Body mass and probability of pregnancy during assisted reproduction treatment: retrospective study

Insulin sensitizing drugs for weight loss in women of reproductive age who are overweight or obese: systematic review and meta-analysis

BACKGROUND

Women of reproductive age, who are overweight or obese, are prone to infertility. Weight loss in these women leads to increased fecundity, higher chances of conception after infertility treatment and improved pregnancy outcome. In spite of the advantages, most patients have difficulty in losing weight and often regain lost weight over time. This review assesses whether treatment with insulin sensitizing drugs contributes to weight loss, compared with diet or a lifestyle modification programme.

METHODS

After a systematic search of the literature, only randomized controlled trials (RCTs), investigating the effect of insulin sensitizing drugs on weight loss compared with placebo and diet and/or a lifestyle modification programme, were included. Subjects were restricted to women of reproductive age. The main outcome measure was change in body mass index (BMI).

RESULTS

Only 14 trials, unintentionally all but two on women with polycystic ovary syndrome (PCOS) only, were included in the analysis. Treatment with metformin showed a statistically significant decrease in BMI compared with placebo (weighted mean difference, -0.68; 95% CI -1.13 to -0.24). There was some indication of greater effect with high-dose metformin (>1500 mg/day) and longer duration of therapy (>8 weeks). Limitations were power, low use of intention-to-treat analysis and heterogeneity of the studies.

CONCLUSION

A structured lifestyle modification programme to achieve weight loss should still be the first line treatment in obese women with or without PCOS. Adequately powered RCTs are required to confirm the findings of this review and to assess whether the addition of high-dose metformin therapy to a structured lifestyle modification programme might contribute to more weight loss.

Obesity in pregnancy: pre-conceptional to postpartum consequences

OBJECTIVE

To review the effects of obesity on reproduction and pregnancy outcome.

METHODS

A search of the literature was performed using key word searching and citation snowballing to identify English language articles published between January 1, 2000, and December 31, 2006, on the subject of obesity and its effects on pregnancy. Once the articles were identified, a thorough review of all results was conducted. Results and conclusions were compiled and summarized.

RESULTS

Obesity during pregnancy was linked with maternal complications ranging from effects on fertility to effects on delivery and in the postpartum period, as well as many complications affecting the fetus and newborn. The maternal complications associated with obesity included increased risks of infertility, hypertensive disorders, gestational diabetes mellitus, and delivery by Caesarean section. Fetal complications included increased risks of macrosomia, intrauterine fetal death and stillbirth, and admission to the neonatal intensive care unit.

CONCLUSION

Obesity causes significant complications for the mother and fetus. Interventions directed towards weight loss and prevention of excessive weight gain must begin in the pre-conception period. Obstetrical care providers must counsel their obese patients regarding the risks and complications conferred by obesity and the importance of weight loss. Maternal and fetal surveillance may need to be heightened during pregnancy; a multidisciplinary approach is useful. Women need to be informed about both maternal and fetal complications and about the measures that are necessary to optimize outcome, but the most important measure is to address the issue of weight prior to pregnancy.

Body fat, energy balance and estradiol levels: a study based on hormonal profiles from complete menstrual cycles

BACKGROUND

Female fecundity is regulated by nutritional status. Although widely cited, this hypothesis is not strongly supported by empirical data from non-obese, healthy women of reproductive age.

METHODS

Healthy, reproductive aged women (n = 141) from Southern Poland collected daily morning saliva samples for one complete menstrual cycle. Levels of 17-beta-estradiol were analyzed by radioimmunoassay. Anthropometric measurements, including body fat percentage, were taken randomly with respect to phase of the menstrual cycle. Energy balance was specified based on changes in body fat percentage from the beginning to the end of the observation period.

RESULTS

Women with very low and high body fat had significantly lower levels of E2 compared with women with low and average body fat. In women of very low to average body fat, a 10% increase in body fat was associated with a 5-7 pmol/l increase in estradiol levels. The association between fat percentage and E2 was even stronger in women with positive energy balance, who also showed significant differences between body fat groups in estradiol profiles across whole the menstrual cycle. No such relationship was found in women with negative energy balance.

CONCLUSIONS

In healthy women, we found a non-linear association between body fat and estradiol levels. Both very low and high body fat was associated with decreased estradiol levels. The relationship between estradiol and body fat was strongly influenced by women's energy balance.

Evidence that obesity alters the quality of oocytes and embryos

Infertility is more common in overweight and obese women, with reproductive impairments occurring at many levels of the hypothalamic-ovarian-uterine axis. These impairments lead primarily to longer times to conception and decreased pregnancy rates and have resulted in increasing numbers of overweight and obese women seeking assisted reproduction technologies, such as in vitro fertilization or IVF. Even after undertaking IVF procedures obese women have decreased pregnancy rates compared to moderate weight women, suggesting there may be intrinsic differences in the oocytes of these patients. Definitive data is lacking however, and thus the effect of obesity on oocyte quality remains one of the biggest controversies in reproductive medicine. This review summarizes the studies to date which have yielded information about the effects of obesity on human oocyte quality and pre-implantation embryo development. In addition recent results from our laboratory which clearly demonstrate that diet-induced obesity in mice impairs oocyte developmental competence are discussed.

Effects of obesity on assisted reproductive technology outcomes

Mounting evidence has shown that increased body mass index has a significant adverse effect on pregnancy and miscarriage rates in women seeking to conceive naturally. Several studies have sought to determine the effects of obesity on the endometrium by analyzing outcomes in patients receiving ovum donation.

The great weight debate: do elevations in body mass index (BMI) exert a negative extraovarian effect on in vitro fertilization outcome?

There is an increasing body of evidence that excess weight is associated with decreased pregnancy rates, lower birth rates, lower implantation rates, and the possibility of decreased follicle development and oocyte numbers as well as an increased gonadotropin requirement in patients undergoing in vitro fertilization or intracytoplasmic sperm injection. Whether the mechanism is ovarian, endometrial, or a combination of the two is unknown.

Body mass index: impact on IVF success appears age-related

BACKGROUND

The objective of this study was to examine the effect of BMI on IVF outcomes.

METHODS

This was a retrospective analysis of all patients undergoing IVF from 1st January 2005 to 1st March 2006 in a large private practice using a single IVF laboratory. The patients underwent standard protocols for controlled ovarian hyperstimulation and embryology parameters. The main outcome measure was clinical pregnancy rate.

RESULTS

A total of 2167 fresh, non-donor IVF cycles were queried, but to minimize bias, only the first treatment cycle for each patient was analyzed (n = 1273). The data were examined by multiple regression models that included BMI and Age as main effects plus a BMI x Age interaction. When examined as a main effect, BMI did not appear to have a major effect on IVF outcome, but there was a significant BMI x Age interaction. At younger ages, a high BMI had a pronounced negative influence on fertility, but this effect diminished as the patient age increased. Clinical pregnancy rates decreased with increasing BMI and increasing Age.

CONCLUSIONS

In younger patients undergoing IVF, BMI has a significant negative impact on fertility that diminishes as patients reach their mid thirties. After Age 36, BMI has a minimal impact on fertility.

Elevated body mass index (BMI) does not adversely affect in vitro fertilization outcome in young women

OBJECTIVE

To determine if elevated body mass index in young women with normal ovarian reserve was associated with poorer ovarian response, difficulty at embryo transfer, and lower clinical pregnancy rates.

MATERIALS AND METHODS

Retrospective study of 417 first, fresh in vitro fertilization cycles performed between October 2004 and December 2006. All women were under the age of 35 and had normal cycle day 3 follicle stimulating hormone and estradiol levels. Subjects were divided into groups by BMI: <18.5, 18.5-24.9, 25-29.9, > or = 30.

RESULTS

Cancellation rates, peak estradiol levels, and mean number of oocytes retrieved were similar in all groups. There was a trend toward increasing difficulty in visualizing the air bubble at time of embryo transfer and lower implantation rates at higher body mass indices. Clinical and ongoing pregnancy rates were similar among groups.

CONCLUSION

Obesity in young women does not adversely affect clinical pregnancy rates in patients treated with in vitro fertilization.

Drug insight: insulin-sensitizing drugs in the treatment of polycystic ovary syndrome--a reappraisal

The recognition that insulin resistance has a pivotal role in the pathogenesis of polycystic ovary syndrome (PCOS) revolutionized our understanding of this complex disorder. PCOS causes major metabolic and reproductive morbidities, including substantially increased risk for type 2 diabetes mellitus and the metabolic syndrome. Insulin-sensitizing drugs (ISDs) ameliorate reproductive abnormalities, restore ovulation and regular menses, increase pregnancy rates and reduce androgenic symptoms in affected women with PCOS. Accordingly, ISDs, specifically metformin, have been widely adopted as therapy for this condition. A recent, large, randomized, multicenter, clinical trial that assessed live-birth rates rather than surrogate end points suggested that metformin alone is inferior to clomiphene citrate in treating infertility associated with PCOS. There is, furthermore, no evidence to support the use of metformin during pregnancy to prevent spontaneous abortions or gestational diabetes mellitus in women with PCOS. Renewed safety concerns about thiazolidinediones followed recent studies that reported increased cardiovascular morbidity with these agents. These concerns might preclude thiazolidinedione use in otherwise healthy women with PCOS. Finally, although ISDs improve insulin action and cardiovascular disease risk, there is no evidence that they provide long-term health benefits in PCOS. This article discusses the role of ISDs in PCOS in light of these new data.

High and low BMI increase the risk of miscarriage after IVF/ICSI and FET

BACKGROUND

The extremes of BMI are associated with an increased risk of miscarriage both in spontaneously conceived pregnancies and after fertility treatment. The aim of the present study was to study the effect of BMI on miscarriage rate (MR) in fresh IVF/ICSI, and in spontaneous and hormonally substituted frozen-thawed embryo (FET) cycles.

METHODS

Analysis was carried out on 3330 first pregnancy cycles, performed during the years 1999-2004, of which 2198 were fresh, 666 were spontaneous and 466 were hormonally substituted FET cycles. A categorical, a linear and a quadratic models of the effect of BMI on miscarriage were studied by logistic regression. Factors related to patient characteristics, protocol and embryo parameters were also examined.

RESULTS

MR was higher in hormonally substituted FET (23.0%), compared with the fresh cycles (13.8%) and spontaneous FET (11.4%, P < 0.0001). Multivariate logistic regression revealed that the relationship between BMI and the risk of miscarriage is not linear but quadratic (U-shaped) (P = 0.01), indicating a higher risk of miscarriage in underweight and obese women. Hormonal substitution for FET was also associated with a 1.7-fold higher MR, compared with the fresh cycles (P = 0.002, 95% confidence interval 1.2-2.3).

CONCLUSIONS

Obese and underweight women have an increased risk of miscarriage, and hormonally substituted FET is associated with an even higher MR.

Effect of increased body mass index on oocyte and embryo quality in IVF patients

Obesity may have an adverse effect on the outcome of IVF/intracytoplasmic sperm injection (ICSI) treatment. In this study, the effects of increased body mass index (BMI) on oocyte and embryo quality during IVF cycles were studied. A retrospective analysis of 426 IVF/ICSI cycles was performed. Cycles were classified according to the BMI: normal BMI (19-24.9 kg/m(2)), overweight (25-29.9 kg/m(2)) and obese (> or = 30 kg/m(2)). Cycles were further stratified based on age (group 1, < 35 years; group 2, > or = 35 years). Markers of oocyte quality (number of oocytes inseminated and fertilization rate) and embryo quality (utilization rate, number of embryos discarded and cryopreserved, and mean embryo grade) were examined. In group 1, obesity had a significant adverse effect on the mean embryo grade (P = 0.02), the embryo utilization rate (P = 0.01), number of embryos discarded (P = 0.007) and cryopreserved (P < 0.05). In group 2, there was no difference in markers of embryo quality between the three BMI ranks. Obesity did not have any significant effect on markers of oocyte quality or clinical pregnancy rates. In conclusion, obesity may adversely affect embryo quality in young women (<35 years) undergoing IVF/ICSI, while the oocyte quality is not affected.

Obesity and infertility

PURPOSE OF REVIEW

To summarize major factors affecting fertility in obesity.

RECENT FINDINGS

Fertility can be negatively affected by obesity. In women, early onset of obesity favours the development of menses irregularities, chronic oligo-anovulation and infertility in the adult age. Obesity in women can also increase risk of miscarriages and impair the outcomes of assisted reproductive technologies and pregnancy, when the body mass index exceeds 30 kg/m. The main factors implicated in the association may be insulin excess and insulin resistance. These adverse effects of obesity are specifically evident in polycystic ovary syndrome. In men, obesity is associated with low testosterone levels. In massively obese individuals, reduced spermatogenesis associated with severe hypotestosteronemia may favour infertility. Moreover, the frequency of erectile dysfunction increases with increasing body mass index.

SUMMARY

Much more attention should be paid to the impact of obesity on fertility in both women and men. This appears to be particularly important for women before assisted reproductive technologies are used. Treatment of obesity may improve androgen imbalance and erectile dysfunction, the major causes of infertility in obese men.

The impact of obesity on female reproductive function

Obesity may be described as the new worldwide epidemic, and its serious impact on morbidity and mortality are well known. As more and more women become obese, the reproductive problems associated with obesity present an ever-growing challenge to physicians involved in their fertility care. The spectrum of reproductive problems associated with obesity encompasses a wide range of disorders including infertility problems, miscarriage and pregnancy complications. In this review, we aim to discuss the impact of obesity on the various aspects of female reproductive function with focus on the clinical aspects of fertility problems in obese women. We finally comment on the available therapeutic options available to this group of women.

Do reproductive hormones explain the association between body mass index and semen quality?

AIM

To examine whether reproductive hormones play a role in the association between body mass index (BMI) and semen quality.

METHODS

Semen quality and testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol (E(2)) were evaluated in 990 fertile males with age 38.9 +/- 9.7 (mean +/- SD) years recruited from the Chinese general population in 2001 and 2002.

RESULTS

Semen quality was reduced among underweight (BMI < 18.5) compared with normal (BMI 18.5-24.9) and overweight (BMI 25.0-29.9), but the associations were independent of reproductive hormones. After adjustment for the potential confounders, underweight men had reductions in sperm concentration (22.4 X 10(6)/mL), total sperm count (52.9 X 10(6)) and percentage of normal sperm forms (6.9%) compared with men with normal BMI. Being underweight may be a risk factor for low sperm concentration (OR: 4.68, 95% confidence intervals [CI]: 2.01-10.91). Otherwise, being overweight may be a protected factor for low sperm concentration (OR: 0.25; 95% CI: 0.08-0.83) and low total sperm count (OR: 0.37, 95% CI: 0.15-0.87).

CONCLUSION

Low BMI was associated with reduced semen quality. The associations between BMI and semen quality were found statistically significant even after adjustment for reproductive hormones. Reproductive hormones cannot explain the association between BMI and semen quality.

Predictors of ongoing pregnancy after single-embryo transfer following mild ovarian stimulation for IVF

OBJECTIVE

To develop a prognostic model for the prediction of ongoing pregnancy after single-embryo transfer (SET) following mild stimulation for IVF in women less than 38 years of age.

DESIGN

Prospective cohort study.

SETTING

Two fertility centers in tertiary referral university hospitals.

PATIENT(S)

A total of 152 women with an elective SET following mild ovarian stimulation (cycle day 5 start of 150 IU/day recombinant FSH and late follicular phase GnRH antagonist cotreatment).

INTERVENTION(S)

Database analysis.

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy.

RESULT(S)

The ongoing pregnancy rate per elective SET was 28% (42 of 152). In a multivariate logistic regression analysis, body mass index, the total gonadotrophin dose needed, and number of oocytes retrieved were negatively correlated whereas the availability of a top-quality embryo was positively correlated with ongoing pregnancy. The predictive ability of the model assessed by the area under the receiver operating characteristic curve was 0.68. At a probability cut-off level of 0.20 the model showed a sensitivity of 37% and a specificity of 90%.

CONCLUSION(S)

The developed prediction model for ongoing pregnancy provides an evidence-based strategy for guidance under which conditions SET may be performed. After external validation, application of the model may help to improve overall singleton pregnancy rates.

Effect of overweight and obesity on assisted reproductive technology—a systematic review

Obesity is known to be associated with sub-optimal reproductive performance but its direct effect on the outcome of assisted reproduction techniques (ART) is less clear. This present study aimed to perform a systematic review of the available evidence to assess the effects of obesity on the outcome of ART. A number of observational studies were identified. Interpretation of the results was compromised by variations in the methods used to define overweight and obese populations and inconsistencies in the choice and definition of outcome measures. Compared with women with a BMI of 25 kg/m(2) or less, women with a BMI > or = 25 kg/m(2) have a lower chance of pregnancy following IVF [odds ratio (OR) 0.71, 95% CI: 0.62, 0.81], require higher dose of gonadotrophins (weighed mean differences 210.08, 95% CI: 149.12, 271.05) and have an increased miscarriage rate (OR 1.33, 95% CI: 1.06, 1.68). There is insufficient evidence on the effect of BMI on live birth, cycle cancellation, oocyte recovery and ovarian hyperstimulation syndrome. Further studies with clear entry criteria and uniform reporting of outcomes are needed to investigate the true impact of weight on the outcome of ART.

Obesity and poor reproductive outcome: the potential role of the endometrium

OBJECTIVE

To analyze the potential role of extraovarian factors such as endometrium in the reproductive outcome of obese patients.

DESIGN

Retrospective study.

SETTING

University-affiliated infertility clinic, between January 2001 and July 2005.

PATIENT(S)

Women undergoing a total of 2656 first ovum donation (OD) cycles with good quality embryos.

INTERVENTION(S)

The oocyte donors underwent controlled ovarian hyperstimulation, and recipients received a well-established hormonal replacement therapy for endometrial preparation. In vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) was performed according to semen characteristics. All first cycles (n = 2656) of ovum donation used good quality embryos and were divided into groups according to body mass index: <20 kg/m(2) (n = 471), 20 to 24.9 kg/m(2) (n = 1613), 25 to 29.9 kg/m(2) (n = 450), and > or =30 kg/m(2) (n = 122).

MAIN OUTCOME MEASURE(S)

The recipient body mass index groups were compared regarding IVF outcome.

RESULT(S)

The rates of implantation, pregnancy, miscarriage, and ongoing pregnancy were similar among the body mass index groups, although there was a negative trend when body mass index increased. Ongoing pregnancy rates per cycle were poorer in the overweight and obese groups than in the underweight and normal groups. In addition, women under 25 kg/m(2) presented an ongoing pregnancy rate per cycle of 45.5%, compared with 38.3% for those with > or =25 kg/m(2).

CONCLUSION(S)

Excess weight exerts an extraovarian detrimental effect. The role of the endometrium or its environment seems to be subtle but should be taken into account.

The impact of lifestyle factors on reproductive performance in the general population and those undergoing infertility treatment: a review

This evidence-based review focuses on the impact of potentially modifiable, non-communicable lifestyle factors on reproductive performance in the general population and the infertile population undergoing assisted reproductive technology (ART) treatment. The impact of several lifestyle factors including; age, weight, smoking, diet, exercise, psychological stress, caffeine consumption, alcohol consumption and exposure to environmental pollutants are included in the review. The databases of Medline, PubMed and Cinahl were searched to identify relevant publications. There is strong evidence that age, weight and smoking impact on general health and adversely on reproductive performance. However there is a need for further research focusing specifically on the relationship between diet and various levels of exercise on reproductive performance. There are several other factors such as psychological stress, caffeine consumption, alcohol consumption and exposure to environmental pollutants that have been implicated but the evidence is equivocal. It is concluded that lifestyle modification can assist couples to conceive spontaneously or optimize their chances of conception with ART treatment.

Association of obesity with treatment outcomes in ovulatory infertile women undergoing superovulation and intrauterine insemination

OBJECTIVE

To evaluate the association between obesity and the outcome of superovulation and intrauterine insemination (IUI) in infertile ovulatory women.

DESIGN

Retrospective chart review.

SETTING

University-based infertility clinic.

PATIENT(S)

Three hundred thirty-three ovulatory women, grouped by body mass index (BMI) categories, who received superovulation and IUI for treatment of infertility.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

PRIMARY OUTCOME

cycle fecundity.

SECONDARY OUTCOMES

total dose of gonadotropins, serum level of E(2), and number of follicles >or=17 mm on the day of hCG injection.

RESULT(S)

Adjusted cycle fecundity was not different among BMI groups (underweight: 0.14 [95% CI: {0.07, 0.29}], normal weight: 0.12 [95% CI: {0.09, 0.16}], overweight: 0.17 [95% CI: {0.12, 0.24}], and obese: 0.14 [95% CI: {0.08, 0.23}]). Adjusted total gonadotropin dose (IU/cycle) was greater in obese women than in underweight or normal-weight women. Although the numbers of large follicles were not different, E(2) levels (pg/mL) were lower in obese women than in normal-weight and overweight women.

CONCLUSION(S)

Our sample of ovulatory infertile women demonstrated that treatment-related cycle fecundity is unaffected by obesity. We conclude that obese, infertile ovulatory women require a greater dose of gonadotropins to achieve similar levels of superovulation than normal, underweight or overweight women.

Management of obese women in assisted conception units: a UK survey

A national audit was performed to ascertain details of the management of clinically obese women at infertility clinics in the UK. This was with particular reference to body mass index (BMI) limits for specific treatments and general advice given to patients regarding obesity. A postal questionnaire was sent to all licensed assisted conception units (ACUs) in the UK offering fertility treatment. The return rate was 86 of 100 (86%). There was a great deal of variation between different units in the practice standards of obese infertile women. This audit demonstrates the wide variation in current UK practice and highlights the need for a broad discussion and adoption of national guidelines for the management of obese infertile women.

Lifestyle choices, diet, and insulin sensitizers in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is significantly affected by environmental regulators impacting on genetic predisposition. Lifestyle changes can significantly modulate the phenotype of this disease. Diet, exercise, smoking, stress, and other factors adversely affect reproductive outcomes in PCOS. These influences can be modulated by structure change in an individual or group. Lifestyle choices should be discussed in this group of patients. The role of insulin sensitizers, including metformin, has still to be determined in this condition.

Obstetric Outcomes After In Vitro Fertilization in Obese and Morbidly Obese Women

OBJECTIVE

In addition to numerous health detriments caused by obesity, fertility and pregnancy success may also be compromised. The aims of this study were to compare the effects of obesity and morbid obesity on in vitro fertilization (IVF) outcomes. We also investigated the effects of obesity on obstetric outcomes after IVF treatment.

METHODS

Retrospective study of women less than 38 years of age during their first fresh IVF cycle (January 1995 to April 2005).

RESULTS

A total of 1,293 women were included in the study, with 236 obese women (body mass index [BMI] = 30-39.9) and 79 morbidly obese women (BMI > or = 40). The morbidly obese group had a 25.3% IVF cycle cancellation rate compared with 10.9% in normal-weight women (odds ratio 2.73, 95% confidence interval 1.49-5.0), P < .001). Morbidly obese women without polycystic ovarian syndrome had an even higher cancellation rate (33%). Women with higher BMI required significantly more days of gonadotropin stimulation but had lower peak estradiol levels (P < .001). There were no significant differences in clinical pregnancy or delivery rates between the four BMI groups. Of the women who delivered, there was a significant linear trend for risk of preeclampsia, gestational diabetes, and cesarean delivery with increasing BMI (P < .03).

CONCLUSION

We report a significantly higher risk for IVF cycle cancellation in morbidly obese patients with no effect of BMI on clinical pregnancy or delivery rate. However, obese and morbidly obese subjects had a significantly higher risk for obstetric complications. This target population should be aggressively counseled regarding their increased obstetric risk and offered treatment options for weight reduction before the initiation of fertility therapy.

LEVEL OF EVIDENCE

II-2.

Effect of a very-low-calorie diet on in vitro fertilization outcomes

A low-calorie diet in a group of overweight or obese patients for a short period before and during IVF results in variable tolerance to the dietary regime and an unsatisfactory IVF outcome.

Interactions of the hormones leptin, ghrelin, adiponectin, resistin, and PYY3-36 with the reproductive system

OBJECTIVE

To summarize the effects of novel hormones (leptin, ghrelin, adiponectin, resistin, and PYY3-36) secreted from adipose tissue and the gastrointestinal tract that have been discovered to exert different effects on several reproductive functions, such as the hypothalamic-pituitary-gonadal axis, embryo development, implantation physiology, and clinically relevant conditions.

DESIGN

A MEDLINE computer search was performed to identify relevant articles.

RESULT(S)

Leptin and ghrelin exert important roles on body weight regulation, eating behavior, and reproduction, acting on the central nervous system and target reproductive organs. As a marker of adequate nutritional stores, these hormones may act on the central nervous system to initiate the complex process of puberty and maintain normal reproductive function. In addition, leptin and ghrelin and their receptors are involved in reproductive events such as gonadal function, embryo development, and embryo-endometrial interaction.

CONCLUSION(S)

Leptin and ghrelin and other adipose tissue-secreted hormones have significant effects on reproduction. Acting through the brain, these hormones may serve as links between adipose tissue and the reproductive system to supply and regulate energy needs for normal reproduction and pregnancy. Future studies are needed to further clarify the role of these hormones in reproductive events and other related gynecological conditions.

Clinical efficacy of body mass index as predictor of in vitro fertilization and embryo transfer outcomes

The aim of this study was to evaluate the clinical efficacy of body mass index (BMI) as a predictor of in vitro fertilization and embryo transfer (IVF-ET) outcomes. Two hundred twenty-three IVF-ET cycles in 164 patients under 37 yr using GnRH agonist long protocols were included in this retrospective study. All of the selected cases were divided into two groups by a cutoff of 24 kg/m2 and these two groups were compared in regard to the outcomes of IVF-ET. There were no significant differences between group 1 (BMI <24 kg/m2) and group 2 (BMI > or = 24 kg/m2) in age, basal serum FSH level, estradiol (E2) level and endometrial thickness on hCG day, number of retrieved oocytes and transferred embryos. However, higher doses of gonadotropins were used in group 2 (30.8+/-12.7 ampoules vs. 35.4+/-15.3 ampoules, p=0.051). The clinical pregnancy rate was significantly lower in group 2 (25.9% vs. 10.5%, p=0.041) and implantation rate tended to be lower in group 2 (12.7% vs. 6.8%, p=0.085). BMI > or = 24 kg/m2 can be a candidate prognosticator of IVF-ET outcomes.

Obesity and assisted reproductive technology outcomes

Obesity is a rising health problem in Western societies. It has been related to increased morbidity and mortality rates due to several pathologies. In the field of gynaecology and reproduction, obesity is associated with menstrual disorders, hirsutism, infertility, miscarriage and obstetric complications. It is known to impair human reproduction through different mechanisms such as insulin resistance, hyperandrogenism and elevated leptin levels. Weight management and dietary intervention can reverse this situation and improve reproductive function. Obesity can also impair the outcome of assisted reproductive technologies. The lower probability of a healthy live birth described in obese women seems to be the result of a combination of lower implantation and pregnancy rates, higher preclinical and clinical miscarriage rates and increased complications during pregnancy for both mother and fetus. Studies performed in infertile women undergoing assisted reproduction technologies indicate that the ovary plays a leading, but not exclusive, role in the fertility prognosis of these patients. The endocrine and metabolic environment may affect oocyte quality and, therefore, embryo development, implantation and pregnancy outcome. The endometrium seems to play a subtle role in the more negative reproductive outcome of obese women, according to recent studies based on the ovum donation model.

Clinical experiences of ICSI-ET thawing cycles with embryos cryopreserved at different developmental stages

PURPOSE

The aim of our study was to analyze factors including survival, implantation and pregnancy rate, patients' age and BMI, abortions and extra uterine pregnancies that might influence the outcome of ICSI-ET thawing cycles.

METHODS

A total of 147 cycles with embryos cryopreserved at different developmental stages were retrospectively evaluated.

RESULTS

No difference was found in the survival, implantation and pregnancy rates of embryos cryopreserved on Day 2-3 and 5. However, in the pregnant group significantly higher implantation rate was observed with Day 5 blastocysts then with Day 2 or 3 early embryos. We found no difference in the number of abortions and extra uterine pregnancies between fresh and frozen ICSI-ET cycles. Higher BMI was found in the pregnant than in the nonpregnant group. However, the age of patient had no effect on the results.

CONCLUSIONS

Developmental stage of embryo and patients' BMI influences the success of ICSI-ET thawing cycles.

Obesity does not impact implantation rates or pregnancy outcome in women attempting conception through oocyte donation

OBJECTIVE

To independently evaluate the effect of body mass index (BMI) on implantation, pregnancy, and incidence of spontaneous miscarriage using the donor oocyte recipient model.

DESIGN

Institutional Review Board-approved retrospective data analyses of donor oocyte cycles from 1999 to 2004.

SETTING

Private assisted reproductive technology (ART) center.

PATIENT(S)

Five hundred thirty-six first cycle recipients of donor oocytes.

INTERVENTION(S)

Data were collected from the first cycle of each donor oocyte recipient included in the study. The body mass index (BMI) of each recipient was calculated using the formula weight (in kilograms)/height (in meters squared). Patients were divided into four groups based on BMI: underweight, normal, overweight, and obese. Pregnancy outcomes in each group were compared.

MAIN OUTCOME MEASURE(S)

Body mass index, implantation rate, pregnancy rate (PR), miscarriage rate.

RESULT(S)

There were no statistically significant differences in the implantation rates, ongoing PRs, or spontaneous abortion rates among patients in the four BMI groups. When further divided into those patients receiving blastocyst vs. day 3 transfers, there was still no effect of BMI on implantation rate, PR, or loss rate among the blastocyst or day 3 donor oocyte recipients.

CONCLUSION(S)

Body mass index has no adverse impact on implantation or reproductive outcome in donor oocyte recipients. Therefore, obesity does not appear to exert a negative effect on endometrial receptivity.

Obesity and Clomiphene Challenge Test as Predictors of Outcome of in vitro Fertilization and Intracytoplasmic Sperm Injection

One hundred and sixty-two consecutive patients undergoing in vitro fertilization (IVF) or IVF/intracytoplasmic sperm injection (ICSI) were studied to determine the effect of obesity on the outcome of this treatment and to evaluate the prognostic value of the Clomiphene Challenge Test (CCT) in controlled ovarian hyperstimulation. In this prospective clinical study, we assessed the mean number of stimulation days, the mean gonadotropin level/day, cancellation rate, the mean thickness of the endometrium, the mean number of oocytes retrieved, the fertilization rate, the clinical pregnancy rate/embryo transfer and the abortion rate. Obese women had a doubled risk of cancellation due to poor response, although this was not statistically significant. Furthermore, they showed up to 45% lower fertilization rates compared to women of normal weight. The CCT was a good predictor of IVF and IVF/ICSI outcome. Women with an abnormal CCT needed more days of stimulation and higher doses of gonadotropins to reach an adequate stimulation, but still overall results were less than in women with a normal CCT. We conclude that obesity negatively affects IVF and IVF/ICSI outcome, and that CCT is a useful prognosticator of response to ovarian stimulation. Obese patients show a tendency to experience more cancellation due to poor response and lower fertilization rates. Obese women should be counseled on their possible poor performance in IVF and IVF/ICSI programs.

Effects of subfertility cause, smoking and body weight on the success rate of IVF

BACKGROUND

We investigated the separate and combined effects of smoking and body mass index (BMI) on the success rate of IVF for couples with different causes of subfertility.

METHODS

The success rate of IVF was examined in 8457 women. Detailed information on reproduction and lifestyle factors was combined with medical record data on IVF treatment. All IVF clinics in The Netherlands participated in this study. The main outcome measures were live birth rate per first cycle of IVF differentiated for the major predictive factors.

RESULTS

For male subfertility the delivery rate per cycle was significantly lower than unexplained subfertility, OR of 0.70 (95% CI 0.57-0.86); for tubal pathology, the delivery rate was slightly lower, OR = 0.86 (95% CI 0.70-1.01). Smoking was associated with a significantly lower delivery rate was slightly lower; for OR = 0.72 (95% CI 0.61-0.84) and a significantly higher abortion rate compared to non-smoking delivery rates of 21.4% and 16.4%, respectively (P=0.02). Women with a BMI of > or = 27 kg/m2 had a significantly lower delivery rate, with an OR of 0.67 (95% CI 0.48-0.94), compared with normal weight women (BMI > or = 20 and <27 kg/m2).

CONCLUSIONS

Both smoking and overweight unfavourably affect the live birth rate after IVF. The devastating impact of smoking on the live birth rate in IVF treatment is comparable with an increase in female age of >10 years from age 20 to 30 years. Subfertile couples may improve the outcome of IVF treatment by lifestyle changes.

Impact of body mass index on in vitro fertilization outcomes

PURPOSE

To determine if body mass index (BMI) impacts IVF outcome.

METHODS

Retrospective, cohort study. Main outcome measure was number of oocytes obtained.

RESULTS

BMI did not correlate with the prestimulation parameters. There was a significant positive correlation between BMI and the number of follicles on ultrasound prior to egg retrieval. A threshold analysis revealed a significant change in parameters at a BMI > 24 kg/m2. Patients with BMI > 24 kg/m2 demonstrated a significant increase in the number of follicles after stimulation (p = 0.03) and a comparative decrease in the number ampules of gonadotropins used (p = 0.04) and days of stimulation required (p = 0.01).

CONCLUSION

These data demonstrated that an elevated BMI significantly correlates with the number of follicles, days of stimulation, and number of ampules of gonadotropins used. Further correlation to an actual increase in number of oocytes and pregnancy rates may be limited by insufficient power in this study.

Body mass index, follicle-stimulating hormone and their predictive value in in vitro fertilization

PURPOSE

The objective was to explore whether body mass and day 3 follicle-stimulating hormone have predictive value on odds of pregnancy after in vitro fertilisation. Few studies show that obesity produces a variety of alterations in the reproductive system, and that women with an elevation of day 3 FSH have declining ovarian function.

METHODS

The data of one-hundred-seventy-one women who underwent a standard regime of controlled ovarian hyperstimulation was analyzed with particular reference to variations in body mass and hormone levels.

RESULTS

By raising BMI and FSH (mIU/mL) by one unit, the odds for pregnancy were decreased by the respective factors 0.84 (95% confidence interval 0.73-0.97) and 0.77 (95% confidence interval 0.59-1.00).

CONCLUSIONS

The results demonstrate that for the purpose of raising the odds of pregnancy BMI should be reduced. A low FSH value may cause the same effect. Nontheless, obesity and hormonal function may be independent risk factors for failure in assisted reproduction.

Impact of overweight and underweight on assisted reproduction treatment

BACKGROUND

Underweight and overweight may affect reproduction and interfere with treatment of infertility. The purpose of this report is to describe the independent effect of body weight on treatment with IVF and ICSI.

METHODS

Records of 5019 IVF or ICSI treatments in 2660 couples were reviewed. The influence of body mass index (BMI) on treatment outcome was examined, after accounting for differences in age and infertility diagnosis.

RESULTS

The cumulative live birth rate within three treatment cycles was 41.4% [95% confidence interval (CI) 32.1-50.7] in obese women with BMI > or =30 kg/m2 and 50.3 (95% CI 47.0-53.7) in normal weight women with BMI 18.5-24.9 kg/m2. Obesity was associated with an increased risk of early pregnancy loss occurring before 6 weeks gestation. Positive correlation between BMI and gonadotrophin requirement during stimulation and negative correlation between BMI and number of collected oocytes were observed. Underweight (BMI <18.5 kg/m2) was not related to an impaired outcome of IVF or ICSI.

CONCLUSIONS

Obesity is associated with lower chances for live birth after IVF and ICSI and with an impaired response to ovarian stimulation.

Position of the American Dietetic Association and Dietitians of Canada: Nutrition and Women’s Health

It is the position of the American Dietetic Association (ADA) and Dietitians of Canada (DC) that women have specific nutritional needs and vulnerabilities and, as such, are at unique risk for various nutrition-related diseases and conditions. Therefore, the ADA and the DC strongly support research, health promotion activities, health services, and advocacy efforts that will enable women to adopt desirable nutrition practices for optimal health. Women are at risk for numerous chronic diseases and conditions that affect the duration and quality of their lives. Although women's health-related issues are multifaceted, nutrition has been shown to influence significantly the risk of chronic disease and to assist in maintaining optimal health status. Dietetics professionals strongly support research, health promotion activities, health services, and advocacy efforts that will enable women to adopt desirable nutrition practices for optimal health.

Overweight infertile patients have a higher fecundity than normal-weight women undergoing controlled ovarian hyperstimulation with intrauterine insemination

There is a positive effect of being overweight or obese on the pregnancy rate in women undergoing controlled ovarian hyperstimulation with intrauterine insemination.

Assisted reproduction in the treatment of polycystic ovarian syndrome

Treatment of patients with polycystic ovary syndrome (PCOS) with assisted reproductive techniques is a great challenge for the infertility specialist. Patients with PCOS demonstrate many problems, such as excessive body weight and hyperinsulinaemia, that render management more complex. Prior to treatment with IVF, the PCOS patient should be thoroughly evaluated for disclosure of endometrial neoplasia, hyperinsulinaemia, and other general health related problems. Ovarian stimulation for IVF carries the risks of overstimulation and severe hyperstimulation, which should be avoidable in most cases with preventive measures. The outcome in terms of pregnancy and implantation rates is similar for patients with PCOS when compared with patients undergoing IVF for other indications. There are some questions regarding oocyte and embryo quality in women with PCOS. This manifests itself in lower fertilization rate and decreased embryo quality in some studies. However, increased numbers of oocytes available for insemination or ICSI compensate for decreased fertilization rates and embryo quality. More recent studies suggest higher cumulative conception rates in women with PCOS when compared with controls. In-vitro maturation (IVM) of oocytes retrieved from non-stimulated or minimally stimulated cycles represents a viable option that should be considered seriously when assisted conception is attempted. Results of IVM, however, should be improved further and generalized before the technique can be advocated as the initial treatment approach in these patients.

Effects of leptin and leukemia inhibitory factor on preimplantation development and STAT3 signaling of mouse embryos in vitro

Preimplantation mouse embryos simultaneously express receptors for leptin and leukemia inhibitory factor (LIF), both of which trigger activation of STAT3 (Signal Transducer and Activator of Transcription) protein. To examine the joint effects of leptin and LIF on embryonic development, we studied preimplantation development and activation of STAT3 signaling of mouse embryos after exposure to leptin and/or LIF in vitro. Two-cell mouse embryos (Day 2) were cultured in the presence of leptin and/or LIF. Significantly fewer leptin-exposed than control embryos hatched by Day 5 and by Day 6 of development. In addition, cells of leptin-exposed Day 5 blastocysts showed a higher rate of DNA fragmentation, which is a sign of apoptosis. Leukemia inhibitory factor alone had no effect on the rates of embryonic development or DNA fragmentation. Simultaneous exposure of embryos to leptin and LIF increased the proportion of hatching embryos and decreased the rate of apoptosis compared to embryos exposed to leptin only. Leptin treatment was associated with an increased phospho-STAT3-specific immunofluorescence in the cell membrane of blastocysts, which was not observed in LIF-exposed embryos. In conclusion, LIF modifies the effect of leptin during preimplantation embryo development in mice, presumably by interfering with activation of STAT3 signaling.

Body mass index and uterine receptivity in the oocyte donation model

OBJECTIVE

To evaluate the relationship of body mass index (BMI) to uterine receptivity under conditions of programmed hormonal support and standardized embryo quality.

DESIGN

Retrospective cohort study.A tertiary referral center.

PATIENTS

Ninety-seven consecutive first-cycle recipients of anonymous oocyte donation. After programmed hormone replacement, recipients had transfer of embryos derived from oocyte donation. Anonymous oocyte donors received ovarian stimulation and underwent transvaginal ultrasound-guided oocyte retrieval.

SETTING

A receiver operator characteristic (ROC) curve of implantation versus BMI. Area under the ROC curve was 0.51, 95% confidence interval (CI) 0.41-0.62, suggesting no relationship between BMI and implantation. There was no difference in implantation rates between obese (BMI >or=30) and nonobese (BMI <30) recipients, odds ratio 1.1, 95% CI 0.5-2.4.

CONCLUSION(S)

Uterine receptivity was unimpaired in women with increased BMI when hormonal support and embryo quality were standardized.

Obesity and the risk of spontaneous abortion after oocyte donation

OBJECTIVE

To determine whether obesity increases the risk of spontaneous abortion.

DESIGN

Retrospective study.

SETTING

Oocyte donation program at the Instituto Valenciano de Infertilidad in Spain.

PATIENT(S)

Seven hundred twelve cycles of recipients of ovum donation with known body mass index (BMI), good-quality embryo transfer, and absence of uterine pathology or clinical history of antiphospholipid antibodies or recurrent abortion.

INTERVENTION(S)

Recipients were divided in four BMI (kg/m(2)) groups: lean, with BMI <20 (n = 92; 12.9%); normal, with BMI = 20-24.9 (n = 398; 55.9%); overweight, with BMI = 25-29.9 (n = 172; 24.2%); and obese, with BMI >/=30 (n = 50; 7%). Clinical parameters were compared among the groups.

MAIN OUTCOME MEASURE(S)

Spontaneous abortion rates according to BMI.

RESULT(S)

No difference was found among the four BMI groups in any of the parameters of the cycle analyzed. The overall abortion rate was 15.8% (57 of 360). There were significant differences in abortion rates between the obese (38.1%), and the normal (13.3%) and overweight (15.5%) groups. When several cutoff BMI values were established (20, 25, and 30), only the obese women demonstrated a greater risk of abortion. Compared with the normal population, the obese group showed a significant fourfold increase in the risk of spontaneous abortion.

CONCLUSION(S)

Our findings confirm that obesity (BMI >/=30) is an independent risk factor for spontaneous abortion. Therefore, it would be advisable for obese patients to reduce weight before becoming pregnant.

Indices of obesity, dyslipidemia, and insulin resistance in apparently healthy Caribbean subjects

Reports from developing countries indicate that a rise in the socioeconomic level is a risk factor for metabolic disorders. We aimed to assess the indices of obesity, dyslipidemia, and insulin resistance among fairly literate healthy adults in a multidisciplinary institution in Trinidad. The study included 156 volunteers (46 males and 110 females, 17-40 years old). The subjects provided information on age, ethnicity, educational attainment, and occupation in self-administered, closed-ended questionnaires. Waist and hip circumferences (cm), weight (kg), and height (m) were measured. Fasting blood samples were taken for glucose, insulin, and lipid determinations in 78 subjects who volunteered for laboratory measurements. Insulin resistance was determined with homeostasis model assessment (HOMA). Of the 156 subjects studied, 83% had received tertiary education, and had no previous record of body mass index (BMI); 8% were obese, 17% were overweight, and 27% were underweight. Laboratory measurements in 78 subjects revealed 28% hypercholesterolemia and 20% hyperinsulinemia. There were no significant gender-related differences in these prevalence rates (P>0.05). The identification of obesity, underweight, hyperinsulinemia, and hypercholesterolemia in this healthy population suggests that screening for the indices of metabolic disorders in a healthy population would be potentially useful for the early identification and treatment of metabolic-related disorders.

Human female attractiveness: waveform analysis of body shape

Two putative cues to female physical attractiveness are body mass index (BMI) and shape (particularly the waist-hip ratio or WHR). To determine the relative importance of these cues we asked 23 male and 23 female undergraduates to rate a set of 60 pictures of real women's bodies in front-view for attractiveness. In our set of images, the relative ranges of BMI and WHR favoured WHR. We based these ranges on a sample of 457 women. We did not limit the WHR range, although we kept the BMI range to 0.5 s.d. either side of the sample means. As a result, WHR averaged 1.65 s.d. either side of its sample mean. However, even with these advantages, WHR was less important than BMI as a predictor of attractiveness ratings for bodies. BMI is far more strongly correlated with ratings of attractiveness than WHR (BMI approximately 0.5, WHR approximately 0.2). To further explore the relative importance of BMI and WHR, we deliberately chose a subset of these images that demonstrated an inverse correlation of BMI and WHR (i.e. a group in which as images get heavier they also become more curvaceous). If WHR is the most important determinant of attractiveness, then the more curvaceous (but higher BMI) images should be judged most attractive. However, if BMI is a better predictor, then the opposite should be true. We found that the more curvaceous (but higher BMI) images were judged least attractive, thereby inverting the expected rating pattern. This strongly suggests that viewers' judgements were influenced more by BMI than WHR. Finally, it is possible that body shape is an important cue to attractiveness, but that simple ratios (such as WHR) are not adequately capturing it. Therefore, we treated the outline of the torso as a waveform and carried out a set of waveform analyses on it to allow us to quantify body shape and correlate it with attractiveness. The waveform analyses address the complexity of the whole torso shape, and reveal innate properties of the torso shape and not shape elements based on prior decisions about arbitrary physical features. Our analyses decompose the waveform into objective quantified elements whose importance in predicting attractiveness can then be tested. All of the components that were good descriptors of body shape were weakly correlated with attractiveness. Our results suggest that BMI is a stronger predictor of attractiveness than WHR.