Adenomyosis as a Potential Risk Factor for Adverse Pregnancy Outcomes: A Multicenter Case-Control Study

The Impact of Adenomyosis on Pregnancy

Adenomyosis is characterized by ectopic proliferation of endometrial tissue within the myometrium. Histologically, this condition is marked by the presence of islands of benign endometrial glands surrounded by stromal cells. The myometrium appears thinner, and cross-sectional analysis often reveals signs of recent or chronic hemorrhage. The ectopic endometrial tissue may respond to ovarian hormonal stimulation, exhibiting proliferative or secretory changes during the menstrual cycle, potentially leading to bleeding, uterine swelling, and pain. Adenomyosis can appear as either a diffuse or focal condition. It is crucial to understand that adenomyosis involves the infiltration of the endometrium into the myometrium, rather than its displacement. The surgical management of adenomyosis is contingent upon its anatomical extent. The high incidence of the disease and the myths that develop around it increase the need to study its characteristics and its association with pregnancy and potential obstetric complications. These complications often require quick decisions, appropriate diagnosis, and proper counseling. Therefore, knowing the possible risks associated with adenomyosis is key to decision making. Pregnancy has a positive effect on adenomyosis and its painful symptoms. This improvement is not only due to the inhibition of ovulation, which inhibits the bleeding of adenomyotic tissue, but also to the metabolic, hormonal, immunological, and angiogenic changes associated with pregnancy. Adenomyosis affects pregnancy through disturbances of the endocrine system and the body's immune response at both local and systemic levels. It leads to bleeding from the adenomyotic tissue, molecular and functional abnormalities of the ectopic endometrium, abnormal placentation, and destruction of the adenomyotic tissue due to changes in the hormonal environment that characterizes pregnancy. Some of the obstetric complications that occur in women with adenomyosis in pregnancy include miscarriage, preterm delivery, placenta previa, low birth weight for gestational age, obstetric hemorrhage, and the need for cesarean section. These complications are an understudied field and remain unknown to the majority of obstetricians. These pathological conditions pose challenges to both the typical progression of pregnancy and the smooth conduct of labor in affected women. Further multicenter studies are imperative to validate the most suitable method for concluding labor following surgical intervention for adenomyosis.

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.

Establishment and validation of a nomogram model for predicting adverse pregnancy outcomes of pregnant women with adenomyosis

PURPOSE

To establish a reliable nomogram model to predict the risk of major adverse pregnancy outcomes in pregnant women with adenomyosis, and to provide a reference tool for the hierarchical management and the prenatal examination of pregnant women.

METHODS

We collected the clinical data of pregnant women with adenomyosis who were treated in the First Affiliated Hospital of Chongqing Medical University, the Women and Children's Hospital of Chongqing Medical University, and Yubei District People's Hospital of Chongqing from January 2014 to June 2020. They were divided into the training cohort and the validation cohort, respectively. In the training cohort, we screened out risk factors associated with major adverse pregnancy outcomes and established a model, which was subsequently validated.

RESULTS

In the training cohort, we found that previous parity, natural conception or not, type of adenomyosis, with or without endometriosis, history of infertility or adverse pregnancy outcomes, and history of uterine body surgery were associated with major adverse pregnancy outcomes of pregnant women with adenomyosis, and based on these factors, a nomogram model was constructed. The calibration curves of the model were well fitted in both the training and validation cohorts. The receiver-operating characteristic curve (ROC curve) showed that the area under the curve (AUC) was 0.873 and 0.851 in the training and validation cohorts, respectively. The optimal risk threshold of the model was 0.22, and this threshold can be applied to risk stratification of pregnant women.

CONCLUSION

The nomogram model established in this study can reliably predict the risk of major APO in pregnant women with AD.

Clinical characteristics and outcomes of women with adenomyosis pain during pregnancy: a retrospective study

OBJECTIVES

Adenomyosis is associated with unfavorable perinatal outcomes, and recent case reports show that some women with adenomyosis experience pain at the adenomyosis lesion during pregnancy and have detrimental perinatal outcomes. This study aimed to clarify the clinical characteristics of this pain and perinatal outcomes associated with this phenomenon.

METHODS

This was a single-center retrospective analysis of pregnant women with adenomyosis. The incidence of pain onset at adenomyosis lesions, defined as persistent pain at the adenomyosis site with administration of analgesics for pain relief, and its association with perinatal outcomes were analyzed.

RESULTS

Among 91 singleton pregnancies with adenomyosis, 12 pregnancies (13.2 %) presented with pain. One pregnancy resulted in second-trimester miscarriage, and 5 of the 11 pregnancies (45 %) developed preeclampsia, which resulted in preterm delivery, and 3 of the 12 pregnancies (25 %) achieved term delivery. The incidence of preeclampsia and preterm delivery was higher in those who experienced pain than in those without (45 % [5/11] vs. 15 % [11/74]; p<0.05, and 73 % [8/11] vs. 34 % [25/74]; p<0.05, respectively). Among women with pain, the maximum C-reactive protein level was significantly higher in women who developed preeclampsia than in those who did not (5.45 vs. 0.12 mg/dL, p<0.05).

CONCLUSIONS

Our study revealed that adenomyosis can cause pain in over one of eight pregnancies with adenomyosis, which may be associated with the increased incidence of preeclampsia resulting in preterm delivery. Women with pain, especially those with high C-reactive protein levels, may be at high risk for future development of preeclampsia and consequent preterm delivery.

Pregnancy Outcomes of Freeze-All versus Fresh Embryo Transfer in Women with Adenomyosis: A Retrospective Study

Adenomyosis has been associated with adverse fertility and pregnancy outcomes, and its impact on the outcomes of in vitro fertilization (IVF) has received much attention. It is controversial whether the freeze-all strategy is better than fresh embryo transfer (ET) in women with adenomyosis. Women with adenomyosis were enrolled in this retrospective study from January 2018 to December 2021 and were divided into two groups: freeze-all (n = 98) and fresh ET (n = 91). Data analysis showed that freeze-all ET was associated with a lower rate of premature rupture of membranes (PROM) compared with fresh ET (1.0% vs. 6.6%, p = 0.042; adjusted OR 0.17 (0.01-2.50), p = 0.194). Freeze-all ET also had a lower risk of low birth weight compared with fresh ET (1.1% vs. 7.0%, p = 0.049; adjusted OR 0.54 (0.04-7.47), p = 0.642). There was a nonsignificant trend toward a lower miscarriage rate in freeze-all ET (8.9% vs. 11.6%; p = 0.549). The live birth rate was comparable in the two groups (19.1% vs. 27.1%; p = 0.212). The freeze-all ET strategy does not improve pregnancy outcomes for all patients with adenomyosis and may be more appropriate for certain patients. Further large-scale prospective studies are needed to confirm this result.

Fertility and Pregnancy Outcomes in Patients With Adenomyosis: Is Adenomyosis Synonymous With Infertility?

Adenomyosis is a disease related to the presence of endometrial glands and stromal cells within the uterine myometrium that used to be linked to females that are more than 40 years old and multiparous. Nowadays, females are delaying their pregnancies to their third or fourth decade, and as diagnostic approaches evolve, the disease has become a common problem for females who desire pregnancy. The aim of this study is to identify the physio-pathological factors by which adenomyosis causes infertility and pregnancy complications, as well as the possible results from infertility treatments and the most common pregnancy complications that females with adenomyosis face. A systematic review based on a systematic search from PubMed, Cochrane, and ScienceDirect databases from the past five years was done. Papers with free full text available were subject to the removal of duplicates, screening for relevant titles and abstracts, and a quality assessment to identify the risk of bias (RoB). A total of 10 papers were selected for this study; they include systematic reviews and meta-analyses, cohorts, literature review, and a case-control study. After the review of the data, we conclude that infertility may be due to several factors that impair adequate sperm mobility through the uterus and an impaired implantation of a product. After some fertility treatments were performed, females with adenomyosis had a lower rate of clinical pregnancy. The pregnancy complications such as preterm delivery and hypertension problems related to pregnancy had an increased risk for females with adenomyosis, while for others such as intrauterine fetal death and gestational diabetes, the information is still controversial. The main limitation of this study was the lack of information of physio-pathological-related information probably due to only including data from the past five years.

The Prevalence and Clinical Impact of Adenomyosis in Pregnancy-Related Hysterectomy

Background: The epidemiology of adenomyosis has been traditionally based on patients undergoing hysterectomy for gynecological indications, while its prevalence among hysterectomies performed for obstetric complications is unknown. The aim of this study was to assess the prevalence and clinical impact of adenomyosis diagnosed through histology among women undergoing pregnancy-related hysterectomy (PH). Methods: This was a retrospective cohort study. Women who delivered at a tertiary care regional obstetric hub in Milan between 2009 and 2020 were reviewed to identify cases of PH. Histopathological reports of surgical specimens were examined. Cases with adenomyosis were compared to those without adenomyosis for baseline characteristics, obstetric history and outcomes. Results: During the study period there were 71,061 births and a total of 130 PH, giving a PH incidence of 1.83 per 1000 deliveries. Adenomyosis cases were 18, giving a prevalence of 13.8%. Adenomyosis was associated with placenta previa (77.8 vs. 45.5%, p = 0.01), chorionamnionitis (27.8 vs. 5.4%, p = 0.008), lower gestational age at birth (32 ± 4.6 vs. 35.5 ± 3.6 weeks’ gestation, p = 0.0004), and intrauterine fetal demise among twin pregnancies (50 vs. 4.5%, p = 0.048). Conclusion: Adenomyosis entails a relevant impact on obstetric and perinatal outcomes related to PH. More evidence is needed on the clinical relevance of an ultrasonographic diagnosis of adenomyosis before conception.

Increased risk of obstetric complications in patients with adenomyosis: A narrative literature review

Background

Reproductive-age women occasionally face the pathological condition of adenomyosis, which is often concurrent with endometriosis. It is believed that endometriosis and adenomyosis increases the risk of obstetric complications. Although new insights into the mechanism of obstetric complications due to endometriosis are emerging, there is little information on the etiology of adverse pregnancy outcomes in pregnant women with adenomyosis.

Methods

We performed a literature review focusing on the pathophysiological pathways of obstetric complications in women with adenomyosis using currently available basic and clinical studies. We used the internet search engines PubMed and Google Scholar to search for studies published between January 2000 and June 2021. We carefully read pertinent sections within each document to ensure relevancy.

Main findings

The prevalence of adverse pregnancy outcomes in women with adenomyosis is increased after adjusting for conceiving by assisted reproductive technology. Thus, adenomyosis emerges as a relevant factor associated with several obstetric complications such as preterm birth, preterm premature rupture of membranes, placental abruption, small for gestational age/fetal growth restriction, and preeclampsia.

Conclusion

It is plausible that the impact of adenomyosis on pregnancy outcomes is not always the same; rather it is dependent on the degree of uterine involvement and subtypes.