Women with Endometriosis, Especially Those Who Conceived with Assisted Reproductive Technology, Have Increased Risk of Placenta Previa: Meta-analyses

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 Impact of Endometriosis on Pregnancy

Despite the increased frequency of endometriosis, it remains one of the most enigmatic disorders regarding its effects on pregnancy. Endometriosis adversely affects both natural and assisted conception. Impaired folliculogenesis, which causes follicular dysfunction and low egg quality, as well as luteal phase problems, reduced fertilization, and abnormal embryogenesis, are some of the mechanisms advocated to explain reproductive dysfunction. There is a rising need for a comprehensive study of the potential negative consequences of this condition on pregnancy outcomes, including the postpartum period, as more women with a medical history of endometriosis become pregnant. Obstetrical complications (small for gestational age [SGA], cesarean section [CS], miscarriage, hemorrhage, low placental adhesion, and preterm delivery) are statistically elevated in women with endometriosis. Furthermore, ruptured ovarian endometrioma, appendicitis, intestinal perforation, and hemoperitoneum have been described in pregnancy. Obstetricians are largely unfamiliar with these complications, as they have not been thoroughly investigated. The development and pathogenesis of endometriosis is an important field of study and has not yet been fully elucidated. Finding these mechanisms is crucial for the development of new and more effective strategies to treat this condition. Endometriosis can have an impact on obstetric and neonatal outcomes of pregnancy, in addition to its potential effects on conception. To date, no additional monitoring is recommended for pregnancies with a history of endometriosis. However, more studies are urgently needed to assess the need for the tailored pregnancy monitoring of women with endometriosis.

The prenatal diagnostic indicators of placenta accreta spectrum disorders

Placenta accreta spectrum (PAS) disorders refers to a heterogeneous group of anomalies distinguished by abnormal adhesion or invasion of chorionic villi through the myometrium and uterine serosa. PAS frequently results in life-threatening complications, including postpartum hemorrhage and hysterotomy. The incidence of PAS has increased recently as a result of rising cesarean section rates. Consequently, prenatal screening for PAS is essential. Despite the need to increase specificity, ultrasound is still considered a primary adjunct. Given the dangers and adverse effects of PAS, it is necessary to identify pertinent markers and validate indicators to improve prenatal diagnosis. This article summarizes the predictors regarding biomarkers, ultrasound indicators, and magnetic resonance imaging (MRI) features. In addition, we discuss the effectiveness of joint diagnosis and the most recent research on PAS. In particular, we focus on (a) posterior placental implantation and (b) accreta after in vitro fertilization-embryo transfer, both of which have low diagnostic rates. At last, we graphically display the prenatal diagnostic indicators and each diagnostic performance.

Endometriosis Increases the Risk of Placenta Previa in Both IVF Pregnancies and the General Obstetric Population

Is there a relationship between endometriosis and placenta previa (PP)? To investigate if there is a relationship between endometriosis and PP, a retrospective study was carried out, using prospectively recorded data from two different databases from Cruces University Hospital. Two different populations were included in the study. The ART (assisted reproduction techniques) population consisted of 246 cesarean sections (CS), from a total of 1170 deliveries, and the obstetric population consisted of 7045 CS, from a total of 50,298 deliveries. A representative subset from the obstetric population was established selecting 4 CS without PP for each CS with PP. In our ART population, the PP rate was 1.71% among all deliveries and 8.13% among CS. In our general obstetric population, the PP rate was 0.34% among all deliveries and 2.41% among the CS. Among the CS in ART pregnancies, the PP rate was 20% in the women with endometriosis vs 5.47% in women without endometriosis (OR = 4.32; 95% CI = 1.67-11.17), while considering all ART deliveries, the PP rates were 6.43% and 1.07%, respectively (OR = 6.36; 95% CI = 2.59-15.65). In the CS-obstetric population, the rate of PP was 9.61% among women with endometriosis vs 2.19% among women without endometriosis (OR = 4.74; 95% CI = 2.91-7.73). Considering all deliveries, the PP rate was 1.35% among women with endometriosis vs 0.30% in women without endometriosis. Differences persisted when adjusting for age, IVF, multiplicity, and previous deliveries. In the CS-obstetric population with PP, mean surgical time and hospital stay were significantly higher in women with endometriosis. Endometriosis is associated with a higher risk of PP even after adjusting for other parameters.

Pregnancy outcomes in women with endometriosis and/or ART use: a population-based cohort study

STUDY QUESTION

What is the association between endometriosis and adverse pregnancy outcomes with ART use and non-use?

SUMMARY ANSWER

Endometriosis and ART use are both associated with increased risk of preterm birth, antepartum haemorrhage, placenta praevia and planned birth (caesarean delivery or induction of labour).

WHAT IS KNOWN ALREADY

There are contradictory findings on the association between endometriosis and adverse pregnancy outcomes, and many large studies have not considered the effect of ART use.

STUDY DESIGN, SIZE, DURATION

Population-based cohort study of 578 221 eligible pregnancies during 2006-2015, comparing pregnancy outcomes across four groups (No endo/no ART, No endo/ART, Endo/no ART and Endo/ART).

PARTICIPANTS/MATERIALS, SETTING, METHODS

All female residents of New South Wales, Australia aged 15-45 years and their index singleton pregnancy of at least 20 weeks gestation or 400 g birthweight. Linked hospital, pregnancy/birth and mortality data were used. Modified Poisson regression with robust error variances was used to estimate adjusted risk ratios (aRRs) and 99% CIs, adjusting for sociodemographic and pregnancy factors.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared to women without endometriosis who had pregnancies without ART use, there was increased risk of preterm birth (<37 weeks) in all groups [No endo/ART (aRR 1.85, 99% CI 1.46-2.34), Endo/no ART (aRR 1.24, 99% CI 1.06-1.44), Endo/ART (aRR 1.93, 99% CI 1.11-3.35)] and antepartum haemorrhage [No endo/ART (aRR 1.99, 99% CI 1.39-2.85), Endo/no ART (aRR 1.31, 99% CI 1.03-1.67), Endo/ART (aRR 2.69, 99% CI 1.30-5.56)] among pregnancies affected by endometriosis or ART use, separately and together. There was increased risk of placenta praevia [No endo/ART (aRR 2.26, 99% CI 1.42-3.60), Endo/no ART (aRR 1.66, 99% CI 1.18-2.33)] and planned birth [No endo/ART (aRR 1.08, 99% CI 1.03-1.14), Endo/no ART (aRR 1.11, 99% CI 1.07-1.14)] among pregnancies with endometriosis or ART use, separately. There was increased risk of placental abruption [No endo/ART (aRR 2.36, 99% CI 1.12-4.98)], maternal morbidity [No endo/ART (aRR 1.67, 99% CI 1.07-2.62)] and low birthweight (<2500 g) [No endo/ART (aRR 1.45, 99% CI 1.09-1.93)] among pregnancies with ART use without endometriosis. There was decreased risk of having a large-for-gestational age infant [Endo/no ART (aRR 0.83, 99% CI 0.73-0.94)] among pregnancies with endometriosis without ART use.

LIMITATIONS, REASONS FOR CAUTION

Endometriosis is often under-diagnosed and women with a history of hospital diagnosis of endometriosis may represent those with more symptomatic or severe disease. If the effects of endometriosis on pregnancy are greater for those with more severe disease, our results may over-estimate the effect of endometriosis on adverse pregnancy outcomes at a population level. We were unable to assess the effect of endometriosis stage or typology on the study outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

These results suggest that women with endometriosis including those who used ART to achieve pregnancy are a higher-risk obstetric group requiring appropriate surveillance and management during their pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Prevention Research Support Program, funded by the New South Wales Ministry of Health. The funder had no role in the design, data collection and analysis, interpretation of results, manuscript preparation or the decision to submit the manuscript for publication. The authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Clinical Analysis of Factors Influencing the Development of Placenta Praevia and Perinatal Outcomes in First-Time Pregnant Patients

Objective

To analyze the risk factors associated with the development of placenta praevia (PP) in first-time pregnant patients and to observe the perinatal clinical outcomes of patients.

Methods

The clinical data of 112 pregnant women with PP (PP group) and 224 pregnant women with normal placental position (general group) who delivered in our hospital from August 2016 to August 2021 were retrospectively analyzed. Baseline demographic data such as age, gestational week, uterine history, assisted reproductive technology use, pregnancy comorbidities, pre-pregnancy body mass index (BMI), smoking, alcohol consumption, placental position, educational level, work were collected from both groups, and logistic regression models were used to analyze the factors influencing the occurrence of PP in patients with first pregnancy. Perinatal outcomes such as implementation of hemostatic treatment (uterine balloon compression, arterial ligation, and B-Lynch suture), maternal postpartum related indicators (amount of postpartum bleeding, incidence of postpartum hemorrhage, blood transfusion rate, blood transfusion volume, and length of hospital stay), and neonatal condition (birth weight, Apgar score at 1 and 5 min after birth) were counted and compared between the two groups.

Results

Histories of endometriosis, use of assisted reproductive technology, and smoking or secondhand smoke inhalation were all high risk factors for PP in patients with first pregnancies, and the proportion of maternal and neonatal adverse outcomes was significantly higher in the PP group than in the general group (P < 0.05).

Conclusion

Histories of endometriosis, smoking (secondhand smoke), and use of assisted reproductive technologies are independent risk factors for PP in patients with first pregnancies, which can increase the risk of labor and death of the newborn.

Placental diseases associated with assisted reproductive technology

The placenta develops from the outer trophoblastic layer following the differentiation of the fertilized ovum and is therefore more susceptible to epigenetic regulatory changes caused by environmental interventions and influences during assisted reproductive technology. Furthermore, the placenta regulates the development of the fetal heart, brain, kidneys, bones, and other tissues and organs [1]. Placental dysplasia leads to poor perinatal outcomes as well as long-term health risks later in life, including neurodevelopmental disorders, tumors, and adult metabolic syndrome [2,3]. In view of the decisive role of the placenta during intrauterine fetal development, Graham J. Burton, an expert in placentology from the University of Cambridge, formally proposed the theory of "placenta-derived chronic diseases" in 2018 based on embryonic-derived diseases [4]. In this review, we summarized the changes in placental morphology and structure, growth dynamics, imprinted and non-imprinted genes, and other aspects attributable to assisted reproduction technology. Our review provides a theoretical basis for further research on placental changes caused by assisted reproductive technology that are most strongly associated with an increased risk of neonatal long-term diseases.

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.

Reproductive, obstetric, and perinatal outcomes of women with adenomyosis and endometriosis: a systematic review and meta-analysis

BACKGROUND

The reproductive impact of adenomyosis and endometriosis is widely researched but the extent of these impacts remains elusive. It has been demonstrated that endometriosis, in particular, is known to result in subfertility but endometriosis and adenomyosis are increasingly linked to late pregnancy complications such as those caused by placental insufficiency. At the molecular level, the presence of ectopic endometrium perturbs the endometrial hormonal, cellular, and immunological milieu, negatively influencing decidualization, placentation, and developmental programming of the embryo. It is unclear if and how such early aberrant reproductive development relates to pregnancy outcomes in endometriosis and adenomyosis.

OBJECTIVE AND RATIONALE

The aims of this systematic review and meta-analysis were to (i) investigate the association of adenomyosis and endometriosis with fertility, obstetric, and neonatal outcomes of women through both assisted reproduction and natural conception and (ii) determine whether endometriosis disease subtypes have specific impacts on different stages of the reproductive process.

SEARCH METHODS

A systematic literature review of NHS evidence electronic databases and the Cochrane database identified all comparative and observational studies between 1980 and December 2018 in any language on adenomyosis and endometriosis with fertility, obstetric, and neonatal outcomes (23 search terms used). A total of 104 papers were selected for data extraction and meta-analysis, with use of Downs and Black standardized checklist to evaluate quality and bias.

OUTCOMES

We found that endometriosis consistently leads to reduced oocyte yield and a reduced fertilization rate (FR), in line with current evidence. Milder forms of endometriosis were most likely to affect the fertilization (FR OR 0.77, CI 0.63-0.93) and earlier implantation processes (implantation rate OR 0.76, CI 0.62-0.93). The more severe disease by American Society for Reproductive Medicine staging (ASRM III and IV) influenced all stages of reproduction. Ovarian endometriosis negatively affects the oocyte yield (MD -1.22, CI -1.96, -0.49) and number of mature oocytes (MD -2.24, CI -3.4, -1.09). We found an increased risk of miscarriage in both adenomyosis and endometriosis (OR 3.40, CI 1.41-8.65 and OR 1.30, CI 1.25-1.35, respectively), and endometriosis can be associated with a range of obstetric and fetal complications including preterm delivery (OR 1.38, CI 1.01-1.89), caesarean section delivery (OR 1.98 CI 1.64-2.38), and neonatal unit admission following delivery (OR 1.29, CI 1.07-1.55).

WIDER IMPLICATIONS

Adenomyosis and the subtypes of endometriosis may have specific complication profiles though further evidence is needed to be able to draw conclusions. Several known pregnancy complications are likely to be associated with these conditions. The complications are possibly caused by dysfunctional uterine changes leading to implantation and placentation issues and therefore could potentially have far-reaching consequences as suggested by Barker's hypothesis. Our findings would suggest that women with these conditions should ideally receive pre-natal counselling and should be considered higher risk in pregnancy and at delivery, until evidence to the contrary is available. In order to expand our knowledge of these conditions and better advise on future management of these patients in reproductive and maternal medicine, a more unified approach to studying fertility and reproductive outcomes with longer term follow-up of the offspring and attention to the subtype of disease is necessary.

Pregnancy outcomes in women with history of surgery for endometriosis

OBJECTIVE

To assess the relationship between history of surgery for endometriosis and adverse obstetrical outcomes.

DESIGN

Retrospective study using prospectively recorded data.

SETTING

Referral center.

PATIENT(S)

Total of 569 women with history of surgery for endometriosis, postoperative conception, and pregnancy evolution over 22 weeks of gestation.

INTERVENTIONS(S)

Surgery for endometriosis.

MAIN OUTCOME MEASURE(S)

Small for gestational age (SGA) status of the newborn, spontaneous preterm birth (PT, before 37 weeks' gestation), and placenta previa.

RESULTS

Among 733 pregnancies included in the study, 566 deliveries were recorded (77.2%), of which 535 were singleton (72.9% of pregnancies) and 31 twins (4.2%). SGA was observed in 81 of 535 (15.1%) singleton pregnancies and in 9 of 31 (29%) twin pregnancies. PT occurred in 53 of 535 (9.9%) singleton pregnancies and in 19 of 31 (61.2%) twin pregnancies. The number of singleton and multiple pregnancies complicated by placenta previa were, respectively, 9 of 535 (1.7%) and 0 of 31. The independent factor found to relate to SGA was the absence of endometriomas; conception with the use of assisted reproductive technologies (ART) only tended toward statistical significance. Independent factors found to increase risk of PT were conception with the use of ART, body mass index >30 kg/m², and surgery of deep endometriosis infiltrating the rectum and the bladder. Independent factors associated with placenta previa were conception with the use of ART and history of stage III or IV endometriosis.

CONCLUSION(S)

The risk of SGA and PT is increased in women with a history of surgery for endometriosis, and a high rate of conception with the use of ART may jeopardize outcomes.