HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Saydah, S. H. Articles by Eberhardt, M. S. Search for Related Content PubMed PubMed Citation Articles by Saydah, S. H. Articles by Eberhardt, M. S. Social Bookmarking                What's this?

Pregnancy Experience Among Women With and Without Gestational Diabetes in the U.S., 1995 National Survey of Family Growth

¹ Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, Georgia
² National Centers for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, Maryland

Address correspondence and reprint requests to Sharon Saydah, PhD, National Centers for Health Statistics, Centers for Disease Control and Prevention, 3311 Toledo Rd., Hyattsville, MD 20782. E-mail: ssaydah{at}cdc.gov

	ABSTRACT

TOP ABSTRACT INTRODUCTION RESEARCH DESIGN AND METHODS RESULTS CONCLUSIONS References

 
OBJECTIVE—To compare the pregnancy experience among women with and without gestational diabetes mellitus (GDM) using a nationally representative survey.

RESEARCH DESIGN AND METHODS—We analyzed data from the 1995 National Survey of Family Growth conducted by National Center for Health Statistics on 3,088 women age 15–44 years with at least one pregnancy between 1991 and 1995 to compare demographics, fecundity, and pregnancy experience by GDM (n = 116) or nondiabetes (n = 2,969) status.

RESULTS—Among women with a pregnancy during 1991–1995, 3.6% reported GDM history. Women with GDM were older at age of delivery (31.8 years) than women without diabetes (29.0 years, P < 0.001). There was no significant difference between the groups by race/ethnicity. Compared with women without diabetes, women with gestational diabetes were more likely to report being currently surgically sterile (20.4 vs. 32.6%) or having impaired fecundity (12.6 vs. 19.7%, P < 0.001). GDM patients were more likely to have had a caesarean section than those without diabetes (31.7 vs. 20.9%, P = 0.02) and were more likely to report at least one of six additional nonroutine medical complications during pregnancy than nondiabetic patients (48.8 vs. 17.1%, P < 0.001). The odds ratio of a maternal medical complication during pregnancy for women with GDM compared with nondiabetic women, after adjusting for age at pregnancy and nongestational hypertension, was 4.3 (95% CI 2.7–6.8).

CONCLUSIONS—These findings suggest that pregnancies in women with GDM are more likely to be associated with maternal medical complications compared with pregnancies in women without diabetes.

Abbreviations: GDM, gestational diabetes mellitus • NHIS, National Health Interview Survey • NSFG, National Survey of Family Growth

	INTRODUCTION

TOP ABSTRACT INTRODUCTION RESEARCH DESIGN AND METHODS RESULTS CONCLUSIONS References

 
Gestational diabetes mellitus (GDM) is estimated to occur in 2.8% of hospital deliveries in the U.S. (1). The prevalence of diabetes in pregnancy, either GDM or preexisting, was 25.3/1,000 births in the U.S. for the period 1993–1995 (2). Based on projected demographic changes in the U.S. and worldwide, there is a projected 120% rise in the total number of cases of GDM by 2025 (3).

Diabetes in pregnancy is associated with increased risk of adverse outcomes for both the mother and the infant (4–11). These adverse outcomes include increased likelihood of birth defects, congenital abnormalities, preterm birth, caesarean delivery, macrosomnia, hypertension, and preeclampsia (4–8,10,12).

Risk factors for GDM include increasing age at pregnancy and being overweight or obese before pregnancy, a family history of diabetes, and belonging to a race/ethnic group (e.g., African American, Native American, Hispanic, South or East Asian, Pacific Islanders) with a high prevalence of GDM (3,13,14). These risk factors are often used in selective screening for GDM. Screening and diagnosis of GDM is thought to lead to reduced birth defects, complications, and macrosomina among women who are found to have GDM (13,15–17).

Most studies of GDM have focused on birth outcomes using vital records or are based in specific clinic populations (4–8,10–12). There are no large-scale population-based studies comparing the maternal pregnancy experience for women with and without GDM. Therefore, we analyzed the 1995 National Survey for Family Growth (NSFG) to compare maternal complications and pregnancies among women with and without GDM in the U.S.

	RESEARCH DESIGN AND METHODS

TOP ABSTRACT INTRODUCTION RESEARCH DESIGN AND METHODS RESULTS CONCLUSIONS References

 
We analyzed data from the 1995 NSFG. The 1995 NSFG, conducted by the National Center of Health Statistics, is a nationally representative survey of women 15–44 years of age and was designed to provide estimates of factors affecting pregnancy and birth rates and the health of women and infants (18). Survey respondents were selected from a national probability sample of 14,000 women 15–44 years of age from households that participated in the 1993 National Health Interview Survey (NHIS). The NHIS is a continuous multistage household survey of the U.S. civilian noninstitutionalized population and is conducted by the National Center of Health Statistics. To obtain sufficient numbers of minority women in the 1995 NSFG, all households with Hispanic and non-Hispanic black women in the NHIS were included in the NSFG sample. Sample weights were used to adjust for different sampling rates for Hispanic, non-Hispanic black, and non-Hispanic white women; for nonresponse; and for undercoverage by age, race, and parity. Of the 14,000 sampled women, 94.6% were successfully located and 10,847 completed interviews for an overall response rate of 78.2%. Interviews were conducted in person by trained interviewers and took on average 105 min to complete. The survey included questions on demographic characteristics, sterilization operations, fecundity impairment, use of family planning and other medical services, use of infertility services, detailed pregnancy history, pregnancy outcomes, and prenatal care.

We used the 1995 NSFG Pregnancy-Based file (18). Of those respondents who had information on at least one pregnancy after 1991 (n = 3,539), we identified the most recent pregnancy that occurred after 1991 and before date of interview in 1995 as the index pregnancy. Pregnancies that occurred after 1991 were selected for analysis because respondents were only asked about complications during pregnancy, such as GDM, for pregnancies that ended after 1991. Respondents who were pregnant at the time of interview (n = 427) were excluded from the analysis; of these, only 4 had established diabetes and none reported GDM. Respondents were classified as having GDM or no diabetes. GDM was defined as reporting diabetes during the pregnancy (n = 116) and not reporting established diabetes. Respondents who reported not knowing if they had had GDM or who had missing information for GDM were excluded (n = 3). Established diabetes was defined for respondents who answered "yes " to "Has a doctor or other medical care provider ever told you that you had diabetes (when you were not pregnant)?" (n = 24). Due to the small sample size, we excluded respondents who reported established diabetes, leaving 3,085 respondents available for analysis.

We compared respondents with GDM and without diabetes by demographics, health status, and fecundity. Demographics included age at interview, age at last pregnancy, race/ethnicity, education, and poverty index. Education level was defined as less than high school, high school, or some college and was only included for women >25 years of age (n = 2,314). Poverty index was reported as at or above poverty threshold or below federal poverty threshold and was based on survey response in the NHIS in 1993. Information on poverty index was missing for 7.1% of women with GDM and 8.3% of women without diabetes, and missing poverty information did not differ significantly by GDM status (P = 0.102).

Fecundity status in 1995 was defined as surgically sterile (which includes contraceptively and noncontraceptively surgical sterilization), impaired fecundity (which includes nonsurgically sterile, subfecund, and an interval of at least 36 months of unprotected sex without contraception), and fecund. Pregnancy outcome was categorized as live birth, induced abortion, or spontaneous loss (which includes stillbirth, miscarriage, and ectopic pregnancy).

Among respondents who reported a single live birth for the pregnancy (n = 2,347), we compared maternal complications during pregnancy, mode of delivery, and infant outcomes for respondents with GDM and no diabetes. Pregnancies resulting in multiple live births were excluded from analysis of maternal and birth outcomes. There were 39 respondents who reported more than one baby in the index pregnancy; 38 respondents reported having twins (GDM n = 2, nondiabetes n = 36), and 1 respondent reported having triplets (nondiabetes). Maternal complications, defined as nonroutine medical problems in pregnancy, were in addition to reports of GDM and included anemia in pregnancy, preeclampsia, toxemia, weak or incompetent cervix, water retention or edema, vaginal bleeding or spotting in the first 6 months, vaginal spotting or bleeding after the first 6 months, or other nonspecified problems. Infant outcomes were recorded as gestational age and baby’s weight. Preterm birth was defined as a live birth <37 weeks’ gestational age. Birth weight was converted to grams and categorized as low birth weight for infants <2,500 g, normal for infants 2,500 to <4,000 g, and macrosomia for infants 4,000 g. Size for gestational age was used to adjust birth weight for gestational age. Small for gestational age was defined as less than the 10th percentile weight for gestational age. Large for gestational age was defined as greater than the 90th percentile weight for gestational age (19).

Information on maternal height and weight was not collected during the NSFG survey. Therefore, BMI was calculated from self-reported height and weight collected during the 1993 NHIS (2 years before the NSFG survey) as weight (in kilograms) divided by the square of height (in meters) . To address the concern that recent pregnancy might affect reported weight, we excluded BMI values for women who reported a pregnancy ending within 6 months of the 1993 NHIS (from July 1992 to June 1994, n = 1,791) from the analysis of BMI.

All analysis was completed using SUDAAN version 8.0 (Research Triangle Institute, Research Triangle Park, NC) with appropriate sampling weights to account for the complex survey design and provide nationally representative estimates. Estimates are weighted to the April 1995 population of women age 15–44 years in the U.S. GDM and nondiabetic groups were compared using ANOVA or Pearson’s ². Logistic regression was used to calculate unadjusted and age-at-pregnancy–and nongestational hypertension–adjusted odds ratios (ORs) for pregnancy outcomes and maternal complications. Further adjustment included demographic confounders, and the most parsimonious models are presented. We did not include BMI as a confounder in the logistic regression model because approximately half of the participants’ BMI values were excluded.

	RESULTS

TOP ABSTRACT INTRODUCTION RESEARCH DESIGN AND METHODS RESULTS CONCLUSIONS References

 
Demographics
Among women with a pregnancy during 1991–1995, 3.6% reported a history of GDM. Women with GDM were older at the time of interview and at the time of pregnancy than women without diabetes (P < 0.001). There was no difference between the groups by race/ethnicity, education, or poverty index (Table 1).

Pregnancy outcomes
There were 2,238 single live births to respondents without diabetes and 109 to respondents with GDM (Table 3). Respondents with GDM were significantly more likely to report a nonroutine medical problem during pregnancy, in addition to GDM, with 21.2% reporting one problem and 27.6% reporting two or more problems compared with respondents without diabetes, with only 6.9% reporting one problem and 10.2% reporting two or more problems (P < 0.001). The most common nonroutine medical problem reported during pregnancy was preeclampsia, which was reported for 20.7% of respondents with GDM compared with 6.0% for respondents without diabetes (P = 0.002).

Logistic regression
Since age at pregnancy and nongestational hypertension are associated with maternal complications and other pregnancy outcomes, we completed logistic regression for maternal pregnancy outcomes adjusting for age at pregnancy and nongestational hypertension (Table 4). After adjusting for age at pregnancy and nongestational hypertension, the OR of a maternal medical complication during pregnancy for women with GDM compared with women without diabetes was 4.30 (95% CI 2.71–6.82). Women with GDM had an OR of 2.05 (1.17–3.57) for preterm birth compared with women without diabetes after adjusting for age at pregnancy and nongestational hypertension. The association of caesarean delivery for women with GDM was only slightly attenuated after adjusting for age at pregnancy and nongestational hypertension. There was no significant association among women with GDM and large- or small-for-gestational-age babies compared with women without diabetes. Further adjustment for other potential confounders, such as race/ethnicity or education, did not significantly change the results (data not shown).

	CONCLUSIONS

TOP ABSTRACT INTRODUCTION RESEARCH DESIGN AND METHODS RESULTS CONCLUSIONS References

 
Women with GDM were more likely to experience medical complications in addition to having GDM during pregnancy, specifically preeclampsia, compared with women in pregnancies without diabetes. In addition, they were more likely to have a caesarean delivery or preterm birth but were not significantly more likely to have a large-for-gestational-age or marcosomia infant compared with women without diabetes. The strength of these findings is that they are based on data from a large nationally representative sample. Furthermore, the NSFG is comprehensive and includes information on pregnancy outcomes, demographics, and health history and allows comparison of pregnancy with and without GDM.

However, there are a number of limitations to this study. First, the number of women reporting a history of GDM is small. Furthermore, since women in the study were interviewed after the pregnancy ended, there is a potential for both recall bias and survival bias. Recall bias may exist if women with GDM were more likely to recall other nonroutine medical complications or be more familiar with these medical terms compared with women without diabetes. This would bias the result away from the null and may explain part of our finding of association with GDM and other medical complications. However, previous prospective studies have found similar magnitudes of association (5,7,11), giving us confidence that if bias is present, it is small. Survival bias may exist since we have no information on women who may have died or who would have been less likely to participate due to complications of pregnancy or delivery. As we observed, women with GDM were more likely to have other medical complications and may therefore be at higher risk of death or serious illness during delivery compared with women without diabetes. Therefore, complications and other pregnancy outcomes may be underreported in the study, biasing results toward the null. However, this is likely to have a minimal effect because the maternal mortality over the study period was 11.8 pregnancy-related deaths per 100,000 live births (20).

In this study, we found that women with GDM had a significantly lower risk of spontaneous loss than women without diabetes. This observation is most likely related to when GDM is typically diagnosed. GDM is not typically screened or tested for until the 24th to 28th week of pregnancy. This may explain why so few women with a history of GDM reported a spontaneous loss for the pregnancy. It is likely that women with GDM experience a spontaneous loss before being tested for GDM. A somewhat surprising finding was the higher percentage of women with GDM who reported seeking medical help to prevent miscarriage, suggesting that women who develop GDM during pregnancy may be experiencing a higher rate of spontaneous loss due to undiagnosed GDM in previous pregnancies and seek medical help to prevent miscarriages in subsequent pregnancies. Another possibility is that women who are diagnosed with GDM have other preexisting conditions that cause them to seek medical help to prevent miscarriages.

Previous studies have shown that GDM was associated with increased risk for adverse outcomes in pregnancy, including birth defects, large-for-gestational-age babies, and pregnancy-induced hypertension and preeclampsia (4–8,10–12). The majority of these studies were of pregnancies delivered in a limited geographic area (7,10,11) or limited hospital-based samples (5,8,12). In a retrospective cohort study of >111,000 pregnancies in Alberta, Canada, Xiong et al. (11) found that women with GDM were 2.5 times more likely to experience preeclampsia than women without diabetes. They also found that women with GDM were more likely to have a large-for-gestational-age baby and/or a caesarean delivery. In addition to the increased maternal complications during pregnancy, women who develop GDM during pregnancy are also likely to develop GDM in a subsequent pregnancy (21,22) and are at an increased risk of developing type 2 diabetes later in life (30–70% increased risk) (23,24).

This study provides further evidence that GDM is associated with adverse maternal complications. It is unknown whether these women were more likely to be screened and diagnosed with GDM due to a diagnosis of one of the other complications during pregnancy or more likely to be diagnosed with another nonroutine medical complication because they had been diagnosed with GDM. It is difficult to disentangle the cause-effect relationship or the possible temporal associations or causality.

Currently, organizations differ on recommendations for screening for GDM. The U.S. Preventative Services Task Force concludes that there are insufficient data to recommend for or against screening (15). The American Diabetes Association recommends targeted screening in the first trimester among women who have at least one of the six risk factors for GDM and again at 24–28 weeks (13). The American College of Obstetricians and Gynecologists acknowledges that there is lack of strong evidence supporting universal screening but recommends that the American Diabetes Association guidelines be followed (25).

GDM is estimated to occur in 2.8% of hospital deliveries in the U.S. (1). Based on changing demographics in the U.S. (for example the growing populations of African Americans, Hispanics, and Asians) and the increase in obesity and delayed childbearing of women, it is predicted that GDM will continue to increase (3). The above-mentioned factors, along with the findings of this study, suggest that women with GDM are more likely to experience maternal medical complications and that occurrence of these complications can also be expected to increase in the coming years.

	Footnotes

 
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

Received for publication September 24, 2004. Accepted for publication January 24, 2005.

	References

TOP ABSTRACT INTRODUCTION RESEARCH DESIGN AND METHODS RESULTS CONCLUSIONS References

 

1. Danel I, Berg C, Johnson CH, Atreash H: Magnitude of maternal morbidity during labor and delivery: United States, 1993–1997. Am J Public Health 93:631–634, 2003[Abstract/Free Full Text]
   
2. Centers for Disease Control and Prevention: Diabetes during pregnancy: United States, 1993–1995. MMWR 47:408–414, 1998[Medline]
   
3. King H: Epidemiology of glucose intolerance and gestational diabetes in women of childbearing age. Diabetes Care 21(Suppl. 2):B9–B13, 1998
   
4. Centers for Disease Control and Prevention: Perinatal mortality and congenital malformations in infants born to women with insulin-dependent diabetes mellitus: United States, Canada and Europe, 1940–1988. MMWR 39:363–365, 1990[Medline]
   
5. Casey BM, Lucas MJ, McIntire DD, Leveno KJ: Pregnancy outcomes in women with gestational diabetes compared with the general obstetric population. Obstet Gynecol 90:869–873, 1997[Abstract]
   
6. Cundy T, Gamble G: Townend K, Henley PG, MacPherson P, Roberts AB: Perinatal mortality in type 2 diabetes mellitus. Diabet Med 17:33–39, 2000[Medline]
   
7. Dunne F, Brydon P, Smith K, Gee H: Pregnancy in women with type 2 diabetes: 12 years outcome data 1990–2002. Diabet Med 20:732–738, 2003
   
8. Martinez-Frias ML, Bermejo E, Rodriguez-Pinilla E, Prieto L, Frias JL: Epidemiological analysis of outcomes of pregnancy in gestational diabetic mothers. Am J Med Genet 78:140–145, 1998[Medline]
   
9. Ray JG, O’Brien TE, Chan WS: Preconception care and risk of congenital anomalies in the offspring of women with diabetes mellitus: a meta-analysis. QJM 94:435–444, 2001[Abstract/Free Full Text]
   
10. Stone CA, McLachlan KA, Halliday JL, Wein P, Tippett C: Gestational diabetes in Victoria in 1996: incidence, risk factors and outcomes. Med J Aust 177:486–491, 2002[Medline]
    
11. Xiong X, Saunders LD, Wang FL, Demianczuk NN: Gestational diabetes mellitus: prevalence, risk factors, maternal and infant outcomes. Int J Gynaecol Obstet 75:221–228, 2001[Medline]
    
12. Ray JG, Vermeulen MJ, Shapiro JL, Kenshole AB: Maternal and neonatal outcomes in pregesational and gestational diabetes mellitus and the influence of maternal obesity and weight gain: the DEPOSIT study: Diabetes Endocrine Pregnancy Outcome Study in Toronto. QJM 94:347–356, 2001[Abstract/Free Full Text]
    
13. American Diabetes Association: Gestational diabetes mellitus (Position Statement). Diabetes Care 27(Suppl. 1):S88–S90, 2004[Medline]
    
14. Major CA, deVeciana M, Weeks J, Morgan MA: Recurrence of gestational diabetes: who is at risk? Am J Obstet Gynecol 179:1038–1042, 1998[Medline]
    
15. Brody SC, Harris R, Lohr K: Screening for gestational diabetes: a summary of the evidence for the U.S. Preventive Services Task Force. Obstet Gynecol 101:380–392, 2003[Abstract/Free Full Text]
    
16. Hanna FW, Peters JR: Screening for gestational diabetes: past, present and future. Diabet Med 19:351–358, 2002[Medline]
    
17. Schmidt MI, Duncan BB, Reichelt AJ, Branchtein L, Matos MC, Costa e Forti et al: Gestational diabetes mellitus diagnosed with a 2-hour 75-g oral glucose tolerance test and adverse pregnancy outcomes. Diabetes Care 24:1151–1155, 2001[Abstract/Free Full Text]
    
18. Kelly JE, Mosher WD, Duffer AP Jr, Kinsey SH: Plan and operation of the 1995 National Survey of Family Growth. Vital Health Stat Series 1 36:1–89, 1997
    
19. Alexander GR, Himes JH, Kaufman RB, Mor J, Kogan M: A United States national reference for fetal growth. Obstet Gynecol 87:163–168, 1996[Abstract]
    
20. Chang J, Elam-Evans L, Berg C, Herndon J, Flowers L, Seed K, Syverson CJ: Pregnancy-related mortality surveillance: United States, 1991–1999. MMWR Surveill Summ 52:1–8, 2003[Medline]
    
21. MacNeill S, Dodds L, Hamilton DC, Armson BA, VandenHof M: Rates and risk factors for recurrence of gestational diabetes. Diabetes Care 24:659–662, 2001[Abstract/Free Full Text]
    
22. Moses RG: The recurrence rate of gestational diabetes in subsequent pregnancies. Diabetes Care 19:1348–1350, 1996[Abstract]
    
23. Cheung NW, Byth K: Population health significance of gestational diabetes. Diabetes Care 26:2005–2009, 2003[Abstract/Free Full Text]
    
24. Kim C, Newton KM, Knopp RH: Gestational diabetes and the incidence of type 2 diabetes: a systematic review. Diabetes Care 25:1862–1868, 2002[Abstract/Free Full Text]
    
25. American College of Obstetricians and Gynecologists Committee on Practice Bulletins-Obstetrics: ACOG Practice Bulletin: clinical management guidelines for obstetrician-gynecologists: number 30, September 2001 (replaces Technical Bulletin number 200, December 1994): gestational diabetes. Obstet Gynecol 98:525–538, 2001[Medline]
    

CiteULike

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				J. M. Lawrence, R. Contreras, W. Chen, and D. A. Sacks Trends in the Prevalence of Preexisting Diabetes and Gestational Diabetes Mellitus Among a Racially/Ethnically Diverse Population of Pregnant Women, 1999-2005 Diabetes Care, May 1, 2008; 31(5): 899 - 904. [Abstract] [Full Text] [PDF]

				S. Y. Chu, W. M. Callaghan, S. Y. Kim, C. H. Schmid, J. Lau, L. J. England, and P. M. Dietz Maternal Obesity and Risk of Gestational Diabetes Mellitus Diabetes Care, August 1, 2007; 30(8): 2070 - 2076. [Abstract] [Full Text] [PDF]

				J. L. Kitzmiller, L. Dang-Kilduff, and M. M. Taslimi Gestational Diabetes After Delivery: Short-term management and long-term risks Diabetes Care, July 1, 2007; 30(Supplement_2): S225 - S235. [Full Text] [PDF]

				J O'Loughlin, E Dugas, K Maximova, and N Kishchuk Reporting of ethnicity in research on chronic disease: update Postgrad. Med. J., November 1, 2006; 82(973): 737 - 742. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Saydah, S. H. Articles by Eberhardt, M. S. Search for Related Content PubMed PubMed Citation Articles by Saydah, S. H. Articles by Eberhardt, M. S. Social Bookmarking                What's this?