Uterine fibroids are associated with increased risk of pre-eclampsia: A case-control study

Association between urinary cotinine level and hypertensive disorders of pregnancy in women with uterine myoma: findings from the Japan Environment and Children's Study

The effect of smoking on hypertensive disorders of pregnancy is a public concern. Recent evidence suggests that the risk of hypertensive disorders of pregnancy is influenced by the presence of uterine fibroids. We explored the association between maternal smoking exposure and the risk of hypertensive disorders of pregnancy in relation to the presence of uterine fibroids using data from Japan's largest birth cohort study. This study focused on first-time mothers, and the study population comprised 2752 and 35,294 first-time mothers with and without uterine fibroids, respectively. Hypertensive disorders of pregnancy was categorized as early-onset (before 34 weeks) and late-onset (after 34 weeks). Maternal smoking exposure was assessed by measuring the urinary cotinine concentration during the mid-trimester. Participants were classified into four quartiles based on their urinary cotinine levels as follows: Q1 (low concentration) to Q4 (high concentration). Multivariate analysis adjusted for potential confounders revealed that in women without uterine fibroids, the Q3 urinary cotinine level was associated with a modified risk of early-onset hypertensive disorders of pregnancy (adjusted odds ratio: 0.63, 95% confidence interval: 0.44-0.89). Conversely, for women with uterine fibroids, Q4 urinary cotinine level was associated with an increased risk of hypertensive disorders of pregnancy (adjusted odds ratio: 1.68, 95% confidence interval: 1.05-2.72). In conclusion, this study indicated that the impact of maternal smoking exposure varied based on the presence of uterine fibroids, underscoring the importance of personalized preconception care.

Uterine fibroids and risk of hypertensive disorders of pregnancy - results from a racially diverse high-risk cohort

Study Question

What is the impact of the presence of uterine fibroids on the risk of developing hypertensive disorders of pregnancy (HDP) in a predominantly urban, low-income, Black, and Hispanic population of women with ultrasound or clinically diagnosed uterine fibroids with rich phenotypic data to carefully control for potential confounders?

Summary answers

The odds of HDP were 39% higher in women with uterine fibroids compared to those without when controlled for age at delivery, race, prepregnancy BMI, education, parity, and smoking status; neither fibroid location or size modified this risk.

What is known already

Studies are conflicting regarding the impact of uterine fibroids on risk of HDP; limitations of prior studies include primarily Western European populations and lack of measurement of potential confounders.

Study design size and duration

A total of 7030 women from the Boston Birth Cohort (a racially diverse cohort recruited from 1998 to 2018) that had clinical and ultrasound data regarding uterine fibroid status were included in this analysis.

Participants/materials setting and methods

Four hundred eighty-nine women with uterine fibroids and 6541 women without were included. Hypertensive disorders of pregnancy were ascertained from medical records. Logistic regression was performed to assess the risk of HDP in women with and without uterine fibroids. Covariates adjusted for included age at delivery, race, pre-pregnancy BMI, education, parity, and smoking status during pregnancy. Sub-analyses were performed to assess the impact of specific fibroid location and overall fibroid volume burden.

Main results and the role of chance

The incidence of uterine fibroids in the cohort was 7% (N=489). Twelve percent of women without uterine fibroids and 17% of women with fibroids developed HDP; in multivariate analyses adjusted for the potential confounders above, the odds of HDP were 39% higher in women with uterine fibroids compared to those without (p=0.03). Women with a uterine fibroid diagnosis based on ICD code (n=297) versus asymptomatic incidental ultrasound diagnosis (n=192) had a significantly greater chance of developing HDP (20 vs 15%, p=0.006). There did not appear to be an association between number of fibroids or total fibroid volume and the risk of developing HDP. Limitations, reasons for caution: This study has a relatively small sample size. While post-hoc power calculation determined that there was adequate power to detect a 4.6% difference in the incidence of development of HDP between participants with uterine fibroids and those without, the sub-analyses based on fibroid size, location, and method of diagnosis were underpowered to determine a similar level of difference.

Wider implications of the findings

In a racially diverse cohort, presence of uterine fibroids was a significant risk factor for developing HDP, regardless of uterine fibroid size or location. This may have implications for additional monitoring and risk stratification in women with uterine fibroids.

Study funding/competing interests

KC supported by WRHR NIH NICHD Award # K12 HD103036, PI Andrew Satin, RD James Segars. The Boston Birth Cohort (the parent study) was supported in part by the National Institutes of Health (NIH) grants (2R01HD041702, R01HD098232, R01ES031272, R01ES031521, and U01 ES034983); and the Health Resources and Services Administration (HRSA) of the U.S. Department of Health and Human Services (HHS) (UT7MC45949). This information or content and conclusions are those of the authors and should not be construed as the official position or policy of, nor should any endorsements be inferred by any funding agencies.

Trial registration number

The BBC is registered under clinicaltrials.gov NCT03228875 .

Uterine Fibroids and Hypertensive Disorders in Pregnancy: A Systematic Review and Meta-Analysis

Capsule

In this study the presence of uterine fibroids was significantly associated with an increased risk of development of hypertensive disorders of pregnancy even when accounting for age and BMI in meta-regression. This finding has potential implications for risk stratification and monitoring for hypertension during pregnancy in this population.

Objective

To examine the association between uterine fibroids and the development of hypertensive disorders in pregnancy.

Data sources

Cochrane, Embase, PubMed, MEDLINE, Scopus, and Web of Science databases were searched from inception through April 2023.

Study Selection and Synthesis

Cohort, case-control, or case series studies including uterine fibroid status and hypertensive disorders of pregnancy status were included. The comparison group was pregnant women without uterine fibroids. Inverse-variance weighted random effects models were used to pool RR and OR estimates separately. Age and BMI were explored as potential sources of heterogeneity using inverse-variance weighted meta-regression.

Main Outcomes

Hypertensive disorders of pregnancy (HDP) defined as gestational hypertension, pre-eclampsia, eclampsia, superimposed preeclampsia, or hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome.

Results

A total of 17 studies were included (Total N=1,374,395 participants, N=64,968 with uterine fibroids). Thirteen studies were retrospective cohorts and four were case-control studies. Women with uterine fibroids had a significantly higher risk of hypertensive disorders in pregnancy compared to women without uterine fibroids with RR 1.74 (95% CI 1.33-2.27, p<0.01), and OR 2.87 (95% CI 1.38-5.97, p<0.01), in cohort studies and case-control studies, respectively. In meta-regression analyses, age did not significantly change the positive association between uterine fibroids and hypertensive disorders in pregnancy.

Conclusion

Uterine fibroids were associated with an increased risk of hypertensive disorders of pregnancy when all available literature was synthesized, including when shared risk factors are examined in meta-regression analyses.

Relevance

If confirmed in future studies, investigations into the mechanisms of this association are needed as this finding potentially has implications for risk stratification and monitoring for hypertensive disorders of pregnancy in this population.

Trial Registration

PROSPERO, ID # 331528.

Possible risks and benefits of adenomyomectomy on pregnancy outcomes: a retrospective analysis

BACKGROUND

Adenomyosis is associated with unfavorable perinatal outcomes; however, the effect of an adenomyomectomy on pregnancy outcomes remains unclear. Pregnancy following an adenomyomectomy has been reported to be associated with a high risk for uterine rupture; however, the actual incidence remains unknown.

OBJECTIVE

This study aimed to evaluate the effect of an adenomyomectomy on pregnancy outcomes by retrospectively comparing the pregnancy outcomes of women who underwent an adenomyomectomy with those of women with adenomyosis.

STUDY DESIGN

This was a single-center retrospective study in which the pregnancy outcomes of women who underwent an adenomyomectomy and for whom complete resection of the affected tissue under laparotomy was achieved were compared with those of women with adenomyosis. The following pregnancy outcomes were examined: second-trimester miscarriage, preterm prelabor rupture of membranes, preterm delivery, spontaneous preterm delivery, preeclampsia, rate of cesarean delivery, blood loss during cesarean delivery, incidence of placenta accreta spectrum, neonatal body weight, and small for gestational age infants.

RESULTS

A total of 18 pregnant women who underwent an adenomyomectomy and 105 pregnant women with adenomyosis were included in this study. All women who underwent an adenomyomectomy delivered via cesarean delivery, and among them, 1 had a uterine rupture at 30 weeks of gestation. Although there was no significant difference between pregnant women who underwent an adenomyomectomy and those with adenomyosis in the incidence of second-trimester miscarriage (0% [0/18] vs 7.6% [8/105], respectively; P=.22), preterm delivery (50% [9/18] vs 32% [34/105], respectively; P=.15), and spontaneous preterm delivery (6% [1/18] vs 15% [16/105], respectively; P=.26), a significant decrease in preterm prelabor rupture of membrane (0% [0/18] vs 12% [13/105], respectively; P<.05), preeclampsia (0% [0/18] vs 12% [13/105], respectively; P<.05), and small for gestational infants (0% [0/18] vs 15% [16/105], respectively; P<.05), as well as a significant increase in the incidence of placenta accreta spectrum (50% [9/18] vs 0% [0/105], respectively; P<.01) and blood loss during cesarean delivery (1748 mL vs 1330 mL, respectively; P<.05) were observed.

CONCLUSION

Uterine rupture following an adenomyomectomy may occur because of the high incidence of placenta accreta spectrum. However, an adenomyomectomy may reduce adverse pregnancy outcomes associated with adenomyosis, such as preterm prelabor rupture of membranes, preeclampsia, and small for gestational age infants. An adenomyomectomy may be a viable option for women among whom the procedure is inevitable before conception.