The theory claims that the location of the placenta, or trophoblast, can define fetal gender as early as six weeks via ultrasound. If the placenta is developing on the left side, the sex is female. If it is developing on the right, the sex is male.
This is what eventually grows into a penis (or a clitoris, in the case of a girl) and it's what the technician will look at most closely to determine your baby's sex. If it's angled upward when looking at baby from the side, you're likely having a boy.
Drawing on this data, they concluded that a placenta on the right side usually indicates a male fetus, while a placenta on the left side is a sign that a fetus is female. This distinction is the basis of the Ramzi theory.
It must be noted that the placenta only develops when a woman is expecting a baby, and it attaches to the wall of the uterus. The position of the placenta can be anywhere—front, back, right, or left.
According to the theory, the placement of your developing placenta can reveal your baby's sex. If your placenta is forming on the right side of your uterus, the baby is most likely a boy, the theory claims. If it's forming on the left side, it's probably a girl.
Or that if you feel your baby moving more on the right side, then you're probably having a boy. But there's no evidence that there's a difference between the movements of boys and girls in the womb (Medina et al 2003).
The right side of the brain is the side responsible for language and interpreting emotional signals, amongst other things. Therefore, when a baby is held on the left, the mother better able to interpret it's physical and emotional cues.
Research shows girls kick as often as boys. Babies who kick a lot in the womb are also more active after birth.
A recent study suggests that carrying a male or female foetus could lead to different immune responses in pregnant women. Pregnant women carrying girls have a greater chance of experiencing nausea and fatigue, according to the results of a study from the USA's Ohio State University Wexner Medical Center.
You will start to feel your baby moving between 16 and 24 weeks of pregnancy. The location of your placenta will not affect this sensation. It is more common for women having their second or subsequent pregnancies to feel their baby move earlier.
Your midwife should be able to tell you during an ultrasound which way round your baby is lying. Saying that, babies will move position during pregnancy and birth.
Baby's position.
Babies are constantly on the move in the womb. They might stretch and push in all different directions. They might also favor one side of the belly over the other, so a head or a back will bulge to one side.
Two variables determine the nature of a pregnant woman's bump. The first is the size of the baby. It is true that on average baby boys weigh more at birth than baby girls, and so this could make the bump for a boy slightly bigger. But this small difference in weight does not change the shape of the bump.
Conclusion. The Chinese birth calendar claims 93-99% accuracy in predicting infant gender based on month of conception and maternal age at delivery. In this large delivery dataset, accurate prediction of fetal gender based on the Chinese birth calendar was no better than a coin toss.
You might get some useful clues about your baby's position from where the kicks are felt. Head-down babies will kick more strongly on one side and towards the top of the bump.
It's all about Dad's genes
A man's X and a woman's X combine to become a girl, and a man's Y combines with a woman's X to become a boy. But if the sperm don't have equal Xs and Ys, or if other genetic factors are at play, it can affect the sex ratio.
Nature is designed to favour the conception of boys from September to November and girls from March to May because of an evolutionary mechanism aimed at keeping the overall sex ratio as near to 50:50 as possible, the scientists said.
Experts recommend lying on your left side. It improves circulation, giving nutrient-packed blood an easier route from your heart to the placenta to nourish your baby. Lying on the left side also keeps your expanding body weight from pushing down too hard on your liver. While either side is okay, left is best.
Just like newborns, fetuses spend most of their time sleeping. Indeed, throughout much of the pregnancy, your baby sleeps 90 to 95% of the day. Some of these hours are spent in deep sleep, some in REM sleep, and some in an indeterminate state—a result of their immature brain.
Boys' and girls' genitals develop along the same path with no outward sign of gender until about nine weeks. It's at that point that the genital tubercle begins to develop into a penis or clitoris. However, it's not until 14 or 15 weeks that you can clearly begin to see the differentiated genitalia.
Women carrying a male fetus have significantly increased maternal weight gain during pregnancy when compared to women with a female fetus. The increased sex ratio remains when adjusting for each newborn weight group.
The energy intake of pregnant women is about 10% higher when they are carrying a boy rather than a girl. Our findings support the hypothesis that women carrying male rather than female embryos may have higher energy requirements and that male embryos may be more susceptible to energy restriction.