Uterine leiomyomata and cesarean birth risk: a prospective cohort with standardized imaging

doi:10.1016/j.annepidem.2013.10.017

Annals of Epidemiology

Volume 24, Issue 2, February 2014, Pages 122-126

https://doi.org/10.1016/j.annepidem.2013.10.017 Get rights and content

Abstract

Purpose

To determine if women with leiomyomata detected using uniform ultrasound methods are at increased risk of cesarean birth, without regard to indication.

Methods

Women were enrolled in Right from the Start (2000–2010), a prospective pregnancy cohort. Leiomyomata were counted, categorized, and measured during first trimester ultrasounds. Women provided information about demographics and reproductive history during first trimester interviews. Route of delivery was extracted from medical records or vital records, if the former were unavailable. Generalized estimating equations were used to calculate risk ratios (RR) and 95% confidence intervals (CIs) for the risk of cesarean birth by leiomyoma presence and characteristics.

Results

Among 2635 women, the prevalences of leiomyomata and cesarean birth were 11.2% and 29.8%, respectively. Women with leiomyomata, compared with those without, had a 27% increase in cesarean risk (RR, 1.27; CI, 1.17–1.37). The association was weaker following adjustment for maternal body mass index and age (adjusted risk ratio [ARR], 1.11; CI, 1.02–1.20). The adjusted risk was elevated for women with a single leiomyoma 3 cm or more in diameter (ARR, 1.22; CI, 1.14–1.32) and women with the largest total leiomyoma volumes (ARR, 1.59; CI, 1.44–1.76).

Conclusions

Women with leiomyomata were at increased risk for cesarean birth particularly, those with larger tumor volumes.

Introduction

During pregnancy, approximately 11% of women have leiomyomata detectable via ultrasound [1]. Black women are disproportionately affected, with a prevalence of 18%, compared with 8% in white women [1]. Estimates of prevalence and risks of pregnancy outcomes vary across studies due to differences in criteria used to define leiomyomata and underlying population characteristics [2], [3], [4], [5], [6], [7]. Presence of leiomyomata has been associated with increased risk of cesarean birth [2], [3], [4], [5], [6], [7].

Studies retrospectively identifying women with leiomyomata via routine clinical ultrasounds report adjusted odds ratios for cesarean birth ranging from 1.2 to 2.1 [3], [4], [5]. Those relying on hospital birth records (i.e., billing codes) to identify these women suggest a six-fold increase in cesarean risk [6], [7]. Many studies are biased to detect large or clinically concerning leiomyomata by ascertaining the presence of leiomyomata with medical record coding or at the time of cesarean, potentially inflating effect estimates. Inclusion criteria and adjustment for potential confounders also differ between studies, making comparisons of risk estimates difficult.

Leiomyoma presence may influence route of birth via complications that occur before the onset of labor (placenta previa and malpresentation) or after the onset of labor (dysfunctional labor and obstruction). Each of these indications has been hypothesized to be in the causal pathway between leiomyomata and cesarean birth. However, the research question of most direct relevance to clinical care is: Are leiomyomata, associated with an overall increased risk of cesarean birth? This is of special interest as average maternal age rises and clinicians speculate about the contribution of increasing age and greater likelihood of leiomyomata as a potential contributor to the rising use of cesarean. Currently, leiomyomata during pregnancy are monitored by “expectant management;” there are no practice recommendations for selecting the route of delivery due to their presence.

Clinical instinct produces both the view that leiomyomata are deleterious during pregnancy and a need to parse out any causal pathways leading to cesarean birth. However, risks for cesarean indicators due to leiomyomata presence are generally small and do not suggest intervening action; once placenta previa or breech presentation occurs, management options for leiomyomata are fixed. Treatment or removal of leiomyomata is actionable between pregnancies. Therefore, in general populations of women planning pregnancies, the magnitude of the overall risk of cesarean birth is most informative (inclusive of risk due to complications and patient/clinician preferences). The overall risk is currently the best estimate of the projected maximal reduction of cesarean risk that could be achieved by intervening on leiomyomata. An analysis that excludes or adjusts for casually related indications, such as breech presentation, will underestimate the net effect of leiomyomata. Therefore, to address biases in prior studies and understand the overall influence of leiomyomata on cesarean risk, we sought to determine if leiomyomata increase risk of cesarean birth, without regard to indication, among women with leiomyomata detected using uniform research ultrasound imaging methods in a prospective community-based pregnancy cohort.

Section snippets

Study population

Right from the Start (RFTS) is a community-recruited, prospective cohort study [8]. Between 2000–2011, the study enrolled women from locations in North Carolina, Texas, Tennessee who were newly pregnant or trying to become pregnant. To be eligible for the study, women were aged at least 18 years, less than 13 weeks pregnant, spoke English or Spanish, planned to carry to term, and did not use assisted reproductive technologies [8].

Women whose information contributed to this analysis were

Results

Among the 2635 women, 785 had a cesarean birth (29.8%) and 295 women had one or more leiomyomata (11.2%). Women who had leiomyomata were more likely to be aged 32 years or older, non-Hispanic black, and overweight (BMI >26.0 and ≤29.0) or obese (>29.0) than women without leiomyomata. Parity, gestational age at delivery, history of prior cesarean birth, household income, and education level were comparable between the two groups (Table 1).

Sonography did not identify any women with more than

Discussion

Cesarean birth is common and associated with increased costs and morbidity for mothers. Increased risk for cesarean birth among women with leiomyomata has been observed [2]. Many studies evaluating this risk have retrospectively identified leiomyomata and/or used hospital-based populations. In our community-based prospective cohort with uniform use of research quality ultrasounds, women with leiomyomata had an unadjusted 27% increase in the risk of having a cesarean (37%) compared with women

Conclusion

Our data indicate that women with larger leiomyomata or greater total tumor volume were at increased risk for cesarean birth. More complete knowledge about leiomyoma characteristic-specific risks could inform decision making for leiomyoma treatment among women planning a pregnancy or allow clinicians to anticipate specific pregnancy and labor complications. Ultimately, the use of data from large clinical consortia may be required to answer nuanced questions about leiomyoma characteristics and

Acknowledgments

The authors thank the Right from the Start study staff and participants for their support and time.

The research was supported by grants from the National Institute of Child and Human Development (R01HD043883 and R01HD049675) and the American Water Works Association Research Foundation (2579). Additional funds were provided by the Building Interdisciplinary Research Careers in Women's Health career development program (5K12HD04383-12) and the Vanderbilt CTSA grant UL1 RR024975-01. This research

References (15)

P.C. Klatsky et al.
Fibroids and reproductive outcomes: a systematic literature review from conception to delivery
Am J Obstet Gynecol
(2008)
G.D. Coronado et al.
Complications in pregnancy, labor, and delivery with uterine leiomyomas: a population-based study
Obstet Gynecol
(2000)
D. Muram et al.
Myomas of the uterus in pregnancy: ultrasonographic follow-up
Am J Obstet Gynecol
(1980)
A.O. Hammoud et al.
Volume change of uterine myomas during pregnancy: do myomas really grow?
J Minim Invasive Gynecol
(2006)
S.K. Laughlin et al.
Prevalence of uterine leiomyomas in the first trimester of pregnancy: an ultrasound-screening study
Obstet Gynecol
(2009)
G.I. Qidwai et al.
Obstetric outcomes in women with sonographically identified uterine leiomyomata
Obstet Gynecol
(2006)
P. Vergani et al.
Large uterine leiomyomata and risk of cesarean delivery
Obstet Gynecol
(2007)

There are more references available in the full text version of this article.

Cited by (33)

Pregnancy outcomes among women with endometriosis and fibroids: registry linkage study in Massachusetts
2022, American Journal of Obstetrics and Gynecology
Citation Excerpt :
Endometriosis and uterine fibroids are common gynecologic disorders; endometriosis burdens approximately 10% of reproductive-aged women1,2 and fibroids are estimated to affect 20% to 40% of women during their reproductive years3 and between 2% to 11% of pregnant women.4–6
Endometriosis and uterine fibroids are common gynecologic conditions associated with a greater risk for infertility. Previous research has suggested that these conditions are associated with adverse pregnancy outcomes, potentially because of increased utilization of fertility treatments.
Our objective was to investigate whether women with a history of endometriosis or fibroids had a greater risk for adverse pregnancy outcomes and whether this risk varied by infertility history and fertility treatment utilization.
Deliveries (2013–2017) recorded in Massachusetts’ vital records were linked to assisted reproductive technology data, hospital stays, and all-payer claims database. We identified endometriosis and fibroids diagnoses via the all-payer claims database before index delivery. Adjusted relative risks for pregnancy complications were modeled using generalized estimating equations with a log link and Poisson distribution. The influence of subfertility or infertility and assisted reproductive technology was also investigated.
Among 91,825 deliveries, 1560 women had endometriosis and 4212 had fibroids. Approximately 30% of women with endometriosis and 26% of women with fibroids experienced subfertility or infertility without utilizing assisted reproductive technology, and 34% of women with endometriosis and 21% of women with fibroids utilized assisted reproductive technology for the index delivery. Women with a history of endometriosis or fibroids were at a greater risk for pregnancy-induced hypertension, preeclampsia, or eclampsia (endometriosis relative risk, 1.17; fibroids relative risk, 1.08), placental abnormalities (endometriosis relative risk, 1.65; fibroids relative risk, 1.38), and cesarean delivery (endometriosis relative risk, 1.22; fibroids relative risk, 1.17) than women with no history of those conditions. Neonates born to women with a history of endometriosis or fibroids were also at a greater risk for preterm birth (endometriosis relative risk, 1.24; fibroids relative risk, 1.17). Associations between fibroids and low birthweight varied by fertility status or assisted reproductive technology (P homogeneity=.01) and were stronger among noninfertile women.
Endometriosis or fibroids increased the risk for adverse pregnancy outcomes, possibly warranting differential screening or treatment.
World Federation for Ultrasound in Medicine Review Paper: Incidental Findings during Obstetrical Ultrasound
2022, Ultrasound in Medicine and Biology
Citation Excerpt :
Ethnicity seems to be an epidemiologic factor significantly affecting the risk of fibroids, as there appears to be a two- to threefold increased possibility of lifetime fibroid occurrence in black women. Depending on their location, myomas have been associated with increased risk for fetal malpresentation, cesarean birth, preterm delivery, premature rupture of membranes, pelvic pain, placental abruption, dysfunctional birth, dystocia and postpartum hemorrhage (Vergani et al. 2007; Vitale et al. 2013; Incebiyik et al. 2014; Michels et al. 2014). Furthermore, myomas are sometimes complicated by secondary changes during pregnancy, such as hemorrhage, necrosis and degeneration and, histologically, may represent a major diagnostic challenge versus the rare leiomyosarcoma.
Although the prevalence of incidental findings revealed during an obstetric ultrasound examination is low, the findings may include adnexal and cervical masses, uterine or urinary congenital malformations, free fluid in the pouch of Douglas or tortuous vessels (varices). Adnexal masses are the most common finding and vary in imaging characteristics. They are mainly unilateral, cystic masses with a low risk of malignancy that are treated conservatively. The International Ovarian Tumor Analysis scoring models may be helpful in differentiating benign from malignant masses. For those masses >5 cm, follow-up is recommended, and resection could be considered to avoid risk of torsion, rupture and hemorrhage, which may compromise pregnancy outcome. Uterine masses such as fibroids are commonly diagnosed early in the first trimester and should be followed up during pregnancy to evaluate any changes. Transabdominal and transvaginal ultrasound is the first-line test for the diagnosis of such incidentalomas; however, magnetic resonance ultrasound may have a useful role in excluding malignancy potential. As a result of their low frequency and the lack of good evidence, there are no specific guidelines on the management of incidentalomas detected at obstetric scans. Their management should follow the related general guidelines for ovarian, cervical and uterine masses, with individualized management depending on the pregnancy status.
Obstetric and perinatal complications in infertile women who become pregnant
2021, Revista Medica Clinica Las Condes
Las pacientes infértiles tienen un riesgo aumentado de resultados obstétricos y perinatales adversos que dependen de los factores de infertilidad subyacentes previos y de factores inherentes a los tratamientos recibidos para lograr el embarazo. La edad materna, las patologías previas ginecológicas, hormonales, endocrinológicas, metabólicas y anatomo funcionales son reconocidas como factores de riesgo para resultados adversos obstétricos y perinatales. Los tratamientos como la hiperestimulación ovárica y los tratamientos de reproducción asistida condicionan riesgos adicionales, especialmente por el aumento de embarazos múltiples que se generan con estas terapias. El aumento de la edad materna de pacientes tratadas por infertilidad y la necesidad creciente de tratamientos de reproducción asistida determinan probablemente, un mayor riesgo futuro de complicaciones obstétricas y perinatales. Muchos de estos factores de riesgo pueden ser modificados y manejados antes de iniciar los tratamientos con la finalidad de mejorar el pronóstico para la madre y el recién nacido. La consideración de estos factores de riesgo y sus consecuencias en el embarazo son parte esencial del consejo reproductivo que debiera recibir toda paciente que se somete a tratamientos por infertilidad.
El objetivo de esta revisión es mostrar la relación existente entre las pacientes que consultan por infertilidad, los tratamientos usados y los potenciales riesgos obstétricos y perinatales cuando se produce el embarazo.
Infertile patients have an increased risk of adverse obstetric and perinatal outcomes that depend on underlying infertility factors and on those treatments recieved to become pregnant. Maternal age, hormonal, endocrinologial, metabolic and anatomic/functional gynecological diseases are widely recognized risk factors for adverse obstetric and perinatal outcomes. Infertility treatments like controlled ovarian hyperstimulation and assisted reproductive technologies add aditional risks, specially related to multiple pregnancies that are associated to. The higher maternal age of patients seeking for infertility treatment and the increasing need of assisted reproductive technologies probably determines a higher and increasing risk of obstetric and perinatal adverse outcomes. In many cases risk factors can be adequately modified and controlled before treatments are initiated thus improving maternal and neonatal prognosis. This risk factors and their consequences in pregnancy have to be strongly considered in reproductive counselling that should recieve every patient treated for infertility.
The aim of this article is to show the relation between infertile patients seeking for treatment and their potential risks of obstetric and perinatal adverse outcomes when they get pregnant.
Uterine fibroid incidence and growth in an ultrasound-based, prospective study of young African Americans
2020, American Journal of Obstetrics and Gynecology
Citation Excerpt :
Women are increasingly delaying their childbearing.25 Older women will be more likely to have fibroids, with the associated problems such as the possibility of reduced fertility,26 pain and bleeding during early pregnancy,27 and increased risk of cesarean birth.28 The higher risk of new fibroid development that we observed among women with existing fibroids compared with the incidence in fibroid-free women may result from population heterogeneity in fibroid susceptibility.
Uterine fibroids are common. Symptoms are debilitating for many, leading to high medical and societal costs. Indirect data suggest that compared with white women, African Americans develop fibroids at least 10 years earlier on average, and their higher health burden has been well documented.
The objective of the study was to directly measure fibroid incidence and growth in a large, community-based cohort of young African-American women.
This observational, community-based, prospective study enrolled 1693 African-American women, aged 23–35 years with no prior diagnosis of fibroids. Standardized transvaginal ultrasound examinations at enrollment and after approximately 18 months were conducted to identify and measure fibroids ≥0.5 cm in diameter. Fibroid growth (change in natural log volume per 18 months) was analyzed with mixed-model regression (n = 344 fibroids from 251 women whose baseline ultrasound revealed already existing fibroids).
Among the 1123 fibroid-free women with follow-up data (88% were followed up), incidence was 9.4% (95% confidence interval, 7.7–11.2) and increased with age (P_trend < .0001), from 6% (confidence interval, 3–9) for 23–25 year olds to 13% (confidence interval, 9–17) for 32–35 year olds. The chance of any new fibroid development was greater than twice as high for women with existing fibroids compared with women who were fibroid free at baseline (age-adjusted relative risk = 2.3 (confidence interval, 1.7–3.0). The uterine position of most incident fibroids (60%) was intramural corpus. Average fibroid growth was 89% per 18 months (confidence interval, 74–104%) but varied by baseline fibroid size (P < .0001). Fibroids ≥2 cm in diameter had average growth rates well under 100%. In contrast, small fibroids (<1 cm diameter) had an average growth rate of nearly 200% (188%, confidence interval, 145–238%). However, these small fibroids also had a high estimated rate of disappearance (23%).
This is the first study to directly measure age-specific fibroid incidence with a standardized ultrasound protocol and to measure fibroid growth in a large community-based sample. Findings indicate that very small fibroids are very dynamic in their growth, with rapid growth, but a high chance of loss. Larger fibroids grow more slowly. For example, a 2-cm fibroid is likely to take 4–5 years to double its diameter. Detailed data on fibroid incidence confirm an early onset in African-American women.
Pregnancy complications in spontaneous and assisted conceptions of women with infertility and subfertility factors. A comprehensive review
2016, Reproductive BioMedicine Online
Citation Excerpt :
Although most available evidence supports an association between fibroids and some pregnancy complications, there is considerable variation among studies (Klatsky et al., 2008; Lam et al., 2014; Stout et al., 2010). Prospective cohort studies suggest that women with large fibroids are at increased risk for pregnancy complications (Michels et al., 2014; Shavell et al., 2012). Women with fibroids measuring more than 5 cm had an excess of about 10% in PTB when compared with those with smaller fibroids or without fibroids (35% versus 24.5% versus 25.5%, respectively) (Shavell et al., 2012).
In the literature, there is growing evidence that assisted reproductive techniques increase the risk of pregnancy complications in subfertile couples. Moreover, many concomitant preconception risk factors for subfertility are frequently present in the same subject and increase the risk of pregnancy complications. This review aimed to summarize in a systematic fashion the best current evidence regarding the effects of preconception maternal factors on maternal and neonatal outcomes. A literature search up to March 2016 was performed in IBSS, SocINDEX, Institute for Scientific Information, PubMed, Web of Science and Google Scholar. An evidence-based hierarchy was used to determine which articles to include and analyse. Available data show that the risk of pregnancy complications in spontaneous and assisted conceptions is likely multifactorial, and the magnitude of this risk is probably very different according specific subgroups of patients. Notwithstanding the only moderate level and quality of the available evidence, available data suggest that the presence and the treatment of specific preconception cofactors of subfertility should be always taken into account both in clinical practice and for scientific purposes.
Pregnancy outcome and uterine fibroids
2016, Best Practice and Research: Clinical Obstetrics and Gynaecology
Citation Excerpt :
The association was weaker after adjusting for maternal body mass index and age (ARR, 1.11; CI, 1.02–1.20). The adjusted risk was elevated for women with a single leiomyoma of ≥3-cm diameter (ARR, 1.22; CI, 1.14–1.32) and women with the largest total leiomyoma volumes (ARR, 1.59; CI, 1.44–1.76) [18]. Similar results were reported in a retrospective study conducted in Italy, which showed that women with fibroids had a significantly higher rate of cesarean section than those without fibroids, although the risk was limited to women with multiple fibroids [15].
Myomas are observed in about 3–12% of pregnant women. Uterine fibroids may affect the outcome of pregnancy. The presence of myomas – in particular of myomas that distort the uterine cavity and larger intramural myomas – has been associated with infertility. In the case of pregnancy, it has been linked to an increased risk of spontaneous abortion, fetal malpresentation, placenta previa, preterm birth, cesarean section, and peripartum hemorrhage. Although fibroids may negatively affect pregnancy outcome, the impact of their treatment, particularly in quantitative terms, is unclear. Hysteroscopic myomectomy is the treatment of choice for submucous fibroids. The comparative efficacy of laparoscopic, laparotomic, or new modalities of treatment of intramural fibroids is not known. Up to date the choice and modalities of treatment of submucous fibroids should not be based on sound evidence but on clinical concerns and the skill of each center.

View all citing articles on Scopus

View full text

Original articleUterine leiomyomata and cesarean birth risk: a prospective cohort with standardized imaging

Abstract

Purpose

Methods

Results

Conclusions

Introduction

Section snippets

Study population

Results

Discussion

Conclusion

Acknowledgments

Am J Obstet Gynecol

Obstet Gynecol

Am J Obstet Gynecol

J Minim Invasive Gynecol

Prevalence of uterine leiomyomas in the first trimester of pregnancy: an ultrasound-screening study

Obstet Gynecol

Obstetric outcomes in women with sonographically identified uterine leiomyomata

Obstet Gynecol

Large uterine leiomyomata and risk of cesarean delivery

Obstet Gynecol

Original article
Uterine leiomyomata and cesarean birth risk: a prospective cohort with standardized imaging