Pregnancy Complications Flashcards
hCG:
What 3 other hormones is it structurally similar to?
which subunits?
LH, FSH, TSH
- alpha subunit identical
- beta subunit unique
hCG
- function
- secreted by what
Human Chorionic Gonadotropin
- ‘rescues’ and maintains the corpus luteum during beginning of pregnancy
- hCG is secreted by the synciotrophlolblast of the placenta.
hCG
- How quickly do hCG levels rise in early pregnancy?
- When during pregnancy do hCG levels rise and fall? When is the peak?
- double every 48 hours in early pregnancy
- Peak hCG: 10 weeks, at 100,000 mIU/mL
(see image)
hCG
-what can exogenous hCG be used to treat? (2)
- induce ovulation in females
- stimulate testosterone production in males
This is because hCG is structurally similar to LH and can function as an LH analogue
Urine pregnancy test
- mechanism
- detection threshold (what is the hCG level at time of missed menses?)
- utilize a monoclonal antibody specific to the beta subunit of hCG.
- detection threshold: 20-100 mIU/ml depending on brand. At time of missed menses, hCG level is ~100 mIU/ml
What is the most sensitive and precise type of pregnancy test?
-what’s its threshold detection level
Quantitative Serum hCG
-Pregnancy is negative if hCG <3-5 mIU/ml
Discriminatory zone of hCG
- what is it, and specifically what #
- what is the practical application
The serum hCG level above which a fetus should be consistently visible on transvaginal Ultrasound.
-hCG level of 1500-2000 (hCG is ~100 at 1 month)
If hCG levels reach the discriminatory zone but there is no visible fetus on US, there is likely an ectopic pregnancy!
Spontaneous abortion/miscarriage/pregnancy loss
- definition
- what % of pregnancies
- Fetal loss before 20 weeks (from last menstrual period)
- 15% of clinical recognized pregnancies
- 80% occur in 1st trimester
Threatened abortion
In pregnant woman:
- Bleeding or cramping
- no passage of tissue, and closed os.
Inevitable abortion
In a pregnant woman:
- bleeding, with open os.
- No passage of conception products (yet)
Incomplete abortion
In pregnant woman:
- partial passage of conception products
- open os, variable bleeding
Missed abortion
- what is it
- divided into what 2 types
This is intrauterine demise <20 weeks w/o any passage of conception products
- Embryonic demise
- embryonic pole visible on US, but no cardiac activity. (fetus died) - Anembryonic demise
- gestational sac but no embryo visible on US
Abortion/Miscarriage:
-what 3 terms to know
- threatened abortion–bleeding, closed os
- inevitable abortion–bleeding, open, no passage of products
- incomplete abortion–partial passage of conception products
Recurrent pregnancy loss
- definition
- what % of couples have this?
3 or more spontaneous pregnancy losses before 20 weeks
-occurs in <1% of couples attempting to have children
Ectopic pregnancy
- what % of pregnancies does this occur?
- most common implantation location
- 2% of all pregnancies
- Fallopian tube 98% of the time (majority in ampulla).
Others include: cervical, ovarian, interstitial, abdominal
Heterotopic pregnancy
- what is it
- risk factors?
Co-existing intrauterine AND extrauterine pregnancy.
- occurs in 1/30,000 pregnancies
- risk factors include:
1. in vitro fertilization
2. ovulation induction
Ectopic pregnancy
-risk factors include: (6)
Think blockage:
- pelvic inflammatory disease
- gonorrhea/chlamydia
- previous tubal ligation, previous tubal pregnancy
- assisted reproductive technologies
- Smoking
- Pregnany with IUD in situ
Ectopic pregnancy
-describe surgical vs medical treatment
Surgical:
Salpingostomy–create hole in tube to remove fetus
Salpingectomy–remove tube
Medical:
Methotrexate–antimetabolite to inhibit DNA synthesis
Surgery for ectopic pregnancy
- feared complication
- how to prevent
Make sure to remove all ectopic tissue. Don’t leave any trophoblast cells behind, which can keep growing.
So, make sure hCG levels go to 0 after operation to ensure all cells were removed.
Gestational trophoblastic disease (GTD)
- what is it
- name the benign and malignant types
abnormal proliferation of trophoblastic tissue.
benign: hydatiform mole (includes complete and partial)
malignant: gestational trophoblastic neoplasia
(includes choriocarcinoma and placental site trophoblastic tumor (PSTT) disease)
Complete molar pregnancy
- etiology
- what is happening at microscopic level
- Gross appearance
- Ultrasound appearance
- results from fertilization of enucleate egg. 2 sets of paternal genes, no maternal. 46 XX or 46 XY (rarely)
- trophoblastic proliferation
- ‘Grape-like’ chorionic villi
- ‘snowstorm’ appearance
Partial molar pregnancy
- etiology
- malignancy risk?
- fertilization of haploid ovum by 2 sperm or single sperm that duplicates. So, 3 sets of gene. 69 XXX, 69XYY, or 69 XXY
- contains fetal tissue
- Yes, malignancy risk of 1-2%
Methotrexate
- mechanism
- treat what pregnancy problems? include: (3)
Antimetabolite: DHFR antagonist
- inhibits DNA synthesis to treat:
1. ectopic pregnancy
2. hydatiform molar pregnancy
3. choriocarcinoma
Extremely high levels of hCG in pregnant woman.
Suspect what?
Suspect gestational trophoblastic disease when hCG is much higher than expected.
You are monitoring hCG levels in a newly pregnant patient. hCG failes to increase by 53% or more over 48 hours. Suspect what?
Suspect a failing intrauterine pregnancy or an ectopic pregnancy.
hCG should be doubling every 48 hours until peaking at week 10 of pregnancy.
What weeks?
1st trimester
2nd trimester
3rd trimester
1st trimester: <13 weeks
2nd: weeks 13-25 and 6 days
3rd: week 26 and onwards
Fetal infections
-list them
TORCH infections
Toxoplasmosis
Other–syphilis, parvovirus B19
Rubella
CMV
Herpes
Toxoplasmosis fetal infection
- clinical presentation at:
1. first trimester
2. 2nd trimester
3. 3rd trimester
- often death
- classic triad: 1) hydrocephalus
2) intracranial calcifications
3) chorioretinitis - often asymptomatic at birth
Classic triad of:
hydrocephalus
intracranial calcifications
chorioretinitis
what is this?
Toxoplasmosis fetal infection, in 2nd trimester
Toxoplasmosis fetal infection
-how to diagnose? (2 tests)
- maternal IgM and IgG
- fetal PCR of amniotic fluid
Syphilis fetal infection
-describe clinical manifestations
- spontaneous abortion, stillbirth
- non-immune hydrops
- preterm birth
- hepatomegaly
- ascites
- anemia, thrombocytopenia
Anemic fetus
-suspect what?
Suspect Parvovirus B19 fetal infection.
-can cause transient aplastic crisis from lysis of erythroid progenitor cells
Parvovirus B19 fetal infection
-clinical presentation
Anemia, from Transient apastic crisis
-from lysis of erythroid progenitor cells
Also: acute myocarditis, edema/hydrops, fetal demise
Parvovirus B19 fetal infection:
-how to treat fetus?
Anemic fetus can be given a blood transfusion directly to fetus itself. Using ultrasound guidance.
Rubella fetal infection
-clinical presentation: symptoms include (4)
- deafness
- eye defects
- CNS defects
- cardiac malformations
other–microcephaly, metnal retardation, etc
CMV fetal infection
-what is the characteristic clinical finding?
Periventricular calcifications
Fetus with intracranial calcifications:
suspect what?
- toxoplasmosis
- CMV (specifically periventricular calcifications)
CMV fetal infection
-histology appearance
-‘Owl’s eye” appearance of cellular inclusions.
Herpes Simplex fetal infection
-how is the virus transmitted to fetus?
- perinatal (contact with vagina during delivery)
- contact after rupture of membrances
- direct contact with affected areas
- transplacental infection is rare
Herpes Simplex fetal infection
-how to diagnose (3)
- HSV culture/PCR assay
- HSV antibodies
- Tzank smear (look for multinucleated giant cells and viral inclusions)
Second trimester fetal complications:
-what are the 3 general categories?
- TORCH fetal infections
- Cervical insufficiency
- Fetal anomalies
Cervical insufficiency
- what is it
- treatment
- 2nd trimester complication
- Painless cervical shortening or dilation leading to pregnancy loss.
- Can be corrected with cervical cerclage (surgical tightening of the os)
Fetal anomalies resulting from 2nd trimester complication:
- how to diagnose?
- risk factors include (2)
- Fetal ultrasound
- risk factors include:
1. chromosomal/genetic abnormalities
2. exposure to teratogens
3rd trimester fetal complications
-List them (6)
- PPROM–preterm premature rupture of membranes
- preterm labor
- hemorrhage secondary to placental abnormalities
- intrauterine fetal demise
- intrauterine growth restriction
- macrosomia
PPROM
- what is it
- how to diagnose?
preterm premature rupture of membrances (PPROM)
- chorioamniotic membrane rupture before labor, <37 weeks gestation
- Microscopy of fluid–you see “ferning”
Preterm labor
- defined by what weeks?
- how to diagnose
- labor/birth between 20 weeks and 36 6/7 weeks
- regular contractions resulting in cervical dilation
Hemorrhage secondary to placental abnormalities, in 3rd trimester
-name 4 such types of complications
- placenta previa
- placenta accreta
- placenta abruption
- velamentous cord insertion
Placenta previa
Placenta is implanted over/near cervical os. Painless, but danger occurs when fetus grows large enough to press upon the placenta.
Placenta accreta
- what is it, and what is the danger
- What is placenta increta and placenta percreta?
-Placenta implantation extends inappropriately deep into the basal zone of the endometrium.
Placenta increta–placenta extends into myometrium
placenta percreta: placenta extends into uterine serosa
-Risk for hemorrhage after delivery. May require hysterectomy immediately after baby’s birth.
Placenta abruption
-placental separation due to hemorrhage into decidual basalis before birth.
Velamentous cord insertion
Umbilical cord attaches to chorion and amnion, rather than placenta.
-Risk for serious bleeding because umbilical vessels easily torn.
Intrauterine fetal demise
-what trimester
-fetus dies secondary to complications in 3rd trimester (eg infection from PPROM)
Intrauterine growth restriction
- 3rd trimester complication
- fetal weight in 3rd trimester is less than 10th percentile via ultrasound
Macrosomia
- 3rd trimester complication
- fetal weight is excessive (>4500 grams)
