3B Scientific Position of the Child before Birth Chart - Manual (Page 3)

®
The developmental period of the child including individual deviations amounts to approximately 270 days.
As the date of the fertilization of the ovocyte is normally unknown, the first day of the last monthly period
is chosen as the basis for calculations. Therefore, the duration of pregnancy amounts to approximately 280
days, i.e. 10 (lunar) months with 28 days each (40 weeks). The embryo repeatedly turns during the progress
of the pregnancy and repeatedly assumes alternating positions in its extra-embryonic membranes. A cer-
tain section of the child (mostly the head) acquires closer relations to the parturient canal of the maternal
pelvis during the final 3 - 4 weeks of pregnancy and maintains this position as well. Not until now, the term
“presentation“ is correct.
Enlargement of the uterus during the indi-vidual months of pregnancy (fig. 1 to 3)
Fig. 1 displays the enlargement of the uterus which can be determined by external examination from the
4th to the 10th month of pregnancy. The recorded numbers correspond with the end of the
respective month. The uterus is externally (through the abdominal wall) not tactual until the beginning of
the 4th month. From the middle of the 4th month on, the upper part of the uterus (fundus uteri) ascends
from the “small pelvis“ over the pubic symphysis, reaches both costal arches at the end of the 9th month
and then descends again during the 10th month of pregnancy.
At the end of the respective month of pregnancy, the fundus is located at the following position:
4th month: closely below the pubic symphysis
5th month: below the umbilicus
6th month: exactly at the level of the umbilicus
7th month: above the umbilicus
8th month: in the middle between the umbilicus and the ensiform appendix of the xiphoid bone
9th month: fundus reaches the costal arch (highest position)
10th month: fundus descends to the position of the 8th month
The descending of the fundus - which takes place in primiparous women 4 weeks and in multiparous
women 3 weeks prior to the delivery - conditions an alteration of the shape of the abdomen of the expec-
tant mother: the abdomen descends and protrudes more intensely (fig. 3 compared with fig. 2), the uterus
becomes wider (refer to fig. 1: condition at the end of the 10th month). The umbilicus lapses and often
protrudes.
Fig. 2 and 3 display the profile of the abdomen of an expectant mother, the position of the uterus and the
position of the infantile head at the end of the 9th month (fig. 2) and during the 10th month (fig. 3). The
highest position of the uterus respectively corresponds with the peak of the outlines displayed in fig. 1. At
the end of the 9th month (fig. 2), the uterus is upright and it touches the costal arch. The head is loosely
positioned above the superior
pelvic aperture.
During the 10th month of pregnancy (fig. 3), the fundus descends, the abdomen “slides“ lower, the uterus
becomes wider (refer to fig. 1, 10th month). The lower section of the uterus is shortened due to the integra-
tion of the lower uterine segment and the infantile head has entered the pelvis.
Presentations (fig. 4 to 13)
The figures serve for the illustration of some essential presentations and positions. The following distinc-
tions are made:
Presentations: Proportion of the infantile to the maternal longitudinal axis
Positions: Direction of the infantile back in proportion to the maternal sides (left, right, front etc.)
English
Presentations of the child prior
to the delivery
3