Pregnant adolescents' preferences for labor pain management.

Objectives: The purpose of this study was to examine the obstetric anesthesia method used, based on the patient's age. Confounding variables analyzed were the effect on labor pain management choices of parity, race, prenatal care participation, insurance status, and length of labor.

Methods: This was a case control study from the Medical University of South Carolina (MUSC). The primary outcome measured was regional anesthesia (RA) use in labor. The exposure groups were based on the patient's age. All women aged 11 years and older who delivered vaginally from 1996 to 2001 were included; 7,583 patients met inclusion criteria. Results were analyzed using [chi square] statistic, univariate analysis, ANOVA, and logistic regression.

Results: We found that primiparous adolescents used RA less than primiparous women over age 20. This association is not found in multiparous teens. Patients with shorter labors, black women, those without prenatal care, and older patients lacking private insurance declined RA more often.

Conclusions: RA is the most utilized form of obstetric pain management in the last decade. In primiparous adolescents, declining RA cannot be explained by length of labor, race, insurance status, or prenatal care participation.

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Much has been written regarding the challenges adolescents face in pregnancy. The medical literature was searched using several combinations of the key words "adolescent, obstetric, analgesia, labor pain, pregnancy, regional anesthesia, epidural, and patient preference," and no publications regarding the type of obstetric pain management preferred by adolescents were found.

In the United States in 2001, there were 7,781 births by those aged 10 to 14 years; 145,324 births in adolescents aged 15 to 17 years; and 300,620 births in patients aged 18 to 19 years. (1) The United States has the highest adolescent pregnancy rate in the industrialized world. (2)

Regional anesthesia (RA) has become the most common form of labor pain management used in the United States over the last decade. (3) Labor and delivery is often the first significant contact pregnant adolescents have with a hospital. A poor experience, such as suboptimal treatment of labor pain, may diminish an adolescent's desire to make future medical appointments for herself or her baby.

The objective of this study was to compare the type of labor pain management used, based on the patient's age. The hypothesis is that adolescents are more likely to decline RA.

Since sociodemographic and biologic factors are related to the risks of adolescent pregnancy, we also examined the confounding effects of parity, race, participation in prenatal care, insurance status, and length of inpatient labor on anesthesia choices.

Materials and Methods

The data used for this investigation were obtained from the Medical University of South Carolina (MUSC) Perinatal Information System (PINS). This is a computerized perinatal surveillance system of all deliveries occurring at MUSC. The data were abstracted from the maternal and newborn inpatient hospital record and entered into a structured database, developed specifically for clinical research. All variables have standardized operational definitions, and data quality control is maintained through ongoing interrater, intrarater, validity, and logical error checks. This study was approved by the Institutional Review Board at MUSC.

The primary outcome measured was regional anesthesia (RA) use in labor. Patients who used both narcotics and RA were included in the RA group. Patients who used narcotics, local anesthesia, or nothing were placed in the "no RA" group. The study population included all females, aged 11 years or more, who delivered a liveborn singleton vaginally, between January 1, 1996 and December 31, 2001 at MUSC. Those who began labor at another hospital and were transferred to MUSC for delivery were excluded, due to the fact that their prenatal care differed from the study population. The exposure groups were based on the patient's age. The cases were adolescents, subdivided into young teens, aged 11 to 14 years, and older teens aged 15 to 19 years. The controls were subdivided into subjects aged 20 to 24 years, and those over 25 years of age.

Secondary exposures evaluated were maternal race (black or nonblack), parity (primipara, multipara), length of labor (LOL) as an inpatient, and insurance status (private, Medicaid, none). Participation in prenatal care was defined as at least 1 separate outpatient visit with a physician before admission for labor.

Differences in the proportion of patients receiving RA and the proportion of those with various insurance categories were assessed by use of the [chi square] statistic, and logistic regression. Differences in the mean and median length of labor by age group and race were assessed with ANOVA and univariate analysis, respectively.

Results

From 1996 to 2001, there were 7,583 women who met inclusion criteria. Of these, 78 were aged 11 to 14 years; 1,850 were aged 15 to 19 years; 2,434 were aged 20 to 24 years, and 3,221 were aged 25 years or more. Table 1 presents the distribution of subjects by age and parity.

Younger women were less likely to use RA, but that association was only statistically significant among the primiparas. For both the primiparas (P = 0.17) and the multiparas (P = 0.65), the mean length of labor (LOL) was not statistically different between maternal age categories. LOL was, as expected, significantly lower for multiparas for each maternal age category (P < 0.001) for each age group.

Table 2 shows that younger women were more often of black ethnicity (P < 0.001). Overall, 68.1% of black patients used RA, as compared with 78.3% of nonblack patients (P < 0.001). Among black patients, the likelihood of using RA increased with younger ages (P < 0.001), while among nonblack patients, there was no discernible pattern (P = 0.38). Based on univariate analysis, the median LOL are not statistically different based on age and race, but there is a trend among black women for longer labors in adolescents. Overall, only 1.3% of subjects did not receive any prenatal care, and there were no statistically significant differences by age, based on race (P = 0.72). The [chi square] statistic is significant (P = 0.002) for all blacks compared with all nonblacks for lack of prenatal care. Furthermore, 0.7% of primiparous subjects had not received any prenatal care, as compared with 1.6% for multiparous subjects (P < 0.001).

Table 3 shows that privately insured women were more likely to be older (P < 0.001), and that women with Medicaid and no insurance were similar in age. Among girls aged 11 to 14 years, 88.5% were Medicaid patients, which limits statistical calculations. In girls aged 11 to 14 years, Medicaid and indigent women were more likely to use RA, but the small comparison groups yield P = 0.29. Among women aged 15 to 19 years, RA rates for all insurance groups were similar, P = 0.82. In older patients aged 20 to 24 years, and those 25 years or older, the trend of RA use with increasing insurance carrier compensation was significant, P = 0.002 and P < 0.001 respectively.

Because of the potential for effect modification between age, prenatal care, parity, and ethnicity on epidural use, their independent effects were modeled by use of logistic regression models. Since there were no multiparous women in the 11 to 14 age group, separate models were constructed for parity groups, and these results are presented in Table 4.

The data from Table 4 suggest that women without prenatal care were at greatest risk for declining RA use regardless of parity, although it is noted that only 1.3% of women were without prenatal care. Black women in both parity groups were at increased risk for declining RA. Among the primipara only, RA use was less likely among younger women (small sample sizes limit the interpretation of the P values).

Discussion

There is debate over the interplay between biologic and social factors when considering the complications that occur in pregnant adolescents. In this study, length of labor (LOL) was considered a confounding biologic factor, and race, enrollment in prenatal care, and insurance status were selected as confounding social factors.

The data on adolescents is not easily explained by the biologic and social factors selected in this study. Primparous adolescents were more likely to decline RA than older primparous patients. However, primiparous adolescents did not differ from older primiparous patients in their lengths of labor, or participation in prenatal care. The association between young age and declining RA did not exist for multiparous patients, but the data is confounded by the fact that no multiparous patients were 11 to 14 years of age. Insurance status also did not influence the labor pain management choices of adolescents, but did influence the choices of older patients. Race was also not related, as black patients, as a group, were less likely to choose RA, but younger black patients were more likely to choose RA.

Although we could not gather objective data on teens' perceptions of labor, a possible explanation for our findings is that adolescents, and particularly primiparous adolescents, fear the invasive procedures of modern anesthesia. It is well known that once adolescents become pregnant, late entry into prenatal care is a major concern. (4) Sporadic prenatal care results in decreased opportunity for education on issues such as labor in general, and pain management choices in particular.

We chose to stratify the teens into young teens (aged 11-14 years) and mature teens (aged 15-19 years). Several studies of adolescent pregnancy stratify teens into young and mature teens, to obtain more specific data on pregnancy complications. (5,6)

Studying the secondary, confounding factors showed interesting information about how race, length of labor, insurance status, and prenatal care influence anesthesia choices. Patients with shorter labors (that is, all multiparas and older black primiparas) were significantly less likely to utilize RA in labor. It may be that they presented at such an advanced dilation that RA could not be secured.

Women who declined prenatal care were more likely to decline anesthetic interventions like RA. Although there was no difference in the age groups of women who had absolutely no prenatal care, we did not stratify the data into women with fewer or more prenatal visits.

Black women were less likely to choose RA than nonblack women. This may reflect biologic and/or social factors, as black women, as a group, had shorter labors, and were more likely to receive no prenatal care before admission.

Obst et al (7) showed that insurance status was related to anesthesia choices in labor. We found a similar trend in older patients, but not in adolescents. It has been shown that women who receive obstetric care from family physicians are less likely to request RA than women whose labors are managed by obstetricians. (8) Our study population did not have this confounding variable, as only 5% of patients were delivered by family physicians, and all our patients had an obstetrical resident involved in their labor management.

Our purpose is not to imply that patients should choose RA, or that RA is superior to natural childbirth or intravenous narcotic pain relief. However, it is clear that over the last decade, more women, whether they deliver in a small community hospital or a large tertiary center, are choosing RA for labor pain management. (3)

Conclusion

This study shows that primiparous adolescents were more likely to decline RA, and that this decision was independent of their length of labor, insurance status, race, and participation in prenatal care. For the rest of our patients, shorter labors, decreased insurance compensation, no prenatal care, and black race intermingled as risk factors for declining regional anesthesia for labor pain management.

I'm all in favor of keeping dangerous weapons out of the hands of fools.
Let's start with typewriters.
--Frank Lloyd Wright

Table 1. Data based on age and parity (a)

                             % Primipara  % Multipara
           %          %        Using RA     Using RA
Age    Primipara  Multipara  (P < 0.001)  (P = 0.39)

11-14    100.0    n = 0 (b)      78.2       n = 0 (b)
15-19     77.5    22.5           79.6       62.4
20-24     37.4    62.7           81.2       65.3
25+       23.0    77.0           87.4       65.8

         Mean (SD)      Mean (SD)
       LOL Primipara  LOL Multipara
Age     (P = 0.17)     (P = 0.65)

11-14   10.1 (8.1)     n = 0 (b)
15-19   10.6 (7.4)     8.0 (6.4)
20-24   10.8 (8.2)     8.0 (6.1)
25+     11.4 (8.1)     7.8 (6.2)

(a) RA, regional anesthesia; LOL, length of labor.
(b) Statistical analysis for multipara only computed for women aged 15
years or more.

Table 2. Data on race, length of labor, and participation in prenatal
care (a)

                                               Median LOL  Median LOL
         %       %      % using    % using RA   (hours),   (hours),
Age    black  nonblack  RA, black   nonblack     black     nonblack

11-14   1.4      0.5       79.7      71.4         8.0        7.0
15-19  29.3     17.0       73.7      80.7         8.0        9.0
20-24  34.5     28.4       68.0      77.0         7.0        8.0
25+    34.7     54.2       63.0      78.2         7.0        7.0

        % no    % no
        PNC,    PNC,
Age    black  nonblack

11-14   0.0     0.0
15-19   1.4     1.2
20-24   1.9     0.9
25+     1.7     0.7

(a) RA, regional anesthesia; LOL, length of labor; PNC, prenatal care.

Table 3. Insurance status and RA use (a)

                                         % Private     %        % No
       % Private                % No     insurance  Medicaid  insurance
Age    insurance  % Medicaid  insurance  using RA   using RA  using RA

11-14     0.4         1.3        0.4        57.1      79.7      100
15-19     8.7        29.6       20.0        77.6      75.6       74.5
20-24    16.1        36.5       37.4        77.8      71.1       63.1
25+      74.8        32.6       42.3        80.8      65.5       56.7

(a) RA, regional anesthesia.

Table 4. Logistic regression of declining RA for labor pain management
(a)

                      Primipara                Multipara
                Odds                     Odds
                Ratio                    Ratio
               (95% CI)        P value  (95% CI)       P value

Age
11-14          1.5 (0.8-2.7)    0.2     NA
15-19          1.4 (1.1-1.8)    0.02    1.1 (0.9-1.3)   0.6
20-24          1.4 (1.0-1.8)    0.04    1.0 (0.8-1.1)   0.6
25+            1.0 (Ref)                1.0 (Ref)
Race
Nonblack       1.0 (Ref)                1.0 (Ref)
Black          1.6 (1.3-2.0)   <0.0001  1.5 (1.3-1.7)  <0.0001
Prenatal care
Yes            1.0 (Ref)                1.0 (Ref)
No             6.6 (2.9-15.1)  <0.0001  4.2 (2.6-6.9)  <0.0001

(a) NA, not applicable; Ref, reference.

Acknowledgment

The authors would like to thank Myla Eberling, for expertise in statistical analysis.

Accepted December 18, 2003.

References

1. Ventura SJ, Hamilton BE, Sutton PD. Revised Birth and Fertility Rates for the United States, 2000 and 2001. Nat Vital Stat Report 2003;51:1-19.

2. Kmietowicz Z. US and UK are top in teenage pregnancy rates. BMJ 2002;324:1354.

3. Marmor TR, Krol DM. Labor pain management in the United States: Understanding patterns and the issue of choice. Am J Obstet Gynecol 2002;186:S173-S180.

4. Polaneczky M, O'Connor K. Pregnancy in the Adolescent Patient: Screening, Diagnosis, and Initial Management. Pediatr Clin North Am 1999;46:649-670.

5. Phipps MG, Sowers M. Defining early adolescent childbearing. Am J Public Health 2002;92:125-128.

6. Satin AJ, Leveno KJ, Sherman L, et al. Maternal youth and pregnancy outcomes: middle school versus high school age groups compared with women beyond the teen years. Am J Obstet Gynecol 1994;171:184-187.

7. Obst TE, Nauenberg E, Buck GM. Maternal health insurance coverage as a determinanat of obstetrical anesthesia care. J Health Care Poor Underserved 2000;12:177-191.

8. Hueston WJ, Applegate JA, Mansfield CJ, et al. Practice variations between family physicians and obstetricians in the management of low-risk pregnancies. J Fam Pract 1995;40:345-351.

RELATED ARTICLE: Key Points

* Primiparous adolescents choose regional anesthesia significantly less often than older primiparous patients.

* Patients with shorter labors, black women, older patients without private health insurance, and patients with no prenatal care also utilize regional anesthesia significantly less often.

* Understanding adolescents' choices in labor will optimize their contact with the health care system.

Andrea R. Thurman, MD, and Thomas C. Hulsey, SCD 

From the Department of Obstetrics and Gynecology and Pediatrics, Medical University of South Carolina, Charleston, SC.

This work was not supported by any corporate or university grants.

This study was approved by the Institutional Review Board at the Medical University of South Carolina (HR #377).

Reprint requests to Andrea Ries Thurman, MD, Medical University of South Carolina, Department of OBGYN, 96 Jonathan Lucas Street, PO Box 250619, Charleston, SC 29425. Email: [e-mail]