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
One or more convulsions in a pregnant woman with preeclampsia
Eclampsia
A malignant proliferation of trophoblastic tissue
•small percentage of patients
•can metastasize widely and kill patient
Choriocarcinoma
- sensitization of mother to a blood group antigen in fetal RBCs
- mother forms antibodies that cross placenta
- maternal antibodies damage fetal RBCs
- fetus increases blood production to compensate for increased RBC destruction
Erythroblastosis fetalis
Occurs most commonly between Rh- mother and Rh+ fetus
•mother becomes sensitized to foreign antigen in infants cells and forms anti-D antibodies that cross placenta into infants blood
•almost never occurs in first pregnancy
Rh hemolytic disease
Partial replacement of blood of infant with hemolytic disease by blood lacking the antigen responsible for hemolytic disease, as when transfusing Rh-negative blood to an Rh-positive infant. Performed to reduce intensity of hemolytic jaundice.
Exchange transfusion
Fluorescent light treatment of jaundiced Babies to reduce the concentration of unconjugated bilirubin in their blood.
Phototherapy
A mild hemolytic disease in group A or B infants or group O mothers as a result of maternal anti-A and anti-B antibodies.
ABO Hemolytic disease
ABO Hemolytic disease occurs in the ____________ ABO incompatible pregnancy because it is caused by pre existing anti-A and anti-B antibodies.
First
ABO hemolytic disease is much _______ severe than Rh hemolytic disease because A and B antigens on fetal cells are not as well developed as on adult cells, so the antibody does not mix as firmly to the fetal red cells and does not cause as much red cell membrane damage.
Less
