Pre-conception Flashcards
What is fertility?
Actual production of children (although commonly used to refer to the ability to bear children - see ‘fecundity’)
What is infertility?
Failure to conceive after 1 year of unprotected sexual intercourse with the same partner
What is subfertility?
Reduced level of fertility characterised by unusually long time to conception (over 12 months) or repeated, early pregnancy losses
What is fecundity?
Biological ability to bear children
What is infecundity?
Biological inability to bear children after 1 year of unprotected sexual intercourse with the same partner
What is miscarriage?
The loss of a foetus in the first 20 weeks of pregnancy. Also known as ‘spontaneous abortion’.
What do unfavourable conditions at pre conception lead to?
Adaptation
Suspension of reproductive function (infertility)
What percentage of cases of infertility are due to male physiological factors and what does that mean for nutritionists?
Whilst we often associate infertility with women, male physiological factors have been shown to be responsible for ∼25% of cases. We therefore must consider the health, wellbeing and nutritional status of both partners.
Se and sperm?
Se appears to have positive effect on sperm by increasing glutathione peroxidase-1 activity an antioxidant enzyme which scavenges hydrogen peroxide and quenches reactive oxygen species. Sperm are particularly susceptible to oxidative stress.
Zn and sperm?
Zn acts as a membrane-stabilizing source by inhibiting membrane-bound oxidative enzymes such as NAD(P) oxidase, which increases sperm concentration and motility. Zn is also required for correct sperm DNA condensation/descondensation. Some studies suggest that chromatin stability of the ejaculated human spermatozoon is Zn-regulated and that Zn controls the formation of disulfide bridges. Low content of sperm chromatin zinc has been related with some cases of male infertility
Omega 3 and sperm?
Studies suggest that they act by modifying the cell membrane composition through their incorporation into the spermatozoa cell membrane, helping functionality of the cell.
CoQ10 and sperm?
can inhibit organic peroxide formation in seminal fluid, reducing sperm OS and increasing the sperm quality
Food sources of selenium?
Many whole grains and dairy products, including milk and yogurt, are good sources of selenium. …
Pork, beef, turkey, chicken, fish, shellfish, and eggs contain high amounts of selenium.
Food sources of zinc?
Whole grains and milk products are good sources of zinc. Many ready-to-eat breakfast cereals are fortified with zinc.
Oysters, red meat, and poultry are excellent sources of zinc. Baked beans, chickpeas, and nuts (such as cashews and almonds) also contain zinc.
Carnitines and sperm?
Carnitines, such as L-acetyl carnitine (LAC) and L-carnitine (LC), act as a transporter of long-chain fatty acids into the mitochondria providing energy for use by spermatozoa.
Food sources of carnitines?
Red meat and in smaller amounts in chicken, milk and dairy products, fish, beans, and avocado.
Fruit and veg and sperm?
High in antioxidants which can act as sperm ROS regulators reducing sperm DNA damage and increasing sperm motility and vitality. Also high in folate which may have an important role in spermatogenesis. folate-deficient diets could result in an alteration of sperm DNA methylation at genes implicated in development and some metabolic processes.
Fibre and sperm?
fibre consumption could reduce plasma estrogen levels. This is important, because high estrogen levels could disrupt endocrine homeostasis, which is essential for normal spermatogenesis
Why might breakfast cereals be good for conception?
they are commonly fortified with antioxidants and minerals which are helpful for conception.
What should red meat be substituted for to improve sperm quality? What is a pontential down side of this.
Fish which is helpful because it is high in omega 3. However, these beneficial effects can be negatively affected by the high concentration of some environmentally-persistent organic pollutants in the fish, as well as mercury (Hg) and other neuro-toxic elements.
Poultry’s effect on sperm?
Positive effect on sperm although has to be interpreted cautiously because of the different use of antibiotics in different places. Researchers are unable to explain why poultry was beneficial.
Are dairy products good for sperm?
Full-fat dairy is bad for sperm, but low fat dairy is good. Low-fat and skimmed milk consumption have been associated with increased levels of insulin, probably via increasing levels of insulin-like growth factor 1 (IGF-1), animal studies indicated that subcutaneous insulin administration may increase sperm motility and concentration.
What kind of nuts should you have to improve sperm quality?
A mix (probably almonds, hazelnuts, and walnuts) because it reduces DNA fragmentation in sperm.
What two diets are helpful for sperm?
prudent diet, which is characterised by a high consumption of fruit, vegetables, fish, legumes, poultry, and whole grains. Mediterranean diet (MD) is characterized by a high consumption of olive oil, nuts, fruits, vegetables, legumes, and whole cereals, along with a moderate consumption of fish, poultry and wine
All the benefits of folate/folic acid for pregnancy? Potential concerns?
Folate, involved in the synthesis of DNA, is crucial in gametogenesis, fertilization, and pregnancy. Therefore, folate (natural form of vitamin B9) or folic acid (synthetic form of vitamin B9) may play an important role in human reproduction. Prevents NTDs and is no longer associated with spontaneous abortion.
What does vitamin D do and what could it potentially be helpful in?
vitamin D stimulates ovarian steroid synthesis, promotes follicular maturation, and regulates gene expression involved in successful
implantation, and its deficiency may be involved in the development of PCOS. Deficiency related to worse ART outcomes but not worse regular fertilisation
What are the recommendations for men before conception? and why?
The male sperm cycle is thought to be 74 days +/- 4.5 days so at least 2 - 3 months prior to intended time of conception consume a balanced and varied diet moderate alcohol intake
Correct grossly abnormal body weight (BMI at upper end of normal range) Normal range is 18.5- 24.9
What are the recommendations for women before conception?
Consume a balanced and varied diet
Correct grossly abnormal weight well in advance of conception (at least 4 months)
BMI at upper end of normal range at most
Stop smoking
Moderate alcohol intake
Commence folate supplementation at least 3 months prior to conception
What might increase ovulatory function in PCOS women but appears to be unrelated in healthy regularly menstruating women?
Reduction in dietary carbohydrates among PCOS women improved insulin sensitivity and decreased circulating testosterone levels, potentially enhancing ovulatory function.
Whole grains and fertility?
Whole grains have phytic acid, vitamins, and selenium, which have antioxidant anti-inflammatory properties and beneficial effects on glucose metabolism, this could boost fertility because insulin resistance and oxidative damage have been implicated in the pathogenesis of subfertility. Lignan in whole grains may exert reproductive benefits. Whole grains eaten before preconception were related to more live births.
Omega 3 and trans-fat’s relationship with pregnancy?
fatty acids are used as energy during oocyte maturation and early embryo development, and they serve as critical precursors for a variety of substrates playing a vital role in implantation and pregnancy maintenance. Trans fatty acids increase insulin resistance, adversely affecting the ovulation, however research is mixed. Increased long-chain u-3 PUFA intake was associated with increases in luteal progesterone concentration, long-chain u-3 PUFA (fish) was associated with increased ovary estrogen and lower risk of anovulation, taken together, higher u-3 PUFA and lower trans fatty acid intake may enhance female fertility.
What meat was bad for ART outcomes?
blastocyst formation following ART was decreased among patients consuming more red meat
How much fish should a pregnant/ women who may become pregnant consume? Which fish to be carful about and why?
Two to three servings of a variety of fish
per week, with no more than one serving per week of fish
such as albacore tuna, and to avoid fish (e.g., bigeye tuna,
king mackerel, swordfish) with the highest mercury
concentrations.
What is menarche and what is the trend that has occurred over the years?
first occurrence of menstruation and over the years it has been occurring younger and younger in women.
What is the critical fat hypothesis? Evaluations?
Critical fat hypothesis states that girls need about 24% body fat to be reproductively mature. Lacks the link between fat mass and hypothalamus which triggers hormonal changes. A hypothesis as to why girls are starting their period younger.
What is the metabolic signal hypothesis?
Proposed the availability and oxidation of metabolic fuels is linked to reproductive ability, possibly by metabolites being sensed by the brain and the liver. Leptin may play a role but it is unclear. This is another theory as to why women are getting their periods earlier.
What can delay puberty in boys?
Under nutrition.
What can happen to a women who starts menarche and then becomes under nourished?
Irregular or infrequent menstruation
Amenorrhoea in excessive weight loss / anorexia nervosa
This can occur in women in particular who do a lot of sport. The reasons this might happen is to prevent pregnancy so they don’t give birth to an infant they cannot sufficiently nourish and to protect the mother so she can conserve energy because she is not getting enough. But pregnancey can still occur lowest weight documented was 14.9 kg/m2.
What is there increases frequency of for undernourished mothers? What should be done?
Spontaneous abortion Congenital abnormalities Perinatal mortality IUGR (Intra-uterine growth retardation) Can have healthy offspring by having a healthy varied diet where she gains weight. Under nourished mothers also have decreased sex drive and performance.
Is there long term effects of a starved mother or is the problem fixed straight away by proper diet?
Long term as in there are still more deaths of babies after a food shortage than without one.
How much weight should an Underweight (< 18.5kg/m2) mother gain during pregnancy?
12.5 – 18kg
How much weight should an Healthy (18.5 – 24.9kg/m2) mother gain during pregnancy?
11.5 – 16kg
How much weight should an overweight (25 – 29.9kg/m2) mother gain during pregnancy?
7 – 11.5kg
How much is normal to gain for an obese (>30kg/m2) mother during pregnancy?
6.8kg minimum
What happens to men in terms of reproductive functions when they are undernourished?
- Loss of libido (early effect of energy reduction and subsequent weight loss)
- Loss of prostate fluid
- Decreases in sperm motility
- Decreases in sperm longevity
- Cessation of sperm production at weight loss of ∼25% normal body weight
Weight gain reverses descending order
Cycle of subfertility caused by obesity in men?
Obesity, insulin resistance, metabolic syndrome
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Reduced androgen secretion and transport
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Altered androgen status and impaired hormone action =subfertility
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Reduced lipolysis and lipid mobilisation, increased adipogenesis (leads back to the start)
What are the causes of decreased sexual activity and function of obese men?
Psychological handicapping (not feeling attractive because your over weight)
Gross obesity may alter sex hormone production (Calloway, 1983)
Obesity is associated with erectile dysfunction and oligospermia in males (the adipose may keep the sperm too warm) (Derby et al, 2000)
Obesity related diseases (interfering with sexual behaviour)
Weight may make it harder to have sex
Reduced reproduction for obese women?
Increase in ovulatory disorder infertility in women with BMI >30 kg/m2 (Chavarro et al. 2007)
Obese women have increased incidence of miscarriage (Norman & Clark, 1998)
NTDs in offspring seen more commonly despite adequate folate supplementation
What is folate?
The term ‘folate’ refers to the many compounds derived from folic acid. Folate is part of the vitamin B complex (B9). Humans are unable to synthesise folate, and therefore must rely on exogenous sources to provide it.
Sources of folate and something to consider?
Rich dietary sources of folate include liver, green leafy vegetables, such as kale and spinach, and also fortified cereal products. The amount of folate that can be absorbed from foods varies.
What can destroy folate?
Overcooking can destroy folate.
What does the body do to folate to absorb it and? Is folic acid the same?
Natural sources of folate, from food, require conversion from polyglutamates to monoglutamates in the upper small intestine in order to be absorbed. However, synthetic folic acid supplements contain only monoglutamates and therefore are more stable and provide better bioavailability, although they are metabolised slightly differently when compared with folate.
Role of folate in the body?
Folate has two known important biological roles. It acts as a cofactor for enzymes that are essential in the synthesis of DNA and RNA, and is required in the transfer of methyl groups in the amino acid methylation cycle, an important step in the recycling of homocysteine back to methionine.
RNI for folate in men and women? Reason for these values?
The RNI for both men and women has been set at 200 μg/d, since the slightly smaller requirement for women due to lower lean body mass may be offset by a greater requirement for reproduction.
Which groups are more likely to be folate deficient in the UK?
Women between 11 and 24
Factors that increase the risk of low folate status?
smoking, non-use of vitamin-mineral supplements, pregnancy, oral contraceptive use, high parity (had 5 or more babies)
What is neurulation?
Neurulation is the process, occurring during early pregnancy, which transforms the flat neural plate into a tube that becomes the brain and spinal cord. The neural tube is formed and closed by the end of the seventh week of pregnancy.
What are NTDs and what are some examples?
Neural tube defects arise as a result of the failure to close the neural tube at specific sites. NTDs are one of the most common congenital malformations and include spina bifida, anencephaly, and encephalocele.
What is spina bifiba?
Spina bifida is when a baby’s spine and spinal cord does not develop properly in the womb, causing a gap in the spine.
What is anencephaly?
a severe congenital condition in which a large part of the skull is absent along with the cerebral hemispheres of the brain.
What is encephalocele?
Encephalocele is a neural tube defect characterized by sac-like protrusions of the brain and the membranes that cover it through openings in the skull.
UK current rate of NTDs?
They affect around one in 1,000 pregnancies, with 190 babies born alive with an NTD in the UK every year
Changes in amount of NTDs in the uk?
Wend down from 1970s to 1990s but went up again but by not as much now.
What were the results of folic acid consumption and why it was or wasn’t consumed after health campaigns?
Awareness of folic acid levels prior to conception improved post-campaign from 6 to 41%. Knowledge about consumption and correct periconceptional use of folic acid also improved. However, in most studies more than 50% of women did not take folic acid as prescribed. Factors associated with or without taking folic acid post-campaign: incomplete outreach, prior awareness and knowledge, closeness to pregnancy, demographics and other personal characteristics. Sustained campaigns are needs.
Recommendations for folate for women who are planning to become pregnant?
take a folic acid supplement containing 400μg (0.4mg) folic acid per day for at least three months prior to conception and continuing until the 12th week of pregnancy.
Recommended dose for those at higher risk of having children with NTDs and who are these People?
recommended to take a 5000 μg (5 mg)
Woman who have/are: coeliac disease (or other malabsorption state), diabetes mellitus, sickle-cell anaemia, is taking anti-epileptic drugs.
Couple: either partner has a neural tube defect, either partner has a family history of neural tube defects, a previous pregnancy affected by a neural tube defect
What else should be considered other than folate supplementation?
shouldn’t just be dependent upon a supplement to achieve a good folate status. Women planning to conceive are encouraged to choose folate fortified foods, and avoid over-cooking folate rich foods
How much folic acid is in 100g of fortified non- wholemeal wheat flour in the uk?
240 μg folic acid/ 100g flour
What did the SACN report find about consuming 1mg/d of folic acid?
It did not mask B12 anaemia or accelerate/aggravate cognitive decline in older adults. However this doesn’t change the UL of folate which is 1mg/d
Folate and cancer?
Unclear if there is a risk with cancer but people aged over 50y and those with a previous history of colorectal adenomas were advised not to consume supplements containing folic acid above the RNI for folate (200 µg/d)
What is a genetic cause for NTDs?
MTHFR C677T genotypes
What can be done to reduce some potential folic acid risk e.g. in relation to B12, cancer and cognitive decline?
curbs on voluntary fortification and some other measures such as population monitoring of folate status and relevant health outcomes.
Which groups are less likely to take folic acid in preparation for pregnancy?
Disadvantaged women under 18, top 10% most deprived women, balck and asian women.
As men get older what happens to them in terms of fertility?
testosterone levels begin to decrease and hypogonadism(decreased functional activity of the gonads) results but if testosterone is administered it can suppress spermatogenesis (process of developing male gametes, known as sperm). Semen volume, viability and motility both decrease and DNA damage increases. Can cause an increase in time to pregnancy.
What happens in terms of fertility as women get older?
increased aneuploidy (wrong amount of chromosomes)/ decreased euploidy (right amount of chromosomes), this may increase spontaneous abortion and implantation lost. Also overall lower fertility.
Obesities effect on male fertility?
more likely to exhibit a decrease in semen quality, concentration and motility. Increase in sperm DNA damage. Erectile dysfunction more comon likely because increased adipose can result in more of the enzyme that converts androgens to estradiol. Decreased inhibin B decreases Sertoli cells (involved in sperm production) and sperm production. Increased levels of leptin which can lead to decrease in leptin receptors in the testes (leptin resistance) could play a negative role in male fertility.
Obesities effect on women’s fertility?
Higher rates of miscarriage may be due to endometrium (womb lining) receptiveness or higher rates of aneuploidy. Also a decreased implantation (where egg buries itself into womb lining). This could be because of increase in follicular fluid levels of insulin, lactate, triglycerides, and C-reactive protein; there may also be decreases in SHBG. These effects of obesity may be reversible.
Impact of being underweight on fertility?
Men: lower sperm concentrations
Women: ovarian dysfunction and infertility, preterm births, women with eating disorders may be at a higher risk of infertility.
Physical exercise and fertility?
Men: physical exercise aided male fertility, decreased DNA damage and ROS except it seems over 5 hours of cycling.
Women: exercise with weight loss for obese women is good for fertility but excessive exercise isn’t because a negative energy balance may occur and may result in hypothalamic dysfunction and alterations in gonadotropin-releasing hormone (GnRH) pulsality, leading to menstrual abnormalities, particularly among female athletes. IVF women suffer if they do excessive exercise. Normal amount of exercise appears to be fine.
Stresses effect on fertility for men?
Two or more stressful events means that a man is likely to be below WHOs standards for sperm concentration, motility and morphology. Stress and depression are thought to reduce testosterone and luteinizing hormone (LH) pulsing, disrupt gonadal function [64], and ultimately reduce spermatogenesis and sperm parameters. It was reported that actively coping with stress, such as being assertive or confrontational, may negatively impact fertility [69,70], by increasing adrenergic activation, leading to more vasoconstriction in the testes. This vasoconstriction results in lower testosterone levels and decreased spermatogenesis.
Stresses effect on women’s fertility?
Stress is bad for fertility, receiving some group cognitive intervention or who were part of a support group or working less hours can help. Anxiety is correlated with still births. Alpha amylase (a biomarker of stress), but not cortisol nor adrenalin may decrease fertility mechanisms are unknown, but it is hypothesized that catecholamine receptors could alter the blood flow in the fallopian tubes
Dietary requirements for folate in men and women? why are they the same?
The RNI for both men and women has been set at 200 μg/d, since the slightly smaller requirement for women due to lower lean body mass may be offset by a greater requirement for reproduction (Department of Health 1991)
