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Файл:Physiology of the development of the reproductive system of girls. Standards for determining physical and sexual maturity. Study aid
.pdf
Federal State Budgetary Educational Institution
of Higher Education «Samara State Medical University»
of the Ministry of Healthcare of the Russian Federation
A.V. Kazakova, O.V. Sazonova,
M.Yu. Gavryushin, D.R. Rustyanova
PHYSIOLOGY OF THE DEVELOPMENT
OF THE REPRODUCTIVE SYSTEM
OF GIRLS. STANDARDS
FOR DETERMINING PHYSICAL
AND SEXUAL MATURITY
Study aid
Рекомендовано Координационным советом по области образования
«Здравоохранение и медицинские науки» в качестве учебного пособия
для использования в образовательных учреждениях, реализующих основные
образовательные программы высшего образования уровня подготовки
кадров высшей квалификации по программам ординатуры по специальности
31.08.01 «Акушерство и гинекология»
Протокол № 069 от 20 апреля 2023 г. заседания Экспертной комиссии по работе
с учебными изданиями (далее ЭКУ) ФГАОУ ВО Первый МГМУ
имени И.М. Сеченова Министерства здравоохранения
Российской Федерации (Сеченовский университет).
Регистрационный номер рецензии: 2213 ЭКУ от 20 апреля 2023 г.
Moscow
IPR Media
2024
UDK 612.62-055.25+612.661(075.8)
BBK 57.319я73
P59
Authors:
Kazakova A.V. — Doctor of Medical Sciences, Head of Department
of Obstetrics and Gynaecology of Institute of Pediatrics FSBEI of HE SamSMU
of the Ministry of Health of Russia;
Sazonova O.V. — Doctor of Medical Sciences, Professor, Director of the Institute
of Preventive Medicine, Head of the Department of Food Hygiene with the Hygiene
Course for Children and Adolescents, Samara State Medical University;
Gavryushin M.Yu. — Candidate of Medical Sciences, Deputy Director of the Institute
of Preventive Medicine, Associate Professor of the Department of Food Hygiene
with a course of hygiene for children and adolescents, Samara State Medical University;
Rustyanova D.R. — Assistant of the Department of Obstetrics and Gynecology
of Institute of Pediatrics
Reviewers:
Shatunova E.P. — Doctor of Medical Sciences, Professor, Head of Department of Obstetrics
and Gynecology with the course of endoscopic surgery and simulation-training training
of the Medical University «REAVIZ»;
Skoblina N.A. — Doctor of Medical Sciences, Professor, Professor of the Department
of Hygiene of the Pediatric Faculty of the Federal State Autonomous
Educational Institution of Higher Education of the Russian National Research
Medical University. N.I. Pirogov of the Ministry of Health of Russia
P59
Physiology of the development of the reproductive system of girls. Standards for
determining physical and sexual maturity : study aid / A.V. Kazakova, O.V. Sazonova,
M.Yu. Gavryushin, D.R. Rustyanova ; Samara State Medical University. — Moscow : IPR Media,
2024. — 52 p. — Text : electronic.
ISBN 978-5-4497-2653-7
The study aid contains information about the formation patterns, in a systematic and
generalized form, reflects the patterns of the formation of the female reproductive system, methods
and standards for determining the physical and puberty of girls.
The study aid is compiled in accordance with the requirements of the current Federal State
Educational Standard for Higher Education for the training of highly qualified personnel in
residency in the specialty “Obstetrics and Gynecology” and the requirements of the work program
for the academic discipline “Obstetrics and Gynecology”, approved by the Central Coordinating
and Methodological Council (CCMC) of the Federal State Budgetary Educational Institution of
Higher Education of the Samara State Medical University of the Ministry of Health of Russia. Мay
be useful for practitioners — obstetrician-gynecologists and pediatric gynecologists.
Educational electronic publication
The study aid is approved by CCMC FSBEI of HE SamSMU of the Ministry
of Health of Russia (protocol No. 6 dated March 28, 2023)
ISBN 978-5-4497-2653-7 © Samara State Medical University, 2024
© LLC IPR Media Company, 2024
Educational publication
Kazakova Anna Vladimirovna
Sazonova Olga Viktorovna
Gavryushin Mikhail Yurievich
Rustyanova Daria Rafikovna
Editor Yu.V. Semenova
Technical editor, computer layout M.V. Polovnikova
Cover by Ya.A. Kirsanov, S.S. Siziumova, photo bank Freepik
Signed for use 29.12.2023. Data volume 7 Mb.
LLC IPR Media Company
8 800 555 22 35 (toll-free in Russia)
E-mail: sale@iprmedia.ru
4
CONTENT
LIST OF ABBREVIATIONS AND SYMBOLS ................................................ 5
INTRODUCTION ................................................................................................. 6
SECTION 1. MAIN PERIODS OF HUMAN
REPRODUCTIVE SYSTEM DEVELOPMENT............................................... 8
1.1. Embryonic period ......................................................................................... 9
1.2. Neonatal and infancy period ...................................................................... 10
1.3. Childhood period ........................................................................................ 12
1.4. Prepubertal period ...................................................................................... 15
1.5. Modern view on the triggers of menarche ................................................. 17
1.6. Puberty period ............................................................................................ 21
SECTION 2. THE STANDARDS OF PUBERTY ........................................... 24
SECTION 3. ANTHROPOMETRIC INDICATORS
OF THE PHYSICAL DEVELOPMENT OF GIRLS
IN THE SAMARA REGION ............................................................................. 30
SECTION 4. MATERIALS FOR SELF-CONTROL ..................................... 45
4.1. Tests for knowledge control ....................................................................... 45
4.2. Answer template ......................................................................................... 47
4.3. Tasks for knowledge control ...................................................................... 48
4.4. Sample responses ....................................................................................... 49
BIBLIOGRAPHIC LIST .................................................................................... 51
5
LIST OF ABBREVIATIONS AND SYMBOLS
ACTH — adrenocorticotropic hormone
GABA — γ-aminobutyric acid
GnRH — gonadotropin-releasing hormone
GH — growth hormone
DEA — dehydroepiandrosterone
BMI — body mass index
LH — luteinizing hormone
STH — somatotropic hormone
TSH — thyroid stimulating hormone
FSH — follicle stimulating hormone
E2 — estradiol
KISS1 — kisspeptin
KISS1R (GPR54) — kisspeptin receptor
PGF — protein growth factor
SRY gene — SexRegionY gene
M — arithmetic mean values
m — error of the arithmetic mean
P3, P10, P25, P50, P75, P90, P97 — percentiles
Rx/y — regression coefficient
σ — standard deviation
σr — standard deviation of the regression coefficient
6
INTRODUCTION
Nowadays, the priority direction of Russian state politics in sphere of health
relates to protection of reproductive health of adolescent girls, general somatic health
promotion, support of scientific researches on detecting risk groups and studying of
the pathogenesis of adolescent gynaecological diseases, leading to generative
disorders (Ye.V. Uvarova, 2013; G.T. Sukhih et al., 2013).
A steadily unfavorable tendency of deteriorating health in children has become
so sustainable nowadays that it creates real threat to national security of the country.
There is a birth rate decrease, an increase of infant mortality, a significant decrease in
percentage of healthy children at birth, an increase in number of the persons disabled
from childhood, and patients with chronic pathology. The frequency of violations in
formation of reproductive system and deviations in psychosomatic health of
adolescents has increased. In this regard, reproductive potential of current adolescent
girls is quite low.
The development and maturation of a child goes through the number of
successive periods, and one of the most important is a period of sexual development
and puberty. The puberty period determines transition from “neutral childhood” to
complete maturation of reproductive system with ability to carry out its main
function, fertility and reproductive ability.
Nowadays, there is no doubt that functioning of female reproductive system is
largely determined by its timely and harmonious development during puberty. For
today, we have increase in number of poorly differential constitutional forms of
accelerating and decelerating sexual development. In general, the number of children
with normal puberty in population has decreased.
At the moment, knowledge about specialties of reproductive system formation
is very relevant in work of medical and pedagogical organizations, as well as timely
ascertaining of pathological deviations of reproductive system formation, and early
prevention of violations, which can further lead to decrease of reproductive potential,
causing reproduction of population and demographic situation in our country.
Ensuring and protecting of children and adolescent health is the most forwardlooking contribution into reproductive, intellectual, economical, political and moral
reserve of society.
7
In the study aid, the author has described evaluation methods of age-related
specific features of puberty and sexual development of the girls, based on analysis of
literature data and her own researches.
Study aid includes the materials for self-control.
Study aid is intended for use in educational process during preparation of
residents by specialty 31.08.01 “Obstetrics and Gynaecology”, also it can be used at
training courses for practitioners: obstetrician-gynaecologists and pediatric and
adolescent gynaecologists.
8
SECTION 1. MAIN PERIODS OF HUMAN REPRODUCTIVE
SYSTEM DEVELOPMENT
The development and formation of mature type of functioning of reproductive
system of female body is a multi-period and multi-component biological process.
Each period of human biological development has the limits, which, however, are
rather conditional, because they are determined by the genetic and phylogenetic
features of individual development.
Taking into account up-to-date knowledge about age-related hormone level
dynamics, caused by structural changes of separate organs, a classification of the
main periods of female reproductive period formation can be represented as follows
(Table 1). Highlighting the period of intrauterine development in proposed
classification is important because exactly at this period of human development, the
forward and backward linkages between hypothalamus, pituitary gland and endocrine
organs are formed.
Table 1
Main periods of female reproductive system formation
(International Symposium on age-related periodization)
Name of period
Age interval
Intrauterine period, including:
Embryonic period from conception to 35 days (8,5–9 weeks)
Fetal period from 8,5–9 weeks to the birth
Neonatal period
to 28 days after birth
Infancy period
from с 28 days to 1 year
Childhood period, including:
Early childhood period
from 1 year to 3 years
Middle childhood period
from 3 to 6 years
Late childhood period
from 6 to 8 years
Puberty period, including:
Prepubertal period
from 8 years to menarche
I phase of pubertal period
from menarche to 15 years
II phase of pubertal period
Including from 16 to 18 (20) years
9
1.1. EMBRYONIC PERIOD
Before 6–7 weeks of embryo development, histogenesis and organogenensis,
including the reproductive system, do not have sex differences and mainly depend on
severity of the influence of peptide and steroid hormones circulating in placental-fetal
blood flow. Se differences begin to appear only after the expression (activation) of
some genes, the main of which is normally located on Y-chromosome (SexRegionY),
that is why it is called SRY-gene.
The functions of SRY-gene:
- initiation of the synthesis of testis determination factor from the cells of
bipotential gonad medullary part (Testis Determination Factor);
- regulatory role in the synthesis of aromatase, which converts testosterone to
estradiol;
- gene expression, including formation of substance inhibiting the Mullerian
ducts.
The development of hypothalamic structures start from 5 weeks of embryonic
period. Even before placenta development, under the direct influence of chorionic
hormone and maternal sex hormones, activation of genes occurs, and these genes
control division and differentiation of hypothalamic and pituitary neurons. As
a result, the neurons of hypothalamus medial nuclei acquire unique feature to
synthesize and secrete numerous peptides that are hormones (releasing hormones and
their inhibitors), also they can carry out the function of neurotransmitters.
From 10th week of fetal life, in response to gonadotropin-releasing hormones
(GnRh), the cells of frontal pituitary gland (gonadotrophs) begin to secrete folliclestimulating (FSH) and luteonizing (LH) hormones. By 12th week of intrauterine
development, complete response of the cells of frontal lobe of pituitary gonadotrophs
to GnRh, which coincides in time with formation of vascular connection between the
nuclei of hypothalamus and the pituitary gland.
Impulse secretion of gonadotropic hormones under the influence of GnRh
increases by 20–28th week to a level, distinctive for woman in postmenopausal
period. At the same time, by this period of intrauterine development, such powerful
endocrine organ, as placenta begins to resist hypersecretion of gonadotropic
hormones. High concentrations of sex steroids and placental lactogen, circulating in
10
fetal blood cause inhibition of GnRH and decrease of pituitary gland sensitivity,
having the biggest intensity in fetuses in the last decade of intrauterine development.
There are following periods in the development of the ovaries:
5–7 weeks — the period of indifferent gonads;
7–8 weeks — the beginning of sexual differentiation;
8–10 weeks — the breeding season of oogonia;
10–20 weeks — the period of undivided oocytes;
20–38 weeks — the period of primary follicles.
The following conditions are required for development of full-fledged ovary:
- the presence of two structurally complete X-chromosomes, either in primary
germ cells (gonadoblasts), or in the cells of the sex cords, which are responsible for
ovary development from cortical part of the biopotential gonad;
- full control of miotic division of oogonia, and formation of oocytes of 1st
order on 17–20th week on intrauterine period;
- ability of oocytes of 1st order to switch mitosis to prophase of the first meiotic
dividion for the formation of primordial follicles.
The hormonal activity of fetal ovaries remains extremely low up to the birth,
because the special features of structural organization at the background of placenta
existence, do not allow them to actively transform progesterone and other C21steroids into androgens and estrogens.
1.2. NEONATAL AND INFANCY PERIOD
From the moment of birth, a drop of hormone level of uteroplacental origin
causes reflexive increase in production of pituitary hormones. The concentration of
growth hormone (GH), adrenocorticotropic hormone (ACTH), thyroid-stimulating
hormone (TSH), and gonadotropins sharply increases. An increase of FSH
concentration in girls in the first days of life exceeds LH secretion, which leads to
significant growth and maturation of ovarial follicular apparatus. A reaction of
vaginal contents becomes acidic, рН 4.0–5.0. Lactobacilli presented mainly by
bifidobacteria are noted in vaginal microcenosis.
A decrease of estrogen level in newborn girls occurs during the first 7–14 days,
which leads to the appearance of desquamation vulvovaginitis (4–8 days), and to
menstrual flows (5–8 days after birth) in 10–15 % girls. The endometrium reaches
10 mm. Secretory changes are most often noted in the endometrium. Sometimes there
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