Preface

It is estimated that 1.2 million caesarean sections are performed in the United States each year, accounting for 31.7% of all births. In most European countries, the rate of caesarean delivery also exceeds 30%. The medical effects of this phenomenon remain unclear.

Factors that contribute to the increased frequency of C-sections include improved technical performance combined with increased security, reduction of maternal mortality rates (estimated at 6–22 women per 100,000 operations), and an overall significant decline in the frequency of forceps delivery.

The increased frequency of primary caesarean incisions has led to an increased number of pregnant women with previous C-sections despite a moderate increase in the rate of vaginal delivery after caesarean delivery.

The estimated total percentage of caesarean deliveries in women older than 35 years is 35%, according to a study by the World Health Organization (WHO). The study certified an increase in the frequency of caesarean births in both primigravidae and multigravidae. Full-term pregnancies with a head presentation in women without previous C-section accounted for 60% of births, whereas pregnancies in women with previous C-section accounted for 11.4% of births. Primigravidae with a head presentation with spontaneous or induced labor accounted for 15.3% and 18.3% of births, respectively. The tendency to have a fewer number of children led to a greater percentage of primigravidae who are at increased risk for caesarean section. The widespread application of assisted reproduction methods has led to increased rates of twin (35%) and multiple (77%) pregnancies and thus an increase in the percentage of C-sections.

According to meta-analyses, the use of cardiotocographic monitoring of the fetoplacental unit led to a 20% increase in the frequency of cesarean sections. Two studies of low-risk pregnancies found that the frequency of C-sections doubled with continuous cardiotocographic monitoring. This is due to an overestimation of the records regarding the presence or absence of perinatal asphyxia.

Several blind studies have compared C-section rates after induction or waiting in prolonged pregnancies without fully documented findings and without significant differences. There are several studies that show that induction of labor is associated with a significant reduction in the frequency of C-sections compared to adherence to waiting. However, these studies focused mainly on pregnancies > 41 weeks or those that were high risk. Several researchers have investigated whether the adoption of a regular induction of labor between 37 and 38 + 6 weeks is associated with a reduction in the frequency of stillbirths, but results have been conflicting. However, there is a trend that supports the view that the induction of childbirth between 39 and 40 weeks of pregnancy helps to reduce the incidence of stillbirths.

Caesarean section is a surgical procedure that should be done only when clinically indicated, as it can lead to potential consequences such as infection, thrombosis, bleeding, emergency hysterectomy, persistent pelvic pain, infertility, and even death.

Active birth control is mainly used to reduce cesarean sections. However, epidural analgesia may increase the frequency of CS (13% vs. 8% in the United States).

The passage of the newborn through the mother's vagina, skin contact after childbirth, and breastfeeding give the newborn the opportunity to colonize with the beneficial germs of the mother. Their penetration into the digestive system of the newborn contributes to the creation of normal intestinal flora as well as the activation of the newborn's defense system with the possibility of maximum development. Microbes that a mother does not have are dangerous to the newborn. When a field of labor is sterile, such as in caesarean section, the newborn will be colonized by the first germs it comes into contact with, which are not those of the mother. From a microbiological point of view, the newborn needs to be in contact with a single person, the mother.

If a neonate is born by caesarean section, it is possible to alternate the "host" of the microbiome, which is of great importance in the transfer of beneficial bacteria from mother to neonate during birth, since the first microbiomes to be colonized are hospital germs, for which the newborn has no antibodies at all. This immune system dysfunction and changes in metabolism, scientists believe, are responsible for the development of diseases. Population studies have shown that infants born via C-section have a 20% increased risk of developing asthma, type 1 diabetes, obesity in adulthood, and a slightly lower risk of developing gastrointestinal disorders such as Crohn's disease or celiac disease (gluten intolerance). Consequently, the infant born via C-section does not develop an immune system like that of an infant delivered vaginally.

Literature confirms that vaginal delivery allows the newborn gastrointestinal tract to be colonized by maternal bacteria, whereas cesarean delivery results in the neonatal gastrointestinal tract being colonized by hospital bacteria. Given that the gastrointestinal tract is where immune cells mature, its invasion by foreign microbiomes has a decisive effect on the pancreas and the physiology and pathology of the infant's immune system.

Scheduled cesarean section is usually performed between 37 and 40 weeks, which is considered full-term, although research has shown that many newborns of this age are not yet mature and may have serious health problems. A study of 13,258 newborns from 12 hospitals (35.8% delivered at 39/40 weeks, 6.3% delivered at 37/40 weeks, and 38.4% delivered at 38/40 weeks) showed that newborns born between 37 and 38 + 6/40 weeks developed respiratory problems and hypoglycemia. They also exhibited low levels of catecholamines, on average five times less compared to newborns delivered vaginally. Most were admitted to the neonatal intensive care unit, so it is best to schedule a cesarean section for no earlier than 39 weeks when possible. It appears that C-section after completion of the 39th week of pregnancy is associated with a decrease in maternal and neonatal morbidity, at least in relation to certain parameters.

Although a caesarean section is considered safe, there are some risks, including increased maternal morbidity and mortality, blood loss, neonatal respiratory distress syndrome, neonatal injuries, joint dystocia, Joint dystocia sometimes

**V**

mother and fetus.

occurs in association to C-section due to the position of the embryo and placental abnormalities. Thus, avoidance of C-section is safe, there are some risks, including increased maternal morbidity and mortality, blood loss, neonatal respiratory distress syndrome, neonatal injuries, joint dystocia, and placental abnormalities.

The role of the obstetrician-gynecologist is to responsibly and objectively inform the pregnant woman about any special conditions of the specific pregnancy and any relevant scientific guidelines. It is also important to inform the pregnant person of the possibility of caesarean section as well as associated risks and potential effects on future pregnancies and deliveries. Ultrasound plays an important role in the decision to avoid or perform a caesarean section in time for the benefit of the

I would like to thank all the authors who contributed their work to this volume.

**Dr. Panagiotis Tsikouras and Dr. Nikolaos Nikolettos**

Democritus University of Thrace,

**Dr. Georg Friedrich Von Tempelhoff**

St. Vinzenz Hospital Hanau,

Komotini, Greece

**Dr. Werner Rath** Kiel University, Germany

Germany

occurs in association to C-section due to the position of the embryo and placental abnormalities. Thus, avoidance of C-section is safe, there are some risks, including increased maternal morbidity and mortality, blood loss, neonatal respiratory distress syndrome, neonatal injuries, joint dystocia, and placental abnormalities.

The role of the obstetrician-gynecologist is to responsibly and objectively inform the pregnant woman about any special conditions of the specific pregnancy and any relevant scientific guidelines. It is also important to inform the pregnant person of the possibility of caesarean section as well as associated risks and potential effects on future pregnancies and deliveries. Ultrasound plays an important role in the decision to avoid or perform a caesarean section in time for the benefit of the mother and fetus.

I would like to thank all the authors who contributed their work to this volume.

**Dr. Panagiotis Tsikouras and Dr. Nikolaos Nikolettos** Democritus University of Thrace, Komotini, Greece

**Dr. Werner Rath**

Kiel University, Germany

**Dr. Georg Friedrich Von Tempelhoff**

St. Vinzenz Hospital Hanau, Germany

Section 1
