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Файл:Physiology of the development of the reproductive system of girls. Standards for determining physical and sexual maturity. Study aid
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certain level of E2 in blood is a signal of ovulatory emission of LG and FSH on
background of constant circhoral rhythm of their selection. But this hypothesis is not
confirmed by researches neither on people, nor on primates (Strauss III J.F., 2009).
So, the factors predisposing proper puberty, are as follows:
- body mass not less than 44–47 kg due to the fat component;
- transitory increase in thyroid gland function;
- increase of growth hormone and increase of tissue growth factors as
a response to increase of androgenic steroids synthesis;
- maintaining of daily rhythms of cortisol secretion and androgen steroidsm
dopamine, endorphins;
- transient insulin resistance.
Hormonal conditions of menarche occurrence are:
- simultaneous increase of KH to 2.8 and FSG to 1.8;
- appearance of ultradian rhythms of GnRH secretion and gonadotropins with
a frequency of 1 time in 90 minutes;
- change in ratio of gonadotropic hormones towards increase in LH, which
begin to exceed the rate of FSH (6 months before menarche);
- increase of plasma estradiol.
1.6. PUBERTY PERIOD
Enlargement of uterus begins in 8 years, but it is especially intensive in 10–
11 years. In 12–13 years, and angle between body and cervix appear, uterus occupies
a physiological position (anteflexio) in small pelvis, the ratio of cervix and uterus
body becomes 3:1. Increase in the mass of ovaries at 11–12 years coincides with
increase in follicle volume. In puberty period, there is also enlargement of anterior
pituitary gland and other endocrine glands, the function of which is determined by the
tropic hormones of pituitary gland.
Development of secondary signs and feminization of figure happens under the
influence of ovarian hormones and adrenal androgens.
During this period, mammary glands and sexual hairiness complete
development, the last to end is hair growth of the armpits, which begins at the age
of 13. Menstrual cycle becomes normal (two-phase), the growth of the body in length
stops and the female pelvis is finally formed.
22
Approximately of girls in first 3–5 years after menarche have menstruation
cycles with a lack of corpus luteum, but more often the cycles are anovulatory. This
explains frequency of dysfunctional uterine bleeding at puberty age.
The first ovulation is culminating period of maturation, but it does not mean
the puberty yet. The puberty occurs by 16–18 years, when not only reproductive
system, but the entire female body is finally formed and ready for conception,
pregnancy, childbirth and feeding of a newborn.
To external factors, influencing onset and course of puberty include climatic
features (illumination, altitude, geographic location) and nutrition (sufficient content
of proteins, fats and carbohydrates, microelements and vitamins). During the puberty
period, such events as heart disease with heart failure, tonsillitis, severe
gastrointestinal disorders with malabsorption, kidney failure, liver dysfunction
weaken the girl`s body and inhibit the normal course of puberty period.
The menstrual cycle is considered to be physiologically flowing it it satisfies
the following conditions:
1) is biphasic (with ovulation and full secretion phase);
2) lasts from 21 to 45 days;
3) duration of menstruation from 2 to 7 days, blood loss from 50 to 80 ml;
4) there is no painful phenomena during menstruation and the general
condition of the body is not disturbed.
The main processes of formation of adolescent girl reproductive system 12–
13 years old:
Menarche, appearance of mature follicle, enlargement of uterus and ovaries,
appearance of pronounced angle between the cervix and uterus, the progression of
sexual hair growth.
13–14 years:
Increase of body mass prevails over increase of body length (jump in
transverse dimensions); enlargement of mammary glands to B 4–5; hairiness to P5
and Ax 3–4; enlargement of uterus, appearance of regular, but anovulatory cycles;
increase in sexual desire.
23
14–16 years old:
Stop of limb growth; spine lengthening; stabilization of body mass; continued
growth of bone pelvis; formation of uterus and cyclic maturation of endometrium;
high frequency of ovulatory cycles; possible occurrence of acne and deepen voice;
increase of intelligence.
17–18 years old:
Sex formula B5/Р5/Ах4-5/Ме3
Stop length growth; predominance of enlarged direct dimensions of bone
pelvis; completion of puberty; regular ovulatory cycles; acquisition of psychosocial
behavior and communication skills.
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SECTION 2. THE STANDARDS OF PUBERTY
Puberty is determined depending on degree of mammary gland development
(B), pubic hairiness (Р), in the armpits (Ах), and menstruation onset (Me) and is
indicated by the sexual formula.
At the present stage in foreign literature, and a part of domestic authors, the
system of conventions for puberty period is accepted, which is recommended by
W. Marschall, J. Tanner in 1969, where the countdown starts from prepubertal stage
P1Ax1B1 (table 2). Tanner system is based on assessment of the degree of mammary
glands development by examination and palpation, and assessment of pubic hairiness,
taking into account its density, nature and growth boundaries.
Also it is necessary to assess physical development based on results of
anthropometry. From anthropometric signs, according to generally accepted and
unified methodology, indicators of mass and length of body, chest circumference,
external dimensions of the pelvis — interspinous, intercrestal, intertrochanteric and
external conjugates are studied.
At assessment of physical development, all measurements are traditionally
compared with girl`s height as indicator, which is mostly related with the level of
biological maturity of the body. The assessment of main anthropometric indicators is
also carried out according to the tables of centile type (Fig. 2), because they most
strictly and objectively reflect the distribution of signs amount healthy children.
A practical use of these tables is exceptionally simple and convenient. Each
individual value of height, body mass, chest circumference and pelvis size can be
placed into certain area or a “corridor” of centile scale. The selected “corridors”
contain a range of values of studied indicators that can be found in one age-sex
population group with a frequency of 3, 10, 25, 50, 75, 90 and 97 %. No calculations
are made during it. Depending on the corridor, in which the studied factor turned out
to be, it is possible to formulate a value judgment and to make a medical decision.
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Table 2
Sexual development of girls.
Tanner stages (LavinN. ed.all., 1999)
№
Phenomenon
Middle age
(years)
Age range
(years)
1
The mammary glands are prepubertal, diameter
of areola is < 2 cm, the nipples can be enlarged
and elevated, but not palpable. Pubic hair is
absent
Prepubertal
period
–
2
Telarche: the beginning of growth of mammary
glands, the nipples are palpable, the areola are
enlarged
10,5–11,5
8–13
Adrenarche: beginning of pubic hair growth
(sparse, long, straight, weakly pigmented hair;
mostly on large labia)
11–12
8–13
Pubertal hair growth and weight gain
12–12,5
9,5–14
3
Further enlargement and engorgement of
mammary glands
12–12,5
10–14,5
Hairiness extend to the pubis
12,5–13
9–14,5
Appearance of axillary hair
12,5–13
10–15
4
A nipple and areola form secondary bump under
mammary gland surface
13–13,5
11–15,5
Pubic hair as in adults, but not extend to
perineum and inner thighs
13–13,5
11–15,5
Appearance of acne
12,5–13,5
12–14,5
Menarche
12,5–13,5
10,5–16
Regular menstruation
14–14,5
12–17
5
Full development of mammary glands
14–15
12–17,5
Pubic hair with sparse hairs on inner thighs
14,5–15
12–17
The following options for arrangement of individual values are possible:
- area or “corridor” No. 1 and No. 7 (from 0 to 3 and from 97 to
100 centiles) — the area of “very low” or “very high” values, occurring no more than
in 3 % of healthy children. A child with such level of indicator must undergo special
consultation and examination for medical reason;
- area or “corridor” No. 2 and No. 6 (from 3 to 10 and from 90 to
97 centiles) — the area of “low” and “high” values, occurring in 7 % of healthy
children. The consultation and examination is indicated, if there are other deviations
in health or development;
26
- area or “corridor” No. 3 and No. 5 (from 10 to 25 and from 75 to
90 centiles) — the range of values “lower” or “above average”, peculiar for 15 % of
healthy children if this age group;
- region or “corridor” No. 4 (from 25 to 75 centiles) is an area of “middle”
values, peculiar for 50 % of healthy children. The values caught in this “corridor”
were assumed to be conditionally normal values, therefore, the most peculiar for this
age and sex group.
The definition of harmony of physical development of child is based on the
difference in the number of areas (“corridors”) between any two of three indicators:
growth, body mass, chest circumference, and when assessing the bone pelvis —
interochanteric size and external conjugates. If this difference does not exceed 1, then
we can talk about harmonious development, and if this difference is 2, then child`s
development should be considered disharmonious, and if the difference is 3 or more,
there is a sharply disharmonious development.
In addition, male and eunuchoid body types are distinguished.
The male type, in turn, has two stages of masculinity.
1) male type: increase in interacromial distance, increase in chest
circumference, decrease in intertrochanteric size, increase in body length (high
growth, broad shoulders, narrow pelvis);
2) viril type: increase in interacromial size, decrease in leg length, decrease in
intertrochanteric size (i.e. medium height, short legs, long torso, broad shoulders and
narrow pelvis).
Eunochoid type: an increase in body length, increase in leg length, equal
interacromial and intertrochanteric dimensions, the upper body is smaller than the
lower. In pituitary dwarfs, the opposite ratios are noted.
27
Figure 2. Centile table for assessment of girl`s physical development1
An assessment of the physique, especially with significant deviations from the
main dimensions, makes it possible to retrospectively determine the features of
puberty course, when skeleton is formed and ossified. So, with hyperandrogenism in
the puberty period, depending on degree of its severity, a male or viril type of body is
formed. In case of insufficiency of hormonal functions on the ovaries, body acquires
eunuchoid features.
1
возраст — age; длина/рост — length/height; масса — mass; центильный интервал —
centile interval; лет — years; мес — months; год — years.
28
In addition, the body mass index should be calculated:
BMI =
body mass, kg .
(body length, m)
2
Normally, after the end of puberty, it is 20–26. Both significant decrease and
increase of this indicator can be accompanied by endocrine disorders.
It is necessary to note that growth potential is sharply limited after menarche
and increases on average to 8 cm. However, this value is subject to various
fluctuations. So, if menarche occurs at 10 years, then the expected body growth takes
10 cm, if menarche occurs in 14 years of age, body height will subsequently increase
by 5 cm.
Registration of increased hairiness (hirsutism) is carried out by special scale
(Table 3), after that hirsute number is calculated as the sum of indifferent number and
hormonal number (the standard is less than 12, on average 4,5±0,1 points).
Indifferent value (IV) is a sum of points of hair growth of the forearms and tibia.
Hormonal number (HN) is sum of points of hair growth of the other areas of body.
Table 3
Hirsutism Quantification Scale
(by D. Ferriman, J. Galway, 1961)
Area
Points
Description
1
2
3
Upper lip
1
2
3
4
Separate hair on outer edge
Small moustaches on outer edge
Mustache, extending half way to the midline of upper lip
Mustache reaching midline
Chin 1 2
3,4
Separate hair
Separate hair and small clumps
Full coverage of hair, sparse or dense
Chest
1
2
3
4
Hair around the nipples
Hair around the nipples and on sternum
Connection of these area with coverage up to 3/4 of surface
Solid coverage
Spine 1 2
3,4
Scattered hair
Many scattered hair
Full coverage with hair, thick or sparse
Lower back
1
2
Bundle of hair on sacrum
Bundle of hair on sacrum, expanding to the sides
29
Area
Points
Description
1
2
3
3
4
Hair cover 3/4 of surface
Full hair coverage
Upper
abdomen
1
2
3,4
Separate hair along the midline
Lots of hair in midline
Hair coverage of half or whole surface
Lower
abdomen
1
2
3
4
Separate hair along the midline
Stripe of hair along the midline
Wide band of hair along the midline
Hair growth in the form of Roman numeral V
Shoulder
1
2
3,4
Sparse hair, covering not more than
¼
of surface
More extensive but incomplete coverage
Full coverage of hair, sparse or dense
Hip 1 2
3,4
Sparse hair covering no more than 1/4 of surface
More extensive but incomplete coverage
Full coverage of hair, sparse or dense
Forearm
1,2,3,4
Full hair coverage of dorsal surface: two points for sparse, and four
points for dense coverage
Tibia 1 2
3,4
Sparse hair covering 1/4 of surface
More extensive, but not full coverage
Full coverage with hair, sparse or dense
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SECTION 3. ANTHROPOMETRIC INDICATORS
OF THE PHYSICAL DEVELOPMENT OF GIRLS
IN THE SAMARA REGION
According to most experts, when choosing standards for intra- and intergroup
assessment of developmental parameters, regional standards are preferable, since in
this case the assessment will take place on the basis of indicators of the normal
development of children in a given population at a specific time and in a specific
region (Table 4–17).
Table 4
Reference values of anthropometric indicators
of the physical development of girls in the Samara region aged 7 to 17 years
Age,
years
N М m
σ
Р
3
Р
10
Р
25
P
50
(median)
Р
75
Р
90
Р
97
Body length, cm
7
166
122,82
0,46
5,93
112,01
115,00
119,00
122,50
126,13
130,00
135,00
8
131
125,59
0,61
6,98
113,00
116,00
120,00
125,00
131,00
135,80
140,00
9
102
128,46
0,91
8,15
113,09
118,00
120,00
128,75
133,25
140,85
149,64
10
106
133,42
0,98
8,92
114,00
119,00
125,00
134,50
141,25
146,00
152,16
11
136
140,62
1,22
9,19
114,50
119,70
126,25
143,00
152,00
158,00
161,00
12
108
141,49
1,50
9,93
116,00
119,90
127,00
145,00
154,75
159,00
166,38
13
114
150,08
1,75
10,28
116,38
120,00
127,25
157,00
163,50
167,00
173,28
14
122
152,49
1,42
10,18
121,00
124,00
147,50
158,00
164,00
167,70
173,55
15
108
163,00
0,90
9,40
135,86
155,00
160,00
163,50
168,00
172,00
174,00
16
115
163,79
0,63
6,71
151,48
155,60
160,25
164,00
168,50
171,10
175,56
17
118
165,15
0,57
6,17
151,71
156,00
160,75
165,00
168,75
171,40
178,00
Body weight, kg
7
166
23,46
0,36
4,63
16,01
18,00
20,00
22,25
25,50
31,00
33,50
8
131
23,79
0,41
4,65
17,00
19,00
20,50
23,00
26,00
31,50
35,14
9
101
27,25
0,77
7,78
17,17
20,24
22,00
25,50
29,50
37,70
46,99
10
106
29,04
0,83
8,51
17,88
20,50
22,88
27,00
33,00
41,30
52,10
11
136
35,38
0,99
11,52
19,02
20,85
24,50
34,00
42,88
49,30
58,00
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