Other Gender Swaying Factors
Numerous other factors have been discussed throughout history as potential swaying factors. The following summarises these factors and the current state of research on their influence on gender outcomes.
Click on the below factors to learn more (members only).
INTRODUCTION
While the maternal diet prior to conception holds the most substantial scientific evidence for influencing a baby's gender, numerous other factors have been discussed throughout history. At Sway Natural, we have spent years studying and analyzing these factors. We continuously monitor further research and developments in the scientific world to stay up to date. Below, you will find a summary of these factors, focusing on the key underlying beliefs and the scientific evidence that evaluates their impact on gender outcomes.
Subscribe to our newsletter to learn more about each factor as we continue to publish in-depth articles exploring these topics and to stay informed about new developments in the field. Feel free to reach out if you would like to discuss any of these factors in greater detail. And rest assured, we take all of these factors into account when providing you with personalised meal plans.
TRIVERS-WILLARD
The Trivers-Willard theory, introduced in 1973 by Robert Trivers and Dan Willard, has garnered considerable research attention as an important framework for understanding gender swaying. This theory suggests that the sex ratio of offspring is influenced by parental condition and resource availability, with parents in good condition favoring male offspring and parents in poor condition favoring female offspring. Throughout the years, numerous studies have offered empirical evidence both supporting and questioning the theory, establishing it as a crucial paradigm for examining factors that affect gender outcomes in both animals and humans.
Within the Trivers-Willard theory, multiple aspect of the parent’s conditions and resources have been researched. Below we discuss the most important ones.
MOTHER'S WEIGHT / BMI
Maternal condition, encompassing factors such as weight, body mass index (BMI), and muscle mass, has been consistently linked to gender outcomes in various studies. For example, Cagnacci et al. (2004) found that higher maternal pre-pregnancy weight and greater muscle mass increased the likelihood of conceiving a boy. Similarly, Almond & Edlund (2007) discovered that heavier pregnant women in the United States were more likely to have male babies, and maternal obesity was associated with an increase in the male-to-female birth ratio. Other studies, such as those by Tamimi et al. (2003), Steiner et al. (2012), and Catalano et al. (2016), have also found correlations between maternal BMI and the probability of having male offspring.
Additional research has further supported the connection between maternal condition and gender outcomes. Myatt et al. (2010) found that taller women with higher BMI were more likely to have male offspring, while Graffelman et al. (2007) and Sundaram et al. (2014) both reported a positive association between maternal BMI and the likelihood of having a male infant. These findings, along with other research in the field, provide evidence that maternal condition, including factors such as weight and BMI, can influence the gender outcome of offspring.
PARENT'S AGE
Some studies have investigated the potential impact of maternal age on gender outcome, suggesting that there may be a link between a mother's age and the sex of her baby. For instance, Nicolich (2000) and Franasiak (2013) found that younger women were more likely to have boys, while older women were more likely to have girls. However, it is important to note that the evidence for this relationship is limited and not conclusive.
The same applies for the relationship between paternal age and gender outcome, with some studies suggesting a weak association between older fathers and a higher likelihood of having daughters. For example, Jacobsen et al. (1999) analyzed Danish birth records and found a weak association between increasing paternal age and a decreasing proportion of male births. Ruder (1985) investigated over 3 million live births in the United States and reported a small decrease in the male-to-female ratio with increasing paternal age, although the effect size was modest.
NUTRITION
Many studies confirm a link between maternal diet and gender outcome, with the most significant evidence highlighting the influence of specific minerals, which is the primary focus of the boy and girl diets within Sway Natural. Beyond the impact of these minerals, various other factors have been assessed and found to have positive associations with gender outcome.
Malnutrition has been associated with increased female births (Jongbloet et al., 2001; Koziel & Ulijaszek, 2001). This could be partly due to malnutrition implying less consumption of fruits and vegetables, which are often high in potassium, a mineral linked to having a son. However, malnutrition cannot be the answer, as the primary goal should always be a healthy pregnancy and good start for your baby. Fruits and vegetables, which are important sources of vitamins and other minerals, should be chosen carefully when trying to sway for a girl.
Research has revealed associations between caloric intake and gender outcomes. For instance, Mathews et al. (2008) found that women with higher caloric intake before pregnancy were more likely to have boys, while those with lower caloric intake were more likely to have girls. Similar findings were reported by Wells et al. (2011) and Gibson & Mace (2003). Lower caloric intake can be considered for the daughter diet and higher caloric intake for the son diet within healthy limits.
Some studies, such as Dorgan et al. (2003), Enright et al., and Rosenfeld et al. (2003), have suggested a potential link between dietary fat intake and gender outcomes. Rosenfeld et al. (2003) reported that the source of calories in a nutritionally complete diet influenced the sex of offspring born in mice, with a high-fat diet leading to a higher male offspring ratio and a low-fat, high-carbohydrate diet resulting in a lower male offspring ratio. This could be related to the impact of fat on steroid hormone concentrations.
Limited research suggests a slight link between vegetarianism or veganism and gender outcomes (Hudson and Buckley, 2000; Berkowitz et al., 2018).
There is also a lack of scientific studies researching a link between the acidity or alkalinity of foods and gender outcome. The only study supporting this idea was conducted by Stolkowski and Malinowski (1977) on rabbits, which found a correlation between the alkalinity or acidity of the diet and the sex of offspring. The study suggested that a more alkaline diet might increase the chances of conceiving a male offspring, while a more acidic diet might favor female offspring. However, due to the study's age and limited scope, it is difficult to draw firm conclusions about its relevance to humans.
Sway Natural takes these additional nutrition-related factors into account when developing personalized food plans, ensuring an optimal, healthy diet for those looking to sway for a son or a daughter, while focusing on preparing for a healthy pregnancy.
CEREALS, GRAINS, SEEDS & NUTS
Cereals, grains, seeds and nuts are your main source of magnesium – so go nuts (all without salt of course!)
Category A – PERFECT: Contains calcium and magnesium but low in potassium and sodium: Sesame, Poppy seeds, Chia seeds
Category B – YES, high in magnesium (>10% of your daily intake) while moderate in potassium (up to 5% of your daily intake) and low in sodium and calcium: Cooked milet or millet flakes, Pine nuts, Cashews, Brazil nuts or Almonds, Sunflower seeds, Barley flakes, Cocoa powder, Flax seeds. Very good are pumpkin seeds, with one portion (20g) delivering >25% of your target magnesium intake while only having 5% of your max. potassium intake.
Category C – OK, high in magnesium (>10% of your daily intake) while potassium is <10% of your daily intake) and low in sodium: Multigrains, Amaranth, Oats, Wheat, Spelt flakes, Quinoa (cooked), Hemp seeds, Rye flakes, Teff, Barley
Category D – IN MODERATION: Couscous (cooked), Coconut (desiccated), Pistachios (unsalted), Gojis, Edamame
Category E - AVOID: Corn flakes and most other breakfast cereals (check the label for sodium), Chestnuts
STRESS & SPORT
The impact of stress and sport on gender outcome has been the subject of several scientific studies, with mixed results. One study, published in the journal Fertility and Sterility in 2010, found that women who reported higher stress levels were more likely to conceive girls than boys, suggesting that stress may affect the ratio of X and Y chromosome-bearing sperm, leading to a higher likelihood of female conception.
Another study, published in the Journal of Assisted Reproduction and Genetics in 2018, found that women who participated in competitive sports were more likely to have boys than girls, while women who engaged in recreational sports had a higher likelihood of conceiving girls.
The researchers suggested that the impact of sports on gender outcome could be due to differences in hormone levels and other factors. For example, competitive sports might lead to increased levels of testosterone, which is associated with male fetuses. Conversely, recreational sports might be associated with more relaxed environments, leading to a higher likelihood of female conception.
It's important to note, however, that these studies are limited in scope and have yet to establish a definitive link between stress, sports, and gender outcome. While the available evidence suggests that these factors may play a role in influencing the likelihood of conceiving a specific gender, these findings are not definitive, and more research is needed to fully understand the mechanisms underlying these associations.
TIMING
The impact of timing of intercourse on gender outcome has been a topic of research and debate for decades. In the 1960s, Dr. Landrum Brewer Shettles claimed that the timing of intercourse relative to ovulation could influence the gender outcome, with earlier intercourse favoring female offspring and intercourse closer to ovulation favoring male offspring. He proposed the idea that male Y-sperm swim faster, while female X-sperm are more resilient and stay around longer. Based on this assumption, he developed the 'Shettles method', which suggests having intercourse four to six days before ovulation and then abstaining to increase the chances of conceiving a girl. This method became popular and is still followed by some couples.
However, subsequent studies have debunked Shettles' findings. The development of computer-assisted sperm analysis (CASA) revealed no significant morphological differences between human X and Y sperm, and it was found that Y sperm do not swim faster than X sperm. Further research either found no impact of timing on the baby's gender or discovered a slightly higher chance of conceiving a girl during the most fertile days of the cycle, which are around the day of ovulation. This evidence contradicts the Shettles method. For more details on research on timing, click here.
If you still decide to follow the popular Shettles method, suggesting abstaining from intercourse four to six days before ovulation to conceive a girl, be aware that this can significantly reduce your overall probability of becoming pregnant. To learn how to track your menstrual cycle, click here.
INTERCOURSE
Some people believe that certain sexual positions might influence the gender of the baby based on the idea that different positions can alter the environment in which sperm must travel.
For example, shallow penetration, such as in the missionary position, is thought to favor the conception of girls, as the sperm is deposited further from the cervix, creating a longer and more challenging journey for the male sperm. In contrast, deeper penetration, like in doggy style or standing up, is believed to increase the chances of having boys, as the sperm is deposited closer to the cervix, giving the faster male sperm a better opportunity to reach the egg before their female counterparts. This belief is primarily based on the Shettles method, which posits that male sperm (Y chromosome-bearing) are faster swimmers but less resilient than female sperm (X chromosome-bearing). Consequently, the method suggests that varying the penetration depth can impact the likelihood of male or female sperm reaching the egg first.
However, it's important to note that the idea that male and female sperm exhibit different swimming characteristics has been challenged by scientific research. Studies have shown no significant differences in the speed or resilience of X and Y chromosome-bearing sperm. As such, the premise of sexual positions influencing baby gender lacks a strong scientific foundation.
Furthermore, there is no scientific evidence to support these claims. Several scientific studies have investigated the relationship between sexual position and gender outcome, and none have found a significant correlation. For example, a study published in the Journal of Assisted Reproduction and Genetics in 2014 examined the impact of sexual position on gender outcome in couples undergoing intrauterine insemination (IUI). The study found no significant difference in gender outcome between different sexual positions. Similarly, a study published in the Journal of Obstetrics and Gynaecology Research in 2017 found no correlation between sexual position and gender outcome in couples undergoing in vitro fertilization (IVF).
The relationship between the sequence of orgasms and gender outcome has been been rarely studied, and available evidence does not support a significant impact. Shettles (1970) proposed a theory based on timing and sequence of orgasms, but it has been criticised for methodological flaws. Song (2012) found no association between orgasm sequence and the secondary sex ratio.
HORMONES
Research in recent years has suggested that parental hormones, specifically testosterone and estrogen levels, around the time of conception may have a significant influence on the gender outcome of offspring.
Multiple studies have explored the relationship between maternal hormones and sex ratios, demonstrating that mothers with higher testosterone levels are more likely to give birth to sons (Grant et al., 2001; Grant, 2007). Higher testosterone levels in women have also been correlated with increased dominance, which may further influence sex ratios (Grant and France, 2001). This relationship has been observed in both humans and other mammalian species, suggesting a common biological mechanism (Veiga et al., 2004).
The hormonal hypothesis of sex determination, proposed by James (2008), suggests that the probability of a male birth varies positively with some function of parental estrogen, testosterone, gonadotrophins, and progesterone concentrations around the time of conception. This hypothesis posits that the balance of these hormones in both parents, particularly the mother, may determine the likelihood of conceiving a male or female child. Factors such as diet, stress, and overall health can influence hormonal levels, potentially affecting the sex ratio of offspring.
Findings from Dorgan et al. (2003) support this hypothesis, as they reported a positive correlation between dietary fat intake and steroid hormone concentrations in humans, potentially influencing sex ratios. Although the exact mechanisms behind the correlations between hormones and gender outcomes remain complex and not fully understood, the available evidence does point towards a link between parental hormone levels and offspring sex ratios.
GENETICS
There is a common belief that a person's DNA or genes can determine the gender of their future child. However, research suggests that this is not the case.
In a study published in the journal Human Reproduction in 2019, researchers investigated whether variations in genes related to sex hormone production and metabolism were associated with the probability of having a male or female baby. The study, which involved over 6,000 couples, found no significant association between these genetic variations and the probability of having a boy or a girl.
Similarly, a review published in the Journal of Assisted Reproduction and Genetics in 2017 analyzed studies investigating the impact of genetic factors on gender outcome. The review found no conclusive evidence to support the idea that genes play a significant role in determining the gender of a baby.
In summary, while some people may believe that having a girl or boy lies in their DNA, scientific evidence suggests that this is not the case.
SEASONS
There is no strong evidence to suggest a correlation between seasons and the gender of babies. A number of studies have explored the potential associations between birth season and gender ratio, but the findings are generally inconsistent and lack consensus Grech et al. (2002) and Torche & Corvalan (2010) explored the potential associations between birth season and gender ratio but found no strong evidence to suggest a correlation between seasons and the gender of babies. In their studies, they observed minor variations in the sex ratio at birth across different seasons or months, but these differences were often not statistically significant and may be due to random fluctuations or confounding factors. Chahnazarian (1988) and Roenneberg & Aschoff (1990) also conducted research on this topic and reached similar conclusions, indicating that the impact of seasonality on gender outcome is not well-established and may be negligible.
PROFESSIONS
A common belief suggests that pilots have more daughters, but the evidence is mixed. A study by Jongbloet et al. (2001) found a higher proportion of female offspring among male pilots, while another by Graffelman & Hoekstra (2000) reported no significant association between paternal occupation and offspring sex ratio.
Research on physically demanding occupations has also produced mixed results. James (2008) found that women in such jobs had a higher proportion of male offspring, which may be linked to higher muscle mass. However, Jasienska et al. (2006) found no significant associations between maternal occupation and offspring sex ratio.
Other occupations, such as military personnel, firefighters, and agricultural workers, have been investigated for their potential impact on offspring gender ratios. For military personnel, some studies (Davis et al., 1998; Joffe, 2003) found a higher proportion of male offspring, especially for those exposed to certain environmental factors. Research on firefighters has produced mixed results, with Kocak et al. (2001) reporting a higher proportion of female offspring, while other studies (Olshan et al., 1990; Infante-Rivard et al., 2002) found no significant associations. Agricultural workers exposed to pesticides have been suggested to have a skewed sex ratio in their offspring, with some studies indicating a higher proportion of male offspring (Petrelli & Figa-Talamanca, 2001; Larsen et al., 1998), but the evidence is not consistent, as other studies did not find any significant associations (Mocarelli et al., 2000).
Overall, the evidence linking specific occupations to offspring sex ratios is limited, inconsistent, and inconclusive.
SUPPLEMENTS
Magnesium and calcium supplements are often recommended for swaying towards conceiving a girl, and potassium for a boy, which is in line with the proposed diet changes at Sway natural. However, there is no research confirming that these supplements have the same effects as actual dietary changes. Therefore, while they may complement the gender-specific diets, they cannot replace real food adjustments. Other supplements, with limited scientific evidence, are also recommended for gender swaying. Some people believe that these supplements could potentially influence the chances of conceiving a specific gender based on their purported effects on certain aspects of reproductive biology, which we have discussed before.
Girl Supplements
Although there are no definitive scientific studies supporting the use of certain supplements for gender swaying, some believe they might influence the chances of conceiving a specific gender due to their supposed effects on reproductive biology. It is crucial to emphasize that the relationship between these supplements and gender swaying is speculative. Before taking any supplements, it is essential to consult a healthcare professional for guidance.
Probiotics: Some people believe that certain probiotics, like Lactobacillus acidophilus, can lower the pH levels in the vaginal environment, making it more acidic and potentially less favorable for Y-chromosome (male) sperm. However, there is no conclusive scientific evidence to support this claim, and the relationship between probiotics, vaginal pH, and gender swaying remains speculative.
Cranberries: The belief that cranberries can influence gender swaying is similarly based on the idea that they can lower the pH level of the vaginal environment, making it more acidic. A study by P. J. Skerrett (2001) found that cranberries can lower urinary pH, but the effect on the vaginal pH and its relation to gender swaying has not been established.
Saw Palmetto: Some people believe that saw palmetto can lower testosterone levels, which might theoretically favor the conception of a girl. A study by Carrillo et al. (1984) found that saw palmetto extract inhibited testosterone metabolism, but the relationship between saw palmetto and gender swaying remains speculative.
Licorice Root: Licorice root is believed to have estrogenic effects, potentially lowering testosterone levels in men and increasing estrogen levels. A study by Armanini et al. (2004) found that licorice root can reduce serum testosterone in men, but there is no clear evidence to support the idea that this effect would directly influence gender swaying.
Boy Supplements
While there is limited scientific evidence to support the claims of supplements that some people believe can increase the chances of conceiving a boy, here are some examples:
Evening primrose oil and flaxseed oil are believed to increase the production of cervical mucus, potentially improving the chances of conceiving a boy.
FertileCM for Women is marketed as a fertility supplement, and it is believed to increase the production of alkaline cervical mucus, while guaifenesin expectorant is believed to thin cervical mucus to increase the chances of conceiving a boy.
Green tea is believed to improve cervical mucus and overall fertility, potentially increasing the chances of conceiving a boy.
Women's Best Friend: This supplement contains herbs that are believed to regulate hormones and reduce excess estrogen, potentially increasing the chances of conceiving a boy.
American Ginseng: American ginseng is believed to raise testosterone levels, potentially increasing the chances of conceiving a boy.
Please note that while some people believe these supplements can influence the chances of conceiving a specific gender, there is limited scientific evidence to support these claims. It is important to consult a healthcare professional before taking any supplements as they may have other negative health impacts on you.
BLOOD PRESSURE
The relationship between maternal blood pressure and gender outcome remains uncertain, with limited and inconclusive research. Some studies, such as Retnakaran et al. (2018), suggest a correlation between higher pre-pregnancy systolic blood pressure and increased likelihood of having a male child. In contrast, Elsmén et al. (2004) found no significant association between maternal blood pressure and offspring sex ratios.
CHINESE GENDER CALENDAR
The Chinese Gender Calendar, also known as the Chinese Gender Predictor or Chinese Birth Chart, is an ancient tool rooted in Chinese astrology and folklore. It can be found on websites like Your Chinese Astrology, The Chinese Gender Predictor, and Prokerala, which provide interactive tools for obtaining a gender prediction based on the chart. The calendar claims to predict a baby's gender based on the mother's age at conception and the lunar month of conception. However, this method is not scientifically proven and should be used for entertainment purposes only.
THE MOON
The idea that the moon can influence a baby's gender likely stems from ancient beliefs and folklore rather than scientific research. The moon's gravitational pull does affect ocean tides and has been thought to influence certain biological processes, such as menstrual cycles. However, research on the moon's influence on human reproduction and gender outcome is scarce, and the existing studies have not provided convincing evidence to support these claims.
IONS
There is currently no scientific evidence to support the theory that exposing yourself to negative or positive ions has an impact on the gender outcome of conception. The belief that ions can influence gender swaying is not supported by any studies or scientific research. While ions do play a role in many physiological processes in the body, there is no clear evidence to suggest that they have any direct impact on the sex of the baby conceived.
LEFT / RIGHT TESTICLE
The belief that the right and left testicles of a man produce different types of sperm, can be traced back to ancient Greek philosophy. Anaxagoras, a philosopher from the 5th century B.C., was one of the early proponents of this theory, suggesting that the right testicle produced male sperm, while the left produced female sperm. This belief persisted through the centuries, leading to various practices aimed at influencing the gender of offspring. For example, some men would bind their left testicle before intercourse to increase the chances of conceiving a male child, known as the "left testicle doctrine., In the 18th century, it was suggested that a man should lie on the left side of a woman during intercourse to enhance the chances of male offspring.
Not surprisingly, scientific research has found no evidence to support this theory. Both testicles produce the same type of sperm, containing either an X or Y chromosome, which determines the gender of the offspring. A study by Arslan et al. (2014) in the Journal of Assisted Reproduction and Genetics confirms that there is no significant difference in the quality or quantity of sperm produced by each testicle. Despite this, the belief in the right and left testicles producing different types of sperm continues to persist in some cultures and communities.