Lumbopelvic Pain in Pregnancy in a Diverse Urban Patient Population: Prevalence and Risk Factors

Abstract

Objective:

Pregnancy lumbopelvic pain (PLPP) is a common ailment during pregnancy with physical, psychosocial, and economic consequences. Prior literature has focused on majority Caucasian patient populations; none have focused on Hispanic populations, especially in the United States. The purpose of this study was to determine the proportion of pregnant people who experience PLPP in mostly Hispanic population.

Materials and Methods:

Cross-sectional survey Setting: Academic medical center Patients: All pregnant people attending a prenatal visit in obstetrical offices from July 2018 through March 2020 were asked to complete a questionnaire compiling demographic, socioeconomic information as well as describe any pain symptoms. Furthermore, the Pregnancy Mobility Index (PMI), Pelvic Girdle Pain Questionnaire (PGQ), and the Questionnaire for Urinary Incontinence Diagnosis (QUID) were included.

Results:

In a cohort (n = 851) that was 62% Hispanic, we found a 63% point-prevalence rate for PLPP. Pregnant people who reported PLPP were further along in their pregnancy, did have significantly higher scores for the PMI and PGQ, indicating a greater level of disability, and reported issues with incontinence (QUID). Results of the logistic regression found that a higher PMI score and financial instability were factors influencing PLPP.

Conclusions:

In a cohort of majority Hispanic people, we found that 63% of respondents had PLPP. Our study found that a higher PMI score and financial instability were factors influencing PLPP. Clinicians should be alert to pregnant people who express their difficulties with activities of daily living as they may be at risk of PLPP, and could benefit from further evaluation and treatment.

Introduction

Pregnancy lumbopelvic pain (PLPP) is a common ailment during pregnancy with physical, psychosocial, and even economic consequences. Overall prevalence of PLPP is variable with reports as high as 75% and as low as 20% when excluding mild cases; most studies have reported a prevalence of ∼50% during pregnancy.^1

–5 This discrepancy in prevalence is thought to be due to heterogeneity in defining PLPP.

PLPP is an umbrella term encompassing the area between the 12th rib and the gluteal fold that can be delineated into two patterns of pain: pregnancy-related lower back pain (PLBP) and pregnancy-related pelvic girdle pain (PPGP).³ PLBP is considered to be pain located between the 12th rib and iliac crest. PPGP is considered pain between the posterior iliac crest and gluteal fold encompassing the pelvis.¹

Risk factors for PLPP have been studied extensively with several studies concurring that prior history of lower back pain, a history of PLPP with prior pregnancy, and increasing parity increased the odds of developing PLBP and/or PPGP.^1,3,6 Other factors that have inconsistently been shown to be significant risk factors, such as maternal weight gain and body mass index (BMI).^1,3,4,6

PLPP can prevent pregnant people from performing their activities of daily living (ADLs) and interfering with quality of life. Of those with PLPP, ∼45% have mild symptoms, 25% have more serious pain, and 8% are severely disabled.¹ Of those with PLPP postpartum, ∼80% have mild symptoms and 7% have severe symptoms.¹ Comorbidities associated with PLPP include sleep disturbances, increased stress, and anxiety throughout pregnancy. As patients progress through their pregnancy, symptoms can worsen, which has been shown to lead to an increased sick leave from work due to debilitating pain.^7
–9

While much of the prior literature has focused on majority Caucasian patient populations, few have focused on Hispanic and/or urban populations, especially in the United States. A study by Wang et al. looking at prevalence of PLPP in patients seeking care in New Haven, Connecticut, had an 80% Caucasian study population and only 3.8% identified as Latino.¹⁰ A multination study by Gutke et al. including three populations of pregnant people in the United States looked at patients from Madison, Wisconsin, Boston, Massachusetts, and Portland, Oregon.⁵

Demographically 79% of these patients were Caucasian, 11% were Asian, and <5% comprised of the remaining ethnic groups. Another study by Skaggs et al. looked at underserved patient populations in St. Louis, Missouri, where 70% of the population was African American and 3% of the population was Hispanic.¹¹ The purpose of this study was to determine the proportion of pregnant people who experience PLPP in a busy urban environment and mostly Hispanic patient population. In addition, our goal was to identify factors, which differentiate those with PLPP from those without PLPP. This unique setting affords us an opportunity to explore aspects of the PLPP not previously examined in the literature.

Materials and Methods

Design

Cross-sectional survey designed to examine factors associated with PLPP in a U.S. urban population.

Participants and setting

All pregnant people attending a prenatal visit from one of four New York Presbyterian–Columbia University Irving Medical Center (NYP–CUIMC) obstetrical offices and clinics in New York, from July 2018 through March 2020, were asked to complete a questionnaire. To be included participants had to be literate in either English or Spanish and >18 years of age. All incomplete questionnaires were excluded.

Survey

A self-report questionnaire was developed, which included demographic and socioeconomic information, pain symptoms, and incorporated three established questionnaires: the Pregnancy Mobility Index (PMI),¹² Pelvic Girdle Pain Questionnaire (PGQ),¹³ and the Questionnaire for Urinary Incontinence Diagnosis (QUID).¹⁴ If the participant reported low back and buttock or groin pain within the last 4 weeks, they were asked to complete additional questions regarding onset and frequency. Severity of pain was rated for current pain and pain in the previous 24 hours using 0–10 numerical rating scale (NRS).

The demographic factors were age (years), height (centimeter), weight (kilogram), weeks gestation, and parity (multiparous, primiparous), and the socioeconomic factors were ethnicity (not Hispanic or Latino, Hispanic, unknown), education (middle school, high school, 2-year college, 4-year college, graduate/professional), insurance (private, self, government), financial stability (good, neutral, bad), work satisfaction (very good/good, not good/not bad, bad/very bad), work hours per week (0–20, 20–40, >40), and exercise per week (0–>4 hours). This composite questionnaire was piloted with a comparable group of English- and Spanish-speaking pregnant people for comprehension and ease of completion.

The PMI is a valid and reliable 24-item self-report questionnaire documenting activity level in pregnant people with low back pain.¹² It is divided into three subsections; daily mobility, which includes transitional movements, the ability to perform normal household activities, and outdoor mobility such as walking and using transportation. Each item of the PMI is scored from zero (no effort) to three (much effort). Scores were summed and expressed as a percentage of the total number possible with a higher percentage, suggesting a greater limitation in function.

Specific for pelvic girdle pain during pregnancy, the PGQ exhibits high reliability and construct validity for measuring activity limitations and symptoms.¹⁵ PGQ scoring is like PMI with a zero to three-point scale of responses for each item. Responses are summed and expressed as a percentage of the total number possible with a higher percentage, indicating greater disability.

The six-item QUID is a questionnaire that exhibits good internal consistency and reliability for diagnosing both stress and urge female urinary incontinence.¹⁴ Each item is scored on a six-point scale from zero (none of the time) to six (all of the time), and the percentage score is determined from the total.

Procedure

The nursing staff asked all pregnant people awaiting obstetrical care if they were willing to complete an optional research questionnaire. Upon completion of the questionnaire, participants returned the questionnaire to the nursing staff who placed it in a secure location for retrieval by the research team. The research was approved by the Columbia University Irving Medical Center Institutional Review Board (Protocol No. IRB AAAR9250, approved October 22, 2019), which also approved the Spanish translation.

The questionnaire contained a preamble, describing that completion indicated consent to participate in the research. Data were manually transcribed from the paper questionnaires to the Research Electronic Data Capture (REDCap) database for secure storage. Based on the participants' responses to the low back, buttock, and/or groin pain questions, respondents were separated post hoc into a PLPP or no PLPP group for further comparisons.

Statistical methods

All statistical analysis was performed using R software (Version 4.1.1) with a significance level set at 0.05. Descriptive statistics for characteristics of the respondents are means and standard deviations for continuous variables, and frequencies or proportions for categorical or dichotomous variables. Bivariate analysis was used to compare characteristics between groups. For comparisons of continuous variables, independent t-tests with Bonferroni adjustment for multiple groups were used. Therefore, to reach a significance level of 0.05, the corrected significance had to reach 0.003. Chi-square with Fisher's exact test was used for group differences in categorical data.

To determine which factors are associated with PLPP, logistic regression with stepwise variable selection using the Alike Information Criterion was used. The independent variables were the demographic factors, the socioeconomic factors, and the pre-existing questionnaires (PMI, PGQ, and QUID). The dependent factor was the presence of PLPP, and was determined by asking if the participant had experienced low back, buttock, or groin pain with this pregnancy.

A full model was fit with our variables of interest, and model assumptions were checked. Examining the variance inflation factors showed that our variables did not show signs of colinearity, scatter plots of our variables against the log-odds showed a roughly linear relationship, and an analysis of the standard residuals did not show the presence of strong outliers. To find the most parsimonious model, every possible combination of predictors was entered into the model, and then the smallest combination of predictors that explained the most variance in the model was selected for the final model.

Results

Of the 1019 questionnaires completed, 168 respondents did not answer the question regarding the presence of PLPP, and these questionnaires were omitted from further analysis. Of those who answered, 538 (63%) of the respondents reported PLPP and 313 (37%) did not report PLPP. For those with PLPP, pain frequency was constant for 15%, daily for 35.5%, weekly for 19%, and monthly for 4% for those who responded to this question. Severity of pain within the last 24 hours was zero for 26.2%, mild for 20.8% (NRS = 1–3), moderate for 31.9% (NRS = 4–7), severe for 9.2%, while 11.9% did not answer the severity question.

Descriptive statistics for both the PLPP and no PLPP groups are shown in Table 1. Upon comparing the groups initially, there was no significant difference in the demographic and socioeconomic characteristics, except that those with PLPP were further along in their pregnancy (Table 1). Pregnant people who reported PLPP did have significantly higher scores for the PMI and PGQ, indicating a greater level of disability, and reported more issues with incontinence (QUID; Table 2).

Table 1.

Descriptive Statistics for Participant Characteristics by Group

Variable	PLPP (N = 538)	No PLPP (N = 313)	p
Age (years)	30.55 ± 6.16	30.45 ± 6.17	0.83
Height (cm)	413.02 ± 19.17	412.08 ± 18.92	0.59
Weight (kg)	32.90 ± 7.57	32.07 ± 7.69	0.09
BMI (kg/m²)	27.38 ± 6.06	26.85 ± 6.11	0.28
Gestation (weeks)	20.20 ± 10.4	16.35 ± 8.50	<0.001
Parity			0.13
Primiparous	251 (46.65)	117 (37.4)
Multiparous	283 (52.6)	181 (57.8)
NA	4 (0.74)	14 (4.47)
Ethnicity			0.29
Not Hispanic or Latino	146 (27.1)	72 (23)
Hispanic	326 (60.6)	205 (65.5)
Unknown	10 (1.9)	8 (2.6)
NAs	56 (10.4)	28 (8.9)
Education			0.20
Middle school	21 (3.9)	16 (5.1)
High school	170 (31.6)	110 (35.1)
2-Year college	116 (21.6)	79 (25.2)
4-Year collage	111 (20.6)	55 (17.6)
Graduate/professional	116 (21.6)	52 (16.6)
NAs	4 (0.7)	1 (0.3)
Financial stability			0.11
Good	315 (58.55)	196 (62.62)
Neutral	182 (33.83)	90 (28.75)
Bad	20 (3.72)	8 (2.56)
NA	21 (3.9)	19 (6.07)
Work satisfaction			0.01
Very good/good	298, (55.4)	189 (60.4)
Not good/not bad	84 (15.6)	35 (11.2)
Bad/very bad	12 (2.2)	2 (0.6)
NA's	144 (26.8)	86 (27.5)
Work hours per week			0.60
0–20	68 (12.6)	35 (11.2)
20–40	149 (27.7)	101 (32.3)
>40	128 (23.8)	63 (20.1)
Exercise per week, hours			0.16
none	223 (41.4)	132 (42.2)
<1/2	101 (18.8)	59 (18.9)
1/2–1	67 (12.4)	35 (11.2)
1–2	51 (9.5)	27 (8.6)
2–3	29 (5.4)	14 (4.5)
3–4	49 (9.1)	20 (6.4)
NA	18 (3.4)	25 (8.0)

Data for continuous variables are mean ± standard deviation. Data for categorical data are number (%).

BMI, body mass index; NA, no answer; PLPP, pregnancy lumbopelvic pain.

Table 2.

Comparison of Questionnaire Scores for Those with Pregnancy Lumbopelvic Pain to No Pregnancy Lumbopelvic Pain

Variable	PLPP	No PLPP	p
PMI	21.44 ± 17.81	7.57 ± 12.38	<0.001
PGQ	33.25 ± 14.99	27.09 ± 11.00	<0.001
QUID	28.76 ± 21.67	27.09 ± 8.47	<0.001

Data are mean ± standard deviation.

PGQ, Pelvic Girdle Pain Questionnaire; PMI, Pregnancy Mobility Index; QUID, Questionnaire for Urinary Incontinence Diagnosis.

The initial logistic regression modeling with all possible variable combinations revealed PMI and financial instability to be significant factors in differentiating those with and without PLPP (Table 3). Due to an insufficient number of responses, the QUID could not be entered into the model. We retained multiparity in the final model as previous research has indicated the importance of this factor.

Table 3.

Results of the Full Model Fit with all the Variables of Interest that Could Define Factors That Affect Lumbopelvic Pain During Pregnancy

Variable	Odds ratio (95% CI)	p
PMI	147.02 (23.35–925.67)	<0.0001
Age	0.99 (0.96–1.03)	0.73
BMI	1.02 (0.99–1.05)	0.26
Weeks gestation	1.00 (0.97–1.03)	0.85
Ethnicity
Non-Hispanic	1.98 (0.59–2.04)	0.76
Hispanic	1.15 (0.64–2.06)	0.64
Other	1.24 (0.68–2.24)	0.48
Financial instability	1.38 (1.05–1.82)	0.02
Multiparity	0.85 (0.55–1.30)	0.44
Exercise	0.87 (0.51–1.47)	0.60
Education	1.09 (0.88–1.34)	0.42

CI, confidence intervals.

Results of the final model (Table 4) indicate that scores on the PMI and financial instability are associated with PLPP. For every percentage increase in PMI score, the odds of a patient experiencing PLPP is multiplied by 2.40. This indicates that mobility during pregnancy is significantly impaired for those with PLPP as compared with those without PLPP. With reports of financial instability, the odds of experiencing PLPP is multiplied by 1.29. Even though multiparity was not statistically significant, it was included in our model to reduce confounding variance, thus improving the overall model.

Table 4.

Results of the Final Logistic Regression Model Indicating Variables Associated with Pregnancy Lumbopelvic Pain During Pregnancy

Variable	Odds ratio (95% CI)	p
PMI	240.84 (54.84–1057.66)	<0.001
Financial instability	1.29 (1.00–1.65)	<0.001
Parity	0.83 (0.56–1.22)	0.368

Discussion

This study surveyed pregnant people for the prevalence of PLPP and evaluated potentially relevant factors for experiencing PLPP in an urban medical center in the United States. Prevalence rates for PLPP vary widely between countries and health care systems. There is evidence that various psychosocial and socioeconomic factors partially explain the variance.^16
–18 There are limited studies examining the prevalence of PLPP in diverse populations within the United States, and none of these studies included a large percentage of Hispanic respondents. In a cohort that was 62% Hispanic, we found a 63% point-prevalence rate for PLPP.

In an underserved Midwest population, which was 70% African American and only 3% Hispanic, Skaggs et al. similarly found that 67% of individuals in their second trimester reported back or pelvic girdle pain.¹¹ In New Haven County Connecticut, Wang et al. found 68.5% prevalence for PLPP in population that was 80% Caucasian and 3.8% Latino.¹⁰ More recently, Gutke et al. reported an 86% prevalence for PLPP in a small U.S. cohort that was 79% Caucasian from three states.⁵ Taken together, these studies suggest that PLPP affects at least two-thirds of pregnant people in the United States regardless of ethnicity.

Results of the logistic regression found that a higher PMI score and financial instability were factors influencing PLPP (Table 4). To our knowledge, a higher PMI score in individuals with PLPP has not been previously reported. Our results did not find that a higher PGQ score was a factor influencing PLPP, which was surprising given that it is generally recognized as a primary screening tool evaluating function in PLPP.¹⁹

This finding may be explained by the different wordings in the directions of the PMI and PGQ survey. The PGQ asks the respondent, “Do you find it problematic to carry out the activities listed below because of your back or pelvic pain” whereas the PMI asks, “Do you experience complaints/limitations when performing the following activities.” It is possible that respondents could have had difficulty in performing their function as captured by the PMI but did not associate the difficulty with their lumbopelvic pain as would be captured by the PGQ.

Transitional movements increase biomechanical stress through the pelvic girdle, which can lead to pain. The types of problematic transitional movements identified by our cohort included getting up from a chair or the floor, rolling in bed, and specific household activities involving transitional motions such as vacuuming and laundry. Our study suggests that difficulty with these transitional movements, as queried by the PMI, may be another useful tool in screening for PLPP.

Our findings agree with previous reports of difficulties with ADLs due to pain symptoms. Using the PGQ, Gutke et al. found that a third of pregnant people in the United States reported limited ADLs.⁵ Wang et al. found that 57% of pregnant people with PLPP reported that low back pain interfered with ADLs, and 49% avoided performing tasks such as climbing stairs, running, heavy work, and lifting objects, which are elements incorporated into the PMI.¹⁰

Respondents with low back pain were noted to have moderate disability when evaluated by their ability to perform their usual ADLs. In another cohort of pregnant people, Gutke et al. found that disability and pain intensity were associated with greater use of sick leave for lumbopelvic pain.⁹ Manyozo et al. studied Malawi pregnant people with back pain and reported greater difficulty with walking >100 yards, lifting and sitting >10 minutes.²⁰ It appears that pregnant people with PLPP exhibit greater difficulty with ADLs than those without PLPP. Our study provides additional detail about the specific transitional movements, which are problematic for pregnant people.

Clinicians should be alert that pregnant people who express their difficulties with ADLs may be at risk of PLPP and require further evaluation. It is assumed that mobility is more difficult during pregnancy; however when coupled with PLPP, these ADLs can be even more challenging. It is imperative to specifically screen for difficulty with transitional movements, ADLs, and mobility as these tend to be much more limiting for pregnant people in pain. Once difficulties with ADLs are identified, potential treatments and interventions can be instituted to improve pain, thereby potentially limiting sick time and leave from work.^8,9

As part of our survey we asked participants how well their household managed finances. We found that respondents described their finances as good 58% of the time, neutral 33% of the time, and bad 4% of the time. In addition, we found that decreased financial stability was a risk factor for PLPP. Gutke et al 2017 found that 72% of respondents in the United States managed quite well or very well, 26% neither good nor bad, and 2% bad, however did not evaluate this factor as a potential link to low back pain in pregnancy.⁵

While Wang et al. noted income levels in the demographics of their study, they did not examine if there was an association between income levels and pain in pregnancy.¹⁰ To our knowledge, financial stability has not been included as a risk factor with PLPP in any of the studies that have been published to date. From the literature, we do know that the stress of financial insecurity may affect the prevalence of low back pain in the general population.²¹ This should be considered in future studies.

Health care disparities for Hispanics have been reported in musculoskeletal conditions and chronic pain. Ethnicity was not found to be a risk factor for PLPP in our study. Wang et al. did find that a significant higher proportion of African American women experienced low back pain in pregnancy compared with other ethnicities.¹⁰ All of the pregnant people in this investigation were insured and were under an obstetrician's care, which may also not reflect the full picture. It has been reported that one in four women of reproductive age from 2000 to 2009 lacked health insurance, and that 10% of pregnant women in the same study were uninsured.²²

Compounding this, Flores reported that some Hispanic patients were found to have higher levels of pain affecting their ADL's, pain related anxiety and pain catastrophizing, however were also found to have a preference for using self-management practices and noninvasive medical treatments in order to treat their pain.²³ Hispanic patients may also under-report their pain, which has influenced their access to certain treatments that may be helpful for these symptoms.^23
–25 This tendency to under-report pain may have also influenced our findings.

Characteristics reported in other studies were not found to be important risk factors in differentiating PLPP in this study. Upon comparing the groups initially, weeks gestation was the only demographic variable that was significantly different between the groups; those with PLPP were further along in their pregnancy. However, when risk factors previously cited in the literature were included in full model, we did not find age, BMI, weeks gestation, parity, amount of exercise, or level of education to be important for distinguishing PLPP in this study.

Due to the disparity of risk factors studied in previous research, it is difficult to compare findings. For example, Wang et al. included use of oral contraceptives, caffeine, smoking, prior epidural anesthesia in their model but did not find them to be significant.¹⁰ Similarly, they did not find that the number of pregnancies was a significant predictor of low back pain in pregnancy. Furthermore, in our study 46.8% of the respondents had mild or no pain in the last 24 hours, which may have influenced how respondents answered our questionnaire.

Limitations

Our study was a self-reported questionnaire, which is limited due to recall and personal bias, especially in those patients who were not having pain at the time of the survey. All participants had some form of health insurance and had access to health care, which may also influence our findings. Therefore, these findings may reflect this unique sample and may not be generalizable throughout the country.

Furthermore, this survey included participants with both back and pelvic girdle pain. While both low back and pelvic girdle pain can lead to disability and loss of function, these diagnoses differ in their management and prognosis. Due to the design of our study in which respondents completed the questionnaire while in the waiting area for the appointment of their health care provider, we were unable to perform in-person or self administered examination maneuvers were unable to be performed leaving us unable to categorize pelvic girdle pain from other types of back pain in pregnancy. This may limit the generalizability of our study conclusions.

Conclusions

PLPP is a common symptom for people who are pregnant. In a cohort of majority Hispanic people, we found that 63% of respondents had PLPP. Our study found that a higher PMI score and financial instability were factors influencing PLPP. Difficulties with functional ADLs as indicated by the higher PMI score and financial instability as a risk factor for PLPP are new findings not previously reported. Clinicians should be alert to pregnant people who express their difficulties with ADLs as they may be at risk of PLPP, and could benefit from further evaluation and treatment.

Footnotes

Acknowledgments

The authors thank Ariana Cesare, DPT, Nura Mariscal, DPT, Rachel Goffman, DPT, Emily Schlaefer, DPT, and Lila Toub, DPT, the research nurses and clinicians in the Department of Obstetrics and Gynecology, and all other staff and students who worked with them to create and facilitate this study.

Author Disclosure Statement

No competing financial interests exist.

Funding Information

No funding was received for this article.

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