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Women Who are Overweight and Underweight have Problems with Fertility

Akashia Anderson

Infertility is a consequence of eating disorders that is not addressed as often as other consequences. What effect does eating disorders have infertility? Eating disorders can have people overweight, underweight and sometimes a normal weight. Body size has been related to several gynecological disorders. Higher risks of infertility have been found in both overweight and underweight women. To what extent being excessively under or overweight increases a woman’s risk for infertility is unknown. Women who are excessively underweight or overweight may be at increased risk of amenorrhea. Women need to have a certain amount of body fat in order to menstruate and conceive children.

Many anorexic girls and women either never get their period or their period stops due to extreme weight loss. The cessation of menstruation, (amenorrhea), can be permanent depending on how long a woman has been suffering from anorexia. But for most women menstruation will start up when they begin to gain weight. Roughly 80% of anorexic women who successfully treat their eating disorder will regain their ability to conceive. When a woman's percentage of body fat falls below a certain minimum her body doesn't produce the levels of hormones necessary to stimulate ovulation. Rapid weight loss and undernourishment leads a woman's body into a state of emergency and she will not menstruate if she is just barely surviving.

Low weight and weight loss is also associated with ovulatory dysfunction and thus infertility. Even a moderate weight loss of 10-15% under ideal body weight can result in menstrual irregularity. It does not need to be the weight alteration of 30% or more as seen in women with anorexia nervosa or bulimia. Weight gain programs in these underweight women have been shown to restore ovulation and pregnancy in up to 73% of women who were able to achieve 95% of their ideal body weight. For many studies affecting eating disorders, a BMI (body mass index) of 17.5 - 20 is underweight and under 17.5 is considered very underweight (Reid and Van Vugt 1987).

Obesity has a strong association with infertility and menstrual irregularities. While some of the ovulation problems and menstrual changes are explainable by women with Polycystic Ovarian Syndrome (PCOS) who are also obese, women who do not have PCOS but are overweight also have the same problems. Group treatment programs that assist obese women with diet and exercise plans have shown return of fertility in many patients. Weight loss of 15 lbs (6.5 kg) has been shown to restore ovulation. For most studies, 20% over ideal weight is considered obese. Officially, a BMI (body mass index) of 25-30 is considered overweight and a BMI of over 30 is considered obese (Reid and Van Vugt 1987).

Furthermore elevated risk are not confined to those acquiring their overweight or underweight in adulthood. Many are related to fatness or thinness in childhood or adolescent. Teenage obesity and thinness on fertility has been emphasized.

In Lake, Powers and Cole’s study they investigated the relationship between childhood and adolescent body mass index, in addition to that in adulthood with subsequent reproductive problems. Heights, weights (at 7,11,16,23 and 33years) and reproductive data were used for 5799 females from the British birth cohort study. They found that early menarcheal age was associated with a higher risks of menstrual problems by the age of 16. Obesity at 23 years and obesity at 7 years both independently increased the risk of menstrual problems by age 33. Overweight and obesity in early adulthood appears to increase the risk of menstrual problem and subfertiltiy. Other than menstrual problems, childhood body mass index had little impact on the reproductive health of women.

Grodstein, Goldmen and Cramer did a study Body Mass Index and Ovulatory Infertility (1993) which they compared body mass index of women diagnosed with ovulatory infertility to controls who had recently given birth. The women in the study were taken from infertility clinics in the United States and Canada. They defined infertility as the "inability to conceive after 12 months of unprotected intercourse or the failure to deliver a liveborn baby". The women were interviewed and the only women they considered in the study were women who had been diagnosed with ovulatory infertility the first or second time diagnosis. Information on their medical history and personal habits was collected during their personal interview. All subjects were asked their height and weight, for the cases their present weight and for the controls their weight before their pregnancy.

Grodstein et al. found that an elevated risk for primary ovulatory infertility in women with a BMI of 27 or greater. The crude relative risk in the women was 3.1 compared with women whose BMI was 20-24.9 the risk decreased to 2.4. a slight increase was found in the risk of ovulatory infertility in women with a BMI less than 17. Studied have shown that weight and menstrual irregularity are related and that weight loss in anovulatory obese women results in ovulation and a return to fertility for many women.

While Grodstein et al. also observed a moderate increase in the risk of ovulatory infertility among lean women, there were few included in the study which was one of the limitations. They did find evidence that excessive thinness leads to hypothalamic dysfunction and anovulatory menstrual cycles. Other limitations of this study include the fact that because the information about each woman’s history was taken by a self-report, misclassification of height or weight may have occurred. The cases were reporting current height and weight while the controls were reporting their information before pregnancy. Finally, women who are referred to infertility clinics and attend may be of higher socioeconomic status than women in the general population. This could have limited the generalizabilty of the results from the study.

Another study concerned about the results of eating disorders on infertility was done by Bulik, Sullivan, Fear, Pickering, Dawn and McCullin Fertility and Reproduction in Women With Anorexia Nervosa: A Controlled Study (1998). Bulik et al. examined fertility and reproductive history in sixty six women who had a history of anorexia nervosa and ninety -eight randomly selected community controls. The interview was performed face to face. Information on fertility, reproductive history, and obstetric complications was obtained by patient report.

The BMI data indicate that women with anorexia nervosa were at a significantly lower body weight at the time of interview than controls. The cases had also had significantly lower minimum past BMIs than the controls, and control reported significantly higher maximum past BMIs. Significantly more women in the anorexia nervosa group than the control group had miscarriages, there was also a statistical trend for more women in the anorexia group to have had abortions. This could have been because they had more complications with the pregnancies or there was early detection of problems with the fetus. The cases had more miscarriages because their body was not capable to carry a baby to full term and therefore the body attacked the fetus.

Finally, the study done by Stewart, Robinson, Goldbloom and Wright Infertility and Eating Disorders (1990) addressed the affects of eating disorders and infertility. Eating disorders result in significant morbidity related to episodes of weight loss, vomiting and reproductive problems. Sixty-six consecutive infertility clinic patients were prospectively screened with the 26 item Eating Attitudes Test and a study questionnaire. Women identified as being at high risk for eating disorder were then interviewed. A total of 7.6% of infertility clinic were found to suffer from anorexia or bulimia. Among these infertile women with amenorrhea or oligomenorrhea 58% had eating disorders.

Stewart et al did an analysis of variance to compare scores of amenorrheic and oligomenorrheic women with those women of normal menses. Total scores on EAT-26 were significantly higher in the abnormal menses group than in the normal menses group. The women with menstrual abnormalities had a higher prevalence of eating disorders than normally cycling women. This suggests that infertile women with menstrual abnormalities are at even higher risk of suffering from an eating disorder.

Eating disorders may play an important role in infertility; recent studies have shown that 73% of normal infertile patients who were below ideal weight conceived spontaneously when their weight was corrected. There are few studies that investigate associations between female infertility, eating disorders and body mass index. Future studies need to pay more attention to the time when the eating disorders were most prevalent in the lives of the cases. It would be good to know how long and how affected the cases were by the disorders. The studies could have had more women and also women who were not able to conceive even after the weight change. They could have just taken women who they knew had eating disorders and then found out if they were infertile instead if just dealing with infertile women and then seeing if they had eating disorders.

The studies all did interviews with the women and asked them their weight and height as oppose to finding it for themselves. They should have not relied solely on the self-report but also found out for themselves. That could have been another way to figure out about the person and their feelings about themselves. By comparing the self-reporting weight and the weighing in weight they could have gauged the women’s self images.

Obesity in early adulthood may increase the risk of menstrual problems and subfertility. Childhood obesity may also carry adverse consequences for menstrual problems but this appears to be partly through its association with adult BMI. These reproductive health problems are likely to increase with the current trends of increasing fatness in the general population. Higher risks of infertility have been found in both overweight and underweight women. It is apparent that weight does have a role in fertility. Some people try to control their weight with eating disorders and this only causes other problems in their lives. The weight loss or gain is over powering to the system and causes the menses to cease. It is usually the case that once the weight is regained or lost the menses return. Without the menses the woman is infertile until they return which is usually not until the weight changes. The body is not able to carry the baby to term even if the lady is lucky enough to conceive. The weight change is too much of a strain on the body’s reproductive organs and therefore they shut down. If the weight change is handled in enough time then the infertility will not be permanent if there was not too much strain on the organs. Any woman who is struggling with an eating disorder should delay trying to get pregnant until she is health and is able to carry a baby in a health environment.


Works Cited

1.Bulik CM, Sullivan PF, Fear JL, Pickering A, Dawn A, and McCullin M: Fertility and Reproduction in Women With Anorexia Nervosa: A Controlled Study. J Clin Psychiatry 60:2,1999

2.Green BB, Weiss NS, and Daling JR: Risk of ovulatory infertility in relation to body weight. Fertility and Sterility 50:5,1988

3.Grodstein F, Goldman MB, and Cramer DW: Body Mass Index and Ovulatory Infertility. Epidemiology 5:2,1994

4.Lake JK, Power C, and Cole TJ: Women’s reproductive health: the role of the body mass index in early and adult life. International Journal of Obesity 21:6,1997

5.Reid RL, and Van Vugt DA: Weight-related changes in reproductive function. Fertility and Sterility 48:6,1987

6.Stewart DE, Robinson GE, Goldbloom DS, and Wright C: Infertility and eating disorders. Am J Obstet Gynecol 163:4,1990


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