Effects of Fertility and Pregnancy in Women with Obesity and the Role of Bariatric Surgery

28 October 2025 –

 Ernesto Escobar

Obesity affects more than 30% of women in El Salvador and several Latin American countries, as well as 27.5% in the United States of America. This condition is associated with complications or disorders during pregnancy and fetal development, but it is also highly linked to infertility.

Fertility

It has been demonstrated that obesity alters the hormonal axis regulated between the hypothalamus, the pituitary gland, and the ovaries. Moreover, it is common for obese patients to suffer from Polycystic Ovary Syndrome (PCOS), which in some cases leads to menstrual disorders or anovulatory cycles (absence of ovulation for fertilization).
When seeking advanced fertilization methods such as In Vitro Fertilization (IVF), obese patients have higher failure rates in achieving pregnancy. This is also due to the fact that obesity affects oocyte quality and is not merely a phenomenon of anovulation (failure to release eggs for fertilization).

Harmful Effects of Obesity on Pregnancy and the Infant
The following are maternal-fetal complications that increase in incidence among obese patients:

  • Miscarriage (occurring before 20 weeks of pregnancy)

  • Fetal demise (fetal death after 20 weeks of pregnancy)

  • Preterm birth

  • Congenital anomalies in the baby

  • Direct placental damage

  • Hypertensive disorders of pregnancy (Preeclampsia, Eclampsia)

  • Gestational Diabetes Mellitus

  • Fetal macrosomia (excessive fetal weight)

  • Dystocia (difficult labor that poses risk to both mother and fetus)

  • Postpartum hemorrhage and need for transfusion

  • Surgical complications

  • Deep vein thrombosis and pulmonary embolism

  • Depression

  • Difficulty breastfeeding

All these previously described complications are directly proportional to body weight; that is, the higher the weight and Body Mass Index (BMI), the greater the rate of maternal-fetal complications and the greater the impact on fertility.

How Can Bariatric Surgery Help in These Circumstances?

  • The objectives of Bariatric Surgery are to:
  • 1. Induce significant weight loss that will in turn produce hormonal changes.
  • 2. Decrease the harmful inflammatory effects of obesity.
  • 3. Regulate the hormonal axis between the hypothalamus, pituitary gland, and ovaries.
  • 4. Reduce insulin resistance.
  • 5. Improve oocyte quality and optimize conditions for a woman to achieve pregnancy.

It has been reported that Metabolic Bariatric Surgery increases fertility rates in both women and men. In fact, it is recommended that women who undergo this type of procedure avoid becoming pregnant during the first year after surgery, as the body is still adapting and patients are adjusting to treatment — modifying eating habits and lifestyle, supplementing with vitamins, and correcting nutritional deficiencies that may have been present before surgery.

Make an appointment

For more information on how Bariatric Surgery can help improve your health condition, prevent pregnancy-related complications, or enhance fertility, you may schedule your appointment by clicking on the following link:

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