Project – Association between Previous Pelvic Inflammatory Disease and the Occurrence of Ectopic Pregnancy among Women Receiving Gynaecological Care

CHAPTER ONE

INTRODUCTION

1.1 Background to the Study

Pelvic inflammatory disease (PID) is an infection and inflammation of the upper female reproductive tract, which may involve the uterus, fallopian tubes, ovaries, and surrounding pelvic structures. It is commonly associated with sexually transmitted infections, particularly Chlamydia trachomatis and Neisseria gonorrhoeae, although other microorganisms may also contribute to its development. Ectopic pregnancy, on the other hand, occurs when a fertilised ovum implants outside the normal endometrial cavity of the uterus, most commonly within the fallopian tube. The relationship between these two conditions is important because infection and inflammation of the reproductive tract may cause scarring, adhesions, and damage to the fallopian tubes, thereby interfering with the normal movement of a fertilised ovum towards the uterus. The Centers for Disease Control and Prevention (CDC, 2023) identifies ectopic pregnancy and infertility among the potential complications of PID, while Shaw et al. (2010) explain that damage to tubal structure and function is an important mechanism underlying human tubal ectopic pregnancy. Therefore, investigating the association between previous PID and ectopic pregnancy is essential for understanding the contribution of reproductive tract infections to adverse pregnancy outcomes among women receiving gynaecological care.

Ectopic pregnancy is a significant reproductive health problem because it may lead to severe internal bleeding, emergency surgery, loss of a fallopian tube, and maternal death when diagnosis and treatment are delayed. Early symptoms may include lower abdominal pain, vaginal bleeding, dizziness, and weakness, but these manifestations can be nonspecific and may resemble other early pregnancy complications. Advances in transvaginal ultrasonography, pregnancy testing, and clinical monitoring have improved early diagnosis; however, the outcome of ectopic pregnancy still depends on timely assessment and access to appropriate treatment. Barnhart (2009) describes ectopic pregnancy as a condition requiring careful diagnosis and management because of its potential for serious maternal complications. Similarly, the systematic review and meta-analysis by Brim et al. (2025), involving 25,051 participants across the included studies, identified previous ectopic pregnancy, PID, infertility, and abdominal or pelvic surgery among factors associated with ectopic pregnancy. These findings demonstrate the importance of identifying women with relevant reproductive histories and improving clinical recognition of ectopic pregnancy, particularly where previous pelvic infection may have affected tubal function.

The association between previous PID and ectopic pregnancy can be explained largely by the potential damage that inflammation causes to the fallopian tubes. Under normal circumstances, the fallopian tubes facilitate the movement of the ovum and provide the environment through which fertilisation and early transport of the embryo occur. When PID causes inflammation, the healing process may result in adhesions, narrowing of the tubal passage, scarring, or damage to the cilia responsible for moving the fertilised ovum towards the uterus. These abnormalities may delay or obstruct embryo transport, increasing the possibility of implantation within the tube. Shaw et al. (2010) identify abnormalities in tubal function and the reproductive tract as central considerations in understanding the development of tubal ectopic pregnancy. The CDC (2023) also explains that PID can produce scar tissue within and around the fallopian tubes, leading to complications such as ectopic pregnancy and infertility. This biological relationship provides a strong basis for examining whether women with a documented or reported history of PID have a higher occurrence of ectopic pregnancy than women without such a history.

Sexually transmitted infections are important in the study of PID because infections involving the cervix may ascend into the upper reproductive tract and cause inflammation. Infections caused by Chlamydia trachomatis may be asymptomatic or produce mild symptoms, allowing some affected women to remain undiagnosed and untreated. Repeated infections or delayed treatment may increase the possibility of reproductive tract damage and subsequent complications. The CDC’s Sexually Transmitted Infections Treatment Guidelines emphasise that PID may be overlooked because some women experience mild symptoms or no recognised symptoms, and that delayed recognition may expose women to reproductive complications (CDC, 2021). Similarly, the CDC’s PID information guidance identifies untreated sexually transmitted infections as an important cause of PID and notes that complications may include tubal scarring, ectopic pregnancy, and infertility (CDC, 2023). These findings indicate that a woman’s history of reproductive tract infection, previous treatment, recurrent symptoms, and access to healthcare may be relevant when examining the association between previous PID and ectopic pregnancy.

Epidemiological evidence supports the need to investigate PID as a risk factor for ectopic pregnancy. In a large population-based case-control study conducted in France, Bouyer et al. (2003) examined a range of factors associated with ectopic pregnancy, including reproductive history and previous pelvic infection. More recently, Brim et al. (2025) conducted a systematic review and meta-analysis of observational studies and reported a pooled odds ratio of 4.00 (95% confidence interval: 3.46–4.61) for the association between PID and ectopic pregnancy. This result suggests that PID was associated with higher odds of ectopic pregnancy in the studies included in the analysis. However, an odds ratio does not mean that every woman with PID will develop ectopic pregnancy, nor does it establish that all cases are directly caused by the infection. Differences in study populations, diagnostic methods, infection severity, and other reproductive risk factors must be considered when interpreting the evidence. Nevertheless, the available research provides a sound empirical basis for examining this association in a Nigerian tertiary healthcare setting.

In Nigeria, ectopic pregnancy remains an important concern in gynaecological practice because it may present as an emergency and result in significant maternal morbidity and, in severe cases, death. The burden and characteristics of ectopic pregnancy may vary between hospitals depending on referral patterns, reproductive health practices, access to early pregnancy assessment, and the availability of diagnostic and emergency treatment services. Evidence from Enugu is particularly relevant to the present study. Egwuatu and Ozumba (1987), in their investigation of ectopic pregnancy at the University of Nigeria Teaching Hospital, Enugu, reported that ectopic pregnancy was prevalent among women with a previous history of PID. In a later review of cases managed at the same institution between 1997 and 2003, Ozumba and colleagues’ published research reported that ectopic pregnancy was prevalent among young women with a history of induced abortion and resultant pelvic infection (Ozumba & Mbanaso, 2005). These studies establish the local relevance of pelvic infection in the context of ectopic pregnancy, but their historical periods mean that their findings cannot automatically be assumed to represent current patterns. A contemporary investigation is therefore warranted to assess the association using clearly defined criteria and a specified study period at UNTH, Ituku-Ozalla.

The University of Nigeria Teaching Hospital (UNTH), Ituku-Ozalla, Enugu State, provides a relevant clinical setting for investigating the relationship between previous PID and ectopic pregnancy among women receiving gynaecological care. As a tertiary healthcare institution, UNTH manages reproductive and gynaecological conditions that may require specialised assessment, diagnosis, and treatment. An investigation conducted at the hospital could help determine the proportion of women with ectopic pregnancy who have a documented or reported history of PID and compare it with the corresponding proportion among an appropriate group of women without ectopic pregnancy. Such an approach would provide stronger evidence of association than a review limited to ectopic pregnancy cases alone. The study could also examine whether the association persists after accounting for factors such as age, previous ectopic pregnancy, infertility, pelvic surgery, and other relevant reproductive histories. The need for this investigation is supported by the local findings of Egwuatu and Ozumba (1987), the clinical review by Shaw et al. (2010), and the pooled evidence reported by Brim et al. (2025). Accordingly, this study seeks to assess the association between previous pelvic inflammatory disease and the occurrence of ectopic pregnancy among women receiving gynaecological care at UNTH, Ituku-Ozalla, Enugu State.

1.2 Statement of the Problem

Pelvic inflammatory disease is an important reproductive health condition because it can damage the fallopian tubes and contribute to complications such as infertility and ectopic pregnancy. Although PID is preventable and treatable in many cases, some infections may remain undiagnosed because their symptoms are mild or absent. Where treatment is delayed, inflammation may result in tubal scarring and impaired transport of a fertilised ovum, increasing the likelihood of abnormal implantation. The CDC (2023) identifies ectopic pregnancy as one of the possible complications of PID, while Shaw et al. (2010) describe tubal dysfunction as an important mechanism in the development of ectopic pregnancy. The problem, therefore, is that previous reproductive tract infection may have consequences that extend beyond the initial infection and affect a woman’s future reproductive health.

A second problem concerns the strength and interpretation of the relationship between previous PID and ectopic pregnancy among women receiving gynaecological care. Although published research supports an association, the magnitude of this association may vary according to the study population, severity and recurrence of infection, diagnostic criteria, and presence of other risk factors. Brim et al. (2025) reported a pooled odds ratio of 4.00 for PID and ectopic pregnancy, indicating a substantial association across the included studies. However, these findings do not establish the precise magnitude of the relationship among women attending UNTH, Ituku-Ozalla. Local evidence is necessary because findings from other countries or healthcare settings may not adequately reflect the clinical characteristics, reproductive histories, and healthcare experiences of women receiving care in Enugu State.

A third problem is the age of the available hospital-based evidence from Enugu. Egwuatu and Ozumba (1987) reported a relationship between previous PID and ectopic pregnancy among women treated at the University of Nigeria Teaching Hospital, while the later study by Ozumba and Mbanaso (2005) documented the relevance of previous pelvic infection in cases managed at the institution between 1997 and 2003. Although these studies provide important historical evidence, they do not establish the current association between previous PID and ectopic pregnancy at UNTH. Changes in infection prevention, access to reproductive health services, diagnostic practices, and treatment-seeking behaviour may influence the characteristics of women presenting with these conditions. A further study using a defined period and consistent criteria is therefore needed to provide more recent, setting-specific evidence.

Finally, without an appropriate comparison of women with and without ectopic pregnancy, it may be difficult to determine whether a history of PID is disproportionately common among women who experience ectopic pregnancy at UNTH. A study restricted to women already diagnosed with ectopic pregnancy could describe the prevalence of previous PID among those cases but would not, by itself, establish the association between PID and the occurrence of ectopic pregnancy. This study will therefore seek to investigate the association using an appropriate comparison group, subject to the availability of eligible participants and ethical approval. The findings may contribute to evidence-based reproductive health education, early identification of women with relevant clinical histories, and improved prevention and management of reproductive tract infections.

1.3 Aim and Objectives of the Study

1.3.1 Aim of the Study

The aim of this study is to assess the association between previous pelvic inflammatory disease and the occurrence of ectopic pregnancy among women receiving gynaecological care at the University of Nigeria Teaching Hospital (UNTH), Ituku-Ozalla, Enugu State.

1.3.2 Specific Objectives

The specific objectives are to:

1. Determine the prevalence of a documented or reported history of pelvic inflammatory disease among women receiving gynaecological care at UNTH, Ituku-Ozalla.

2. Determine the occurrence of ectopic pregnancy among women with and without a previous history of pelvic inflammatory disease at UNTH.

3. Examine the association between previous pelvic inflammatory disease and the occurrence of ectopic pregnancy among the study participants.

4. Assess whether the association between previous pelvic inflammatory disease and ectopic pregnancy remains after accounting for selected factors, including age, previous ectopic pregnancy, infertility history, and previous pelvic surgery.

1.4 Research Questions

The following research questions will guide the study:

1. What is the prevalence of a documented or reported history of PID among women receiving gynaecological care at UNTH, Ituku-Ozalla?

2. What is the occurrence of ectopic pregnancy among women with and without a previous history of PID?

3. What association exists between previous PID and the occurrence of ectopic pregnancy among the study participants?

4. Does the association between previous PID and ectopic pregnancy remain after accounting for selected sociodemographic and reproductive factors?

1.5 Research Hypothesis

The study will test the following null hypothesis at a 0.05 level of significance.

H₀: There is no statistically significant association between previous pelvic inflammatory disease and the occurrence of ectopic pregnancy among women receiving gynaecological care at the University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu State.

1.6 Significance of the Study

The findings of this study are expected to be useful to healthcare professionals, women of reproductive age, hospital administrators, public health practitioners, policymakers, and future researchers.

1.6.1 Healthcare Professionals

The study may provide evidence to assist doctors, nurses, midwives, and other healthcare professionals in understanding the relationship between previous PID and ectopic pregnancy. A better understanding of this association may encourage appropriate reproductive history-taking and careful assessment of women presenting with symptoms of early pregnancy complications. Shaw et al. (2010) emphasise the importance of tubal abnormalities in the development of ectopic pregnancy, while the CDC (2021) highlights the need for early recognition and treatment of PID to limit reproductive complications.

1.6.2 Women of Reproductive Age

The study may contribute to greater awareness of the reproductive consequences of untreated or recurrent pelvic infections. By providing evidence on the association between previous PID and ectopic pregnancy in the study setting, the findings may encourage women to seek timely medical attention for symptoms suggestive of reproductive tract infection and to complete prescribed treatment. The CDC (2023) identifies ectopic pregnancy and infertility among the possible long-term complications of PID.

1.6.3 Hospital Management

The findings may assist UNTH management in identifying opportunities to strengthen reproductive health education, clinical documentation, and the assessment of women with a history of pelvic infection. The results may also support the development of evidence-informed protocols for recording previous PID and other relevant reproductive histories during gynaecological consultations.

1.6.4 Public Health Practitioners and Policymakers

The study may provide local evidence that can inform programmes on sexually transmitted infection prevention, timely diagnosis of PID, treatment adherence, and reproductive health education. Its findings may be useful in identifying areas where improved access to infection screening and treatment could be prioritised. The CDC (2021) identifies delayed recognition of PID as an important clinical concern because reproductive tract damage may occur even when symptoms are mild.

1.6.5 Future Researchers and Academic Institutions

The study may contribute to the literature on reproductive tract infections and ectopic pregnancy in Nigeria, particularly in Enugu State. It may also provide a basis for future comparative studies involving other teaching hospitals, different patient populations, and longer observation periods. The findings could be compared with earlier Enugu-based research by Egwuatu and Ozumba (1987) and Ozumba and Mbanaso (2005) to investigate similarities and differences in the reported relationship between pelvic infection and ectopic pregnancy.

1.7 Scope of the Study

The study will focus on the association between previous pelvic inflammatory disease and the occurrence of ectopic pregnancy among women receiving gynaecological care at the University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu State.

The geographical scope will be limited to UNTH. The population will comprise eligible women of reproductive age receiving gynaecological care during the approved study period. The principal exposure variable will be a documented or reported history of PID, while the outcome variable will be the presence or absence of ectopic pregnancy, established using the hospital’s clinical diagnostic criteria.

The study will also consider selected potential confounding variables, including age, previous ectopic pregnancy, infertility history, and previous pelvic surgery. The period of data collection will be determined by the approved research protocol and the availability of eligible participants or clinical records.

To establish the association between PID and ectopic pregnancy, the study should include an appropriate comparison group of women without ectopic pregnancy. A case-control design may be suitable, with women diagnosed with ectopic pregnancy compared with eligible women whose pregnancies are confirmed to be intrauterine. This would permit estimation of the odds ratio and adjustment for potential confounding variables.

1.8 Limitations of the Study

The study may encounter limitations that could influence the interpretation of its findings.

First, some hospital records may contain incomplete information about previous PID, including the date of diagnosis, number of episodes, treatment received, and laboratory confirmation. This may lead to misclassification of participants according to their exposure history.

Second, where information is obtained through interviews, participants may not accurately recall previous infections or may be reluctant to disclose sensitive reproductive health information. The use of confidential interviews and standardised questions may help reduce this limitation.

Third, other factors, such as previous ectopic pregnancy, infertility, pelvic surgery, and age, may influence the relationship between PID and ectopic pregnancy. Appropriate statistical adjustment will therefore be important when the required information is available.

Finally, the study will be conducted at one teaching hospital. Its findings may not be generalisable to all women in Enugu State or Nigeria. Nevertheless, the study may provide useful evidence about the relationship between previous PID and ectopic pregnancy among women receiving care at UNTH.

1.9 Operational Definition of Terms

Association: A statistical relationship between previous pelvic inflammatory disease and the occurrence of ectopic pregnancy, assessed using appropriate statistical methods.

Ectopic pregnancy: A pregnancy in which implantation occurs outside the normal endometrial cavity of the uterus, most commonly in the fallopian tube.

Occurrence of ectopic pregnancy: The identification of ectopic pregnancy among eligible study participants based on the hospital’s diagnostic criteria.

Pelvic inflammatory disease (PID): An infection and inflammation of the upper female reproductive tract, potentially involving the uterus, fallopian tubes, and ovaries.

Previous pelvic inflammatory disease: A history of PID diagnosed or documented before the index pregnancy, based on medical records or the study’s predefined participant-reporting criteria.

Women of reproductive age: Women within the age range defined by the study protocol. The study may adopt the commonly used range of 15–49 years, subject to the approved eligibility criteria.

Gynaecological care: Clinical services provided for conditions affecting the female reproductive system, including assessment, diagnosis, treatment, and follow-up.

Risk factor: A characteristic, exposure, or prior condition associated with an increased likelihood of a particular health outcome. In this study, previous PID is the principal exposure under investigation.

Comparison group: Eligible women without ectopic pregnancy who are selected to compare the history of PID with that of women diagnosed with ectopic pregnancy.

UNTH: University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu State, the healthcare institution selected as the study setting.

Project – Association between Previous Pelvic Inflammatory Disease and the Occurrence of Ectopic Pregnancy among Women Receiving Gynaecological Care