Lecture 10: Early Pregnancy Loss, Ectopic, and Rh Isoimmunization Flashcards
Which weeks constitute the first, second, and third trimesters?
- First = first day of last menstrual period - 13 + 6 weeks
- Second = 14 weeks - 27 + 6 weeks
- Third = 28 weeks - 42 weeks
A full term delivery is between which weeks of gestation?
37-42 weeks
What is the “discriminatory level” of hCG where a gestational sac be seen with transvaginal ultrasound (TVUS)?
1500-2000 mIU/L
Which abnormal rise of hCG in 48 hours confirms a nonviable IUP or ectopic pregnancy?
Abnormal rise in hCG of <53% in 48 hrs
80% of spontaneous abortions occur during which trimester?
First
What are the most common cause of first trimester SAB’s?
Chromosomal abnormalities
What is the most common chromosomal abnormality and most common class of chromosomal abnormality responsible for first trimester SAB’s?
- 45 XO (Turner Syndrome) is most common chromosomal abnormality
- Most common class is the Trisomy class, with trisomy 16 most common
What constitutes a threatened abortion; how are they managed?
- Vaginal bleeding + closed cervix
- Treatment is expectant management
What constitutes an inevitable abortion; how are they managed?
- Vaginal bleeding + the cervix is partially dilated
- Loss is inevitable
What constitutes an incomplete abortion; how are they managed?
- Vaginal bleeding, cramping lower abdominal pain w/ dilated cervix
- Passage of some but not all products of conception
- Treatment is usually suction D&C
What constitutes a complete abortion; how are they managed?
- Passage of all products of conception (fetus + placenta) with a closed cervix
- With resolution of pain, bleeding, and sx’s of pregnancy
- No tx needed
What constitutes a missed abortion; how are they managed?
- Fetus has expired and remains in uterus; typically no symptoms
- Coagulation problems may develop, check fibrinogen levels weekly until SAB occurs or proceed w/ suction D&C
- Expected management vs. misoprostol vs. D&C
What constitutes a septic abortion; how are they managed?
- Fever, uterine and cervical motion tenderness + purulent discharge + hemorrhage and rarely renal failure
- Retained infected products of conception
- Start IV antibiotics (Ampicillin + Gentamycin + Clindamycin)
- Proceed w/ suction D&C
What is anembryonic gestation (blighted ovum); how is it managed?
- Fertilized egg develops a placenta, but no embryo
- U/S reveals gestational sac too large to not have embryo (>25 mm)
- Tx: expected management vs. misoprostol vs. D&C
How are induced or elective abortions most often carried out in the first semester?
Suction D&C
Recurrent abortions are defined as what?
- Defined as 3 successive SAB
- Excluding (ectopic and molar pregnancies)
How many cigarettes a day and alcoholic beverages a week are associted with a 4-fold increased risk for SAB?
- 20-cigs a day
- 7 alcoholic drinks/week
What are some underlying medical disorders which are associated with recurrent abortions?
- Diabetes
- Hypothyroidism
- SLE
- Antiphospholipid Ab syndrome
How does the % rate of spontaneous abortion change from women <30 yo to women >40?
- Women <30 = 11.2%
- Women >40 = 56%
Which cause of second trimester pregnancy loss is associated with “painless dilation” and delivery?
Incompetent cervix
What is the treatment for incompetent cervix as a cause of recurrent SAB’s?
Cervical cerclage
What is the purpose of karyotyping both parents whom are trying to get pregnant?
To detect balanced reciprocal and Robertsonian translocations that could be passed onto the fetus unbalanced
What is the most common immunologic abnormality contributing to recurrent and SAB’s?
Antiphospholipid Syndrome
What is the treatment of antiphospholipid syndrome for patient trying to conceive?
Prophylactic dose of heparin and low dose aspirin
Tests for what 3 serum markers can be done for antiphospholipid syndrome?
- Lupus anticoagulant
- Anticardiolipin antibodies (IgG and IgM)
- Anti-B2-glycoprotein 1 antibodies (IgG and IgM)
What is the leading cause of maternal death in the first trimester?
Ectopic pregnancy
Who’s at greater risk of ectopic pregnancy someone with an IUD or someone without?
- Women without an IUD are at greatest risk
- But IF woman with IUD gets pregnant they are at an ↑ risk of having an ectopic pregnancy
Classic triad of ectopic pregnancy signs/sx’s includes?
- Prior missed menses
- Vaginal bleeding
- Lower abdominal pain
What is the most common clinical presentation of ectopic pregnancy?
- Possible ectopic
- Often pt is seen more than 1 visit before diagnosis is confirmed: follow serial B-hCG quants and TVUS accordingly
- Mild non-specific sx’s
What is seen on ultrasound of pt with possible ectopic pregnancy?
- Thickened endometrial stripe (Arias-Stella rxn)
- Rarely do you see the ectopic pregnancy
Which type of ectopic pregnancy is a surgical emergency?
Acutelt ruptured ectopic pregnancy
What will an U/S of an acutely ruptured ectopic pregnancy show?
Empty uterus w/ significant amount of free fluid
Transvaginal U/S for ectopic pregnancy may be nondiagnostic, what is the importance of following closely with serial hCG?
Wait until hCG is in 1500-2000 IU/L discriminatory zone and then repeat U/S to see if there is a gestational sac
In compliant women who are hemodynamically stable what can be used as medical management for ectopic pregnancy; how often are hCG levels checked?
- Methotrexate = folic acid antagonist; DNA synthesis and cell wall inhibitor
- Check hCG levels on day 4 and 7 –> levels ↓ 15%, continue to follow weekly; if levels plateua or fall slowly give another dose
Patient with ectopic pregnancy taking methotrexate should be instructed to avoid what?
Folate containing vitamins
What are some of the absolute contraindications for using methotrexate in medical management of ectopic pregnancy?
- Non-compliant pt
- Intrauterine pregnancy
- Breastfeeding
- Active pulmonary disease or PUD
- Hepatic, renal, or hematologic dysf.
- Alcoholic
- Ruptured ectopic or hemodynamically unstable
Which patients may qualify for expected managment of an ectopic pregnancy?
- If they are stable and sx’s are spontaneously resolving
- Follow closely w/ serial hCG testing and give strong ectopic precautions
What is the preferred surgical approach for an ectopic pregnancy in hemodynamically stable vs. unstable pt?
- Stable = laparoscopy
- Unstable= laparotomy
Which surgical approach to ectopic pregnancies has been associatd with better long-term tubal function?
Salpingostomy
How soon following surgery for ectopic pregnancy should you repeat hCG titers?
3-7 days post-op
What is Rhesus Isoimmunization?
- Immunologic disorder that occurs when Rh-negative women is carrying an Rh-positive fetus
- Ab’s to fetal Rh antigen can cross placenta and destroy fetal RBC’s —> severe hemolytic disease in the fetus/newborn
Which antigen is most commonly involved in Rhesus Isoimmunization?
- Rh D antigen
- Women who carry Rh D antigen are “Rh positive”
- Women who lack the Rh D antigen are “Rh negative”
Which prophylactic treatment is used to prevent maternal production of antibodies to Rh antigen?
Rh immune globulin (RhoGAM)
Who should RhoGAM be administered to and when is it given?
- Rh-negative woman who is not Rh D-alloimmunized
- Give at 28 weeks and within 72 hrs after delivery of a Rh D positive infant
Which test can identify fetal RBC’s in maternal blood and will determine if additional RhoGAM is necessary?
Kleinhauer-Betke test
For prevention of Rh isoimmunization every pregnant women should get what 3 things at her first prenatal visit?
- ABO blood group
- Rh D type
- Antibody screen
If pregnant women is Rh-negative and has anti-D antibody titers that are positive, what does this mean; what should be done next?
- She is Rh D sensitized
- Next test the father of baby for the Antigen status in question
- If he is Rh-D negative then no further workup or tx is necessary
- If he is Rh-D positive, will either be homo- or heterozygous
Which titers are used as a screening tool to estimate the severeity of fetal hemolysis in Rh disease?
Maternal Rh-antibody titers
What do maternal Rh-antibody titers of <1:8 and >1:16 indicate; what is management for each of these situations?
- <1:8 = indicates fetus not in serious jeopardy; recheck titers q 4 wks
- >1:16 will require further eval.; detailed U/S to detect hydrops and Doppler studies of the Middle Cerebral Artery (MCA)
What is the most valuable tool for detecting fetal anemia; how often should it be performed?
- Doppler assessment of peak systolic velocity in the fetal MCA in cm/sec
- Should perform this test q 1-2 wks from 18-35 wks
Which fetal MCA value peak systolic velocity for gestational age is predictive of moderate to severe fetal anemia?
>1.5 MOM
Which Hct level is considered severe fetal anemia; when are intrauterine transfusions done and with what?
- Hct is below 30% or 2 standard deviations below the mean Hct for the gestational age
- Intrauterine transfusions using fresh group O, Rh-negative packed RBC’s performed between 18-35 weeks
What type of transfusions for severe fetal anemia are preferrd due to more rapid and reliable therapeutic benefits?
Intravascular transfusions into umbilical vein
What is the management of Rh-isoimmunization after 35 weeks gestation?
Consider delivery and transfuse the neonate
What is the risk of hydrops with subsequent pregnancies after the first affected pregnancy?
90%
If father is heterozygous for Rh-D antigen, what 2 ways can the fetal RhD status be determined?
- Non-invasively w/ cell-free fetal DNA in maternal plasma
or
- Invasively w/ fetal antigen testing (amniocentesis)
In addition to serial ultrasounds with MCA dopplers, what other 2 tests should be used in the management of Rh-isoimmunization?
- Antepartum testing: 2x weekly non-stress test or biophysical profiles
- Serial growth scans q 3-4 weeks
