2. Early PG loss, ectopic PG, Rh isoimmunization Flashcards
Which weeks constitute the 1st , 2nd, and 3rd trimesters?
- 1st = first day of last menstrual period (FDLMP) => 13 weeks + 6 days
- 2nd = 14 => 27 weeks + 6 days
- 3rd = 28 => 42 weeks
What weeks do the following occur?
- Estimated date of confinement (EDC)
- Abortion
- Preterm delivery
- Full term delivery
- Postdates
- Estimated date of confinement (EDC): due date = 40 weeks after FDLMP
- Abortion: < 20 weeks
- Preterm delivery: 20 => 36 weeks + 6 days
- Full term delivery: 37- 42 weeks
- Postdates: >42 weeks
What is the “discriminatory level” of hCG where a gestational sac be seen with transvaginal US (TVUS)?
1500-2000 mIU/L
***however, these are not always exact
What 2 things occur than can confirm a pregnancy?
- 1. Vaginal bleeding (occurs in 40% of W due to implantation bleeding)
- 2. hCG (detected 6-8 days after ovulation)
hCG: indicate the levels at the following stages
- Negative
- Amount reached when menstruation SHOULD be expected
- Amount a urine PG test detect
- How much do we see increase in pregnancy?
- Peak levels?
- Abnormal IUP or ectopic pregnancy
hCG
- Negative: <5
- Amount reached when period is expected: 100
- Amount a urine PG test can detect: 25
- How much do we see increase in PG? Doubles every 2 days
- Peaks at 10 weeks at 100,000
- Abnormal rise of less than 53% in 48 hours.
What is biochemical pregnancy?
Initial pregnancy test/hCG is (+) 7-10 days after ovulation, but does not progress into a clinical pregnancy because menstruation occurs.
Spontaneous abortions occur in 10-15% of clinically recognized cases.
When does the risk of fetal loss decrease to 2%?
If at 8 weeks, US shows a live, appropriately grown fetus with cardiac actvity.
What is an abortus?
an aborted fetus specifically : a fetus before 20 weeks, less than 500 grams.
80% of spontaneous abortions (SABs) occur during which trimester?
1st trimester
What are the most common cause of 1st trimester SAB’s?
Chromosome abnormalities
What is the most common single chromosomal abnormality and most common class of chromosomal abnormality responsible for 1st trimester SAB’s?
- 45 XO (Turner Syndrome) is most common single chromosomal abnormality
- Most common class is the Trisomy class, with trisomy 16 most common
SABs are defined by whether
- All of the products of conception have passed
- Dilation of the cervix.
What is a threatened abortion; how are they managed?
Threatened abortion: Cervix is closed, but vaginal bleeding is occuring.
- Treatment: Expectant management
SABs are defined by whether
- All of the products of conception have passed
- Dilation of the cervix.
What is a incomplete abortion; how are they managed?
Incomplete abortion: Cervix is dilated + passage of SOME products ( => vaginal bleeding is occuring) + cramping in lower abdomen.
- Treatment: Suction D&C
SABs are defined by whether
- All of the products of conception have passed
- Dilation of the cervix.
What is a inevitable abortion; how are they managed?
Inevitable abortion: Cervix is partially dilated + no passage of tissue + vaginal bleeding is occuring.
- Treatment: Loss is inevitable
SABs are defined by whether
- All of the products of conception have passed
- Dilation of the cervix.
What is a missed abortion; how are they managed?
Missed abortion: Fetus has expired and stays in uterus; typically no symptoms/bleeding.
- Coagulation problems may occur so check fibrinogen levels weekly until SAB occurs or perform suction D&C
- Treatment: Expected management vs. misoprostol vs. D&C
.
SABs are defined by whether
- All of the products of conception have passed
- Dilation of the cervix.
What is a septic abortion; how are they managed?
Septic abortion: Retain infected products of conception causes => fever, uterine and cervical motion tenderness + purulent discharge + hemorrhage and rarely renal failure
- Treatment: IV ABX (Ampicillin + Gentamycin + Clindamycin), follow with suction D&C.
What is anembryonic gestation (blighted ovum); what do we see on US, how is it managed?
- Fertilized egg develops a placenta, but no embryo.
- US shows empty gestational sac >25 mm (too big to not have embryo)
- Tx: expected management vs. misoprostol vs. D&C
How are induced or elective abortions most often performed in the 1st semester?
Suction D&C;
*More successful 1st therapy then medical or expectant managment.
Recurrent abortions occur in 1% of women and often have no cause.
Recurrent abortions are defined as what?
3 successive SAB, excluding ectopic and molar pregnancies.
What general maternal factors increase risk of recurrent abortions?
- Infection (Mycoplasma, Chlamydia, Listeria or Toxoplasma) is rare. Tx = ABX
- Smoking and alcohol (4x risk is smoke 20 ciggs/day and 7 drinks/week)
- Medical disorders: antiphospholipid syndrome *** (main), DB, hypothyroidism, SLE.
- Age of mom
How does the % rate of spontaneous abortion change from women <30 yo to women >40?
- W <30: 11.2%
- W >40: 56%
What is usually seen with 2nd trimester pregnancy loss, causing “painless dilation” and delivery?
Incompetent cervix
RF and treatment for incompetent cervix as a cause of recurrent SAB’s?
- RF:
- Utermine anomalies
- Previous trauma
- Hx of conization
- Treatment: cervical cerclage.
What is recommended for both parents whom are trying to get pregnant?
Karyotyping to detect balanced reciprocal and Robertsonian translocations that could be passed onto the fetus unbalanced. There is a 3% chance one is a asyx carrier.
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, a gestation that implants outside of the uterus, most often in the fallopian tube (98%)
What occurs during an ectopic pregnancy?
Trophoblasts implant into the mucosa of the fallopian tube and rapidly erods through the underlying BV. Too much bleeding can cause pressure necrosis of the overlying tubal serosa => acute rupture and hemoperitoneum.
Who’s at greater risk of ectopic pregnancy: woman with IUD or 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 symptoms of ectopic pregnancy
- Prior missed menses
- Vaginal bleeding
- Lower abdominal pain
What is the most common clinical presentation of ectopic pregnancy?
Possible ectopic
- Often, we see pt more than once 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?
- Thickening of the endometrium/endometrial stripe (Arias-Stella rxn), however, you RARELY see the ectopic pregnancy.
What are the symptoms, PE and US of the probable ectopic pregnancy.
- Symptoms: Lower abdominal/pelvic pain and vaginal spotting/bleeding
- PE: Abdominal/adnexal tenderness and cervical motion tenderness.
- US: Fluid in the abdomen (cul de sac) and you may the ectopic pregnancy.
Which type of ectopic pregnancy is a surgical emergency?
Acutely ruptured ectopic pregnancy
What will an U/S of an acutely ruptured ectopic pregnancy show?
Empty uterus w/ significant amount of free fluid
Symptoms and PE of an acutely ruptured ectopic pregnancy.
- Symptoms: severve abdominal pain and dizziness due to intraperitoneal hemorrhage)
-
PE:
- Abdomen is distended and tender (guarding and rebound)
- Cervical motion tenderness
- Hemodynamic instability => diaphoresis, tachycardia, loss of consciousness.
Diagnostic tests for ectopic pregnancies.
- Abnormal rise in hCG of <53% in 48 hrs
- Transvaginal US
Transvaginal US can sshow what
- IUP or extrauterine pregnancy
- Non-diagnostic (nothing in or outside the uterus): wait until hCG is in 1500-2000 IU/L discriminatory zone and then repeat U/S to see if there is a gestational sac
Medical management for ectopic pregnancy
- Compliant women who are hemodynamically stable with an unruptured ectopic PG: Medical management with methotrexate (MTX), a folic acid ANT; DNA synthesis and cell wall inhibitor
- Check hCG levels on day 4 and 7 –> compare at both days and if levels ↓ 15%, continue to follow weekly; if levels plateau or fall slowly give another dose of MTX.
Avoid ________ when taking methotrexate (MTX)
Vitamins with folate
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
What are some of the relative contraindications for using methotrexate in medical management of ectopic pregnancy?
- Gestational sac is greater than or equal to 3.5 cm.
- Embryonic cardiac motion
- hCG levels > 6000 mIU/ml
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 surgery do we do 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 (wants to still be fertile)
Salpingostomy
Which surgery is best for ectopic pregnancies when there has been significant damage to the tube?
Salpingectomy - removal of the entire fallopian tube
After surgery for an ectopic pregnancy, what should be done?
- Repeat hCG titers 3-7 days later
What is Rhesus Isoimmunization?
- Immunologic disorder that occurs when Rh (-) women is carrying an Rh (+) fetus =>
-
Rh (+) antigens cross the placenta into mom (perhaps through fetomaternal hemorrhage), causing mom to make Ab to Rh (+) antigen:
- IgM abs first, but do not cross placenta => IgG abs cross placenta and enter fetal circulation.
-
Destroy fetal RBC’s —>
- Mild hemolysis => fetus can compensate by increasing erythropoiesis
- Severe hemolytic disease in the fetus/newborn => anemia => hydrops fetalis from CHF and intrauterine fetal death
- Rh complex is made up of ___________ antigens.
- _________ => Rh (+)
- _________ => Rh (-)
- Rh complex = C, D, E, c, d, e antigens
- Rh D antigen => Rh (+)
- No Rh D antigen => Rh (-)
Rh (-) W is most common in ______.
- Caucasions (15% of whites have it) > AA (8%)
Which prophylactic treatment is used to prevent mom from making antibodies to Rh antigen?
300 mcg of Rh immune globulin (RhoGAM)
- Prevent isoimmunization after exposure of up to 30mL of RhD (+) whole blood or 15mL of fetal RBC -
Who should RhoGAM be administered to and when is it given?
- Rh (-) woman who is not Rh D-alloimmunized @ at 28 weeks and within 72 hrs after delivery of a Rh D (+) infant
How can we prevent Rh isoimmunization, which can occur in high risk situations that cause a larger volume of fetomaternal hemorrhage.
- Kleinhauer-Betke test: ID’s fetal RBC in maternal blood and determines if more RhoGAM is needed.
3 things to get at 1st prenatal visit to prevent Rh isoimmunization:
- ABO blood group
- Rh D type
- Antibody screen
If pregnant women is Rh (-) and has (+) anti-D antibody titers, 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 (-) => no further workup or tx is necessary
- If he is Rh-D (+) =>
- homo- (all fetuses will be Rh +)
- heterozygous for D antigen (50% will be Rh +/-)
If father of the baby is heterozygous for RhD antigen, what must be done?
-
Determine fetal RhD status
- Non-invasively with cell-free fetal DNA in maternal plasma
- Invasively with fetal antigen testing via amniocentesis
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 = fetus not in serious jeopardy; recheck titers q 4 wks
-
> 1:16 = require further eval:
- US to detect fetal hydrops
- Doppler studies of the Middle Cerebral Artery (MCA)
US can detect fetal hydrops.
What would we see on US that would indicate it?
- Ascites
- Pleural effusion
- Pericardial effusion
- Skin or scalp edema
- Polyhydramnios
_______________ most valuable tool for detecting fetal anemia and should be performed _____________.
- Doppler of the peak systolic velocity in the fetal MCA in cm/sec
- every 1-2 wks from 18-35 wks
__________ fetal MCA value peak systolic velocity for gestational age = moderate to severe fetal anemia.
> 1.5 MOM
It fetal MCA peak systolic velocity > 1.5 MOM, what should be done?
- Percutaneous umbilical blood sampling to assess the true concentration of Hb
- If indicated, perform a intrauterine tranfusion.
Which Hct level is considered SEVERE fetal anemia; when are intrauterine transfusions done and with what?
-
Severe fetal anemia: Hct is < 30% or 2 standard deviations below the mean Hct for the gestational age.
- Intrauterine transfusions using fresh group O, Rh (-) 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 1st affected pregnancy?
90%
In addition to serial US w/ MCA dopplers, what other 2 tests should be used to manage Rh-isoimmunization?
- Antepartum testing: 2x weekly non-stress test or biophysical profiles
- Serial growth scans q 3-4 weeks
