Pregnant Uterus Flashcards
How does the uterus differ in pregnancy?
60g non pregnant 900g pregnant
Weight and size changes controlled by oestrogen which acts on myometrium to increase the size of the individual muscle cells and the number of muscle cells. This is until approx 20 weeks when the fetus is responsible for growth of the uterus
What happens to the uterus after implantation?
The endometrium of the uterus becomes thicker and increasingly vascular under the influence of oestrogen , progesterone from the corpus luteum. In pregnancy the endometrium is known as the decidua.
What is the decidua?
Thickest, most vascular in the fundus and upper body of the uterus
Most frequently blastocyst embeds here
Decidua provides all nourishment to the blastocyst until chorionic villi taken over
What does growth of the uterus indicate
External abdominal measurements signify good neonatal health and growth
12 weeks- symphysis pubis
20-22 normally umbilicus
36 weeks- xiphisternum
How does the uterus change shape?
The narrow isthmus at the junction between the uterus and cervix measures 7mm when not pregnant and becomes elongated from implantation.
Overall uterus takes on globular shape sitting in a n elongated stalk form the stretched isthmus
At 12 weeks uterus is upright having risen out of the pelvic cavity
What is the right obliquity of the uterus?
The favoured right lie due to the position of colon
How does the external appearance change at around 36 weeks?
Presenting part moves into lower uterine segment
Appearance of decrease in fundal height
Brings fetal head into true pelvis (engagment) commonly occurs in primigravida
Engagment in multiparous women often occurs when labour has begun
What are Braxton hicks contractions?
From 16 weeks the uterine muscle undergoes intermittent gentle contractions to maintain muscle tone.
Painless
Discuss the function of the cervix
Barrier against infection
In early pregnancy progesterone forms a mucous plug to occlude the cervical canal, this operculum remains in the cervical canal until labour
What is an incompetent cervix?
Cervix may have been damaged (abortions)
Cervical cerclage is performed, absorbable ribbon or suture placed around the cervix , is removed nearer to time of labour or when it starts
How does the vagina change in pregnancy?
High levels of circulating hormones
Fluid increase causes leucorrhea
Normal equilibrium of vagina is disturbed by increased hormones,more acidic environment preventing invasions by many bacteria a,othough thrush is more likely
Outline changes to other reproductive organs in pregnancy
Ovaries cease function due to high levels of oestrogen and progesterone
Uterine tubes become more stretched by the growing uterus
External genitalia have increased vascularity due to increased hormonal activity
