Posted in Science & Nature

Caesarean Section

(To read about how babies are made and born, read the From Cell to Birth miniseries! https://jineralknowledge.com/tag/arkrepro/?order=asc)

Most animals give birth through a female’s vagina. Of course humans are the same when it comes to natural birth, but nowadays, it is not uncommon to find women wanting a caesarean instead of the traditional method. A caesarean (also called C-section) is a surgical procedure where the fetus is taken out by cutting through the lower abdomen into the uterus. The history of caesareans is quite dark. Back in the old days when medicine was not advanced, caesareans were mostly used to rescue fetuses from mothers who had died during childbirth. The first record of a successful caesarean where the mother survived dates back to the 1500s. Many people believe the word “caesarean” came from the Roman emperor Julius Caesar, who was allegedly born via a caesarean. However, it was rare for caesareans to be performed in Roman times and even if they were, the mothers almost certainly died in the process. Given that his mother was alive and healthy well into his adulthood, it is highly unlikely that Caesar was born by caesarean (there are no concrete records of it either).

There is much debate to whether a caesarean is better or worse than natural birth (except in emergency situations where a caesarean is required). According to research (in cases without known risks to the fetus), the mortality rate is definitely higher in babies born by caesarean compared to those born naturally. This is most likely due to a caesarean bypassing some of the physiological changes that occur during vaginal birth.

Another debate is about the use of general versus regional anaesthesia (spinal block) when doing a caesarean. A fascinating fact about childbirth is that when a baby is born, it cries to expand its lungs but then quietens down for about an hour (unless it is in pain or there is some stimuli). This is possibly a mechanism to allow bonding between the mother and baby. New mothers often remember the moments following the birth of the child as extremely emotional and blissful. Contrastingly, mothers who are under general anaesthesia and not awake when their child is born bond less with the baby initially (some mothers do not even recognise the baby as their own). Thus, unless it is an emergency caesarean, a spinal block (which allows the mother to be awake and painless) is preferable over general anaesthesia.

Lastly, it is common tradition to cut the umbilical cord straight after the child is born. But is this okay? When the fetus is in the uterus, it shares its cardiovascular system with the placenta. The umbilical cord connects the two and carries blood to and fro. At any given point, the placenta contains 30~50% of the fetal blood. If the umbilical cord is suddenly cut, the fetus essentially loses this blood, being born in a state of low blood volume. If you look at the umbilical cord, you can see that it is about 1m in length, which is enough for the baby to be put next to the mother’s breasts for breastfeeding and bonding. Perhaps we are cutting the cord too soon, not letting the blood flow back from the placenta to the fetus.

If you think about it, humanity has been giving birth without too many problems to survive generation after generation for 200,000 years (otherwise we would not exist). Although the mortality rate was high, Mother Nature has optimised childbirth over time through evolution. Ergo, it is possible that modern medicine is intervening too much in a natural process. We must always consider whether medical advances are helpful or harmful to us.

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Posted in Science & Nature

Grandmother Hypothesis

There are many physiological events that puzzle scientists. Menopause is one of these as it is very uncommon in other mammals. Why do human females stop having periods after aging? From an evolutionary point of view, an organism that has lost reproductive function cannot aid evolution and thus it is a mystery how a trait like menopause survived natural selection. The leading theory in how such a phenomenon happened is the grandmother hypothesis.

According to this hypothesis, as humans are social animals menopause can still be an evolutionary advantage despite not being able to produce offspring. This is because older women can invest the massive amount of energy and time required to upkeep childbearing in other places. For example, they can help their family and society grow by working or taking care of children instead. Furthermore, as the probability of miscarriages and congenital defects rise with aging (generally after a woman hits the age of 30, the chances of a healthy pregnancy decreases), menopause has the function of protecting the gene pool of the species. These facts combined lead to the conclusion that after an individual has reached a certain age, taking care of their children or grandchildren instead of birthing more offspring is more effective in propagating their own genes. Also, there is no one that can propagate massive amounts of wisdom and information to the next generation like the elderly.

In modern society, menopause has more significance than at any point in the history of human beings. As our average life span has surpassed 80 and heading towards 90, almost half of a woman’s life is post-menopause. In some ways, the grandmother hypothesis contains within it a certain philosophy regarding life. As we age, we give birth to children and raise them until they become independent, at which point we escape our basic biological duty of reproducing to lead our “own” lives. Senescence is like a second spring after one’s “biological” life. It is the start to a new life – a more “human” life of your own where you can focus on seeking pure happiness.

Posted in Science & Nature

From Cell To Birth: Childbirth

The onset of labour signals that the birth of the child is imminent. Strong contractions of the uterus under the influence of oxytocin cause intense pain for the mother. This escalates as oxytocin creates a vicious cycle for more and more powerful contractions. Other signs include a bloody show, where blood and mucus leaks out, and the water breaking, where amniotic fluid bursts out as the membranes rupture.
When the cervix has fully dilated to 10cm wide, the baby is ready to come out, and this is the end of the first stage. It may take over 24 hours for this stage to be over – all the while the mother is in extreme pain as her body transforms for the process.

The second stage concerns the delivery of the baby, and follows a precise series of steps.

  1. The baby, oriented head-down, facing either right or left, leans against the pelvis.
  2. The baby begins to descend, passing through the pelvis.
  3. It flexes its head as it comes through the cervix, turning towards the mother’s back as it does so.
  4. As the head crowns, the baby turns back to its side-facing position so the shoulders can come out.
  5. The rest of the body comes out with the shoulder. Forceps may be used to help.

The passage of such a large head and body is only possible through the massive dilation of the cervix, the stretch of the vagina, and the soft, malleable skull of the baby (a newborn’s head often looks conical and alien-shaped). Quite often, the opening of the vagina is not wide enough, and the opening may be cut open more to ensure it does not rip.

After the baby is safely delivered, the umbilical cord and the placenta are also delivered, thus ending the third stage (afterbirth). The cord is clamped and cut, and the baby is then thoroughly checked to ensure it is healthy and has no developmental issues.

Although in the past childbirth was extremely risky and often led to the death of the mother and/or baby in the process, nowadays protocols and health professionals ensure that both survive the procedure, thus ending the incredible 40-week journey until the birth of a new life. Only after understanding the arduous steps and the risks a mother takes to give birth to her child can one truly appreciate the value of life.

(Full series here: https://jineralknowledge.com/tag/arkrepro/?order=asc)

Posted in Science & Nature

From Cell To Birth: Growth

After implantation, the embryo quickly grows from a ball of cells into what will be a fully-formed baby. However, it first needs a way to feed: the placenta.
It is an organ that actively takes nutrients and oxygen from the mother’s blood, exchanging it for the embryo’s waste products. It is extremely effective in keeping the fetus alive and protects it from infections or the mother’s immune system.
The blood is carried by the umbilical cord, which plugs into the belly button. This cord is the lifeline throughout term, and disrupting the blood supply will lead to permanent brain damage or even death.

In the first 10 weeks, the blastocyst develops into a very primitive disk-like object that shares no resemblance to a person. It keeps growing and differentiating at a rapid rate (almost doubling in size per week) until it forms an embryo that is more familiar, roughly about week 6. Interestingly, a human embryo looks almost identical to embryos of rabbits, chickens, turtles and fish, showing how all animals shared a common ancestor in the course of evolution. At this stage, the embryo has features such as gills, a tail and a fish-like appearance.

After 10 weeks, the embryo has grown to about 5~8cm (almost 10~20 times the size at week 6), and is now called a fetus. It begins to properly grow organs, and resembles a miniature baby with primitive features.
It continues to grow for the next 30 weeks, continuously relying on the mother for nutrition and life support.

Many different factors contribute to premature birth and IUGR (intrauterine growth restriction), which leads to the birth of a small baby. This may result in less developed organs (especially the lungs) and may affect the health of the newborn throughout its life. There are also many poisons known to harm the development of the embryo/fetus, such as alcohol, nicotine, cocaine, heroin and much more. These should be avoided from a few weeks before conception onwards (even after birth while breastfeeding).

By about 38 weeks, the lungs (the last organs to fully mature) are ready and the fetus is upside down. It is ready to leave the womb, and thus sends a signal to the mother, known as labour. This is when the arduous process of childbirth begins.

(Full series here: https://jineralknowledge.com/tag/arkrepro/?order=asc)

Posted in Psychology & Medicine

Vertex

The vertex, also known as the crown of the head, is the uppermost point on the human body on the top of the head. It is the part of the body that comes out first (usually) during childbirth.

There are some interesting properties regarding this anatomic location.

Firstly, if one places a cellphone on top of their head, they cannot feel the vibration when they receive a call or text message. Almost every other part of the body can feel the vibration, but not the vertex. This is because the top of the skull is not covered by any muscles, which have receptors that sense vibrations. Ergo, no vibrations can be felt.

Secondly, when one places their hand on top of their head, they experience a sudden drop in muscle strength. This applies to the whole body and can be seen through basic activities such as lifting weights or even through arm-wrestling. The degree of weakness can be up to 10~15% of the muscle’s normal strength. 

The reason for this is slightly more complicated. The nervous system remembers trauma and responds to it, such as childbirth where almost everyone (assuming they were born through vertex presentation, the most common) experiences trauma on the top of the head. For example, as labour is quite an intensive procedure, significant pressure is placed on top of the baby’s head as it tries to push out.
Because of this, when pressure or electric signals are exerted on the vertex, the nervous system responds negatively, remembering the trauma from childbirth, and “weakens” throughout the body. This results in decreased force exertion by muscles. The same effect can be achieved when a cellphone is placed on top of the head, as it emits electric signals.

Lastly, the top of the head is not sealed until a few months after birth. This makes a baby’s skull very malleable, and two fontanels, which are gaps between pieces of the skull, remain open for that time. This is seen as “soft spots” on the head which pulsates as there is no bone beneath it.