Molar pregnancy (mechanism of disease)

This is a flowchart on molar pregnancy, covering the etiology, pathophysiology, manifestations, and complications of complete and partial moles.

ADDITIONAL TAGS:
The placental-maternal interface swells with water and is destroyed
Overgrowth of placental- maternal interface
Hydropic degeneration of chorionic villi
Risk factors / SDOH
Cell / tissue damage
Structural factors
Molar pregnancy
Medicine / iatrogenic
Infectious / microbial
Biochem / metabolic
Immunology / inflammation
Signs / symptoms
Tests / imaging / labs
Environmental / toxin
Reproductive pathology
Growth / neoplastic
Pathophysiology
Etiology
Manifestations
Fertilization of an empty egg
Haploid chromosomes of the sperm are duplicated
Fertilization of a normal egg (haploid) with two sperm (each haploid)
Complete mole: trophoblastic tissue without fetal or embryonic parts
Partial mole: trophoblastic tissue containing fetal or embryonic parts
Rare: simultaneous fertilization of empty egg by two sperms (each haploid)
Fetal karyotypes: 46XX 46XY
Fetal karyotypes:
69XXX, 69XXY, 69XYY
Prior molar pregnancy
History of miscarriage
Age 15 and 35 years
Uniparental disomy
Triploidy
Proliferation of cytotrophoblasts and syncytiotrophoblasts
Death of the embryo
Pelvic tenderness
First trimester vaginal bleeding
Symptoms milder in partial moles
Passage of vesicles, may resembles bunch of grapes
Transvaginal US: echogenic mass interspersed with many hypoechogenic cystic spaces that represent hydropic villi; “swiss cheese”, “honeycomb”, “bunch of grapes”, “snowstorm”
Transvaginal ultrasound: +/- fetal parts, +/- fetal heart tones, ↑ placental thickness
↑↑ β-hCG (100,000 mIU/mL); complete partial
Preeclampsia
Hyperemesis gravidarum
hCG resembles LH
hCG resembles TSH
Ovarian theca lutein cysts: tender, bilateral, large, cystic, adnexal masses
Hyperthyroidism
Trophoblasts invade the myometrium
↑ risk of bleeding
Hematogenous spread
Invasive mole
Malignant transformation of trophoblastic tissue
Choriocarcinoma
Brain → seizures
Lungs → dyspnea, hemoptysis
Vagina → Vascular lesions
Postpartum bleeding
Inadequate uterine regression after delivery
Complications: gestational trophoblastic neoplasia