Long-Term,Reversible Contraception Use Among High-Risk Women Treated in a University-Based Gynecology Clinic: Comparison Between IUD and Depo-Provera

Abstract

Background:

The study was conducted to compare rates of sexually transmitted diseases (STD) and side effects in a cohort of high-risk women who received either an intrauterine device (IUD) or depo-medroxyprogesterone acetate (DMPA).

Methods:

We performed a retrospective chart review study of women seeking contraception at an innercity resident obstetrics/gynecology clinic. We compared 194 women with IUDs vs. 191 women receiving DMPA. Mean age was 31.9 years, with 75.1% and 69.2% being nonwhite and single, respectively. More white women received the IUD (34.5% vs. 15.0%, p < 0.001), and significantly more single women received DMPA (85.2% vs. 53.9%, p < 0.001).

Results:

After controlling for potentially confounding variables, DMPA women were significantly more likely to have a subsequent STD, although this effect disappeared when interaction terms were added to the model. Overall, duration of contraception use and being black were the best predictors of subsequent STD infection. Women who received IUDs were more likely to report side effects but less likely to discontinue use of their birth control (18.8% vs. 67.0%, p < 0.001).

Conclusions:

Although sexual risk factors may have influenced provider prescribing practices in selecting IUD or DMPA, overall rates of STDs and discontinuation rates for IUDs were equivalent or superior to rates for DMPA.

Introduction

Unplanned and unwanted pregnancy presents a significant social and economic challenge to women during their reproductive years. Contraceptive methods that are effective and affordable and require a minimum of motivation during each act of intercourse may reduce the rates of undesired pregnancy. Two such methods are the intrauterine device (IUD) or progesterone-impregnated intrauterine system (IUS) and long-acting injectable progestins.

Despite providing the most cost-effective, reversible contraception, IUD use has been limited in the United States because of concerns about the risk of ascending pelvic infections. Initial studies with the IUD, in particular the Dalkon Shield (A. H. Robins Company, Richmond, VA), showed higher rates of pelvic inflammatory disease (PID), but more recent studies have indicated that the IUD does not increase the risk of PID when inserted in women free from cervical infections using aseptic procedures.^1
–3 Further, the IUS may offer some protective effect against PID and other upper genital tract infections compared with nonhormonal IUDs.^4,5 Regardless of medical evidence to the contrary, the package inserts of both the Paragard^™ IUD (Duramed Pharmaceuticals Inc., Cincinnati, OH) and progesterone IUS continue to recommend its use only in parous women considered low risk for exposure to sexually transmitted diseases (STDs). This has limited accessibility of this affordable, long-acting contraceptive method to women who might benefit most from its user-independent effectiveness. In our initial evaluation of the acceptability of IUDs in an innercity population of women who were considered high risk, we found that women actually had a decrease in STDs after insertion, possibly related to counseling they received with this contraceptive choice.⁶ A recent study also concluded that the IUD/IUS is a safe and highly effective form of contraception in both nulliparous and parous women.⁷ A recent meta-analysis of IUDs found that most women still had their IUD in place 12 months after initial insertion, indicating a high level of acceptance of this method.⁸

Women at high risk for STD exposure have traditionally been offered other contraceptive methods, such as depo-medroxyprogesterone acetate (DMPA), an aqueous progestin injection that has been proven to be highly effective at preventing pregnancy, with a typical use annual failure rate of 0.3%, which is even lower than that of sterilization 0.5%.⁹ DMPA provides 3 months of contraception per injection, the longest contraceptive activity of any form of birth control that does not have to be surgically removed. Although not requiring a surgical intervention, it does require a visit to a healthcare provider every 13 weeks for administration of another injection, which may be problematic for those with lack of regular access to a healthcare provider. Another notable fact is that although DMPA is not associated with an increased risk of PID, two studies have found that users of DMPA have a higher likelihood of acquiring chlamydial infection.^10,11 Other potential side effects of DMPA include breakthrough bleeding, weight gain, depression, and osteopenia. These side effects may account for the observation in a study of contraception continuation rates that DMPA had the lowest level of continuation rates among the tested methods of contraception, which also included oral contraceptives, implants, and IUDs.¹²

The purpose of the present study was to compare the characteristics of women who received DMPA and IUDs at a resident obstetrics/gynecology clinic, a community sample of women with high rates of previous exposure to STDs. Limited comparative information about the impact of their use (e.g., rates of STDs, discontinuation rates) in women most at risk for unwanted pregnancy is available in the literature.

Materials and Methods

After obtaining IRB approval, a retrospective, chart review study was performed of 194 IUD and 191 DMPA patients at a tertiary care, innercity, resident obstetrics/gynecology clinic who were treated between January 2000 and December 2005. Patients were first identified by billing code; then, the patient's medical record was obtained for review. We recorded deidentified data on data extraction forms and entered deidentified data into the study database. Patient demographics, such as date of birth, marital status, race/ethnicity, and smoking status, were recorded. From the medical record, we identified the type of IUD used (e.g., ParaGard or Mirena^™, Berlax Laboratories, Wayne, NJ) and recorded the month and year of insertion. We also identified the date of DMPA injections using the medical record and confirming with the computerized billing code. Other information that was extracted from the medical records included the obstetric history before and after IUD insertion or DMPA injection, history of STDs (e.g., Chlamydia, herpes) and PID before and after IUD insertion or DMPA injection, history of other gynecological infections (e.g., yeast infections, bacterial vaginosis), early discontinuation of IUD or DMPA, reason for discontinuation, and any complaints, complications, or side effects of IUD or DMPA. At each annual visit, patients were given a full review of systems, which includes symptoms of depression, STDs, and other gynecological complaints. For interim visits, routine evaluation of these symptoms was not done, but any patient complaints would be recorded in the progress notes, which were also reviewed during the chart extraction. Osteopenia was not routinely evaluated for women on DMPA. In addition to chart review, we used the computerized charting system to confirm dates of IUD insertion or DMPA injection as well as laboratory results of STDs and other gynecological disease testing.

Data analysis

We used descriptive statistics to characterize the population. A mean compliance rate was determined for the DMPA injection by dividing the number of actual injections received over the number of injections that should have been given over a specific time frame. We compared women who received an IUD with women who received a DMPA injection on rates of STDs, gynecological infections, obstetric histories, side effects or complications with injection, and discontinuation rates of these methods using chi-square analyses and t tests as appropriate. We compared length of use of each method using t tests. Finally, a logistic regression analysis was performed to determine predictors of developing an STD after use of either birth control method that controlled for potential confounding variables, such as age, race, marital status, and length of use of the contraceptive method.

Results

A total of 194 women had an IUD inserted, and 191 received at least one DMPA injection given between 2001 and 2005. Overall, the sample predominantly comprised nonwhite (75.1%), single (69.2%) women. The average age of the sample at the time of data extraction was 31.9 years (SD 7.8 years), and the average age at the time of either receiving an IUD or DMPA injection was 28.0 years (SD 8.2 years). The average length of time patients had used the IUD or DMPA was 26.4 months (IQR 8–39 months). Compliance rates of DMPA injections were calculated, and patients who initiated DMPA received 91.6% of their injections within the recommended 3-month time.

Table 1 shows the demographics of the sample by type of birth control. Significantly more white women were given the IUD (34.5% vs. 15.0%, p < 0.001), and significantly more single women were given DMPA (85.2% vs. 53.9%, p < 0.001). Although no differences were found in the current age of patients in this sample, women who received the DMPA were more likely to be younger at the time of injection (24.9 years vs. 31.1 years) and to have used it for a longer time compared with women who received the IUD (38.5 months vs. 13.7 months).

Table 1.

Demographic Characteristics (n = 385)

	IUD (n = 194)	Depo-Provera (n = 191)
Characteristic	n (%)	n (%)	p value
Race
White	67 (34.5)	28 (15.0)
Nonwhite	127 (65.5)	159 (85.0)	<0.001
Ethnicity
Hispanic/Latina	11 (5.7)	7 (3.8)
Non-Hispanic	183 (94.3)	178 (96.2)	0.39
Marital status
Married	88 (46.1)	27 (14.8)
Other	103 (53.9)	155 (85.2)	<0.001

	Mean (SD)	Mean (SD)	p value
Current age, years	32.6 (7.9)	31.1 (7.8)	0.07
Age initiated birth control	31.1 (7.7)	24.9 (7.5)	<0.001
Total time of birth control (months)	13.7 (11.6)	38.5 (33.7)	<0.001

A comparison of STD rates before the women received their IUD or DMPA showed that few significant differences (Table 2) existed. Only rates of Trichomonas vaginalis infection were higher in women who received DMPA compared with IUDs (16.8% vs. 9.8%, p = 0.05). However, women who received DMPA had higher rates of PID (4.7% vs. 0.5%, p = 0.01) and bacterial vaginosis (33.0% vs. 20.6%, p < 0.01) before injection compared with women who received IUDs. Conversely, women who received IUDs had higher rates of endometritis compared with women who received DMPA (2.1% vs. 0, p = 0.05). Women who received the IUD also reported a history of more pregnancies and a higher number of live births compared with women who received DMPA (2.89 vs. 1.92 and 2.11 vs. 1.34, respectively).

Table 2.

Comparison of Obstetric and Gynecological Characteristics of Women before IUD Insertion or Depo-Provera Injection (n = 385)

	IUD (n = 194)	Depo-Provera (n = 191)
Characteristic	n (%)	n (%)	p value
Sexually transmitted diseases
History of STDs	63 (32.5)	66 (34.6)	0.67
Gonorrhea	20 (10.3)	28 (14.7)	0.20
Chlamydia infection	30 (15.5)	37 (19.4)	0.31
Syphilis	2 (1.0)	2 (1.0)	0.99
Trichomonasis	19 (9.8)	32 (16.8)	0.05
Herpes simplex virus types 1 and 2	10 (5.2)	4 (2.1)	0.11
Human papillomavirus	18 (9.3)	14 (7.3)	0.49
Gynecological infections
History of other infections	62 (32.0)	76 (39.8)	0.11
Pelvic inflammatory disease	1 (0.5)	9 (4.7)	0.01
Bacterial vaginosis	40 (20.6)	63 (33.0)	<0.01
Candida infection	28 (14.4)	30 (15.7)	0.73
Endometritis	4 (2.1)	0	0.05

	Mean (SD)	Mean (SD)	p value
Obstetric history
Number of pregnancies	2.89 (1.79)	1.92 (1.78)	<0.001
Live births	2.11 (1.36)	1.34 (1.30)	<0.001

Table 3 displays the rates of STDs, gynecological infections, and obstetric histories of women after they received either the IUD or DMPA. Women who received DMPA had higher overall rates of STDs compared with women who received the IUD (33.0% vs. 5.4%, p < 0.001). Specifically, women who received DMPA had higher rates of gonorrhea (8.4% vs. 1.1%, p = 0.001), Chlamydia infection (16.2% vs. 2.2%, p < 0.001), trichomoniasis (12.6% vs. 2.7%, p < 0.001), and human papillomavirus (HPV) infection (2.9% vs. 0, p = 0.001) compared with women who used the IUD. Similarly, women who used DMPA had higher rates of other gynecological infections compared with women who used the IUD (53.4% vs. 19.4%, p < 0.001), including bacterial vaginosis (43.5% vs. 15.6%, p < 0.001) and candidiasis (27.7% vs. 7.5%, p < 0.001). Only endometritis was higher among women who received the IUD compared with women who received DMPA (2.2% vs. 0, p < 0.05). Although no significant differences were found in the number of unintended pregnancies reported, there was one live birth among women who used DMPA compared with no live births among women who received IUDs.

Table 3.

Comparison of Obstetric and Gynecological Characteristics of Women after IUD Insertion or Depo-Provera Injection (n = 385)

	IUD (n = 194)	Depo-Provera (n = 191)
Characteristic	n (%)	n (%)	p value
Sexually transmitted diseases
History of STDs	10 (5.4)	63 (33.0)	<0.001
Gonorrhea	2 (1.1)	16 (8.4)	0.001
Chlamydia infection	4 (2.2)	31 (16.2)	<0.001
Syphilis	0	0	—
Trichomonasis	5 (2.7)	24 (12.6)	<0.001
Herpes simplex virus; types 1 and 2	3 (1.6)	9 (4.7)	0.09
Human papillomavirus	0	11 (2.9)	0.001
Gynecological infections
History of other infections	36 (19.4)	102 (53.4)	<0.001
Pelvic inflammatory disease	4 (2.2)	4 (2.1)	0.97
Bacterial vaginosis	29 (15.6)	83 (43.5)	<0.001
Candida infection	14 (7.5)	53 (27.7)	<0.001
Endometritis	4 (2.2)	0	<0.05

Obstetric history	Mean (SD)	Mean (SD)	p value
Number of pregnancies	0.03 (0.18)	0.05 (0.27)	0.39
Live births	0	0.04 (0.25)	<0.05

A comparison of side effects and complaints between the two groups is shown in Table 4. Overall, women who received the IUD reported significantly more side effects or complaints associated with their IUD use compared with women who received DMPA (34.9% vs. 23.6%, p = 0.02). Specifically, women who received the IUD complained of pain (3.2% vs. 0, p = 0.01), partner complaint (3.8% vs. 0, p < 0.01), and vaginal discharge (4.9% vs. 0, p < 0.01). Only depression was associated more with DMPA use than IUD use (2.1% vs. 0, p = 0.05).

Table 4.

Comparison of Side Effects/Complaints and Reasons for Early Discontinuation Between IUD and Depo-Provera Injection (n = 385)

	IUD (n = 194)	Depo-Provera (n = 191)
Characteristic	n (%)	n (%)	p value
Side effects/complaints
Total SE/complaints	65 (34.9)	45 (23.6)	0.02
Bleeding	32 (17.2)	41 (21.5)	0.30
Pain	6 (3.2)	0	0.01
Partner complaint	7 (3.8)	0	<0.01
Vaginal discharge	9 (4.9)	0	<0.01
Early expulsion	4 (2.2)	N/A
Weight gain	2 (1.1)	5 (2.6)	0.27
Depression	0	4 (2.1)	0.05
Pregnancy	3 (1.6)	2 (1.0)	0.63
Osteopenia	0	2	0.15
Early discontinuation
Total early discontinuation	35 (18.8)	128 (67.0)	<0.001
Bleeding	11 (5.9)	13 (6.8)	0.72
Pain	4 (2.2)	0	0.05
Partner complaint	5 (2.7)	0	0.02
Vaginal discharge	4 (2.2)	0	0.05
Pregnancy	3 (1.6)	2 (1.0)	0.63
Desired fertility	5 (2.7)	3 (1.6)	0.45
Weight gain	1 (0.5)	5 (2.6)	0.11

Despite a higher rate of reported side effects, rates of discontinuation were significantly lower in the IUD group compared with the DMPA group (18.8% vs. 67.0%, p < 0.001). In most cases of discontinuation of the DMPA injection, no reason was specified (80.4%). Reasons for discontinuation of the IUD included pain, partner complaint, and vaginal discharge, although all of these discontinuations involved 5 patients or fewer for each reason (Table 4).

To determine the best predictors of contracting an STD after initiation of IUD or DMPA contraceptives, logistic regression was conducted, with birth control method (IUD or DMPA), age of first use, duration of contraceptive use, race, history of STDs prior to IUD or DMPA, and marital status entered as predictors in the model and STD after birth control initiation as the dependent variable (Table 5). Being black and a longer duration of contraceptive use were both significant independent predictors of contracting an STD. However, use of DMPA was also a significant independent predictor of contracting an STD and increased the odds of contracting a STD by almost 3-fold, even when accounting for other factors, such as marital status, race, duration of use, prior history of STDs, and age. Finally, we investigated the inclusion of two interaction terms, age of birth control by birth control type (IUD or DMPA) and length of birth control use by type of birth control, into the model. When these terms were added to the existing model, being black and a longer duration of birth control remained significant predictors of STD after initiation of contraceptives, whereas use of IUD or DMPA was no longer significant (Table 5).

Table 5.

Logistic Regression Predictors of STDs After Use of Depo-Provera or IUD

	Without interaction terms				Interaction terms
Variable	Beta	p value	OR	95% CI	Beta	p value	OR	95% CI
Single	0.087	0.12	2.39	0.79-7.18	0.89	0.11	2.44	0.82-7.29
Black	1.33	0.03	3.77	1.16-12.21	1.35	0.02	3.84	1.19-12.37
History of STDs prior to IUD or Depo-Provera	0.61	0.07	1.83	0.94-3.56	0.65	0.06	1.91	0.98-3.71
Age at first use of birth control	−0.05	0.06	0.96	0.91-1.00	−0.04	0.15	0.96	0.92-1.01
Average duration of birth control	0.03	<0.001	1.03	1.01-1.04	0.02	<0.001	1.02	1.01-1.04
Depo-Provera	0.98	0.04	2.67	1.05-6.78	0.07	0.97	1.07	0.03-35.63
Age at first use of birth control with Depo-Provera	^**	^**	^**	^**	−0.06	0.40	0.94	0.83-1.08
Average duration of birth control with Depo-Provera	^**	^**	^**	^**	0.04	0.14	1.04	0.99-1.09

= Missing.

Discussion

In this retrospective chart review study of two long-acting reversible methods of contraception in women with a high rate of prior gynecological infections, we found that overall discontinuation rates and complications favored the intrauterine system. Traditionally, women in this demographic were advised against this contraceptive method because of concerns about ascending infections.^13
–15 Before initiation of either form of birth control, rates of STDs were documented in more than one third of each cohort, with little differences in STD history noted between the groups. After IUD placement, however, rates of gonorrhea, Chlamydia infection, trichomonasis, and HPV infection were all significantly lower than in the cohort who received DMPA, and rates of PID were not increased. The reason for the dramatic reduction in STD prevalence in the IUD group is unclear but most likely can be attributed to counseling about the need for safe sexual practices with this contraceptive method. Although there is no specific STD educational program for women considering an IUD in our resident clinic, we believe that healthcare providers are more likely to stress the historical association between IUDs and PID and emphasize the need for additional barrier methods. Women considering DMPA may not benefit from the intensity of this message and, therefore, continue to demonstrate a high rate of sexually acquired infections. From the logistic regression analysis performed, women who received DMPA had higher rates of postinitiation STDs even when controlling for demographic variables, such as age at the time of use, race, prior history of STDs, duration of contraceptive use, and marital status. However, this effect disappeared when interaction terms were added to the model, although race and duration of contraceptive use continued to be the most robust predictors of contracting a STD after contraception initiation. Higher rates of bacterial vaginosis and candidiasis were also reported in the DMPA group, for which a scientific explanation may not exist. It is possible that the frequency of clinic visits to receive an injection merely provided an opportunity to voice a complaint about vaginal discharge, thereby increasing the rate of diagnosis.

Discontinuation rates of DMPA and IUDs in our cohort perhaps provide the most compelling evidence for a need to reconsider which method is recommended for women at high risk for unwanted pregnancy. Sixty-seven percent of women who initiated DMPA did not continue with this method compared with 18.8% of women who received an IUD. The need to return to the clinic every 3 months probably provided the biggest barrier to continuation, as such specific side effects as bleeding, weight gain, depression, and pain were cumulatively reported in <10% of those studied. Continuation rates of other short-term contraceptive agents, such as birth control pills, are notoriously low,^16,17 which highlights the need to select user-independent methods, such as the IUD. Finally, the observed rate of pregnancy was low in each group, which again confirms that both provide an excellent form of contraception while being used.

This study had limitations that should be mentioned. First, we relied on a retrospective data extraction from charts for our variables of interest. Conducting a chart review limited us to the data available in the chart, and omissions by physicians about important information pertinent to our outcomes may have occurred. In particular, other risk factors for STD transmission, such as number of sexual partners, sexual networks, and use of barrier methods, may have been known by providers but were not documented in the chart and could have influenced birth control prescribing practices. Further, given that the data were collected as part of clinical practice and not for the purposes of research means that physicians may have reasons for the selection of birth control methods that were not documented, such as patient preference or other variables. Finally, although fewer women discontinued their use of the IUD, women who received DMPA had been receiving injections for longer periods of time and had to be seen more frequently, which allowed for more assessment of STDs. This study needs to be replicated using a prospective, randomized design to overcome these limitations.

Despite these limitations, this study was important in demonstrating the different characteristics of women who received DMPA and IUD in a real-world clinical setting. This study challenges the historical recommendation that IUDs should be limited to parous, married, monogamous women with low-risk of acquiring an STD, as we found that IUD use was associated with improved continuation and lower risk of infections than use of DMPA.^1,18,19 Efforts should be made to provide birth control methods that achieve efficacy against pregnancy and can sustain use across the many years that women have reproductive potential.

Footnotes

Acknowledgments

A paper reporting these results was presented at the Annual Clinical Meeting of the American College of Obstetricians and Gynecologists, New Orleans, Louisiana, May 2008.

Disclosure Statement

The authors have no conflicts of interest to report.

References

Toivonen

. Intrauterine contraceptive device and pelvic inflammatory disease. Ann Med, 1993; 25:171–173.

Steen

, Shapiro

. Intrauterine contraceptive devices and risk of pelvic inflammatory disease: Standard of care in high STI prevalence settings. Reprod Health Matters, 2004; 12:136–143.

Gareen

. Intrauterine devices and pelvic inflammatory disease. Curr Womens Health Rep, 2003; 3:280–287.

Toivonen

, Luukkainen

, Allonen

. Protective effect of intrauterine release of levonorgestrel on pelvic infection: Three years' comparative experience of levonorgestrol- and copper-releasing intrauterine devices. Obstet Gynecol, 1991; 77:261–264.

Grimes

. Intrauterine devices and infertility: Sifting through the evidence. Lancet, 2001; 358:6–7.

Campbell

, Cropsey

, Matthews

. Intrauterine device use in a high-risk population: Experience from an urban university clinic. Am J Obstet Gynecol, 2007; 197:193e1–193e7.

Veldhuis

, Vos

, Lagro-Janssen

. Complications of the intrauterine device in nulliparous and parous women. Eur J Gen Pract, 2004; 10:82–87.

French

, Van Vliet

, Cowan

et al.

Hormonally impregnated intrauterine systems (IUSs) versus other forms of reversible-contraceptives as effective methods of preventing pregnancy [Review]

Cochrane Library, 2005; 4:1–50.

Trussell

. Contraceptive efficacy. Hatcher

, Trussell

, Stewart

et al. Contraceptive technology. New York: Ardent Media Inc, 1998; 779–845.

10.

Baeten

, Nyange

, Richardson

et al. Hormonal contraception and risk of sexually transmitted disease acquisition: Results from a prospective study. Am J Obstet Gynecol, 2001; 185:380–385.

11.

Jacobson

, Peralta

, Graham

, Zenilman

. Histologic development of cervical ectopy: Relationship to reproductive hormones. Sex Transm Dis, 2000; 27:252–258.

12.

Rakhshani

, Mohammadi

. Contraception continuation rates and reasons for discontinuation in Zahedan Islamic Republic of Iran. East Mediterr Health J, 2002; 10:260–267.

13.

Kaufman

, Watson

, Rosenberg

et al. The effect of different types of intrauterine devices on the risk of pelvic inflammatory disease. JAMA, 1983; 250:759–762.

14.

Marks

, Tideman

, Estcourt

, Berry

, Mendel

. Assessment for risk of pelvic inflammatory disease in an urban sexual health population. Sex Trans Infect, 2000; 76:470–473.

15.

Harper

, Blum

, de Bocanegra

et al. Challenges in translating evidence to practice: The provision of intrauterine contraception. Obstet Gynecol, 2008; 111:1359–1369.

16.

Aubeny

, Buhler

, Colau

, Vicaut

, Zadikian

, Childs

. Oral contraception: Patterns of non-compliance. The Coraliance Study. Eur J Contracept Reprod Health Care, 2002; 7:155–161.

17.

Rosenberg

, Waugh

, Burnhill

. Compliance, counseling and satisfaction with oral contraceptives: A prospective evaluation. Fam Plann Perspect, 1998; 30:89–92104.

18.

Morrison

, Murphy

, Kwok

, Weiner

. Identifying appropriate IUD candidates in areas with high prevalences of sexually transmitted infections. Contraception, 2007; 75:185–192. Epub December 12, 2006.

19.

Johnson

. Insertion and removal of intrauterine devices. Am Fam Physician, 2005; 71:95–102.