Impact of Endometriomas and Deep Infiltrating Endometriosis on Pregnancy Outcomes and on First and Second Trimester Markers of Impaired Placentation

Untangling the independent effect of endometriosis, adenomyosis, and ART-related factors on maternal, placental, fetal, and neonatal adverse outcomes: results from a systematic review and meta-analysis

BACKGROUND

Women with endometriosis may constitute a group at a particularly increased risk of pregnancy-related complications. Furthermore, women selected for assisted reproductive technology (ART) are exposed to additional endocrinological and embryological factors that have been associated with adverse pregnancy outcomes.

OBJECTIVE AND RATIONALE

This study aimed to investigate the independent effect of endometriosis, adenomyosis, and various ART-related factors on adverse maternal, placental, fetal, and neonatal outcomes.

SEARCH METHODS

Published randomized controlled trials, cohort studies, and case-control studies were considered eligible. PubMed, MEDLINE, ClinicalTrials.gov, Embase, and Scopus were systematically searched up to 1 March 2024. This systematic review and meta-analysis was performed in line with the PRISMA and the MOOSE reporting guidelines. To thoroughly investigate the association between endometriosis/adenomyosis and adverse pregnancy outcomes, sub-analyses were conducted, whenever possible, according to: the method of conception (i.e. ART and non-ART conception), the endometriosis stage/phenotype, the coexistence of endometriosis and adenomyosis, any pre-pregnancy surgical treatment of endometriosis, and the form of adenomyosis. The odds ratio (OR) with 95% CI was used as effect measure. The quality of evidence was assessed using the GRADE approach.

OUTCOMES

We showed a higher risk of placenta previa in women with endometriosis compared to controls (34 studies, OR 2.84; 95% CI: 2.47, 3.26; I2 = 83%, moderate quality). The association was observed regardless of the method of conception and was particularly strong in the most severe forms of endometriosis (i.e. rASRM stage III-IV endometriosis and deep endometriosis (DE)) (OR 6.61; 95% CI: 2.08, 20.98; I2 = 66% and OR 14.54; 95% CI: 3.67, 57.67; I2 = 54%, respectively). We also showed an association, regardless of the method of conception, between endometriosis and: (i) preterm birth (PTB) (43 studies, OR 1.43; 95% CI: 1.32, 1.56; I2 = 89%, low quality) and (ii) cesarean section (29 studies, OR 1.52; 95% CI: 1.41, 1.63; I2 = 93%, low quality). The most severe forms of endometriosis were strongly associated with PTB. Two outcomes were associated with adenomyosis both in the main analysis and in the sub-analysis that included only ART pregnancies: (i) miscarriage (14 studies, OR 1.83; 95% CI: 1.53, 2.18; I2 = 72%, low quality) and (ii) pre-eclampsia (7 studies, OR 1.70; 95% CI: 1.16, 2.48; I2 = 77%, low quality). Regarding ART-related factors, the following associations were observed in the main analysis and confirmed in all sub-analyses conducted by pooling only risk estimates adjusted for covariates: (i) blastocyst stage embryo transfer (ET) and monozygotic twinning (28 studies, OR 2.05; 95% CI, 1.72, 2.45; I2 = 72%, low quality), (ii) frozen embryo transfer (FET) and (reduced risk of) small for gestational age (21 studies, OR 0.59; 95% CI, 0.57, 0.61; P < 0.00001; I2 = 17%, very low quality) and (increased risk of) large for gestational age (16 studies, OR 1.70; 95% CI, 1.60, 1.80; P < 0.00001; I2 = 55%, very low quality), (iii) artificial cycle (AC)-FET and pre-eclampsia (12 studies, OR 2.14; 95% CI: 1.91-2.39; I2 = 9%, low quality), PTB (21 studies, OR 1.24; 95% CI 1.15, 1.34; P < 0.0001; I2 = 50%, low quality), cesarean section (15 studies, OR 1.59; 95% CI 1.49, 1.70; P < 0.00001; I2 = 67%, very low quality) and post-partum hemorrhage (6 studies, OR 2.43; 95% CI 2.11, 2.81; P < 0.00001; I2 = 15%, very low quality).

WIDER IMPLICATIONS

Severe endometriosis (i.e. rASRM stage III-IV endometriosis, DE) constitutes a considerable risk factor for placenta previa and PTB. Herein, we recommend against superimposing on this condition other exposure factors that have a strong association with the same obstetric adverse outcome or with different outcomes which, if coexisting, could determine the onset of an ominous obstetric syndrome. Specifically, we strongly discourage the use of AC regimens for FET in ovulatory women with rASRM stage III-IV endometriosis or DE. We also recommend single ET at the blastocyst stage in this high-risk population.

REGISTRATION NUMBER

CRD42023401428.

The relationship between hypertensive disorders in pregnancy and endometriosis: a systematic review and meta-analysis

BACKGROUND

Endometriosis is a chronic and debilitating disease that can affect the entire reproductive life course of women, with potential adverse effects on pregnancy. The aim of the present study is to investigate the association between hypertensive disorders in pregnancy and endometriosis.

METHOD

Relevant articles were searched from the Cochrane Library, PubMed, Scopus and Web of Science from inception up to December 2023. The full-text observational studies published in English that had a confirmed diagnosis of endometriosis were included. The case group included pregnant women diagnosed with endometriosis at any stage, while the control group consisted of pregnant women who had not been previously diagnosed with endometriosis. Two authors extracted and analyzed the data independently. Disagreements were reconciled by reviewing the full text by a third author. Endnote X9 was used for screening and data extraction. We used fixed and random effects models in Review Manager 5.3 to analyze the pooled data. The quality of the included studies was assessed using the Downs and Black checklist.

RESULTS

Out of the 9863 articles reviewed, 23 were selected for meta-analysis. According to the results of this study, there was an association between endometriosis and gestational hypertension (OR = 1.11, 95% CI: 1.06, 1.16; I2 = 45%, P < 0.00001; N = 8), pre-eclampsia (OR = 1.26, 95% CI: 1.18, 1.36; I2 = 37%, P < 0.00001; N = 12), and hypertensive disorders in pregnancy (OR = 1.13, 95% CI: 1.06, 1.21; I2 = 8%, P = 0.0001; N = 8).

CONCLUSIONS

This study confirmed that endometriosis may elevate the risk of developing gestational hypertensive disorders. Raising awareness of this issue will help to identify effective strategies for screening and early diagnosis of hypertensive disorders in pregnancy.

Women with Endometriosis-Who Is at Risk for Complications Associated with Pregnancy and Childbirth? A Retrospective Case-Control Study

Women with endometriosis (EM), particularly the manifestations of adenomyosis (AM) and deep infiltrating endometriosis (DIE), suffer from pain and sterility. DIE also appears with several specific obstetric complications. To determine the risk profile, we designed a retrospective case-control study. Primary outcomes were defined as the risk of preterm birth and caesarean delivery (CD). Primiparous singleton pregnancies in women with DIE were compared with controls without EM. We matched for mode of conception and maternal age. A total of 41 women diagnosed with DIE and 164 controls were recruited. A total of 92.7% of the cases were also diagnosed with AM. Preterm birth occurred in 12.2% of cases and in 6.7% of controls. The difference was not statistically significant (OR: 1.932; 95% CI: 0.632-5.907). The rate of CD was similar in both groups. Remarkably, placental implantation disorders in the form of placenta praevia were eight times more frequent in women with DIE (9.8%) than in controls (1.2%, OR: 8.757; 95% CI: 1.545-49.614). Neonatal outcome was similar in both groups. Four out of fourteen cases reported abdominal wall endometriosis after CD. Women with DIE/AM and with placenta praevia are at risk of bleeding complications. After CD, they can develop abdominal wall EM. We therefore suggest evaluating the birth mode in each woman with DIE/AM.

Association between Endometriosis and Risk of Preeclampsia in Women Who Conceived Spontaneously: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the association between endometriosis and the risk of preeclampsia and other maternal outcomes in spontaneously conceived women.

DATA SOURCES

PubMed, MEDLINE, Embase, Scopus, Cochrane Library, Web of Science, and Google Scholar were systemically searched for studies published from inception to November 2021 (CRD42020198741). Observational studies published in English or French that investigated the risk of preeclampsia in women with endometriosis who conceived spontaneously were included.

METHODS OF STUDY SELECTION

A total of 610 articles were reviewed once duplicates were removed. Inclusion criteria included spontaneous conception and surgical and/or imaging ascertainment of an endometriosis diagnosis. Exclusion criteria included conception using assisted reproductive technologies, multiple pregnancies, chronic hypertension, and unclear diagnoses of endometriosis.

TABULATION, INTEGRATION, AND RESULTS

Data of selected studies were extracted, and analysis was performed on Review Manager, version 5.4. Quality assessment of included studies for potential risk of bias was evaluated using the Newcastle-Ottawa Scale for cohort studies. Three cohort studies of spontaneous pregnancies were included. Endometriosis was associated with an increased risk of preeclampsia (risk ratio [RR] = 1.47, 95% CI 1.13 -1.89, p = .003; I2 = 0%; n = 3 studies). A sensitivity analysis excluding a study with adenomyosis cases yielded similar risk (RR = 1.44; 95% CI, 1.11-1.87; p = .006; I2 = 0%; n = 2 studies). Having endometriosis did not significantly increase risk of cesarean delivery (RR = 1.38; 95% CI, 0.99-1.92; p = .06; I2 = 80%; n = 2 studies) or postpartum hemorrhage (RR = 1.16; 95% CI, 0.46-2.91; p = .76; I2 = 50%; n = 2 studies).

CONCLUSION

We detected an increased risk of preeclampsia in women with endometriosis who conceived spontaneously. Endometriosis did not seem to increase the risk of cesarean delivery and postpartum hemorrhage, but the number of studies was limited, and the heterogeneity was high.

Deep Infiltrating Endometriosis and Adenomyosis: Implications on Pregnancy and Outcome

Endometriosis (EM), especially deep infiltrating endometriosis (DIE) and adenomyosis (AM), are known to cause pain and sterility in young women. More recently, they have also been described as risk factors for obstetric complications. While the pathophysiology is not yet completely understood, they seem to share a common origin: archimetrosis. Methods: A systematic literature review was conducted to summarize the existing evidence on DIE and AM as risk factors for obstetric complications. Results: Preterm birth, caesarean section delivery (CS) and placental abnormalities are associated with the diagnosis of DIE and AM. Women with AM seem to experience more often hypertensive pregnancy disorders, premature rupture of membranes and their children are born with lower birth weights than in the control groups. However, many of the studies tried to evaluate AM, EM and DIE as separate risk factors. Moreover, often they did not adjust for important confounders such as multiple pregnancies, parity, mode of conception and maternal age. Therefore, prospective studies with larger numbers of cases and appropriate adjustment for confounders are needed to explore the pathophysiology and to prove causality.

Endometriosis and Risk of Adverse Pregnancy Outcome: A Systematic Review and Meta-Analysis

Background: This systematic review and meta-analysis summarizes the evidence for the association between endometriosis and adverse pregnancy outcome, including gestational hypertension, pre-eclampsia, low birth weight, and small for gestational age, preterm birth, placenta previa, placental abruption, cesarean section, stillbirth, postpartum hemorrhage, spontaneous hemoperitoneum in pregnancy, and spontaneous bowel perforation in pregnancy. Methods: We performed the literature review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), by searches in PubMed and EMBASE, until 1 November 2020 (PROSPERO ID CRD42020213999). We included peer-reviewed observational cohort studies and case-control studies and scored them according to the Newcastle–Ottawa Scale, to assess the risk of bias and confounding. Results: 39 studies were included. Women with endometriosis had an increased risk of gestational hypertension, pre-eclampsia, preterm birth, placenta previa, placental abruption, cesarean section, and stillbirth, compared to women without endometriosis. These results remained unchanged in sub-analyses, including studies on spontaneous pregnancies only. Spontaneous hemoperitoneum in pregnancy and bowel perforation seemed to be associated with endometriosis; however, the studies were few and did not meet the inclusion criteria. Conclusions: The literature shows that endometriosis is associated with an increased risk of gestational hypertension, pre-eclampsia, preterm birth, placenta previa, placental abruption, cesarean section, and stillbirth.