Infertility

Emre Seli, Emre Seli

• Publisher: Wiley-Blackwell
• Year: 2011
• ISBN:
  9781444393941
• Edition: 1
• Topic: Medicine
• Subtopic: Gynecology, Obstetrics & Midwifery

Help your patients through the maze of infertility treatments

Infertility is suffered by around 1 in 7 couples and can be a source of confusion for both partners, providing high stress on relationships. 25% of cases are explained through male infertility, 50% through female infertility, whilst 25% are generally unexplained. The possible causes and solutions are many and complex.

Infertility, one of the first in the new Gynecology in Practice series, assists gynecologists and family practitioners to better care for their patients who have trouble conceiving. The authors provide a strong focus on effective diagnosis and management. Following a review of the factors that affect fertility, Infertility takes a practical approach to:

• Evaluation of fertility
• Management and treatment
• Complications
• Pre-implantation screening
• Fertility preservation

Gynecology in Practice

The Gynecology in Practice series provides clinical 'in the office' or 'at the bedside' guides to effective patient care for gynecologists. The tone is practical, not academic, with authors offering guidance on what might be done and what should be avoided. The books are informed by evidence-based practice and feature:

• Algorithms and guidelines where they are appropriate
• ''Tips and Tricks' boxes – hints on improving outcomes
• 'Caution' warning boxes – hints on avoiding complications
• 'Science Revisited' – quick reminder of the basic science principles
• Summaries of key evidence and suggestions for further reading

1

Factors Affecting Fertility

Enrique Soto¹ and Alan B. Copperman²

¹Mount Sinai School of Medicine, New York, NY, USA

²Mount Sinai Medical Center and Reproductive Medicine Associates, New York, NY, USA

In order to take optimal care of patients who seek preconceptional counseling and of patients who present with infertility, the treating physician needs to have an extensive knowledge of the multiple factors that influence human reproduction.

Fecundability and time to pregnancy (TTP) are used in the literature as markers of fertility. Fecundability is defined as the probability of conceiving in a single menstrual cycle while TTP is the length of time in months that it takes a couple to conceive. Infertility is defined as the failure to achieve a successful pregnancy after 12 months or more of regular unprotected intercourse in a woman under the age of 35 years and 6 months without success in a woman 35 or older.

Although the current literature describes a number of factors that are likely to play a role in the ability that a patient or couple has to conceive, it is important to highlight that evidence from randomized controlled trials is lacking for the majority of these regarding quantification and certainly causality of each factor.

In this chapter we summarize the most relevant factors that affect fertility, making evidence-based recommendations where appropriate to better counsel our patients to improve their ability to conceive. Our recommendations will include the practice committee opinions of the American Society for Reproductive Medicine (ASRM) and the American College of Obstetricians and Gynecologists (ACOG) as leading institutions in reproductive medicine and women’s health in the United States.

Weight

Body mass index (BMI) is used in the literature as an objective marker to classify underweight, overweight and obesity in adults. BMI is a calculated measurement that compares a person’s weight and height and it is defined as the weight in kilograms divided by the square of the height in meters (kg/m²). Even though there is a growing debate on the possible need to develop different BMI cut-off points for each ethnic group, BMI is applicable to all ethnic groups, is the same for both sexes and is age-independent.

The World Health Organization (WHO) and the National Institutes of Health (NIH) describe underweight as a BMI < 18.5, normal weight as BMI 18.5–24.9, overweight as BMI 25–29.9 and obesity as BMI > 30.

TIPS & TRICKS

Always calculate and document your patient’s BMI in the first office visit (weight in kilograms divided by the square of the height in meters) and determine if she falls under the category of underweight (BMI < 18.5), normal weight (BMI 25–29.9), overweight (BMI 25–29.9) or obese (BMI > 30). Appropriate counseling should follow.

BMI should then be calculated in the follow-up visits to determine any changes as well as to track response to treatment or interventions.

Fecundability has been found in multiple studies to be lower at the extremes of BMI in patients trying to conceive spontaneously. This finding was confirmed in a recent prospective cohort study by Wise et al., in which a longer TTP was seen in women who were overweight, obese and very obese (BMI ≥ 35), compared with normal weight women. Additionally being underweight (BMI < 20) was associated with reduced fecundability among nulliparous women.

Although some authors have linked male obesity with subfecundity, the evidence is not compelling and there are no randomized controlled studies to address this association. Male obesity was not linked to subfecundity in the recent prospective cohort study by Wise et al.

The direct effect of being overweight and obese on assisted reproduction technologies (ART) is less clear than for spontaneous pregnancies. In a meta-analysis by Maheshwair et al., women with a BMI ≥ 25 had a lower chance of pregnancy following in vitro fertilization (IVF) [odds ratio (OR) 0.71], required a higher dose of gonadotropins and had an increased miscarriage rate (OR 1.33) in comparison to women of normal weight. In a recent study by Bellver et al., implantation, pregnancy and live birth rates were lower in obese women; in fact, pregnancy and live birth rates were reduced progressively with each unit of BMI, independent of embryo quality, suggesting an alteration in the uterine environment as a likely factor in these patients.

Evidence is accumulating that suggests that effective treatment of women with elevated BMI may improve reproductive outcome. Nonsurgical treatment for patients with overweight and polycystic ovary syndrome (PCOS) was shown to improve fertility in patients that lost at least 5% of their weight in a small prospective study by Crosignani. Surgical treatment may show benefit as well, as evidenced by a recent meta-analysis by Merhi which concluded that although “the majority of the present data tend toward reporting an improvement in fertility status after surgical weight loss, it remains unclear whether this is a direct result of the significant weight reduction per se”.

Recommendations

All patients should be advised to follow a healthy diet according to the United States Department of Agriculture (USDA) guidelines. Patients should consume a variety of nutrient-dense foods and beverages within and among the basic food groups while choosing foods that limit the intake of saturated and trans fats, cholesterol, added sugars, salt and alcohol.

ACOG recommends folic acid supplementation of 400 µg/day on all women capable of becoming pregnant, since it has shown to reduce the occurrence and recurrence of neural tube defects.

Weight loss and exercise should be advised for all women who are overweight or obese for all the associated health benefits.

There is not enough evidence to recommend surgical treatment for obesity on the ground of fertility improvement. Patients who wish to pursue bariatric surgery should have appropriate medical management with an expert in the field to monitor possible nutritional deficiencies and other complications.

TIPS & TRICKS

Refer your patients to the USDA website to obtain detailed information on following a healthy diet with help of the USDA Food Guide and the DASH Eating Plan:

http://www.health.gov/DietaryGuidelines/dga2005/document/

Age

The incidence of infertility increases with advancing maternal age. In a prospective study by Dunson et al., the percentage of infertility was 8% for women aged 19–26 years, 13–14% for women aged 27–34 years and 18% for women aged 35–39 years.

There is also evidence that the age of the male partner may affect fertility after the age of 35 years. In the study by Dunson et al., the proportion of couples failing to spontaneously conceive within 12 cycles increased from 18% when the male partner was 35 years old to 28% when the male partner was 40.

There is a similar decline in the success of IVF as the age of patient increases. In 2007, the percentage of transfers of fresh embryos from nondonor oocytes resulting in live births in the United States was 46.1 for patients <35 years of age and showed a progressive decline to 16.4 in patients 41–42 years of age.

Recommendations

Although according to the ASRM guidelines a patient is diagnosed with infertility after 12 months or more of being unable to achieve a successful pregnancy, earlier evaluation and treatment may be justified based on medical history and physical findings and is warranted after 6 months for women over age 35 years.

The ASRM additionally states that “times to conception increases with age. For women over age 35 years, consultation with a reproductive specialist should be considered after 6 months of unsuccessful efforts to conceive.”

Important reproductive potential and ovarian reserve tests that are commonly performed by specialists include a sonogram to assess general pelvic anatomy and basal antral follicular count (BAFC) as well as the day 3 serum biomarkers follicle stimulating hormone (FSH) and estradiol.

As part of the counseling process for treatment of infertility, the reproductive specialist should be familiar with the new and innovative options that are available for each individual patient, including options that halt the reproductive aging process such as oocyte cryopreservation.

Smoking

Approximately 30% of reproductive age women and 35% of reproductive age men in the United States smoke, and up to 13% of infertility may be attributable to cigarette smoking. Most studies that address the effect of active smoking of the female partner on fertility to date report a decreased fecundability independent of other confounding influences. In the largest available population study by Hull et al., the increasing delay to conception correlated with increasing daily numbers of cigarettes smoked.

In a meta-analysis by Waylen et al., which included 22 studies, patients who smoked had significantly lower odds of live birth per cycle (OR 0.54), significantly lower odds of clinical pregnancy per cycle (OR 0.56), significantly higher odds of spontaneous abortion (OR 2.65) and significantly higher odds of ectopic pregnancy (OR 15.69).

The ASRM in the Practice Committee Opinion on Smoking and infertility concluded that smoking (1) appears to accelerate the loss of reproductive function, (2) may advance the time of menopause by 1–4 years and (3) is associated with an increased risks of spontaneous abortion, ectopic pregnancy and gamete mutagenesis. Additionally, smokers require nearly twice the number of IVF attempts to conceive as nonsmokers.

A definite causality between male partner smoking and infertility has not been proven but there are data that suggest that there may be adverse effects in male smokers, as well. Smokers have an average 23% decrease in sperm concentration and 13% decrease in sperm motility in comparison to nonsmokers.

The largest meta-analysis to date on the effect of female and male smoking on IVF in...

Table of contents

• Cover
• Half title page
• Title page
• Copyright page
• Series Foreword
• Preface
• Contributors
• 1 Factors Affecting Fertility
• 2 Evaluation of the Infertile Couple
• 3 Diagnosis and Management of Tubal Factor Infertility
• 4 Diagnosis and Management of Uterine Infertility
• 5 Diagnosis and Management of Infertility Due to Endometriosis
• 6 Diagnosis and Management of Infertility Due to Anovulation
• 7 Diagnosis and Management of Infertility Due to Diminished Ovarian Reserve
• 8 Diagnosis and Management of Male Infertility
• 9 Diagnosis and Management of Unexplained Infertility
• 10 Endocrine Disorders and Infertility
• 11 Physiologic Basis of Ovulation Induction
• 12 Intrauterine Insemination
• 13 In-vitro Reproductive Technologies
• 14 Egg Donation and Surrogacy
• 15 Complications of Infertility Treatment
• 16 Preimplantation Genetic Diagnosis
• 17 Fertility Preservation
• 18 Infertility Treatment: Varying Approaches Across Continents
• Index