8: No. 6, November 2011
Chloe Zera, MD, MPH; Susan McGirr; Emily Oken, MD, MPH
Suggested citation for this article: Zera C,
McGirr S, Oken E. Screening for obesity in reproductive-aged women. Prev
Chronic Dis 2011;8(6):A125.
http://www.cdc.gov/pcd/issues/2011/nov/11_0032.htm. Accessed [date].
Although obesity screening and treatment are recommended by the US
Preventive Services Task Force, 1 in 5 women are obese when they conceive.
Women are at risk for complications of untreated obesity particularly during
the reproductive years and may benefit from targeted screening. Risks of
obesity and potential benefits of intervention in this population are
well characterized. Rates of adverse pregnancy outcomes including
gestational diabetes, preeclampsia, cesarean delivery, and stillbirth
increase as maternal body mass index increases. Offspring risks include
higher rates of congenital anomalies, abnormal intrauterine growth, and
childhood obesity. Observational data suggest that weight loss may reduce
risks of obesity-related pregnancy complications. Although obesity screening
has not been studied in women of reproductive age, the effect of obesity and
the potential for significant maternal and fetal benefits make screening of
women during the childbearing years an essential part of the effort to
reduce the impact of the obesity epidemic.
Back to top
In 2009, 26% of US adult women reported a body mass index (BMI) in the obese
range (≥30 kg/m2) (1). With rates of both adult and adolescent
obesity increasing, the prevalence of obesity among women of childbearing age
(aged 15-44 y) can also be expected to increase. The US Preventive Services Task
Force (2) and the National Heart, Lung, and Blood Institute (NHLBI) (3) recommend
screening all adults for obesity in clinical settings, but neither
specifically mentions screening for women during their reproductive years.
Although the Centers for Disease Control and Prevention’s Select Panel on
Preconception Care released recommendations in 2006 to improve the preconception
care of women, which included addressing prepregnancy obesity, obesity remains
an undertreated chronic disease that affects at least 1 in 5 pregnancies (4).
One factor contributing to the gap between recommendation and practice may be
that for the 20% of women of childbearing age who are uninsured, preventive care
services are often provided episodically in settings such as federally funded
family planning programs rather than in traditional primary care settings.
The effect of untreated obesity among women of childbearing age includes
adverse reproductive outcomes as well as adverse outcomes for these women’s
offspring. Although women who are obese may be at increased risk for unplanned
pregnancy and contraceptive failure (5), infertility rates are higher among
obese women than among normal-weight women (6). Once a woman is pregnant, both maternal and
fetal risks are increased by high maternal BMI. Pregnancy-associated morbidity
and mortality are higher in obese women than in normal-weight women (7). The
offspring of obese women face an increased risk of obesity and other chronic
metabolic diseases (8). Women of childbearing age are therefore a uniquely
at-risk population who may benefit from targeted screening.
Our objective was to develop recommendations for screening in women of
childbearing age by focusing on the efficacy, benefits, and potential harms of screening
in this population. This article is part of a series of articles focused on
screening women of reproductive age for chronic health conditions, particularly
women seeking care at clinics that receive Title X Family Planning funding.
We systematically reviewed the literature on obesity screening in women of
reproductive age. We searched the MEDLINE database for articles published from
January 1, 1998, to July 1, 2010. We used the search terms “obesity” or “BMI”
and “screen” or “assessment” limited to humans aged 19 to 64 years to identify
potentially relevant articles. Using these parameters, we were unable to
identify any studies that focused on the feasibility, acceptability, risks,
benefits, or costs of obesity screening in women of childbearing age. We
therefore chose to frame our discussion of screening by summarizing the current
evidence surrounding the risks of obesity before and during pregnancy, reviewing
potential risks and benefits of obesity treatment as part of preconception care,
highlighting gaps in current screening practices, and proposing recommendations
for screening opportunities in the population of women who may become pregnant.
Back to top
Risks Associated With Obesity in Women of Childbearing
Although unplanned pregnancy is of concern in a population at high risk for
complications during pregnancy, obese women are less likely to use contraception
than normal-weight women (9). Furthermore, the counseling of obese women
regarding contraceptive options is more complex than for women of normal weight.
Although contraceptive efficacy is generally high, there may be higher rates of
failure of combined hormonal methods in obese women (10), and both intrauterine
contraception placement and surgical sterilization are more technically
challenging and more likely to result in complications (11) in women with a high
BMI than in women of normal weight. Although the absolute risk of venous
thromboembolism is small in obese women who use combined hormonal contraception,
the risk is elevated relative to women who are not using combined contraception,
and further study is needed to determine whether risks are higher in obese women
than in normal-weight women (5).
The risks of adverse pregnancy outcomes increase as maternal BMI increases
beyond the normal range (BMI ≥25 kg/m2). Achieving pregnancy can be
more difficult for obese women because they are less likely to ovulate
regularly, have decreased fecundity, and have increased risk of miscarriage (6).
Gestational diabetes affects as many as 20% of pregnancies in women who are
obese, a 4-fold increase compared with normal-weight women (12). Hypertension in
pregnancy is more frequent in obese women, and they have a 2- to 3-fold increased
odds of preeclampsia (12). The risk of preterm delivery in obese women is also
elevated, likely in part because of their increased risk of preeclampsia (12).
High maternal BMI is associated with intrapartum complications. Induction of
labor is more common in women with high BMI than in normal-weight women (12).
Rates of both primary and repeat cesarean delivery increase with increasing
maternal BMI, with trial of labor after cesarean less likely to be successful
than in normal-weight women (12,13). The peripartum complications faced by obese
women include a greater likelihood of infection, need for blood transfusion, and
venous thromboembolism, particularly with cesarean delivery (14). Prepregnancy
obesity is also associated with a 3-fold increase in maternal death and
near-miss morbidity (7).
In addition to the maternal consequences of obesity, there are significant
implications of excess maternal weight to offspring. The risk of fetal anomalies
including cleft palate, neural tube defects, and congenital heart disease is
increased (15), and detection of anomalies is made more difficult because of the
technical challenges of ultrasound in obese women. The risk of stillbirth among
obese women is approximately double that among normal-weight women (16). Obese
women are more likely to give birth to infants who are large for gestational age
or macrosomic (14); these infants are at higher risk than their normal birth weight
counterparts for long-term cardiometabolic complications, including obesity (8).
Even normal birth weight offspring of obese mothers are more likely to be obese
than offspring of normal-weight mothers (8), further fueling the obesity
Back to top
The NHLBI has recommended treating all obese patients who are receptive to
intervention, while acknowledging that a limitation of all therapies, including
lifestyle intervention, medical therapy, and surgical therapy, is a low rate of
long-term weight maintenance (3). Nonetheless, randomized controlled trials of
multiple weight-loss strategies have demonstrated short-term efficacy. None of
these trials has specifically focused on the treatment of obesity during a
woman’s reproductive life, particularly before conception. Observational data
suggest that interpregnancy weight loss is associated with a decreased risk of
preeclampsia, large-for-gestational-age birth weight, and cesarean delivery (17),
compared with the previous pregnancy. Few studies have examined the effect of
lifestyle interventions or medical therapy before conception on pregnancy
outcomes. Several case series have attempted to examine the effect of bariatric
surgery by comparing outcomes in women who have had pregnancies both pre- and
postoperatively, or by choosing normal-weight controls. There may be a decrease
in infertility and spontaneous abortion in women who have undergone bariatric
surgery (5). Consistent findings include lower rates of gestational diabetes and
hypertensive complications (18) after surgical intervention, without increases
in fetal or maternal morbidity. One study of children of mothers who had
undergone bariatric surgery found that, compared with children born before their
mothers had bariatric surgery, fewer children born after their mothers had
bariatric surgery showed abnormalities in anthropometry and hormonal markers of
cardiometabolic risk (19). While these data suggest that aggressive treatment of
obesity may be warranted, prospective study is needed to quantify the risks and
benefits of both medical and surgical management before pregnancy.
Back to top
The rate of obesity screening in clinical practice is low. Obesity is underdiagnosed in primary care settings (20); consistently fewer than half
of obese patients have a documented obesity diagnosis. Similarly, a minority
of obese people report receiving weight-loss advice from their health care
provider (21). Although some clinicians have argued that screening is
unnecessary because patients have an adequate perception of body weight,
misperception of weight status is in fact widespread, with 1 study reporting
that only 14% of obese women recruited from urban health centers in Atlanta
correctly identified their weight status (22).
Theoretical risks of obesity screening include stigmatization or
psychological effects associated with the diagnosis of obesity; however, we were
unable to identify literature substantiating these risks. In fact, data suggest
that awareness of weight status is beneficial. The 2003-2008 National Health and
Nutrition Examination Survey found that 98% of the women who correctly perceived
themselves as overweight desired to weigh less and 72% were actively attempting
to lose weight, compared with only 37% of women who did not perceive themselves
as overweight (23). Moreover, overweight and obese women who had received a
diagnosis of overweight or obesity from their health care provider were twice as
likely to endorse weight control behaviors (ie, diet, exercise) as women
who did not have a formal diagnosis (23). The potential benefits of obesity
screening as a part of preconception counseling remain unexplored.
Back to top
Recommendations for Screening
Screening for obesity in women of reproductive age remains understudied as a
population-level intervention. There are data, however, that support the basic
tenets of screening for obesity in women during childbearing years. Obesity is a
disease with measurable public health impact during the reproductive years, not
just later in life. Screening for obesity by calculating BMI is a reproducible,
simple, and inexpensive technique that reliably estimates adiposity without the
time and expense of less practical methods such as measurement of total body
water (8). Although there are theoretical risks, including misdiagnosis, stigma
associated with diagnosis, and extra cost associated with treatment, these risks
have not been demonstrated in current literature.
Finally, the potential benefits of screening include appropriate treatment
with resultant weight loss, which may improve outcomes for women and their
children. In particular, weight loss before pregnancy may have immediate
benefits including reduced maternal morbidity and decreased risk of long-term cardiometabolic consequences for children, even if weight loss is not sustained
over time. At a minimum, identification of obesity before conception allows for
appropriate preconception counseling. Current recommendations from the American
Congress of Obstetricians and Gynecologists include discussion of specific
maternal and fetal risks of prepregnancy obesity, counseling regarding the
benefits of weight reduction, and management to identify early or minimize
possible complications of obesity (24).
We are unaware of prior reviews of obesity screening that have focused on
women of reproductive age. Although we were not able to identify sufficient
literature regarding obesity screening to perform a meta-analysis, evidence
regarding the risks of untreated obesity in women of reproductive age is
substantial. The limited data on pregnancy outcomes following the surgical
treatment of obesity are promising and suggest there may be benefit to
identifying and treating obesity in women who are planning pregnancy.
The American Congress of Obstetricians and Gynecologists is the only national
body that has issued specific guidelines for screening women of reproductive age
for obesity, with the recommendation that BMI be calculated for all women (24).
Despite these recommendations, current screening rates are low (20). Recognizing
that many young women access the health care system sporadically and that nearly
50% of pregnancies are unplanned, we believe that screening should be performed
in settings beyond primary care clinics, including community health centers,
college health service centers, and family planning clinics. We suggest that
women of childbearing age presenting for care in these settings should be told
their BMI after a measured weight and height are obtained.
The potential benefits of screening all women of childbearing age include
identification of women at high risk and referral to appropriate treatment
before pregnancy. The American Dietetic Association and the American Society for
Nutrition have issued a joint statement supporting counseling all overweight and
obese women of reproductive age on dietary modification and physical activity
(25). Further data are needed to understand the effect that losing a small
amount of weight has on pregnancy outcomes. A potential harm is stigma, although
this risk has not been studied, and additional costs may be incurred with
increased diagnosis of obesity. In resource-poor settings, follow-up care may be
inadequate to ensure appropriate treatment of women identified in broad
screening programs. Although we acknowledge these potential pitfalls of widespread
screening, we argue that simply identifying obesity may itself be an
intervention because women who accurately perceive that they are overweight may be
more likely to change their diet or demonstrate healthy weight-related behaviors
than women who misperceive their weight status (23).
Back to top
Although obesity screening has not been studied specifically in women of
reproductive age, there are compelling reasons to prioritize screening in this
population. Women of childbearing age who are obese are at increased risk of
infertility, miscarriage, and other adverse pregnancy outcomes. Mounting
evidence supports the intergenerational transmission of obesity as a result of
an abnormal intrauterine environment. Although randomized controlled trials of
intensive treatment of obesity before pregnancy have not yet been performed,
observational data suggest the possibility that weight reduction may ameliorate
these risks. Furthermore, clinicians who identify women as obese may be more
likely to provide appropriate care and screening to identify and reduce risks
for secondary complications of obesity. Screening of reproductive-aged women is
an essential part of broadening efforts to reduce the effect of the obesity
epidemic in this country.
Back to top
Corresponding Author: Chloe Zera, MD, MPH, Division of Maternal-Fetal
Medicine, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham
and Women’s Hospital, 75 Francis St, Boston MA 02115. Telephone: 617-732-5452.
Author Affiliations: Susan McGirr, Harvard Medical School, Boston,
Massachusetts; Emily Oken, Obesity Prevention Program, Department of Population
Medicine, Harvard Medical School and Harvard Pilgrim Health Care, Boston,
Back to top
- Centers for Disease Control and Prevention.
prevalence of obesity among adults — United States, 2009. MMWR Morb Mortal Wkly Rep
- US Preventive Services Task Force.
Screening for obesity in
adults: recommendations and rationale. Ann Intern Med
- Clinical guidelines on the identification, evaluation, and
treatment of overweight and obesity in adults: the evidence report.
National Heart, Lung, and Blood Institute, National Institutes of Health;
1998. http://www.nhlbi.nih.gov/guidelines/obesity/ob_gdlns.pdf. Accessed
May 27, 2011.
- Johnson K, Posner SF, Biermann J, Cordero JF, Atrash HK, Parker
CS, et al.
Recommendations to improve preconception health and health
care — United States. A report of the CDC/ATSDR Preconception Care Work
Group and the Select Panel on Preconception Care. MMWR Recomm Rep 2006;55(RR-6):1-23.
- Murthy AS.
Obesity and contraception: emerging issues. Semin
Reprod Med 2010;28(2):156-63.
- Shah DK, Ginsburg ES.
Bariatric surgery and fertility. Curr Opin
Obstet Gynecol 2010;22(3):248-54.
- Goffman D, Madden RC, Harrison EA, Merkatz IR, Chazotte C.
Predictors of maternal mortality and near-miss maternal morbidity. J Perinatol 2007;27(10):597-601.
- Oken E, Gillman MW.
Fetal origins of obesity. Obes Res
- Chuang CH, Chase GA, Bensyl DM, Weisman CS.
Contraceptive use by
diabetic and obese women. Women Health Issues 2005;15(4):167-73.
- Holt VL, Scholes D, Wicklund KG, Cushing-Haugen KL, Daling JR.
Body mass index, weight, and oral contraceptive failure risk. Obstet
- Jamieson DJ, Hillis SD, Duerr A, Marchbanks PA, Costello C,
Complications of interval laparoscopic tubal sterilization:
findings from the United States Collaborative Review of Sterilization. Obstet Gynecol 2000;96(6):997-1002.
- Weiss JL, Malone FD, Emig D, Ball RH, Nyberg DA, Comstock CH, et
Obesity, obstetric complications and cesarean delivery rate — a
population-based screening study. Am J Obstet Gynecol
- Chu SY, Kim SY, Schmid CH, Dietz PM, Callaghan WM, Lau J, et al.
Maternal obesity and risk of cesarean delivery: a meta-analysis. Obes
- Perlow JH, Morgan MA.
Massive maternal obesity and perioperative
cesarean morbidity. Am J Obstet Gynecol 1994;170(2):560-5.
- Stothard KJ, Tennant PW, Bell R, Rankin J.
and obesity and the risk of congenital anomalies: a systematic review
and meta-analysis. JAMA 2009;301(6):636-50.
- Chu SY, Kim SY, Lau J, Schmid CH, Dietz PM, Callaghan WM, Curtis KM.
Maternal obesity and risk of stillbirth: a metaanalysis. Am J Obstet
- Villamor E, Cnattingius S.
Interpregnancy weight change and risk
of adverse pregnancy outcomes: a population-based study. Lancet
- Bennett WL, Gilson MM, Jamshidi R, Burke AE, Segal JB, Steele KE, et
Impact of bariatric surgery on hypertensive disorders in
pregnancy: retrospective analysis of insurance claims data. BMJ
- Smith J, Cianflone K, Biron S, Hould FS, Lebel S, Marceau S, et
Effects of maternal surgical weight loss in mothers on
intergenerational transmission of obesity. J Clin Endocrinol Metab
- Waring ME, Roberts MB, Parker DR, Eaton CB.
management of overweight and obesity in primary care. J Am Board Fam
- Ko JY, Brown DR, Galuska DA, Zhang J, Blanck HM, Ainsworth BE.
Weight loss advice US obese adults receive from health care
professionals. Prev Med 2008;47(6):587-92.
- Moore SE, Harris C, Wimberly Y.
Perception of weight and threat
to health. J Natl Med Assoc 2010;102(2):119-24.
- Yaemsiri S, Slining MM, Agarwal SK.
Perceived weight status,
overweight diagnosis, and weight control among US adults: the NHANES
2003-2008 Study. Int J Obes (Lond) 2010 Nov 2.
- Obesity in pregnancy. Washington (DC): The American Congress of
Obstetricians and Gynecologists; September 2005.
- Siega-Riz AM, King JC.
Position of the American Dietetic
Association and American Society for Nutrition: obesity, reproduction,
and pregnancy outcomes. J Am Diet Assoc 2009;109(5):918-27.
Back to top