Early Pregnancy Loss, Ectopic, & Rh Isoimmunization Flashcards
Define trimesters of pregnancy
First trimester = first day of LMP to 13 weeks (+6 days)
Second trimester = 14-27 weeks (+6 days)
Third trimester = 28-42 weeks
What is estimated date of confinement (EDC)
40 weeks after FDLMP (First date of last menstrual period)
Define parameters for abortion vs. preterm delivery vs. full term delivery
Abortion = <20 wks
Preterm delivery = 20-36 weeks (+6 days)
Full term delivery = 37-42 weeks
T/F: up to 40% of women will have some vaginal bleeding during early pregnancy
True — this is likely implantation bleeding
hCG is first detected in serum 6-8 days after ovulation. Titers <5 mIU/L is negative. A level of 100 IU/L is reached about the time of expected menstruation, and a UPT can detect titers of 25 mIU/L.
During pregnancy, the level of hCG doubles every 2 days and peaks at 10 weeks at 100,000 IU/L.
What is the “discriminatory level” of hCG?
hCG levels of 1500-2000 mIU/L — level at which you should see gestational sac
_____ ____ refers to the presence of hCG 7-10 days after ovulation but in whom menstruation occurs when expected
Biochemical pregnancy
80% of SABs occur in the first trimester. What is the most common cause of first trimester SABs?
Chromosomal abnormalities
The most common cause of first trimester SAB is chromosome abnormalities. What is the most common single abnormality vs. most common class of abnormalities?
Most common single abnormality is 45 XO Turner’s syndrome
Most common class of abnormalities is Trisomy class — Most common of these is trisomy 16
Type of spontaneous abortion in which there is vaginal bleeding and a closed cervix, 25-50% of which result in loss of the pregnancy, and treatment involves expectant management
Threatened SAB
Type of SAB in which there is vaginal bleeding and the cervix is partially dilated
Inevitable SAB
Type of SAB characterized by vaginal bleeding, cramping lower abd pain with a dilated cervix + passage of some but not all products of conception
Incomplete SAB
[tx is usually suction D and C]
Type of SAB in which there is passage of all products of concception with a closed cervix, resolution of pain, bleeding, and pregnancy symptoms; no tx needed
Complete abortion
Type of SAB in which fetus has expired and remains in the uterus, usually asymptomatic but coagulation problems may develop
Missed abortion
[check fibrinogen levels weekly until SAB occurs or proceed with suction D and C]
Type of SAB characterized by fever, uterine and cervical motion tenderness, purulent discharge, hemorrhage, and rarely renal failure d/t retained products of conception
Septic SAB
[start IV abx, proceed with suction D and C]
Type of SAB referred to as anembryonic gestation in which fertilized egg develops a placenta but no embryo [US reveals empty gestational sac]
Blighted ovum
[tx is expectant management, misoprostol, or D and C]
Define recurrent abortions
Defined as 3 successive SAB, excluding ectopic and molar pregnancies
Possible etiologies of recurrent abortions include general maternal factors, local maternal factors, fetal factors, chromosomal factors, and immunologic factors.
What are some general maternal factors that may lead to recurrent SABs?
Infection (mycoplasma, chlamydia, listeria, or toxoplasma)
Smoking and EtOH
Medical disorders (diabetes, hypothyoid, SLE, ANTIPHOSPHOLIPID AB SYNDROME and other clotting disorders)
Increasing maternal age
Possible etiologies of recurrent abortions include general maternal factors, local maternal factors, fetal factors, chromosomal factors, and immunologic factors.
What are some local maternal factors associated with recurrent SABs?
Uterine abnormalities (congenital anomalies, submucosal fibroids, uterine septum, asherman syndrome)
Cervical incompetence
Describe cervical incompetence as a potential cause of recurrent SAB, including risk factors and tx
Usually seen with 2nd trimester loss
Presents with “painless dilation” and delivery
Risk factors: uterine anomalies, previous trauma, and hx of colonization
Tx: cervical cerclage
Possible etiologies of recurrent abortions include general maternal factors, local maternal factors, fetal factors, chromosomal factors, and immunologic factors.
What is the most common immunologic factor associated with recurrent SABs?
Antiphospholipid Syndrome
[has also been associated with recurrent fetal loss, preeclampsia, venous and arterial thromboembolism and stroke]
Tests include lupus anticoagulant, anticardiolipin abs, and anti-b2-glycoprotein 1 abs
Tx with prophylactic dose of heparin and low dose ASA [may also use lovenox]
Leading cause of maternal death in the first trimester
Ectopic pregnancy [usually in ampulla of fallopian tube]
Risk factors for ectopic pregnancy
Hx of tubal infection
Previous ectopic
Previous tubal surgery or sterilization
In utero exposure to DES
Pregnancy with concurrent IUD
IVF or ART
Cigarette smoking
Classic triad associated with ectopic pregnancy
Prior missed menses
Vaginal bleeding
Lower abd pain
Clinical presentation of ectopic pregnancy includes possible ectopic, probable ectopic in symptomatic female, and acutely ruptured ectopic.
Describe the designation “possible ectopic” in terms of symptoms, PE, and US findings
[MOST COMMON clinical presentation]
Sxs: mild nonspecific sxs including abd pain, vaginal spotting or bleeding
PE: uterus soft and normal size; may not feel any adnexal mass
US: thickened endometrial stripe (arias-stella rxn), rarely do you see the ectopic pregnancy
Clinical presentation of ectopic pregnancy includes possible ectopic, probable ectopic in symptomatic female, and acutely ruptured ectopic.
Describe the designation “probable ectopic” in terms of symptoms, PE, and US findings
Sxs: lower abd/pelvic pain and vaginal spotting or bleeding
PE: abdominal, adnexal tenderness, and/or cervical motion tenderness
US: variable amounts of fluid in cul de sac; may see ectopic
Clinical presentation of ectopic pregnancy includes possible ectopic, probable ectopic in symptomatic female, and acutely ruptured ectopic.
Describe the designation “acutely ruptured ectopic” in terms of symptoms, PE, and US findings
Sxs: severe abdominal pain and dizziness (secondary to intraperitoneal hemorrhage)
PE: distended and acutely tender abdomen, usually cervical motion tenderness, signs of hemodynamic instability (diaphoresis, tachycardia, loss of consciousness)
US: reveals empty uterus with significant amount of free fluid
[surgical emergency!!!]
Diagnostic tests for ectopic pregnancy
Quantitative hCG — an inappropriate rise of <53% over 2 days is associated with either an ectopic pregnancy or nonviable IUP
Transvaginal US — would not show IUP
Medical management of ectopic pregnancy can be used only in compliant women who are hemodynamically stable with an unruptured ectopic.
What is the medical management used in these cases? What is the MOA and when should hCG levels be checked?
Methotrexate (MTX)
Folic acid antagonist which inhibits DNA synthesis and cell replication
Check hCG levels on day 4 and day 7 [if levels decrease by 15%, continue to follow weekly until negative. If levels plateau or fall slowly, give another dose of MTX. If pt becomes symptomatic or hCG titers increase then proceed with surgery]
Absolute vs. relative contraindications to MTX
Absolute: IUP, breastfeeding, overt immunodeficiency, alcoholism, preexisting blood dyscrasia, allergy to MTX, active pulmonary disease, PUD, hepatic/renal/hematologic dysfunction, ruptured ectopic and/or hemodynamically unstable pt, noncompliant pt
Relative: gestational sac >3.5cm, embryonic cardiac motion, hCG levels >6000 mIU/mL
When is expectant managment an acceptable tx for ectopic pregnancy?
If the pt is stable and symptoms are spontaneously resolving [up to 80% of ectopics with hCG levels of <1000 mIU/mL will not rupture and will resolve spontaneously]
Still must follow closely with serial hCG testing and give strong ectopic precautions
There are several surgical options for the management of ectopic pregnancy. What is the preferred approach for pts who are hemodynamically unstable?
Laparotomy
There are several surgical options for the management of ectopic pregnancy. What is the preferred approach for stable pts?
Laparoscopy
There are several surgical options for the management of ectopic pregnancy. What is the recommended approach when significant damage to the tube is noted, requiring removal of the entire fallopian tube?
Salpingectomy
There are several surgical options for the management of ectopic pregnancy. What is the difference between salpingostomy and salpingectomy?
Salpingostomy — incision is made parallel to the axis of the tube over the site of implantation and incision is left open to heal by secondary intention; most studies reveal salpingostomy results in better long-term tubal function [but there is up to 20% risk of residual trophoblastic tissue]
Salpingotomy — incision is sutured closed
There are several surgical options for the management of ectopic pregnancy. After surgery is performed, when should hCG titers be repeated?
3-7 days postop
Rhesus isoimmunization is an immunologic disorder that occurs in a pregnant Rh-_____ woman carrying an Rh-_____ fetus
Negative; postive
This results in mother’s immune system producing Abs to the fetal Rh Ag, which can cross placenta and destroy fetal RBCs —> serious hemolytic disease in fetus/newborn (anemia, hydrops fetalis, fetal death)
> 90% of cases of Rh isoimmunization are d/t Abs to D antigens
Medication used to prevent maternal production of Abs in the case of rhesus isoimmunization
Prophylactic Rh immune globulin (RhoGAM)
Decreases the availability of the RhD to the maternal immune system; usually given in a single 300 mcg dose which can prevent isoimmunization after an exposure of up to 30 mL of RhD + whole blood or 15 mL of fetal RBCs
When is RhoGAM administered?
In a Rh-negative woman: Given at 28 weeks and within 72 hours after delivery of a RhD positive infant
[may be given earlier in the presence of otehr factors that increase chance of fetomaternal hemorrhage — ECV, amniocentesis, CVS, MVA, etc.]
Certain high risk situations (placental abruption, manual removal of placenta, etc.) may result in larger volume of fetomaternal hemorrhage and require more than 1 dose of RhoGAM
What is the Kleinhauer-Betke test?
Identifies fetal RBCs in maternal blood; will determine if additional RhoGAM is necessary
Every pregnant woman at her first prenatal appt should get an ABO blood group, RhD type, and antibody screen. If tests reveal Rh negative woman whose anti-D antibody titers are positive (RhD sensitized), what are the next steps?
Test father of baby for Ag status; if he is RhD negative, no further workup or tx is necessary because the fetus will be Rh negative
If he is positive homozygous for RhD Ag, all fetuses will be Rh positive. If he is positive heterozygous for RhD, the fetal RhD status needs to be determined (cell-free fetal DNA or amniocentesis)
Maternal Rh-antibody titers are used as a screening tool to estimate the severity of fetal hemolysis in Rh disease. What result on these titers requires further evaluation?
Titers > 1:16 require further evaluation including detailed ultrasound to detect hydrops and Doppler studies of the middle cerebral a.
[titers <1:8 usually indicate the fetus is not in serious jeopardy; recheck titers q4w]
US findings of fetal hydrops
Ascites Pleural effusion Pericardial effusion Skin or scalp edema Polyhydramnios
Doppler assessment of peak systolic velocity in the fetal middle cerebral artery in cm/sec is th emost valuable tool for detecting fetal _____
Anemia
[should perform this test q1-2 weeks from 18-35 weeks; fetal MCA value peak systolic velocity >1.5 MOM for gestational age is predictive of moderate to severe fetal anemia — need to proceed with percutaneous umbilical blood sampling to assess true hemoglobin concentration]
Management of severe fetal anemia
Intrauterine transfusions (usually performed between 18-35 wks) using fresh group O Rh-negative PRBCs
