Infertility
Videos
Overview
Obesity is one of the most common and modifiable causes of reduced fertility in both women and men. In women, excess weight disrupts ovulation, lowers the chance of conception even when ovulation is regular, reduces success rates of fertility treatments, and increases the risk of miscarriage and pregnancy complications (Broughton & Moley, Fertility and Sterility, 2017). In men, obesity is associated with lower testosterone and a higher likelihood of low sperm count (Sermondade et al., Human Reproduction Update, 2013).
Polycystic ovary syndrome, which is closely linked to insulin resistance and weight, is the most common cause of ovulatory infertility; see PCOS. Even modest weight loss of 5% to 10% can restore ovulation in many women (Teede et al., Journal of Clinical Endocrinology & Metabolism, 2023), and larger weight loss through medication or bariatric surgery can substantially improve fertility and pregnancy outcomes.
Planning Pregnancy After Weight Loss
Fertility often returns quickly after bariatric surgery, sometimes unexpectedly. Guidelines recommend avoiding pregnancy for 12 to 18 months after surgery, while weight is changing rapidly, and using reliable contraception during that time. GLP-1 medications should be stopped before attempting pregnancy.
Causes
- Insulin resistance and high insulin, which disrupt ovarian hormones
- Excess estrogen produced by fat tissue
- Irregular or absent ovulation
- Reduced egg and embryo quality (Broughton & Moley, Fertility and Sterility, 2017)
- In men: lower testosterone, higher estrogen, heat effects and reduced sperm quality (Sermondade et al., Human Reproduction Update, 2013)
Risk Factors
- Obesity, particularly abdominal obesity
- PCOS
- Insulin resistance and diabetes
- Older age
- Smoking and heavy alcohol use
Who It Affects
Obesity-related infertility affects women and men of reproductive age and is common among patients seeking weight-loss treatment.
Complications
- Difficulty conceiving
- Lower IVF success
- Miscarriage
- Gestational diabetes, preeclampsia and cesarean delivery
- Larger-than-expected babies
Symptoms
- Irregular or absent periods
- Inability to conceive after 12 months of trying, or 6 months if over 35
- Signs of PCOS such as acne and excess hair growth
- In men: low libido or erectile dysfunction
Diagnosis
- Ovulation assessment and hormone testing
- Pelvic ultrasound
- Semen analysis for male partners
- Screening for insulin resistance, diabetes and thyroid disease
Differential Diagnosis
- Tubal disease and endometriosis
- Thyroid disease and high prolactin
- Diminished ovarian reserve
- Male-factor infertility from other causes
Lifestyle Modifications
- Lose 5% to 10% of body weight if overweight (Teede et al., Journal of Clinical Endocrinology & Metabolism, 2023).
- Exercise regularly.
- Stop smoking and limit alcohol.
- Take folic acid when planning pregnancy.
Treatment Options
- Ovulation induction with letrozole, especially in PCOS
- Fertility treatments such as IUI and IVF
- Medical weight loss before conception; see medical weight loss
- Bariatric surgery for women with severe obesity planning future pregnancy; in a large Swedish study, pregnancies after bariatric surgery had lower rates of gestational diabetes and excessively large babies, though small-for-gestational-age babies were more common, underscoring the need for nutritional monitoring (Johansson et al., New England Journal of Medicine, 2015). See bariatric surgery and the pregnancy and contraception guide.
When to See a Doctor
See a doctor if you have irregular periods or have been unable to conceive after 12 months (or 6 months if over 35).
When to Seek Treatment
Seek earlier evaluation if you have PCOS, known male-factor concerns, or are considering bariatric surgery and want to plan a future pregnancy.
Long-Term Outlook
With planning, nutritional monitoring and coordinated obstetric care, many patients achieve healthy pregnancies after weight loss.
Related Reading and Videos
Read more in our articles The Real Results After Bariatric Surgery: A Complete Patient Guide and Why Obesity Is a Metabolic Disease — Not a Willpower Problem. Watch What Nobody Tells You About Bariatric Surgery and Obesity Is a Disease, Not a Failure: What That Really Means on our video library. Related conditions include Metabolic Adaptation, Chronic Kidney Disease (CKD), Hyperinsulinemia and Depression. Treatments that may be involved include Duodenal Switch (DS).
Prognosis
Weight loss improves ovulation, fertility treatment success and pregnancy outcomes for many patients (Broughton & Moley, Fertility and Sterility, 2017).
Why Choose Dr. de la Cruz-Muñoz
Dr. de la Cruz-Muñoz is a board-certified metabolic and bariatric surgeon who works with gynecologists and fertility specialists to time weight-loss treatment and pregnancy safely, with careful nutritional monitoring.
Dr. de la Cruz-Muñoz has been performing bariatric surgery for over 25 years and has completed more than 9,000 bariatric operations — a volume few surgeons reach.
Featured Procedures
FAQ
Patients should consider medical or surgical treatment when obesity is causing health problems (diabetes, hypertension, sleep apnea, fatty liver disease), when weight is affecting quality of life, or when repeated dieting has failed. Metabolic surgery is the most effective option for patients with severe obesity or obesity‑related diseases, offering durable weight loss and powerful metabolic improvements.
Yes. The Society of American Gastrointestinal and Endoscopic Surgeons recommends laparoscopic appendectomy as the treatment of choice for suspected appendicitis in pregnant women (Moris et al., JAMA, 2021). Prompt diagnosis with ultrasound or MRI and timely surgery help protect both mother and baby, because a ruptured appendix is far more dangerous in pregnancy than the operation itself.
Do not panic. Many healthy babies are born to patients who conceive in the first year. Contact your bariatric surgeon and obstetrician immediately. They will guide you on increasing caloric and protein intake, adjusting your supplement regimen, and ensuring you are not taking medications that are harmful during pregnancy.
Yes. Your pregnancy will be considered higher-risk, requiring closer monitoring by an obstetrician and your bariatric care team. This includes frequent lab work to check for nutrient deficiencies, potentially higher doses of supplements, and avoiding standard glucose tolerance tests if you have had bypass or duodenal switch.
