How to Optimize Fertility in Males & Females

Fertility and Fertilization

• Fertility is about producing offspring with genetic components from both parents
• Two types of cells in the body: 
  • Somatic cells: all cells except egg and sperm
  • Germ cells: egg in females and sperm in males
• Germ cells are not modifiable by experience or behavior

Germ Cells

• Germ cells are a unique and protected set of cells
• Generated in a particular way and their genetic components are not modifiable by experience
• Exceptions in the negative direction: 
  • Exposure to chemicals that can mutate DNA of egg or sperm
  • Fertilizing an embryo in a certain way or at a certain stage of life that results in an extra chromosome

By understanding fertility and fertilization, you can maximize your vitality and longevity. This podcast will provide knowledge and actionable tools to help conceive children, if desired, and improve overall health. Topics covered include science-​​based tools, behavioral tools, nutrition-​​based tools, supplementation-​​based tools, and prescription drugs.

Onset of Puberty and Fertility

• Distinction between somatic cells and germline cells (egg and sperm) 
  • Germline cells are highly protected populations of cells
  • Females generate a “vault” of eggs during embryogenesis
• Female eggs contain 23 pairs of chromosomes (diploid)
  • 22 autosomes and 1 sex chromosome (X)
• Goal of fertilization: bring egg cell and sperm cell together 
  • Sperm cell contains 23 chromosomes (haploid), including 22 autosomes and 1 sex chromosome (X or Y)
  • Fertilization creates a cell with 23 pairs of chromosomes, half from mom and half from dad
• Ovulatory and menstrual cycle 
  • Eliminate half of the chromosomal pairs in the female egg
  • Bring egg and sperm cells into close proximity for fertilization
• Onset of puberty controlled by various factors 
  • Earlier onset of puberty in females today
  • Signals from both brain and body control onset of puberty 
    • Hypothalamus and pituitary gland play key roles
    • GABA neurotransmitter inhibits release of gonadotropin-​​releasing hormone (GnRH) prior to puberty

Female Component of Fertility and Fertilization

• Females have all their eggs at birth, but they are very immature 
  • Puberty allows ovulatory and menstrual cycle to commence
• Onset of menses/​​menstruation/​​menarche controlled by various factors 
  • Hormones and neurotransmitters from the brain
  • Hypothalamus releases GnRH, which communicates with the pituitary gland
  • Pituitary gland releases hormones into the bloodstream

• Earlier onset of puberty not necessarily detrimental

  • Various factors contribute to earlier onset, including environmental and genetic factors
    Neurons Suppressing GnRH and Puberty

• Neurons in the brain actively suppress the release of GnRH, delaying puberty

• These cells release GABA, an inhibitory neurotransmitter
• Puberty is also suppressed by the tonic release of melatonin in children

Body Fat, Leptin, and Puberty

• Low body fat stores in children may contribute to delayed puberty
• Accumulation of body fat releases leptin, a hormone that can trigger puberty
• Leptin travels to the hypothalamus, activating neurons that release GnRH
• Earlier puberty in females may be due to increased body fat at younger ages

Obesity Crisis and Puberty

• Obesity crisis may contribute to earlier puberty, but it’s not the only factor
• Improved nutrition and availability of quality nutrition may also play a role
• Trends show puberty occurring earlier with each passing decade

Onset of Puberty in Females Over Time

• Over the last 100 years, the onset of puberty in females has occurred earlier
• Data from various countries show similar trends
• Example: In the US, the average age of puberty onset in females was 14 in 1900, and 11 in 1990

Behavioral and Psychosocial Interactions Influencing Puberty

• Exposure to the scent of a reproductively competent male can trigger earlier puberty in females
• This effect can be partially buffered by the presence of the scent from the female’s biological father
• Odors of related and non-​​related individuals can shape neural and hormone systems that influence puberty

GnRH, LH, and FSH in Puberty

• GnRH from the hypothalamus activates cells in the anterior pituitary gland
• The anterior pituitary gland releases luteinizing hormone (LH) and follicle-​​stimulating hormone (FSH)

• LH and FSH travel in the blood, accessing cells and tissues, changing genetic expression and maturing cells
  Hormones and the Female Reproductive Cycle

• Hormones like testosterone, estrogen, and prolactin can have different effects on different cells in the body

  • Testosterone can stimulate hair growth
  • Estrogen can enlarge breast tissue cells
  • Prolactin can control milk production and secretion, and affect libido in males
• Luteinizing hormone (LH) and follicle-​​stimulating hormone (FSH) have different effects on the ovaries and testes

Ovulation and Menstruation

• The female reproductive cycle includes the menstrual cycle and the ovulatory cycle
• The average cycle is 28 days long, but can range from 21 to 35 days 
  • Consistency in cycle length is more important than the exact number of days
• No causal relationship between the lunar cycle and the menstrual cycle

Follicular Phase

• First 14 days of the menstrual/​​ovulatory cycle
• FSH triggers the maturation of a subset of follicles containing immature eggs
• LH is also present, but at relatively low levels
• The main goal is to get the follicles to mature and develop the eggs
• The eggs inside the follicles also produce their own hormones

Egg Maturation and Chromosome Separation

• One follicle containing an egg is selected, while the others degenerate and die
• The selected egg contains 23 pairs of chromosomes
• Chromosomes are pulled apart by spindles within the egg, resulting in 23 individual chromosomes on each side

• This process prepares the egg for potential fertilization by sperm, which will donate its own 23 individual chromosomes to create a complete set of 46 chromosomes
  Female Reproductive System and Ovulatory Cycle

• First half of the ovulatory menstrual cycle: Follicular Phase

  • Triggered by Gonadotropin-​​Releasing Hormone (GnRH) from the hypothalamus
  • GnRH stimulates the release of Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) from the pituitary gland
  • FSH and LH travel to the ovary and activate a subset of immature follicles with immature eggs
  • The growth of these eggs increases estrogen production
  • Low levels of estrogen trigger negative feedback on LH and FSH, preventing too much production
  • Just prior to ovulation, estrogen levels increase, triggering a positive feedback loop on the pituitary, releasing more FSH and LH
  • This leads to the release of one mature egg with 23 individual pairs of chromosomes into the fallopian tube (ovulation)

• Second half of the ovulatory menstrual cycle: Luteal Phase

  • The follicle that housed the mature egg becomes the corpus luteum
  • The corpus luteum produces three hormones: estradiol, inhibin, and progesterone
  • Progesterone levels increase by 1400 fold compared to the first half of the cycle
  • Progesterone prepares the uterine lining (endometrium) for potential implantation of a fertilized egg
  • If fertilization does not occur, the uterine lining sheds (menstruation) and inhibin levels drop
  • Inhibin, along with other hormones, prevents the secretion of FSH and LH, preventing more eggs from maturing

Key Components of the Female Reproductive System

• Hypothalamus: releases GnRH
• Pituitary gland: releases LH and FSH
• Ovary: contains immature eggs in a “vault,” activated by FSH and LH each month
• Polar body: discarded chromosomes during egg maturation
• Corpus luteum: remnants of the follicle that produce progesterone and inhibin
• Uterine lining (endometrium): prepared by progesterone for potential implantation of a fertilized egg

Hormonal Regulation of the Ovulatory Cycle

• Estrogen: produced by growing eggs, triggers negative feedback on LH and FSH when levels are low, and positive feedback when levels are high
• Progesterone: produced by the corpus luteum, prepares the uterine lining for potential implantation
• Inhibin: produced by the corpus luteum, prevents the secretion of FSH and LH when fertilization does not occur

Summary of the Ovulatory Cycle

1. GnRH from the hypothalamus triggers the release of FSH and LH from the pituitary gland
2. FSH and LH activate a subset of immature follicles and eggs in the ovary
3. One egg matures and is released into the fallopian tube (ovulation)
4. The follicle becomes the corpus luteum, producing progesterone and inhibin
5. Progesterone prepares the uterine lining for potential implantation

6. If fertilization does not occur, the uterine lining sheds (menstruation) and inhibin levels drop, preventing the secretion of FSH and LH and allowing for another ovulatory cycle to begin
   Female Reproductive Cycle and Hormones

7. Menstrual cycle: orchestrated by hormones and feedback loops

8. Follicular phase: maturation of follicles, triggered by FSH
9. Luteal phase: accumulation of progesterone, thickening of uterine lining
10. Hormone fluctuations can impact libido, mood, and physical symptoms
11. Variation in experiences during menstrual cycle among individuals

Sperm and Male Reproductive System

• Sperm: germline cells, similar to eggs, protected from most lifestyle factors
• Job of sperm: deliver genetic material from father (23 chromosomes)
• Sperm created through cell division (meiosis), resulting in haploid cells
• 22 autosomes and 1 sex chromosome (X or Y) in sperm
• Y chromosome contains genes that suppress female reproductive development and promote male development

Karyotype, Genotype, and Phenotype

• Karyotype: complement of chromosomes (XX, XY, XXY, etc.)
• Genotype: specific genes an individual has
• Phenotype: how genes are expressed (e.g., eye color, physical traits)

Impact of Hormones on Libido and Mood

• Increase in libido for some women 4–5 days prior to ovulation
• Spike in FSH, LH, and androgens (DHEA, testosterone) can trigger libido
• Malaise during menstrual cycle varies among individuals
• Some women experience malaise during luteal phase, associated with depletion in estrogen levels
• Other factors, such as sensitivity to caffeine and cramping, also vary among individuals

Lifestyle Factors and Sperm Quality

• Lifestyle factors, nutrition, supplements, and prescription drugs can modify sperm quality
• Sperm quality refers to factors that impact the sperm’s ability to fertilize an egg
• Sperm cells are protected from most lifestyle factors, but some can still impact their quality
  Spermatogenesis and Factors Affecting Sperm Quality

Phenotype and Genotype

• Phenotype: observable traits (eye color, height, hair color)
• Genotype: genetic makeup

Spermatogenesis

• Generation of sperm cells
• Sperm’s job: deliver genetic material from dad to the egg within the female
• Sperm are haploid, have a head, mid-​​region, and tail
• Mid-​​region is key for forward progression (swimming)

Sperm Development

• Takes place in the testes
• Continuous process, unlike female ovulation
• Takes about 60 days for sperm to be born from parent cells and mature
• At any given time, there are immature, mature, and dying sperm

Hormones Involved in Spermatogenesis

• GnRH (gonadotropin-​​releasing hormone) from the hypothalamus
• FSH (follicle-​​stimulating hormone) — stimulates maturation of sperm cell
• LH (luteinizing hormone)
• Target organ: testes

Temperature and Sperm Quality

• Testes reside outside the body in the scrotum
• Optimal temperature for spermatogenesis is about 2 degrees cooler than the rest of the body
• Heat exposure can mutate and disrupt developing sperm and kill sperm
• Avoid hot tubs, hot baths, and saunas if trying to conceive in the next 90 days

Boxers vs. Briefs

• No significant difference in sperm quality between boxers, briefs, or no underwear
• Scrotum has the ability to move testicles far enough away from the body to achieve lower temperatures
• Creamaster muscle: temperature-​​dependent smooth muscle that allows testicles to descend or contract to maintain optimal temperature range

Factors That Can Increase Scrotal Temperature

• Big thighs (muscular or overweight)
• Sitting for long periods
• Seat heaters in cars

Sperm Development Process

• Spermatogonia differentiate into spermatocytes
• Spermatocytes undergo meiosis, reducing chromosome number to 23 individual strands (haploid)
• Meiosis process involves spindle-​​like structures within the cell
• Function of the spindle is heavily dependent on mitochondrial function

Mitochondria and Sperm Quality

• Mitochondria are important for energy-​​demanding aspects of cell biology
• Also crucial for the separation of chromosomes in egg and sperm cells

• Improving mitochondrial function can lead to better egg and sperm quality
  Importance of Spindles and Mitochondria in Fertilization

• Failures at fertilization, implantation, miscarriages, and birth defects can occur due to issues with spindles

  • Spindles help pull apart chromosomes in eggs and sperm
  • Mitochondria are rich on the spindle, crucial for generating haploid sperm (23 individual strands of chromosomes)

Sperm Development and Migration

• Sperm development occurs inside the testes
• Immature sperm sit in compartments along the edge of seminiferous tubules (network of tubes in the testicle) 
  • As they mature, they move towards the center of the tubes
• Mature sperm cells drop into the hollow of the tube and travel through the tubes to the epididymis (series of ducts) 
  • From the epididymis, sperm move to the vas deferens and are contained in the ejaculate along with seminal fluid

Impact of Lifestyle Factors on Semen Quality

• Heavy drinking, smoking, and regular cannabis use can negatively impact semen quality 
  • Reactive oxygen species from smoking disrupt the chemistry of seminal fluid, which can harm sperm cells
  • Carcinogens and mutagens in smoked tobacco or cannabis can mutate DNA and debilitate sperm

Vasectomy

• Vasectomy is a surgical procedure that involves cutting the vas deferens 
  • Prevents sperm from exiting the testicle and being contained in the ejaculate
  • Seminal fluid is still released, but without sperm
  • Effective form of birth control, but not always reversible

Sperm Cell Anatomy

• Sperm cells have 23 pairs of single-​​strand chromosomes (haploid)
  • Either an X or Y sex chromosome as the 23^rd chromosome
• Sperm cells have a head, mid-​​region, and tail 
  • Head contains enzymes and proteins for fusing with the egg
  • Mid-​​region is full of mitochondria and generates tail movement for swimming
  • Tail propels the sperm forward

Spermatogenesis

• Spermatogenesis is the process of sperm production and maturation 
  • Occurs continuously throughout a male’s life after puberty

• Hypothalamus releases gonadotropin-​​releasing hormone (GnRH) after puberty

  • GnRH triggers the release of follicle-​​stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland
  • FSH and LH travel to the testes, triggering the production of testosterone and sperm cells
    Spermatogenesis and Hormonal Elements

• Spermatogenesis: production of sperm, ongoing from puberty to late age

  • Diminished sperm production in very late age (80s, 90s, 100s)
• Hormonal elements involved in spermatogenesis: 
  • GnRH from the hypothalamus
  • Luteinizing hormone (LH) and follicle-​​stimulating hormone (FSH) from the pituitary gland
  • Testosterone from Leydig cells in the testes
  • Androgen binding protein (ABP) from Sertoli cells in the testes
• Disruption of any of these hormonal elements can lead to marked disruption or elimination of sperm

Ejaculate Quality and Sperm Parameters

• Ejaculate quality parameters include: 
  • Number of mature sperm
  • Sperm with one tail (not two)
  • Sperm motility (scored on a scale of 0–3)
    • More than 50% of sperm should be motile (score of 1, 2, or 3)
  • Concentration of sperm per milliliter of ejaculate 
    • Higher concentration increases probability of fertilization
• Ideal sperm parameters for fertilization: 
  • More than 15 million sperm per milliliter of ejaculate
  • Sperm counts seem to be declining, reasons unclear

Fertilization and Implantation

• Most often, only one ovary gives rise to an ovulating egg 
  • Rare for two mature eggs from both ovaries to be deployed during a single ovulation 
    • If both are fertilized, results in fraternal twins
  • If a single egg is fertilized and splits, results in identical twins
• Sperm, once ejaculated into the vaginal duct, pass through the cervix and swim toward the egg 
  • Egg could be at varying locations along the female reproductive axis
• Ectopic pregnancy: pregnancy occurs within the fallopian tubes, not ideal for embryo development or mother’s safety 
  • Ideally, fertilized egg implants into the endometrial lining of the uterus
• Faster swimming sperm and more far along the ovulatory trajectory of the egg increase the probability of successful fertilization 
  • Proximity to the implantation zone of the uterus is crucial

Possible Factors Affecting Sperm Quality

• Electromagnetic fields (EMFs) have been discussed as a potential factor in diminishing sperm counts, but the safety and impact of EMFs remain unclear
  Smartphones and Sperm Count

• Metaanalysis and reviews correlate smartphones in pockets with diminishing sperm counts

  • Other factors, such as endocrine disruptors, also contribute to diminishing sperm counts
• Dr. Shana Swan’s work on phthalates and BPAs 
  • Endocrine disruptors found in pesticides and printed receipts
  • Reductions in testosterone and disruptions to Sertoli cells and androgen-​​binding protein
  • Impact on sperm counts still debatable

Ejaculate Volume and Sperm Concentration

• Clinicians prefer ejaculate volume of more than 2 mL for conception 
  • Volume ranges from 1.5 to 5 mL, determined by frequency of ejaculation
• Sperm concentration varies from 15 million/​​mL to 100 or 200 million/​​mL
  • Causes of variation unclear, but frequency of ejaculation plays a role

Frequency of Ejaculation and Fertility

• Goal: maximum number of high-​​quality, rapidly forward motile sperm with correct morphology
• Ovulation occurs on one day during the menstrual cycle, egg available for fertilization for approximately 24 hours 
  • Sperm can survive in the female reproductive tract for 3–5 days, sometimes up to 7 days
• Regular duration ovulatory cycles ideal for timing ovulation and maximizing chances of fertilization

Intercourse Frequency for Fertilization

• Optimal strategy: maximize concentration of healthy sperm within each ejaculate, center around day of ovulation 
  • Abstain from intercourse with ejaculation 2–3 days before ovulation
  • Introduce as much semen and ejaculate into the female reproductive pathway on the day prior to ovulation and on the day of ovulation
• Alternative strategy: maximize concentration of healthy sperm within each ejaculate, but not so frequently that it diminishes sperm concentration 
  • Intercourse once or twice on the day prior to ovulation, maximal number of times on the day of ovulation
• Optimal strategy varies among individuals due to differences in sperm concentration and timing of ovulation

Female Biology and Ovulation Timing

• Some women can accurately estimate ovulation timing within a couple of hours

  • Interoceptive awareness: awareness of sensory events within the body
  • Sensory endings within the ovary may allow some women to feel ovulation
    Sensing Ovulation and Tracking Methods

• Some women can sense changes within their ovary, including the deployment of the egg

• Different ways to track ovulation: 
  • Temperature method: measuring intravaginal temperature for changes consistent with ovulation
  • Using apps: inputting temperature information and marking the onset of menstruation
• Regularity of cycle duration helps predict ovulation
• Increase in libido just prior to ovulation due to increase in androgens like DHEA and testosterone
• Changes in the pH of the mucosal lining near the cervix and vaginal secretions to support sperm motility and health

Commercial Lubricants and Sperm Health

• Some commercially available lubricants can be detrimental to sperm health even without spermatocide
• Discuss with OBGYN or urologist about lubricants that are more conducive to sperm environment

Optimal Strategies for Conception

• How often couples should have intercourse with ejaculation around the time of ovulation to maximize probability of successful fertilization and pregnancy
• How long couples should apply this method over time depending on age and quality of egg and sperm

Fecundability and Cumulative Pregnancy Rate

• Fecundability: the amount of time over which a given couple needs to attempt to conceive
• Age-​​dependent effect, largely based on the age of the female
• For females 30 years old or younger, 20% chance of successful fertilization and pregnancy on the first month of attempting
• Typical advice from OBGYN: attempt to conceive over a period of six months
• Cumulative pregnancy rate takes into account multiple probabilities at work, such as the biology of the egg and sperm, and the likelihood of them meeting and fertilizing

Factors Affecting Egg and Sperm Quality

• Egg quality: number of follicles deployed each month, mitochondrial function, spindle that pulls chromosomes apart
• Sperm quality: number of motile sperm, number of morphologically correct sperm

• Genetic and environmental variables can be adjusted to improve egg and sperm quality
  Cumulative Pregnancy Rate and Fertility

• Cumulative pregnancy rate: how much of the biology of the woman is skewed towards fertilization to be likely to occur

  • Age plays a significant role in the probability of getting pregnant
  • Probability of getting pregnant on any one attempt to conceive: 
    • 20% for women 30 years old or younger
    • 18% for women 31 to 33 years old
    • 11% for women 34 to 37 years old
    • 5% for women 38 to 39 years old
    • 1–3% for women 40 years old or older
  • OBGYNs typically advise trying for a certain number of months based on age before seeking medical intervention
• Miscarriage rates increase with age 
  • 25% of successful fertilizations lead to miscarriages for women 35 years or older
  • 50% for women 40 years or older
  • Miscarriages can arise from genetic defects, issues in the uterus, or issues with sperm
  • Chromosomal abnormalities can be a common reason for miscarriages
• Assessing fertility in women 
  • Age is a major factor, but not the only one
  • Ovarian reserve: the number of eggs in the “vault”
    • Strong positive correlation between the size of the population released from the vault each month and the size of the reserve in the vault itself
    • Women can evaluate their fertility by asking their OBGYN about the number of follicles they have in a given month
    • More follicles generally indicate a higher ovarian reserve and higher fertility
  • These numbers are averages and should not be taken as absolute guarantees

Fertility and Conception

Egg and Follicle Count in Women

• Women have varying numbers of follicles and eggs released each month 
  • Some have fewer but are more fertile, others have more but struggle to conceive
• More eggs and follicles released each month indicate a higher ovarian reserve
• Antro follicles: small follicles (2–9mm) released each month 
  • Measured via ultrasound at OBGYN office
  • Gives an estimate of a woman’s ovarian reserve
• AMH (antimullarian hormone): released by anthro follicle population 
  • Blood test to measure AMH levels
  • Indicates the number of eggs leaving the ovarian reserve each month
• Women should regularly measure AMH levels and follicle count to estimate their ovarian reserve 
  • Helps in planning for future conception

Sperm Count and Quality in Men

• Common misconception: only one sperm needed for fertilization 
  • In reality, a large number of quality sperm needed for a high probability of successful fertilization
• Sperm analysis: relatively inexpensive and provides insight into sperm count and quality 
  • Men should consider freezing sperm for future use
• Age of father and sperm can impact pregnancy outcomes (e.g., increased risk of autism) 
  • Men should get sperm analyzed every five years and consider freezing younger sperm

Recommendations for Men and Women

• Women: measure egg count (antro follicle count) and AMH levels regularly
• Men: have a sperm analysis every five years and consider freezing sperm

• Early measurements provide a reference point for future fertility planning
  Fertility Misconceptions and Importance of Analysis

• One in five couples with fertility issues have problems with sperm quality or quantity

• Misconception that fertility issues are always related to egg quality
• Importance of sperm and egg analysis, as well as hormone analysis for both males and females
• Having a reference point for hormonal composition can help identify issues and changes over time

Factors Affecting Fertility

• Sleep is fundamental for balancing hormones, mental health, physical health, and fertility 
  • Most people need 6–8 hours of sleep per night
  • Proper sleep can help regulate cortisol, testosterone, and estrogen levels
• Smoking (nicotine and cannabis) can disrupt fertilization and pregnancy 
  • Increases reactive oxygen species, which can damage egg and sperm quality
  • Smoking cannabis can decrease the probability of a healthy fertilization and pregnancy
• Alcohol consumption should be limited when trying to conceive 
  • For healthy adults not trying to conceive, limit is two drinks per week
  • For pregnant women, no alcohol consumption is advised

Recommendations for Maintaining Fertility

• Quit smoking (including cannabis) and vaping
• Limit alcohol consumption to two drinks per week when trying to conceive
• Ensure adequate sleep (6–8 hours per night) for hormone regulation and overall health

• Consider regular sperm, egg, and hormone analysis to monitor fertility and identify potential issues
  Alcohol and Fertility

• Limit alcohol intake to 2 drinks per week or less

  • Excessive alcohol intake increases cellular mutation, oxidative stress, and cancer risk
  • Binge drinking (5–6 drinks in a night) greatly increases the likelihood of mutations in the embryo and reduces the probability of fertilization
  • Negative effects of binge drinking can last for weeks, impacting sperm and egg quality
  • Zero alcohol is better than any alcohol for fertility and pregnancy

Stress and Fertility

• Reduce stress by getting enough quality sleep and using stress-​​buffering tools 
  • Excessive stress can negatively impact fertility and pregnancy
  • Find episodes on stress reduction and sleep at hubermanlab​.com

Nicotine, Cannabis, and Fertility

• Limit or eliminate nicotine and cannabis use when trying to conceive and during pregnancy

Sexually Transmitted Infections (STIs) and Fertility

• Get an STI check when trying to conceive or evaluating fertility 
  • Chlamydia, in particular, can increase the probability of miscarriage and negatively impact male reproductive health

Viral Infections and Fertility

• Severe viral illnesses can negatively impact sperm and egg quality

  • For men, a viral illness in the previous 70–90 days can diminish sperm count and quality
  • For women, a viral illness in the previous 30 days can impact egg quality
  • Viral infections during pregnancy, such as influenza, may have correlations with negative mental health outcomes in offspring (e.g., schizophrenia)
  • Consult with an OBGYN if you have had a viral infection while trying to conceive or during pregnancy
    Cystic Fibrosis and Male Fertility

• One in 25 men carry a mutation for cystic fibrosis

  • Carriers have one copy of the gene and do not show symptoms
  • Can cause defects in the vas deferens, affecting sperm transport
• Surgical repair of vas deferens or sperm extraction can help with fertility

Factors Affecting Male Fertility

• Testicles need to be about 2 degrees cooler than the rest of the body 
  • Avoid hot tubs and saunas while trying to conceive
  • Use ice packs to keep testicles cool in hot environments
• Keep laptops and other hot devices off the lap
• Reduce total time spent sitting to maintain optimal scrotum temperature
• Avoid seat heaters in cars
• Be mindful of leg size (obesity or overly muscular thighs) affecting scrotum temperature

Smartphone Use and Sperm Quality

• Electromagnetic fields (EMFs) and heat from smartphones can negatively affect sperm quality and testosterone levels 
  • Radio frequency waves and EMFs can have negative impacts on biological tissues
• Carrying a phone in the front pocket can reduce sperm count and motility 
  • Turning off WiFi or cellular access does not eliminate heat-​​related effects

• To maintain optimal sperm quality, avoid carrying a phone close to the body, especially in front pockets
  Mobile Phones and Sperm Quality

• Mobile phone usage may be linked to reduced sperm count and quality

  • Not solely responsible for reductions in sperm quality and testosterone levels, but likely a major player
• Meta-​​analysis of 18 studies with 4280 samples 
  • Separated radio frequency and heat effects
  • Eliminated time of usage variable
  • Exposure to any cell phone contact can diminish sperm quality
• Mitigation strategies:
  • Keep phone away from groin area
  • Avoid carrying phone in front or back pocket

Cold Exposure and Fertility

• Deliberate cold exposure may have positive effects on fertility for both males and females 
  • Males: Increased testosterone, improved sperm quality (indirectly by reducing testicle temperature)
  • Females: Regulating cortisol and hormone production (indirectly by restricting stress to a specific time of day)
• Cold exposure should be uncomfortably cold but safe 
  • Duration: 1–3 minutes a day, early in the day
  • Method: Cold shower or immersion up to the neck in cold water
• Cold exposure can be beneficial for fertility, but not necessary if stress, sleep, and other factors are managed properly

Exercise and Fertility

• Regular exercise can help maximize fertility for both females and males

  • Supports overall health, hormone balance, and stress management
  • Should be tailored to individual needs and preferences
    Exercise and Mitochondrial Health

• Exercise improves mitochondrial health

  • Both resistance training and cardiovascular exercise
  • 30–60 minutes per day, 6–7 days per week recommended
• Exercise impacts sleep, mood, and stress reduction
• Exercise during pregnancy may need adjustments

Intermittent Fasting and Fertility

• Intermittent fasting (time-​​restricted feeding) can have positive outcomes for organ, cellular, and tissue health 
  • Controversial and data still incoming
• For females:
  • If having regular menstrual cycles, intermittent fasting likely not disrupting fertility
  • During pregnancy, consult doctors before trying intermittent fasting
• For males:
  • No clear data on intermittent fasting and spermatogenesis/​​testosterone production
  • Focus on losing weight if overweight to maximize sperm quality and health
  • If already lean, restricting calories further may not increase testosterone
  • Intermittent fasting may be fine if getting enough calories to maintain weight or lose weight if overweight

Testosterone Replacement Therapy and Fertility

• Exogenous testosterone can shut down testicles’ own testosterone production due to negative feedback loops 
  • Testosterone replacement therapy (TRT) can be administered through creams, patches, pellets, or injections
  • Aim for clinically appropriate, not super physiological, testosterone levels

• TRT may impact spermatogenesis and fertility, consult with a medical professional before starting treatment
  Exogenous Testosterone and Fertility

• Taking testosterone from an external source can reduce or eliminate spermatogenesis

  • Pituitary gland stops making luteinizing hormone (LH) and follicle-​​stimulating hormone (FSH) due to high levels of circulating testosterone
• To offset sperm-​​reducing effects, some men take: 
  • Human chorionic gonadotropin (HCG) to stimulate testes to continue making testosterone
  • FSH to stimulate Sertoli cells to support spermatogenesis
  • Clomiphene (Clomid) or other methods
• Consult a urologist or endocrinologist if considering TRT and planning to have children

Supplements and Fertility

• Supplements like Tongkat Ali can support healthy hormone production without disrupting ovulation or spermatogenesis 
  • Different from taking hormones or bioidentical hormones, which can reduce egg and sperm quality
• Be cautious of supplements containing testosterone or testicle extracts, as they may affect endogenous testosterone production

Sex Determination

• Factors influencing whether a child is male or female (XX or XY chromosomes) are determined by the egg and sperm
• No evidence to support theories about sexual positions or thoughts during ejaculation affecting sex determination
• In vitro fertilization (IVF) allows for sex selection by analyzing the genetic makeup of embryos before implantation 
  • Involves administering supra-​​physiological levels of FSH and LH, suppressing ovulation, and collecting mature eggs and sperm for fertilization in a dish
  • Embryos can be selected based on karyotype (XX or XY) and normal chromosomal arrangements

Emerging Methods for Sex Selection

• Some clinics are developing methods to separate sperm based on sex chromosomes before fertilization

  • Involves spinning sperm samples in a centrifuge to separate them into different fractions
  • Still an emerging data set and mainly conducted in clinics outside the United States
    Sperm Centrifugation and Sex Selection

• Sperm samples can be spun in a centrifuge to separate sperm that give rise to male or female offspring

  • Different fractions can be applied to eggs in in vitro fertilization (IVF) or intrauterine insemination (IUI)
• Some couples opt for IUI to select the biological sex of their child 
  • This method is not yet commonplace, but is emerging

Body Position and Fertility

• There is a debate among experts about whether a woman’s body position after ejaculation can influence the probability of pregnancy 
  • One group says it doesn’t matter, as sperm swim quickly and know what to do
  • Another group suggests tilting the pelvis back and lying stationary for 15 minutes after intercourse can increase the likelihood of fertilization 
    • This is a low-​​investment method that could potentially bias the likelihood of fertilization

Cannabis and Sperm Quality

• Cannabis use can disrupt sperm motility and morphology 
  • Sperm generated in the 60 days after cannabis use may have reduced forward motility and altered morphology

• To increase the chances of conception, it is recommended to avoid cannabis use

  • This does not mean that using cannabis once will forever disrupt sperm quality, but it can have an impact on sperm generated within the 60-​​day window after use
    Cannabis and Fertility

• Cannabis use can negatively impact fertility in both men and women

  • For men, it can disrupt sperm motility and quality
  • For women, it can negatively affect egg quality
• Approximately 15% of pregnant women continue to use cannabis during pregnancy 
  • This is concerning as it can be detrimental to the fetus’ brain development
• It is recommended to avoid cannabis use when trying to conceive and during pregnancy

Body Position and Fertility

• Tilting the pelvis back by about 20 degrees for 15 minutes post-​​ejaculation may increase the probability of fertilization 
  • This is based on the consensus among experts who believe that pelvic tilt can be beneficial for increasing the likelihood of fertilization
• No clear information on the ideal body position for males after ejaculation to increase the probability of fertilization

Acupuncture and Fertility

• Acupuncture has been shown to improve both female and male fertility 
  • For females, it can balance hormones across the ovulatory menstrual cycle, regulate FSH levels, and improve blood flow and health of the ovary
  • For males, it can improve semen volume, sperm quality, sperm motility, and increase levels of endogenous testosterone
• Acupuncture can also improve the likelihood of a successful pregnancy carried to term and not premature
• Clinical trials funded by government agencies like the National Institutes of Health support the effectiveness of acupuncture for fertility and pregnancy

Resources for Acupuncture and Fertility

• “Acupuncture and Herbal Medicine for Female Fertility: An Overview of Systematic Reviews” (2021) — a review of reviews on acupuncture for female fertility
• A link to a review on acupuncture for male fertility and hormone augmentation will also be provided
• To find the most relevant and recent research, look for references that appear most often in the introduction of scientific papers

Maximizing Fertility for Overall Health

• Maximizing fertility can be a measure of overall health status, vitality, and longevity

• Even for those not looking to conceive, considering ways to maximize fertility can contribute to overall well-​​being
  Tools and Interventions for Improving Hormone Status, Egg and Sperm Quality

• L‑carnitine supplementation

  • Present in various foods, especially red meats
  • Difficult to obtain sufficient levels through diet alone
  • Shown to improve egg and sperm quality in peer-​​reviewed studies 
    • Chromosomal arrangements, fertility likelihood, sperm motility, and morphology
  • Recommended dosage: 1–3 grams per day in capsule form 
    • Can be taken all at once or spread throughout the day
    • Can be taken with or without food
  • Effective after 30–60 days of supplementation
  • Mechanism: L‑carnitine involved in lipid processing and mitochondrial function 
    • Mitochondria vital for spindle organization and action in egg cells
    • Mitochondria important for sperm motility and cellular morphology
  • Beneficial for those trying to conceive or wanting to maximize egg and sperm quality
  • Recommendation: Take L‑carnitine for at least 30 days prior to attempting conception 
    • Can continue trying for pregnancy before taking L‑carnitine
    • Aim to maximize egg and sperm quality even without fertility issues

L‑carnitine: Importance and Benefits

• Involved in lipid processing and mitochondrial function 
  • Mitochondria crucial for egg and sperm cell functions 
    • Female: spindle organization and action, cell division, and egg fusion during ovulation
    • Male: sperm motility, flagellation, and cellular morphology
• Supplementation can improve egg and sperm quality 
  • Increases likelihood of fertility and pregnancy
  • Enhances chromosomal arrangements, sperm motility, and morphology
• Recommended for those trying to conceive or wanting to optimize reproductive health 
  • Take 1–3 grams per day in capsule form for at least 30 days prior to conception
  • Continue supplementation to maintain improved egg and sperm quality