Systematic review and meta-analysis regarding the association of endometriosis and preeclampsia in women conceiving spontaneously or through assisted reproductive technology

Histopathologic characteristics of term placentas in singleton pregnancies in women with endometriosis-related infertility after ART treatment: case-control study

OBJECTIVES

Endometriosis is one of the leading causes of infertility, due to negative impact on ovarian folliculogenesis and endometrial receptivity. Literature show that endometriosis could be associated with perinatal complications such as preterm birth (PTB) and preeclampsia (PE). Authors hypothesized that women with endometriosis-related infertility conceived by assisted reproductive technology (ART) treatment have higher frequency of placental disorders. Main outcome is the occurrence of histopathologic alterations of term placentas in singleton pregnancies of women with endometriosis conceived by ART treatment, compared to healthy women with infertility due to male factor (MF) conceived by ART and to healthy women with spontaneous pregnancies. Secondary outcome include the occurrence of perinatal complications and the relationship of endometriosis and placental histopathologic characteristics.

METHODS

Single-center, case-control study of term placentas that were collected within Department of Obstetrics and Gynecology of University Hospital Center (UHC) Split and analyzed in the Pathology department of the same hospital, by one senior perinatal pathologist. Histopathologic analysis was reported using Amsterdam Placental Workshop Group Consensus. All the noted placental lesions were divided into following categories: anatomic, inflammatory, villous maturation and vascular malperfusion disorders. Required sample size was 80 placentas, and study results were reported with descriptives, and analyzed with chi-squared, Fisher's exact test and Kruskal-Wallis ANOVA. Multivariate regression analysis was carried with adjustment for confounding factors. Ethics approval: Class n. 520-03/24-01/83.

RESULTS

Study included term placentas of 107 women, of which 36 were women with endometriosis conceived by ART, 31 were healthy women with MF infertility conceived by ART and 40 healthy women with spontaneous pregnancies. Endometriosis women were predominantly primiparas, with longer infertility duration. Endometriosis group had higher occurrence of early pregnancy bleeding and imminent preterm labor. Endometriosis and MF groups had higher occurrence of Cesarian delivery (CS), while endometriosis group had newborns with lowest birthweight. Endometriosis group had shorter placental cords (PC), higher rates of increased syncytial knotting and vascular malperfusion disorders (subchorionic and perivillous fibrin, intervillous thrombosis, high grade fetal vascular malperfusion). Finally, endometriosis is showed to be associated with increased syncytial knots' formation and PC hypercoiling, after adjustment for confounding factors in the multivariate regression analysis.

CONCLUSIONS

Despite low rates of perinatal complications, we report endometriosis to have higher occurrence of increased syncytial knotting and vascular malperfusion placental disorders, compared to control groups. Endometriosis is also associated with increased syncytial knotting and PC hypercoiling. Further studies are needed to elucidate the endometriosis impact on endometrial receptivity and immunopathogenesis in placental disorders and perinatal complications.HighlightsEndometriosis women were predominantly primiparas, with longer infertility duration.Endometriosis group had higher occurrence of early pregnancy bleeding and imminent preterm labor. Moreover, endometriosis and MF groups had higher occurrence of Cesarian delivery, while endometriosis group had newborns with lowest birthweight.Endometriosis group had shorter placental cords, higher rates of increased syncytial knotting and vascular malperfusion lesions.Endometriosis is showed to be associated with increased syncytial knots formation and hypercoiling of placental cord, after adjustment for confounding factor.

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.

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.

Mode of conception in patients with endometriosis and adverse pregnancy outcomes: a population-based cohort study

OBJECTIVE

To evaluate the association between endometriosis and adverse pregnancy outcomes.

DESIGN

Population-based retrospective cohort study using linked universal health databases through ICES Ontario.

PATIENT(S)

All singleton pregnancies with an estimated date of confinement between October 2006 and February 2014.

INTERVENTION(S)

Endometriosis was determined based on a surgical and/or medical diagnosis (defined as an in-hospital admission or surgery with a diagnosis code of International Classification of Diseases [ICD]9-617 or ICD10-N80 and/or 2 medical consults billed as ICD9-617).

MAIN OUTCOME MEASURE(S)

The association between endometriosis and pregnancy outcomes was quantified by relative risks, derived using modified Poisson regression, and adjusted for maternal age, income quintiles, and history of fibroids (aRR). Mediation analysis was conducted to estimate direct effects of endometriosis diagnosis and indirect effects through mode of conception, namely: infertility without fertility treatment (known infertility but conceived without assistance), ovulation induction or intrauterine insemination, and in vitro fertilization or intracytoplasmic sperm injection, relative to unassisted conception.

RESULT(S)

A total of 19,099 pregnancies had an antecedent diagnosis of endometriosis, while 768,350 did not. Mean time (standard deviation) from endometriosis diagnosis to the index pregnancy was 5.6 (4.3) years. Endometriosis was associated with an increased risk of hypertensive disorders of pregnancy (aRR, 1.09; 95% confidence interval [CI], 1.02-1.16), preterm birth <37 weeks (aRR, 1.26; 95% CI, 1.20-1.33), early preterm birth <34 weeks (aRR, 1.33; 95% CI, 1.17-1.50), placenta previa (aRR, 2.07; 95% CI, 1.84-2.33), placenta abruption (aRR, 1.55; 95% CI, 1.31-1.83), other placental disorders (aRR, 1.77; 95% CI, 1.36-2.30), cesarean delivery (aRR, 1.18; 95% CI, 1.16-1.21), and stillbirth (aRR, 1.32; 95% CI, 1.09-1.59). Mediation analysis suggests that endometriosis directly affects most adverse pregnancy outcomes studied, except for stillbirth where infertility diagnosis or fertility treatment indirectly accounted for part of the increased risk.

CONCLUSION(S)

Endometriosis was associated with adverse pregnancy, independent of infertility diagnosis, or fertility treatment. Future studies should investigate the mechanisms of action and potential interventions.

Impact of endometriosis on obstetric outcome after natural conception: a multicenter Italian study

Purpose

To evaluate obstetric outcome in women with endometriosis who conceive naturally and receive standard obstetric care in Italy.

Methods

Cases were consecutive women with endometriosis managed in eleven Italian referral centers. Controls were women in whom endometriosis was excluded. All women filled in a questionnaire addressing previous natural pregnancies. Marginal logistic regression models were fitted to evaluate the impact of endometriosis on obstetric outcome. A post hoc analysis was performed within the endometriosis group comparing women with severe adenomyosis versus women with absent or mild adenomyosis.

Results

Three hundred and fifty-five pregnancies in endometriosis group and 741 pregnancies in control group were included. Women with endometriosis had a higher risk of preterm delivery < 34 weeks (6.4% vs 2.8%, OR 2.42, 95% CI 1.22–4.82), preterm delivery < 37 weeks (17.8% vs 9.7%, OR 1.98, 95% CI 1.23–3.19), and neonatal admission to Intensive Care Unit (14.1% vs 7.0%, OR 2.04, 95% CI 1.23–3.36). At post hoc analysis, women with endometriosis and severe adenomyosis had an increased risk of placenta previa (23.1% vs 1.8%, OR 16.68, 95% CI 3.49–79.71), cesarean delivery (84.6% vs 38.9%, OR 8.03, 95% CI 1.69–38.25) and preterm delivery < 34 weeks (23.1% vs 5.7%, OR 5.52, 95% CI 1.38–22.09).

Conclusion

Women with endometriosis who conceive naturally have increased risk of preterm delivery and neonatal admission to intensive care unit. When severe adenomyosis is coexistent with endometriosis, women may be at increased risk of placenta previa and cesarean delivery.

Trial registration

Clinical trial registration number: NCT03354793.

Obstetrical complications and outcome in patients with endometriosis

Endometriosis is a disease that has a profound impact on the quality of life of women, due to the associated chronic pelvic pain, dysmenorrhea, dyspareunia and infertility. However, even getting long-awaited pregnancy (often after assisted reproductive technologies), patients with endometriosis have a high risk of obstetric complications, such as miscarriage, preterm birth, preeclampsia, placental abnormalities, hemorrhage in labor, birth of small for gestational age infants, stillbirth and higher cesarean section rate. In addition, during pregnancy acute complications of endometriosis may occur, such as spontaneous hemoperitoneum, which is rare but life-threatening conditions that in most cases require surgical intervention. The mechanisms of the observed complications in pregnant women with endometriosis are not fully understood. This review presents literature data and personal considerations on the effect of endometriosis on pregnancy outcome and the occurrence of complications, as well as their possible underlined mechanisms. Based on this, we proposed ways to reduce the risk of obstetric complications in pregnant women with a history of endometriosis.

Adverse Pregnancy Outcomes in Endometriosis - Myths and Realities

PURPOSE OF REVIEW

There is increasing interest in the long-term health and comorbid conditions associated with endometriosis for both women and neonates. The purpose of this review was to synthesize and discuss the current state of the literature investigating endometriosis and risk of adverse pregnancy outcomes.

RECENT FINDINGS

Methodologic considerations for studying endometriosis and adverse pregnancy outcomes include complexities regarding the comparison population, endometriosis definition, sample size, residual confounding, and interactions. The current research on endometriosis and adverse pregnancy outcomes should be interpreted cautiously. To date, evidence suggests that endometriosis may be associated with higher risk of ectopic pregnancy, placenta previa, preterm birth, and cesarean section. While an association with miscarriage and stillbirth has been consistently observed, the relative risk was small.

SUMMARY

Pregnant women with endometriosis may be at higher risk for certain adverse pregnancy outcomes and may therefore benefit from additional monitoring. However, additional research is needed to confirm these associations and should focus on ensuring studies have internal and external validity, as well as, investigate the potential for differences in endometriosis phenotypes. Moreover, future research should focus on understanding potential mechanisms of association and better understanding how early interventions, through increased monitoring or screening during pregnancy, may improve outcomes.

Endometriosis Is Associated with Adverse Pregnancy Outcomes: a National Population-Based Study

Pregnancy and neonatal outcomes in women diagnosed with endometriosis were investigated using data collected from the Korea National Health Insurance Claims Database and the National Health Screening Program for Infants and Children. A total of 3,778,561 women who gave birth between 2007 and 2015 were identified, and 1,938,424 primiparous women and their newborns were included in this study. Women with a diagnosis of endometriosis had a significantly higher incidence of multiple pregnancy, cesarean section, breech presentation, postpartum hemorrhage, placental abruption, placenta previa, and stillbirth than women without endometriosis (P < 0.0001). The rates of preterm birth and low birth weight were also increased in women with endometriosis (P < 0.0001). After adjusting for age, the estimated risks of these outcomes remained significant. Women previously diagnosed with endometriosis have an increased risk of adverse pregnancy and neonatal outcomes. Particular attention and information regarding these conditions should be provided to women with endometriosis during the preconception or antenatal periods.

Endometriosis and Risk of Adverse Pregnancy Outcomes

OBJECTIVE

To investigate the relationship between endometriosis and adverse pregnancy outcomes.

METHODS

Women between ages 25 and 42 years in 1989 (n=116,429) reported detailed information on pregnancies and reproductive health at baseline and every 2 years thereafter in the Nurses' Health Study II, a cohort study. In 2009, they completed a detailed, pregnancy-focused questionnaire. A total of 196,722 pregnancies were reported. Adverse pregnancy outcomes included spontaneous abortion, ectopic pregnancy, stillbirth, gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (preeclampsia or gestational hypertension), preterm birth, and low birth weight. We estimated the relative risks (RRs) and 95% CIs of adverse pregnancy outcomes comparing pregnancies in women with and without a history of laparoscopically confirmed endometriosis using multivariable log-binomial regression, with generalized estimating equations to account for multiple pregnancies per woman.

RESULTS

Endometriosis was associated with a greater risk of pregnancy loss (spontaneous abortion: RR 1.40, 95% CI 1.31-1.49; ectopic pregnancy: RR 1.46, 95% CI 1.19-1.80). Endometriosis was also associated with a greater risk of GDM (RR 1.35, 95% CI 1.11-1.63) and hypertensive disorders of pregnancy (RR 1.30, 95% CI 1.16-1.45).

CONCLUSIONS

We observed an association between laparoscopically confirmed endometriosis and several adverse pregnancy outcomes. Future research should focus on the potential biological pathways underlying these relationships to inform screening or preventive interventions.

Evidence for shared molecular pathways of dysregulated decidualization in preeclampsia and endometrial disorders revealed by microarray data integration

Microarray data of chorionic villous samples (CVSs) obtained from women of ∼11.5 gestational weeks who developed preeclampsia with severe features (sPE; PE-CVS) revealed a molecular signature of impaired endometrial maturation (decidualization) before and during early pregnancy. Because endometrial disorders are also associated with aberrant decidualization, we asked whether they share molecular features with sPE. We employed microarray data integration to compare the molecular pathologies of PE-CVS and endometrial disorders, as well as decidua obtained postpartum from women with sPE. Eight public databases were reanalyzed with R software to determine differentially expressed genes (DEGs) in pathologic tissues relative to normal controls. DEGs were then compared to explore overlap. Shared DEGs were examined for enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Principal component and network analyses were subsequently applied to selected DEGs. There was significant overlap of DEGs changing in the same direction for PE-CVS and endometrial disorders, suggesting common molecular pathways. Shared DEGs were enriched for cytokine-cytokine receptor interaction. Genes in this pathway revealed expression patterns forming 2 distinct clusters, one for normal and the other pathologic endometrium. The most affected hub genes were related to decidualization and NK cell function. Few DEGs were shared by PE-CVS, and PE decidua obtained postpartum. sPE may be part of a biologic continuum of "endometrial spectrum disorders."-Rabaglino, M. B., Conrad, K. P. Evidence for shared molecular pathways of dysregulated decidualization in preeclampsia and endometrial disorders revealed by microarray data integration.