Why do men like women with thin waists and big hips?

What kind of women are most attractive to men? A widely circulated joke says: No matter how many advantages a woman has, men will ultimately choose the one with big breasts. However, researchers at the University of Wellington in New Zealand found that women with slim waists and big hips are the most attractive to men.

Researchers analyzed that waist-to-hip ratio is the determining factor in men's attractiveness. A thin waist and big hips indicate that a woman is healthy and has strong fertility, and is more sexually attractive to men in the process of evolution. And big breasts can give people aesthetic pleasure.

The researchers randomly selected 36 male subjects ranging in age from 22 to 42 years old. Without knowing the content of the test in advance, the researchers showed each subject the same frontal photo of a woman. Instruments were used to record the time and specific location of their gaze on the photos. The researchers then used software to modify the measurements of the women in the photos and showed them to the men again. The results showed that an increase in bust size does not increase a woman's attractiveness to men, but a change in waist-to-hip ratio does increase her attractiveness to men.

1. Is it true that having a big butt is good for giving birth?

Experts say: Childbirth is a complex subject that tests the mother's self-confidence and the doctor's clinical experience. Relying on the mother's big buttocks cannot guarantee a smooth delivery.

2. Big hips = big external pelvic structure

The buttocks are covered by the bone tissue and soft tissue of the pelvis: the bone tissue is what we often call the skeleton, and the soft tissue is fat. Are the big buttocks visible to the naked eye because the passage (pelvic entrance and exit) through which the fetus must pass during delivery is large, or are they large because of fat hypertrophy? If it is because of thick fat, then it is not only of no help to normal delivery, but may even have a negative impact.

Types of Pelvis

Because the female pelvis and the planes of each pelvis vary greatly, it is impossible to make a rigid classification of the pelvis. For practical purposes, we can divide the pelvis into the following types according to the shape of the pelvic inlet:

1. Female type, that is, round or transversely oval.

2. Men's style, that is, heart-shaped or wedge-shaped.

3. The ape style, which is long front and back oval.

4. Flat type, that is, transversely oval, but the anterior-posterior diameter is very short.

Among these four types of pelvises, the "female type" and "ape type" are more conducive to childbirth. Both the "male style" and the "flat style" are not conducive to vaginal delivery. Of course, the shape of the pelvis cannot be seen with the naked eye, and the idea that women with bigger butts are more likely to give birth is just speculation.

4. You can measure your pelvic size yourself

The pelvis is composed of the sacrum , coccyx, and two hip bones (formed by the fusion of the ilium, ischium, and pubis). Want to know how big your pelvis is?

Experts tell you how to measure your pelvis by yourself: put your hands on your hips and look down, you can feel some arc-shaped bones on both sides of the body, which are the ilium; go down to the place commonly known as the coccyx, which is the coccyx; the section below the waist and above the coccyx is the sacrum ; then the one you feel above the perineum is the pubic bone; finally, sit down, the protruding bone you feel when you sit is the ischium. The parts touched above roughly cover the entire pelvis.

So, what does a successful natural birth have to do with? The pelvis is only one important factor that affects childbirth. Other factors such as labor force, the mother's psychological state, uterine contraction state, fetal size, delivery posture, etc. are all key. Among them, factors such as labor force, birth canal, fetus, and labor pain are particularly important.

5. Productivity

The force that pushes the fetus and its appendages out of the uterus is called labor force. Labor force includes uterine contraction (abbreviated as uterine contraction), abdominal muscle and diaphragm contraction (collectively referred to as abdominal pressure) and levator ani muscle contraction.

1. Uterine contraction is the main force of labor after delivery and runs through the entire delivery process. Uterine contractions after labor can force the cervical canal to shorten until it disappears, the cervix to dilate, the fetal presenting part to descend, and the placenta and fetal membranes to be delivered.

2. The contraction force of the abdominal muscles and prostate muscles The contraction force of the abdominal wall muscles and diaphragm (abdominal pressure) is an important auxiliary force for delivering the fetus during the second stage of labor.

3. Contraction force of the levator ani muscle The contraction force of the levator ani muscle helps the fetal presenting part to rotate internally in the pelvic cavity. When the occipital part of the fetal head is exposed under the pubic arch, it can assist in the extension of the fetal head and delivery. After the fetus is delivered, when the placenta descends into the vagina, the contraction of the levator ani muscles helps the placenta to be delivered.

The mother will feel that each contraction becomes stronger and stronger, and after maintaining for a certain period of time, it gradually weakens and disappears. Later, the interval between two contractions gradually shortens and the duration of contractions gradually lengthens. This is the uterine contraction before delivery, also known as labor pains.

Uterine contractions initially occur every 20-30 minutes, gradually shortening to every 15 minutes, 10 minutes or even every 5 minutes, and the duration of contractions increases from the initial 20 seconds to 40 seconds or even 1 minute.

The time between contractions, duration and intensity of contractions are regular. As the time between contractions shortens and the duration of contractions increases, the intensity of contractions will continue to increase, and the time of delivery will be approaching. Under the action of uterine muscle contraction, the fetal membrane ruptures. The compressed fetus can no longer stay in the uterine cavity and slowly moves toward the cervical opening. The cervical opening begins to expand and expel the fetus out.

If the uterine contraction is too strong and the labor process is too short, it will cause birth canal laceration; if the labor process is too long, it means that the uterus is not contracting well or the fetus and pelvis are not matched, which should be dealt with in time and a caesarean section should be performed if necessary.

6. Birth Canal

The birth canal is the passage through which the fetus is delivered, and it is divided into two parts: the bony birth canal and the soft birth canal.

1. Bony birth canal The bony birth canal refers to the true pelvis, which is an important part of the birth canal. The size and shape of the bony birth canal are closely related to delivery.

2. Soft birth canal The soft birth canal is a curved tube formed by the lower segment of the uterus, cervix, vagina and soft tissue of the pelvic floor.

7. Fetus

Whether the fetus can pass through the birth canal smoothly depends not only on the force of labor and the birth canal, but also on the size of the fetus, the fetal position and the presence of any deformities.

1. Fetal size During the delivery process, fetal size is one of the important factors that determine the difficulty of delivery. When the fetus is too large compared to the diameter of the fetal head, even though the pelvis is normally large, the skull is harder and the fetal head is not easy to deform, which can cause relative cephalopelvic disproportion and lead to dystocia. This is because the fetal head is the largest part of the fetus and is also the most difficult part for the fetus to pass through the birth canal.

2. The birth canal is a longitudinal tube. If it is a longitudinal birth (head first or breech first presentation), the longitudinal axis of the fetus is consistent with the pelvic axis, making it easy to pass through the birth canal. Occipital presentation is when the fetal head passes through the birth canal first, which is easier to deliver than breech presentation, but the sagittal suture and anterior and posterior fontanelles must be palpated to determine the fetal position.

The sagittal suture and fontanelle are important landmarks for determining fetal position. When the head is presented first, the skull bones overlap during delivery, causing the fetal head to deform and its circumference to become smaller, which is facilitating the delivery of the fetal head. When the buttocks are presented first, the buttocks are delivered first. They are smaller and softer than the fetal head. The vagina will not expand fully, and there is no chance of deformation when the fetal head is delivered, making delivery of the fetal head difficult. When the shoulder is presented first, the longitudinal axis of the fetus is perpendicular to the pelvic axis, and a full-term living fetus cannot pass through the birth canal, posing a great threat to the mother and child.