High Risk Pregnancy Flashcards
Sem. 2
1
Q
What are things that can cause a pregnancy to be high risk?
A
antepartum hemorrhage, maternal risk factors vs fetal complications of pregnancy, screening tests, diagostic tests, hypertension and pregnancy, diabetes and pregnancy, adnexal cysts and pregnancy, fibroids and pregnancy, systemic lupus erythematosus and pregnancy, preterm labor
2
Q
What is the leading cause of prenatal death?
A
antepartum hemorrhage
3
Q
Etiology of antepartum hemorrhage depends on the trimester. What can cause 1st triemester bleeding?
A
spontaneous abortion, ectopic pregnancy, normal pregnancy
4
Q
Name the two types of third trimester bleeding.
A
obstetric and nonobstetric
5
Q
What are nonobstetric causes of antepartum hemorrhage?
A
cervical, vaginal, and other
6
Q
What is a nonobstetric cause of antepartum hemorrhage mean?
A
not related to the fetus or pregnancy itself
7
Q
What is the pronosis for antepartum hemorrhage with a nonobstetric cause?
A
generally good outcome
easy to treat
easy to dianose
no uterine contraction
8
Q
What are obstetric causes of antepartum hemorrhage?
A
maternal (uterine rupture), fetal (fetal vessel rupture), and placental (abruption, placenta previa, vasa previa)
9
Q
What can lead to a uterine rupture?
A
placenta percreta, a large fetus, multifetal pregnancy, iatrogenically
10
Q
What are clinical signs of uterine abruption?
A
sudden severe pain, vaginal bleeding, abnormal abdomen contour, fetal distress
11
Q
Where do most uterine ruptures take place?
A
90% occur where c-section scar is
12
Q
What is the prognosis for a uterine rupture?
A
can hapen during labor, likely to cause death (due to shock)
13
Q
What are maternal high risk factors for uterine rupture?
A
advanced maternal age (greater than or equal to 35), abnormal maternal lab values, vaginal bleeding, insulin-dependent diabetes mellitus, hypertension, preeclampsia, maternal systemic disease, infectious diseases of pregnancy
14
Q
What are fetal high risk factors for uterine rupture?
A
disorders of fetal growth, disorders of amniotic fluid, Rh incompatibility, fetal hydrops, fetal demise, multiple gestations
15
Q
What is the difference between a screening test and a diagnostic test?
A
a screening test assesses ow risk population for high risk and a diagnostic test is specific to confirm a diagnosis
16
Q
What is a first trimester screening looking for?
A
first trimester testing looks for the pattern of biochemical markers associated with plasma protein A (PAPP-A) and free beta hCG3
nuchal translucency
17
Q
What serum markers are looked at during 2nd/3rd trimester screening (quad screen)?
A
alpha fetoprotein (AFP), human chorionic gondaotropin (HCG), unconjugated estriol (uE3), inhibin-A
18
Q
What is a targeted ultrasound?
A
detailed evaluation of all fetal anatomy seen at time of exam
19
Q
For prenatal testing, what is a high order screening test?
A
fragments of fetal DNA in maternal blood
noninvasive, new, costly, not useful in twins
20
Q
What does a prenatal dianostic test do? What types are there?
A
analysis of fetal cells
amniocentesis, CVS, PUBS [(pericutaneous umbilical blood sampling)- assesses number of chromosomes]
21
Q
What is CVS?
A
chorionic villi sampling
ultrasound directed biopsy of placenta or chorionic villi
22
Q
What happens during a CVS?
A
chorion frondosum is active trophoblastic tissue that becomes the placenta
more cells are obtained than in an amniocentesis(faster result)
because chorionic villi is fetal origin, chromosomal abnormalities may be detected when cells from villi are grown and analyzed
risk of complications is higher than amniocentesis
23
Q
When can CVS be performed?
A
between 9 and 12 weeks
24
Q
Which test has the greater risk of complications, CVS or amniocentesis?
A
CVS
25
What are the potential complications of CVS?
preterm labor, premature rupture of membrances, fetal injury, fetal limb anomalies(if prior to 9 weeks)
26
What is the most common reason for performing an amniocentesis?
advanced maternal age
all pregnant women are at risk for having child with chromocomal defect, but risk greater in woman of advanced maternal age
27
What is the risk of having a fetus with Down syndrome in women 35 or older? For women 21 years old?
1 in 365
| 1 in 2000
28
What is the risk of having a fetus with any chromosomal anomaly in women 35 or older? For women 21 years old?
1 in 180
| 1 in 500
29
What is an amniocentesis?
a test offered to patients at risk for chromosomal abnormalities or biochemical disorder that may be prenatally detectable
results available within 1 to 3 weeks
30
What can be done if rapid results are desired with an amniocentesis?
fluorescence in situ hybridization (FISH) provides limited analysis within 24 to 48 hours
31
What does FISH look for?
most commonly evaluates for numeric abnormalities of chromosomes 21, 13, 18, X, Y
32
When is an amniocentesis usually performed?
between 15 and 20 weeks gestation
| may be done as early as 12 weeks (may lead to development of fetal scoliosis or clubfoot secondary to reduced AF)
33
List common risks with amniocetesis.
rupture of membranes, preterm labor, fetal injury(rare)
34
What is the optimal location for an amniocentesis?
away from fetus, away from contral portion of placenta, away from umbilical cord, near maternal midline to avoid maternal uterine vessels
35
How much fluid is collected with an amniocentesis?
20-30 mL of fluid
36
What is the risk of pregnancy loss following an amniocentesis?
1-200 or 1-300 risk of pregnancy lost from amniocentesis
37
How is a PUBS done?
percutaneous umbilical blood sampling
| fetal blood obtained through needle aspiration of umbilical cord
38
What is the most common reason used for cordocentesis?
transfusions to treat fetal isoimmunization
39
Describe the difference between gestational diabetes and pregestational diabetes.
with gestational diabetes, there is no high risk of congential anomalies
when a woman has diabetes mellitus prior to pregnancy (pregestational diabetes) there is high risk for congential anomalies
40
What are maternal obstetric complications of insulin dependent diabetes mellitus?
preeclampsia, miscarriage, postpartum hemorrhage, infection, increased c-section
41
List fetal complications of maternal diabetes during pregnancy.
polyhydramnios, macrosomia, delayed organ maturia, congenital malformations, premature rupture of membranes, IUGR, intrauterine death
42
What is the most common congenital malformation with fetal complications of diabetes?
cardiovascular
specifically tetralogy of fallot
overriding aorta, pulmonary stensis, ventricularseptal defect (PSD), right ventrical hypertrophy
43
What are other congenital malformations seen with diabetes (other than tetralogy of fallot)?
neural tube defects (also common), caudal regression syndrome, situs inversus, duplex renal ureter
44
What does hypertension have to do pregnancy?
places mother and fetus at risk
45
How does hypertension affect pregnancy?
small placentas
if placenta develops poorly, blood supply to fetus may be restricted, and IUGR may result
growth restricted fetuses at increased risk of fetal distress and death in utero
46
What is considered preeclampsia?
| severe preeclampsia?
blood pressure greater than 140/90 mmHg
| greater than 160/110 mmHg
47
What are the hypertensive states throughout pregnancy?
1. pregnancy induced hypertension (gestational hypertension, preeclampsia, severe preeclampsia, elcampsia - vasoconstriction)
2. chronic hypertension (present before pregnant, found before 20 weeks gestation)
3. chronic hypertension with superimposed preeclampsia
48
Define preeclampsia.
pregnancy condition in which high blood pressure develops with proteinuria or edema
49
What happens if hypertension is neglected?
patient may develop seizures that can be life threatening to both mother and fetus
50
What is severe preeclampsia?
may develop in some cases
| refers to severity of hypertension and proteinuria
51
What is eclampsia?
represents occurrence of seizures or coma in preeclamptic patient
52
List complications included with eclampsia.
cerebral hemorrhage, hypoxic encephalopathy, renal failure, liver failure, thromboembolic events, death
53
List fetal complications of preeclampsia/
acute uteroplacental insufficiency: placental infarct and/or abruption, intrapartum fetal distress, fetal death
chronic: IUGR, oligohydramnios
54
What is the treatment for preeclampsia?
delivery
55
What is hyperemesis gravidarum?
persistent vomiting, weight loss greater than 5% of pregnancy body weight secondary to dehydration and electrolyte imbalance
56
When in hyperemesis gravidarum common?
in the setting of molar pregnancy
57
What is the treatment for hyperemesis graidarum?
hospitilization with IV fluis administration usually necessary
58
What is systemic lupus erythematosus?
chronic autoimmune disorder that can affect almost all organ systems in body
59
What is the incidence of systemic lupus erythematosus?
most common in women of childbearing age; may cause multiple peripartum complications
60
With systemic lupus erythematosus, what is the incidence of spontaneous abortion and fetal death?
22%
| 49%
61
How does systemic luous erythematosus effect pregnancy?
- placenta affected by immune complex deposits and inflammatory responses in placental vessels; maternal antigen antibody complex crosses placenta and causes lupus in neonate; may account for increased number of spontaneos abortions, stillbirths, and IUGR fetuses
- irreversible congenital heart block
62
What can a fibroid cause?
pain and premature labor
63
What is preterm labor?
onset of labor before 37 weeks gestation;
| obstetric complication occurring in 15-20% of all pregnancies
64
Prematures infants are at greater risks for having what types of problems?
respiratory distress syndrome, intracranial hemorrhage, bowel immaturity, feeding problems
65
What are potential etiologies of preterm labor?
premature rupture of membrances, intauterine infection, bleeding, fetal anomalies, polyhydraminos, multiple pregnancy, growth restriction, maternal illness (diabetes of hypertension), incompetent cervix, uterine abnormalities
66
What should the sonographer assess for preterm labor?
AFI, cervical assessment, fetal number, placental assessment, targeted ultrasound
67
When taking a cervial assessment, which cervical length is used?
the shortest
68
What is the mean cervical length?
35-40mm
69
When does the cervix shorten?
progressively shortens after 30 weeks
| short cervix is difficult to identify before 14 weeks
70
When are cervical lengths recommended?
highest risk: 15-16 weeks (75% with a cervical length of less than or equal to 25mm at 16-18 weeks will deliver prematurely)
lower risk: 18-20 weeks
71
What is associated with a short cervix?
intra-amniotic infection
patients with a cervical length of less than 15mm have a higher rate of positive amniotic fluid cultures than those with a cervical length greater than 15mm
the earlier the gestational age and the shorter the cervix, the higher the likelihood of intra-amniotic infection
72
What describes a condition in which membranes rupture abnormally, resulting in loss of AF and/or oligohydramnios?
premature rupture of membranes, preterm premature rupture of membranes and spontaneous rupture of membranes
73
What are the clinical findings of ruptured membranes?
sudden gush or leaking of fluid
74
What tests are done to determine ruptured membranes?
nitrazine paper and fern test (used as screening test to determine presence of AF in vaginal secretions)
also, patient is checked for cervical dilation and for leaking of fluid with coughing or fundal pressure
75
What is the role of sonography in ruptured fetal membranes?
document integrity of placenta, fetal size, AF volume, fetal well-being, and to perform fetal Doppler studies
*common for patients to be evaluated daily
76
Define hydrops fetalis.
a condition in which excessive fluid accumulates within fetal body cavities
77
What are the two classifications of fetal hydrops? Describe each.
```
immune hydrops (developing conflict of maternal and fetal immune system - Rh conflict is most common) and
non-immune hydrops (result is same as other - cause is unidentified - common one is cardiovascular)
```
78
How is immune hydrops initiated?
initiated by the presence of maternal serum immunoglobulin G antibody against one of the fetal RBC antigens
79
When does immune hydrops occur?
anytime mother exposed to RBCs antigens different from her own
in subsequent pregnancies, antibodies pass through placenta and destroy fetal blood cellsm resulting in fetal anemia
80
Under what conditions will the mother be exposed to antigens different than her own?
father and fetus Rh-, mother Rh-, is maternal-fetal hemorrhage (mixing of blood), maternal antibodies are produced against antigen
81
What are the sonographic findings of fetal hydrops?
scalp edema, pleural effusion, pericardiac effusion, ascites, polyhydramnios, thickened placenta, anasarca (overal edematos fetus)
82
If Rh conflict is noticed in pregnancy and is not treated, what could be the results?
erythroblastosis fetalis, icterus gravis neonatorum, kernicterus (staining of brain tissue), hydrops fetalis
83
Describe the Rh conflict.
It is when mother and fetus have antibodies - fetal blood can enter the maternal system. The mother would see that as an intruder and develops an antibody to destroy it.
It usually does not happen in the 1st pregnancy, but with each additional pregnancy, the maternal system fights this in early stages (of pregnancy)
84
What is the role of sonography when there is an Rh conflict?
look for signs of hydrops, doppler evaluation of medial cerebral artery (assess degree of anemia), amniocentesis, cordocentesis, and PUBS (percutaneous umbilical blood sampling)
85
What can cause nonimmune hydrops?
CHF, anemia, unknown
cardiovascular lesions/functional disorders of the heart can cause CHF, which can cause hydrops
86
What is the treatment of hydrops?
depends on the cause
| fetal blood transfusions (for treatment of anemia)
87
What are two ways to do a fetal blood transfusion?
intro of blood through fetal peritoneal cavity (then gets absorbed)
direct transfusion of blood into fetal umbilical vein (more common)
3% of fetal death
88
What symptoms can a woman present with in the first trimester of pregnancy where her physician can diagnose pregnancy loss?
vaginal bleeding, cramping, passage of tissue
ultrasound may show blighted ovum or fetus with no heart motion
89
When should IUFD be used?
intrauterine fetal death
| used for pregnancy losses after 20 weeks gestation
90
By 20 weeks gestation, how should the uterus present clinically?
fundal height should have risen to umbilicus
| uterus should measure about 20cm above symphysis pubis
91
When should the mother feel fetal motion?
everyday beginning between 16 and 20 weeks
92
When will ultrasound be used with IUFD?
if uterus is not at height it should be, if fetal motion is not felt, absence of fetal heart rate
if none are present, US will be used to confirm or rule out demise
93
What are the US findings associated with fetal demise?
absent heart beat, absent fetal movement, overlap of skull bones (Spalding's sign), exaggerated curvature of fetal spine;gas in fetal abdomen, development of dolichocephaly, skin edema, echogenic amniotic fluid
94
Why is MSAFP screened?
| Why may this be elevated?
to detect neural tube defects
| can be elevated because of a twin pregnancy or if there is a neural tube defect
95
With a multifetal pregnancy, what risks are increased?
increased risk for obstetric complications, premature delivery and congenital anomalies(most common)
5 times greater chance of perinatal death than singleton
96
In a multiple gestation ultrasound, what should the sonographer evalute?
placental type
97
How does impantation occur with dizygotic twins?
each ovum implants seperately in uterus
placentas may implant in different parts of uterus and be distinctly seperate or may implant adjacent to each other and fuse (blood circulation will remain seperate)
98
What will the placenta look like for dizigotic twins?
twin peak sign - lambda sign
99
For dichorionic, diamniotic twins, when will division occur?
between days 0 and 3
100
For monochorionic, diamniotic twins, when will division occur?
between days 4 and 8
| more common vs DiDi
101
For MoMo twins, when will division take place?
days 8-13
102
What happens when division occurs between days 13 and 15?
conjoined twins
| when the embryonic disk begins to seperate
103
Name the different types of conjoined twins.
thoracopagus: joined at thorax
omphalopagus: joined at anterior wall
craniopagus: joined at cranium
pygopagus: joined at ischial region
ischiopagus: attached at buttocks
104
What is syncephalus?
conjoined twins with one head
105
What type of twin is at risk for twin-to-twin transfusion?
monchorionic diamniotic twins
106
Describe what a "vanishing" twin refers to.
if demise occurs very early, complete reabsorption of both embryo and gestational sac or early placenta may occur
once reabsorbed, products of conception of this twin will no longer be seen on US
107
What is fetus papyraceous? How will the fetus appear?
when fetus dies after reaching size too large for resoprtion
| fetus markedly flattened from loss of fluid and most of soft tissue
108
What does the term "stuck twin" refer to?
```
when oligohydramnios (smaller twin) exists in one sac and polyhydramnios in the other
the small twin may appear stuck in position within uterus
```
109
What is twin transfusion syndrome?
exists when there is arteriovenous shunt within placenta
| aterial blood of one twin is pumped into venous system of other twin
110
What happens to the "donor" twin in TTS?
becomes anemic and growth restricted
| has less blood flow through kidneys, urinates less and develops oligohydramnios
111
What happens to the other twin in TTS?
| non donor
gets too much blood flow
normal to large size
excess flow though kidneys and urinates too much developing polyhydramnios
may go into heart failure and become hydropic
112
With TTS, who is at greater risk of dying and why?
both twins
smaller one because its nutritional and oxygen rich blood supply is severely restricted
larger one because of heart failure
113
What is the treatment for stuck twin transfusion syndrome?
serial amniocentesis, selective feticide, umbilical cord ligation of one twin, laser occlusion of anastomosing placental vessels
114
What is acardiac anomaly?
rare, occuring in monochorionic twins
| one twin develops without a heart and often absence of upper half of body
115
Why does acardiac anomaly occur?
proposed that this occurs due to artery to artery connection in placenta that leads to perfusion of abnormal twin via co-twin
reversed direction of blood flow in abnormal twin alters hemodynamic properties needed for normal cardiac formation
116
What is the sonographic approach to pregnancy?
<6weeks, count gestational sacs and small ys
>6weeks, count embryos
when scanning multifetal preg. always determine how many amnion there are
location of placenta
number of placenta
twins scanned for dates and size (BPD, HC, AC, FL)
gender
possibly umbilical cord doppler
117
If twins are different genders, can twin to twin transfusion exist?
no
118
What are the differences between monozygotic and dizygotic pregnancies?
monozygotic: twins arise from single fertilized egg and divide
dizygotic: twins arise from two seperately fertilized ova
119
How can the sonographer determine if twinning is identical or fraternal?
if two different genders are seen, twins are fraternal
other than that it is difficult to say - if monozygotic twins and egg divided between day 1 and 3, twins would be dichorionic, just like in a dizygotic pregnancy
120
What is the physiologic reason for twin-to-twin transfusion syndrome? What sonographic signs should a sonographer look for?
when there is an arteriovenous shunt within the shared placenta
arterial blood of one twin is pumped into venous system of the other
Sonographically: one twin with oligohydramnios and another with polyhydramnios
121
What is the physiology of Rh sensitization and the effect of anemia on the fetus?
When the mother is exposed to RBC antigens different from her own (father and fetus Rh+, mother Rh-, maternal/fetal hemorrhage - mixing of blood, maternal antibodies are produced against Rh antigen).
In subsequent pregnancies, antibodies pass through placenta and destroy fetal blood cells, resulting in fetal anemia
122
What tests/procedures are employed to screen, diagnose, treat, and monitor the affected Rh fetus?
direct Rh testing of fetus through amniocentesis and monitor isoimmunized pregnancy with deltaoptical density - 450 analysis of AF (staining of bilirubin of AF)
Can be prevented with RhoGAM
treatment of fetal anemia includes fetal blood transfusion
123
What are the causes of non-immune hydrops?
cardiovascular lesions/functional disorders of the heart,
| CHF, anemia, unknown cause
124
What fetal anomalies can be found in the diabetic pregnancies?
polyhydramnios, macrosomia, delayed organ maturity, congenital malformations (caudal regression syndrome, situs inversus, neural tube defects, cardiovascular defects, duplex renal ureter), premature rupture of membranes, IUGR, intrauterine death
125
What should a sonographer expect to see when maternal diseases are present (such as hypertension; lupus; renal disease)?
hypertensive: small placenta/placental infarction/abruption, intrapartum fetal distress, fetal death, IUGR, oligohydramnios
lupus: affected placenta, inflammatory vessels, irriversable congenital heart block
renal:
126
What are complications of respiratory distress syndrome?
cerebral intraventricular hemorrhage, hemorrhagic intestinal necrosis
