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OBESITY IN FERTILITY

OBESITY IN FERTILITY

What is obesity?

Body mass index (BMI) is a measure of the relationship between a person’s height and weight. BMI of 30 or more is labelled as Obesity.

The recommended BMI range is between

  1. Normal BMI: 18 and 25 kg/m2.
  2. Over weight: 25-30 kg/m2
  3. Obese when the BMI is 30 kg/m2
  4. Moderate obesity 30;    
  5. Severe obesity 35;                                                                                    

Obesity and related morbidity significantly affects fertility and reproduction in both men and women

Why are some people obese?

Many factors contribute to obesity including family history, eating habits, and levels of physical activity. Factors in the environmental such as the ready access to processed food, fast food and sugary drinks, and the reliance on cars for transport, also influence obesity rates.

How can people lose weight?

There is no easy route or short cut route for weight loss but some of the necessary ingredients for achieving sustained weight loss include:

1) an environment where health professionals and family and friends provide encouragement and support rather than blaming.

2) Achievable weight loss goals and a realistic time frame to reach those goals.

3) Knowledge about nutrition and healthy eating.

4) Access to fresh food

5) Increase levels of physical activity.

In couples affected by obesity-related fertility problems, weight reduction can improve chances of natural conception.

EFFECT OF OBESITY ON NATURAL REPRODUCTIVE POTENTIAL

FEMALE OBESITY: 

1) Reduces ovulation frequency & reduced chances of conception.

2) Will halve their spontaneous conception rate.

3) Strong associations between obesity, Polycystic Ovarian Syndrome (PCOS) and insulin resistance.

4) Increased prevalence of infertility & 3 fold higher risk of infertility.

5) The duration to achieve a spontaneous pregnancy rate is increased.

6) Difficult to treat anovulatory infertility in obese women.

MALE OBESITY: Possible effects of obesity on male reproductive potential have been less studied.

  • Lower testosterone levels and other endocrine abnormalities,
  • Higher scrotal temperature
  • Higher rates of erectile dysfunction.

EFFECT OF OBESITY ON IVF TREATMENT &RESULTS:

  1. Poor outcomes of assisted reproduction.
  2. Need higher doses of gonadotropins results in higher IVF cost.
  3. Lower chance of pregnancy (decrease around 30%)
  4. Increased miscarriage rate (increase around 30%).
  5. Association of poor embryo quality
  6. less chance of having cryopreserved embryos
  7. High risk of ovarian hyper stimulation syndrome
  8. Impaired IVF outcome even with a good quality embryo.
  9. The endometrium receptivity may also be affected by obesity.

EFFECT OF OBESITY ON PREGNANCY COMPLICATIONS AND OUTCOMES:  Higher risk of serious pregnancy and peripartum complications, including

  1. Higher miscarriage rate
  2. Still born baby
  3. Pre-eclampsia
  4. Gestational diabetes
  5. Hypertensive disorders
  6. Thromboembolic disorders
  7. Preterm labour and delivery
  8. Macrosomia / Large babies
  9. Increased Induction of labour
  10. Increased caesarean delivery rates.

Reproduction after weight loss will not only lead to improved fertility, but also to improved reproductive outcomes.

EFFECT OF OBESITY ON THE HEALTH OF THE CHILD INFANTS OF OBESE MOTHERS:

  1. Increased risk of birth complications and perinatal death.
  2. Significantly higher risk of a range of congenital abnormalities, including neural tube defects (80% increase) and cardiovascular anomalies (30% increase).
  3. Development of overweight in the child.
  4. Higher risk of hypertension, dyslipidaemia, glucose intolerance developing in the offspring.

SUMMARY: Weight loss can

  • Improve reproductive outcomes, including fertility.
  • Improvements in ovulation, pregnancy rate.
  • Increased total sperm count and sperm morphology
  • Reduce the poor obstetrical outcomes due to obesity
  • Increased chance of spontaneous conception
  • Reduced requirement of the dose and henceforth the cost of treatment.
  • Improve outcomes for both mother and baby

 

Recommended lifestyle modifications for obese individual include a weight loss of 7% of body weight and at least 150 minutes weekly of moderate activity such as walking.

It is estimated that a 500-1000 kcal per day decrease from usual food consumption should lead to 0.5-1 kg weight loss per week.

A low-calorie diet of 1000-1200 kcal per day would be expected to achieve a 10% decrease on total body weight over 6 months.