Pregnancy Complications

Question 1

hCG:

What 3 other hormones is it structurally similar to?

which subunits?

Answer 1

LH, FSH, TSH

• alpha subunit identical
• beta subunit unique

Question 2

hCG

• function
• secreted by what

Answer 2

Human Chorionic Gonadotropin

• ‘rescues’ and maintains the corpus luteum during beginning of pregnancy
• hCG is secreted by the synciotrophlolblast of the placenta.

Question 3

hCG

• How quickly do hCG levels rise in early pregnancy?
• When during pregnancy do hCG levels rise and fall? When is the peak?

Answer 3

• double every 48 hours in early pregnancy
• Peak hCG: 10 weeks, at 100,000 mIU/mL

(see image)

Question 4

hCG
-what can exogenous hCG be used to treat? (2)

Answer 4

1. induce ovulation in females
2. stimulate testosterone production in males

This is because hCG is structurally similar to LH and can function as an LH analogue

Question 5

Urine pregnancy test

• mechanism
• detection threshold (what is the hCG level at time of missed menses?)

Answer 5

• 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

Question 6

What is the most sensitive and precise type of pregnancy test?

-what’s its threshold detection level

Answer 6

Quantitative Serum hCG

-Pregnancy is negative if hCG <3-5 mIU/ml

Question 7

Discriminatory zone of hCG

• what is it, and specifically what #
• what is the practical application

Answer 7

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!

Question 8

Spontaneous abortion/miscarriage/pregnancy loss

• definition
• what % of pregnancies

Answer 8

• Fetal loss before 20 weeks (from last menstrual period)
• 15% of clinical recognized pregnancies
• 80% occur in 1st trimester

Question 9

Threatened abortion

Answer 9

In pregnant woman:

• Bleeding or cramping
• no passage of tissue, and closed os.

Question 10

Inevitable abortion

Answer 10

In a pregnant woman:

• bleeding, with open os.
• No passage of conception products (yet)

Question 11

Incomplete abortion

Answer 11

In pregnant woman:

• partial passage of conception products
• open os, variable bleeding

Question 12

Missed abortion

• what is it
• divided into what 2 types

Answer 12

This is intrauterine demise <20 weeks w/o any passage of conception products

1. Embryonic demise
   - embryonic pole visible on US, but no cardiac activity. (fetus died)
2. Anembryonic demise
   - gestational sac but no embryo visible on US

Question 13

Abortion/Miscarriage:

-what 3 terms to know

Answer 13

1. threatened abortion–bleeding, closed os
2. inevitable abortion–bleeding, open, no passage of products
3. incomplete abortion–partial passage of conception products

Question 14

Recurrent pregnancy loss

• definition
• what % of couples have this?

Answer 14

3 or more spontaneous pregnancy losses before 20 weeks

-occurs in <1% of couples attempting to have children

Question 15

Ectopic pregnancy

1. what % of pregnancies does this occur?
2. most common implantation location

Answer 15

1. 2% of all pregnancies
2. Fallopian tube 98% of the time (majority in ampulla).

Others include: cervical, ovarian, interstitial, abdominal

Question 16

Heterotopic pregnancy

• what is it
• risk factors?

Answer 16

Co-existing intrauterine AND extrauterine pregnancy.

• occurs in 1/30,000 pregnancies
• risk factors include:
  1. in vitro fertilization
  2. ovulation induction

Question 17

Ectopic pregnancy

-risk factors include: (6)

Answer 17

Think blockage:

1. pelvic inflammatory disease
2. gonorrhea/chlamydia
3. previous tubal ligation, previous tubal pregnancy
4. assisted reproductive technologies
5. Smoking
6. Pregnany with IUD in situ

Question 18

Ectopic pregnancy

-describe surgical vs medical treatment

Answer 18

Surgical:

Salpingostomy–create hole in tube to remove fetus

Salpingectomy–remove tube

Medical:

Methotrexate–antimetabolite to inhibit DNA synthesis

Question 19

Surgery for ectopic pregnancy

• feared complication
• how to prevent

Answer 19

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.

Question 20

Gestational trophoblastic disease (GTD)

• what is it
• name the benign and malignant types

Answer 20

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)

Question 21

Complete molar pregnancy

1. etiology
2. what is happening at microscopic level
3. Gross appearance
4. Ultrasound appearance

Answer 21

1. results from fertilization of enucleate egg. 2 sets of paternal genes, no maternal. 46 XX or 46 XY (rarely)
2. trophoblastic proliferation
3. ‘Grape-like’ chorionic villi
4. ‘snowstorm’ appearance

Question 22

Partial molar pregnancy

• etiology
• malignancy risk?

Answer 22

• 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%

Question 23

Methotrexate

• mechanism
• treat what pregnancy problems? include: (3)

Answer 23

Antimetabolite: DHFR antagonist

• inhibits DNA synthesis to treat:
  1. ectopic pregnancy
  2. hydatiform molar pregnancy
  3. choriocarcinoma

Question 24

Extremely high levels of hCG in pregnant woman.

Suspect what?

Answer 24

Suspect gestational trophoblastic disease when hCG is much higher than expected.

Question 25

You are monitoring hCG levels in a newly pregnant patient. hCG failes to increase by 53% or more over 48 hours. Suspect what?

Answer 25

Suspect a failing intrauterine pregnancy or an ectopic pregnancy. hCG should be doubling every 48 hours until peaking at week 10 of pregnancy.

Question 26

What weeks? 1st trimester 2nd trimester 3rd trimester

Answer 26

1st trimester: \<13 weeks 2nd: weeks 13-25 and 6 days 3rd: week 26 and onwards

Question 27

Fetal infections -list them

Answer 27

TORCH infections Toxoplasmosis Other--syphilis, parvovirus B19 Rubella CMV Herpes

Question 28

Toxoplasmosis fetal infection - clinical presentation at: 1. first trimester 2. 2nd trimester 3. 3rd trimester

Answer 28

1. often death 2. classic triad: 1) hydrocephalus 2) intracranial calcifications 3) chorioretinitis 3. often asymptomatic at birth

Question 29

Classic triad of: hydrocephalus intracranial calcifications chorioretinitis what is this?

Answer 29

Toxoplasmosis fetal infection, in 2nd trimester

Question 30

Toxoplasmosis fetal infection -how to diagnose? (2 tests)

Answer 30

1. maternal IgM and IgG 2. fetal PCR of amniotic fluid

Question 31

Syphilis fetal infection -describe clinical manifestations

Answer 31

- spontaneous abortion, stillbirth - non-immune hydrops - preterm birth - hepatomegaly - ascites - anemia, thrombocytopenia

Question 32

Anemic fetus -suspect what?

Answer 32

Suspect Parvovirus B19 fetal infection. -can cause transient aplastic crisis from lysis of erythroid progenitor cells

Question 33

Parvovirus B19 fetal infection -clinical presentation

Answer 33

Anemia, from Transient apastic crisis -from lysis of erythroid progenitor cells Also: acute myocarditis, edema/hydrops, fetal demise

Question 34

Parvovirus B19 fetal infection: -how to treat fetus?

Answer 34

Anemic fetus can be given a blood transfusion directly to fetus itself. Using ultrasound guidance.

Question 35

Rubella fetal infection -clinical presentation: symptoms include (4)

Answer 35

1. deafness 2. eye defects 3. CNS defects 4. cardiac malformations other--microcephaly, metnal retardation, etc

Question 36

CMV fetal infection -what is the characteristic clinical finding?

Answer 36

Periventricular calcifications

Question 37

Fetus with intracranial calcifications: suspect what?

Answer 37

1. toxoplasmosis 2. CMV (specifically periventricular calcifications)

Question 38

CMV fetal infection -histology appearance

Answer 38

-'Owl's eye" appearance of cellular inclusions.

Question 39

Herpes Simplex fetal infection -how is the virus transmitted to fetus?

Answer 39

1. perinatal (contact with vagina during delivery) 2. contact after rupture of membrances 3. direct contact with affected areas - transplacental infection is rare

Question 40

Herpes Simplex fetal infection -how to diagnose (3)

Answer 40

- HSV culture/PCR assay - HSV antibodies - Tzank smear (look for multinucleated giant cells and viral inclusions)

Question 41

Second trimester fetal complications: -what are the 3 general categories?

Answer 41

1. TORCH fetal infections 2. Cervical insufficiency 3. Fetal anomalies

Question 42

Cervical insufficiency - what is it - treatment

Answer 42

- 2nd trimester complication - Painless cervical shortening or dilation leading to pregnancy loss. - Can be corrected with cervical cerclage (surgical tightening of the os)

Question 43

Fetal anomalies resulting from 2nd trimester complication: - how to diagnose? - risk factors include (2)

Answer 43

- Fetal ultrasound - risk factors include: 1. chromosomal/genetic abnormalities 2. exposure to teratogens

Question 44

3rd trimester fetal complications -List them (6)

Answer 44

1. PPROM--preterm premature rupture of membranes 2. preterm labor 3. hemorrhage secondary to placental abnormalities 4. intrauterine fetal demise 5. intrauterine growth restriction 6. macrosomia

Question 45

PPROM - what is it - how to diagnose?

Answer 45

preterm premature rupture of membrances (PPROM) - chorioamniotic membrane rupture before labor, \<37 weeks gestation - Microscopy of fluid--you see "ferning"

Question 46

Preterm labor - defined by what weeks? - how to diagnose

Answer 46

- labor/birth between 20 weeks and 36 6/7 weeks - regular contractions resulting in cervical dilation

Question 47

Hemorrhage secondary to placental abnormalities, in 3rd trimester -name 4 such types of complications

Answer 47

1. placenta previa 2. placenta accreta 3. placenta abruption 4. velamentous cord insertion

Question 48

Placenta previa

Answer 48

Placenta is implanted over/near cervical os. Painless, but danger occurs when fetus grows large enough to press upon the placenta.

Question 49

Placenta accreta - what is it, and what is the danger - What is placenta increta and placenta percreta?

Answer 49

-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.

Question 50

Placenta abruption

Answer 50

-placental separation due to hemorrhage into decidual basalis before birth.

Question 51

Velamentous cord insertion

Answer 51

Umbilical cord attaches to chorion and amnion, rather than placenta. -Risk for serious bleeding because umbilical vessels easily torn.

Question 52

Intrauterine fetal demise -what trimester

Answer 52

-fetus dies secondary to complications in 3rd trimester (eg infection from PPROM)

Question 53

Intrauterine growth restriction

Answer 53

- 3rd trimester complication - fetal weight in 3rd trimester is less than 10th percentile via ultrasound

Question 54

Macrosomia

Answer 54

- 3rd trimester complication - fetal weight is excessive (\>4500 grams)