Toxins, Stress, and What They're Doing to Your Hormones with a Top Reproductive Endocrinologist

In this episode of unPAUSED, Dr. Mary Claire Haver continues her conversation with Dr. Natalie Crawford, double board certified obstetrician, gynecologist, and reproductive endocrinologist, and author of The Fertility Formula. In part two of this conversation, Dr. Crawford gets specific about the forces working against our hormones every day, chronic stress, disrupted sleep, inflammatory food, and the endocrine disrupting chemicals most women have never been warned about.

She explains how cortisol triggers insulin resistance, how insulin resistance drives inflammation and ovarian dysfunction, and why resistance training and building skeletal muscle is one of the most direct interventions a woman can make at any age, including perimenopause. On sleep, she makes the case that it is the single most under addressed factor she sees clinically, explaining how FSH and LH are released in the early morning hours and why disrupted sleep directly interferes with ovulation, estrogen, and progesterone production.

The conversation also covers anti-inflammatory nutrition and gut health, the difference between unscented and fragrance-free, why forever chemicals and phthalates are disrupting the hormone system from inside most women's homes, birth control timing and uterine lining recovery, and what egg freezing actually is and is not, and who it is most likely to benefit.

Guest links:

• Natalie Crawford, MD
  
• Natalie Crawford, MD (Instagram)
  
• Natalie Crawford, MD (TikTok)
  
• Natalie Crawford, MD (Threads)
  
• Natalie Crawford, MD (Facebook)
  
• Natalie Crawford, MD (YouTube)
  
• Natalie Crawford, MD (LinkedIn)

Books:

• “The Fertility Formula,” by Dr. Natalie Crawford
  
• “The New Perimenopause,” by Dr. Mary Claire Haver
  
• “The New Menopause,” by Dr. Mary Claire Haver
  

Articles:

• Time to pregnancy: results of the German prospective study and impact on the management of infertility (Human Reproduction)
  
• The effect of physical activity on fertility: a mini-review (F&S Reports)
  
• Association between the systemic immune-inflammation index and GnRH antagonist protocol IVF outcomes: a cohort study (Reproductive BioMedicine Online)
  
• Male Infertility (StatPearls)
  
• Male Preconception Marijuana Use and Spontaneous Abortion: A Prospective Cohort Study (Epidemiology)
  
• Clinical efficacy of PGT-A according to maternal age and embryo quality in blastocyst stage (Human Reproduction)
  
• A comparison of app-defined fertile days from two fertility tracking apps using identical cycle data (Contraception)
  
• Female fecundability is associated with pre‐pregnancy allostatic load: Analysis of a Chinese cohort (Acta Obstetricia et Gynecologica Scandinavica)
  
• Menstrual cycles and the impact upon performance in elite British track and field athletes: a longitudinal study (Frontiers in Sports and Active Living)
  
• Menstrual Disturbances in Athletes: A Focus on Luteal Phase Defects (Medicine & Science in Sports & Exercise)
  
• The Prevalence of Menstrual Cycle Disorders and Menstrual Cycle-Related Symptoms in Female Athletes: A Systematic Literature Review (Sports Medicine)
  
• High Frequency of Luteal Phase Deficiency and Anovulation in Recreational Women Runners: Blunted Elevation in Follicle-Stimulating Hormone Observed during Luteal-Follicular Transition (Journal of Clinical Endocrinology & Metabolism)
  
• Chronotype and sleep duration interact to influence time to pregnancy: Results from a New York City cohort (Sleep Health)
  
• The Association Between Periconceptual Maternal Dietary Patterns and Miscarriage Risk in Women With Recurrent Miscarriages: A Multicentre Cohort Study (BJOG)
  
• The impact of food intake and social habits on embryo quality and the likelihood of blastocyst formation (Reproductive BioMedicine Online)
  
• The effects of perfluoroalkyl and polyfluoroalkyl substances on female fertility: A systematic review and meta-analysis (Environmental Research)
  
• Return of fertility after discontinuation of contraception: a systematic review and meta-analysis (Contraception and Reproductive Medicine)
  
• Ongoing pregnancy rates in single euploid frozen embryo transfers remain unaffected by female age: a retrospective study (Reproductive BioMedicine Online)
  
• In vitro fertilization with single euploid blastocyst transfer: a randomized controlled trial (Fertility & Sterility)

Other Resources:

• Total IVF births soar to more than 13 million (Scimex)
  
• Infertility Affects 1 in 6 People Globally (JAMA Network)
  
• How Many People Have Infertility? (Resolve)
  
• Infertility: Frequently Asked Questions (Centers for Disease Control and Prevention)
  
• How common is male infertility, and what are its causes? (NIH)
  
• Age and Fertility (American Society for Reproductive Medicine)
  
• The use of preimplantation genetic testing for aneuploidy: a committee opinion (American Society for Reproductive Medicine)
  
• The Use of Antimüllerian Hormone in Women Not Seeking Fertility Care (ACOG)
  
• American College of Obstetricians and Gynecologists (ACOG)
  
• EB Research: Longitudinal Investigation of Fertility and the Environment (LIFE) Study (NIH)
  
• Per- and Polyfluoroalkyl Substances (PFAS) (EPA)
  
• Having a Baby After Age 35: How Aging Affects Fertility and Pregnancy (ACOG)