki. All participants provided informed consent for the IVF/PGT procedures and for the use of their anonymized data for research purposes. Data was handled confidentially, and no personally identifiable information was collected or analyzed.