Chapter 14 - Pregnancy Flashcards
Total duration of pregnancy from fertilization to delivery
- from conception: 38 weeks
- 9 calendar months; divided into 3 periods called trimesters
Gestation
Endometrium of pregnancy
Decidua
Enclosed within chorion, forms a protective environment
Amniotic sac
Forms intestinal tract
Yolk sac
•double circulation of blood:
-fetoplacental circ- from fetus to villi
-uteroplacental circ- maternal blood circulates around villi
•no mixing b/w fetal and mother blood
•fetus connected via umbilical cord
Functions:
-provides O2 and nutrition for fetus
-has endocrine function: synthesizes hormones: (estrogen, progesterone, protein hormones)
•human placental lactogen, HPL
•human chorionic gonadotropin, HCG
Placenta
- produced by filtration and excretion
- filtration from maternal blood early in pregnancy
- fetal urine later in pregnancy
Amniotic fluid
Increased volume of amniotic fluid
- fetus unable to swallow and fluid accumulates
- fluid is swallowed but not absorbed due to congenital obstruction of fetal upper intestinal tract
Polyhydramnios
Reduced volume of amniotic fluid
- fetal kidneys failed to develop and no urine is formed
- congenital obstruction of urethra does not allow urine to form amniotic fluid
Oligohydramnios
- hyperglycemia: harmful to fetus
* pregnancy hormones induce maternal insulin resistance
Gestational diabetes
10-20% of all pregnancies •early abortion results from -chromosome abnormalities -defective implantation -maldevelopment of fetus
Spontaneous abortion
- detachment of placenta
- obstruction of blood supply through cord
- complication: disseminated intravascular coagulation
- cocaine abuse: disturbs blood flow to placenta and may cause placental abruption and intrauterine fetal death
Late abortion causes
•development of embryo outside uterine cavity •most common site: Fallopian tubes •predisposing factors -previous infection -failure of normal muscular contractions of tubal wall •consequences -rupture of Fallopian tube -profuse bleeding from torn vessels -potentially life threatening to mother
Ectopic pregnancy
Normally, placenta attaches ___________________________
High on the anterior or posterior uterine wall
Placenta attached at lower part of uterus; may cover cervix
•causes episodes of bleeding late in pregnancy
•hazardous to both mother and infant
Placenta previa
A pregnancy related complication characterized by hypertension and proteinuria, which usually occurs after the 20th week of gestation, thought to be caused by placental dysfunction.
Preeclampsia