9.8 Abnormal Pregnancies Flashcards
Define ectopic pregnancy
Pregnancy which the fertilised egg attaches in a location other than uterine endometrium
Ectopic pregnancy risk factors
- Previous tubal surgery
- Infertility
- Confirmed previous genital infection
- Past or current smoker
- Previous ectopic pregnancy
- Sexual promiscuity
- Sterilisation
- Documented tubal pathology
Ectopic pregnancy pathology
- invasion of tubal mucosa by trophoblastic villi
- most of growth occurs between mucosa and muscular layer of fallopian tube
- Invasion of small blood vessels -> extraluminal bleeding and haematoma formation
- Intraluminal bleeding -> haematosalpinx with bleeding and extrusion from the fallopian tube
- The conceptus produces chorionic gonadotropin which keeps the corpus luteum functional
- Progesterone secreted by the CL initiates decidualisation of the endometrium
- When the trophoblast and embryo die hormonal support of the decidua is lost
- With resultant sloughing of the decidual cast and bleeding
Ectopic pregnancy symptoms
- signs and symptoms 4–6 weeks after their last menstrual period
- LAP and guarding
- Vaginal bleeding
- Signs of pregnancy -> amenorrhea, nausea, breast tenderness, frequent urination
- Tenderness in the area of the ectopic pregnancy
- Cervical motion tenderness, closed cervix
- Interstitial pregnancies tend to present late, at 7–12 weeks of gestation, because of myometrial distensibility
Tubal rupture
- Acute course with sudden and severe LAP (acute abdomen)
- Signs of hemorrhagic shock (e.g., tachycardia, hypotension, syncope)
Miscarriage
Duration
Type
Duration
First-trimester(early) pregnancy loss
- intrauterine pregnancy within the first trimester up to 13 weeks
- most common type
Second-trimester pregnancy loss
- 13-20 weeks of gestation
Type
- Spontaneous (sporadic, recurrent)
- Induced (unsafe, therapeutic)
Miscarriage clinical description
Incomplete miscarriage
- persistent pregnancy tissue in the uterus after a diagnosis of pregnancy loss
Inevitable miscarriage
- miscarriage that cannot be avoided because the cervix is open, bleeding is heavy or increasing, and abdominal cramping is present
Missed abortion
- a nonviable pregnancy in the absence of symptoms
Threatened miscarriage
- patient experiencing bleeding in early pregnancy but without a clear diagnosis of pregnancy loss
Complete
- describe patients with an empty uterus after documentation of prior intrauterine pregnancy.
- important since an empty uterus can be seen by ultrasound in the setting of normal early pregnancy that is too early to visualize, miscarriage, or ectopic pregnancy
Septic miscarriage
- any miscarriage, spontaneous or induced, that is complicated by uterine infection
Miscarriage causes
Maternal
Fetoplacental
Miscellaneous
Maternal
Abnormalities of the reproductive organs
- Septate uterus
- Uterine leiomyomas
- Uterine adhesions
- Cervical incompetence
Systemic diseases
- diabetes mellitus, hyperthyroidism, hypothyroidism, genetic disorders, infections, autoimmune diseases
Fetoplacental
- chromosomal abnormalities
- congenital abnormalities
Miscellaneous
- Trauma
- Iatrogenic (e.g., amniocentesis or chorionic villus sampling)
- Environmental (exposure to toxins such as drugs or maternal smoking during pregnancy)
- Unknown
Gestational trophoblastic disease
Classification
- diseases arising from abnormal proliferation of placental trophoblast
- lead to excess in highly vascular placental tissue
1. Benign trophoblastic leisons (GTD)
- Hydatidiform mole
- Exaggerated placental type
- placental site nodule
- abnormal (non-molar) villous lesions
2. Malignant GTN
- Invasive mole
- choriocarcinoma
- placental site trophoblastic tumour
- epithelioid trophoblastic tumour
Hydatiform mole
Definition
2 types
Risk factors
Characteristics
- type of GTD resulting from abnormal fertilization of an egg that can invade the uterus and metastasize
Complete mole: a type of hydatidiform mole typically resulting from fertilization by a single sperm of an abnormal egg that lacks maternal chromosomes
Partial mole: a type of hydatidiform mole typically resulting from fertilization of an egg by two sperm or a diploid sperm
Risk factors
- prior molar preg
- age _<15 and _>35 years
- history of miscarriage and infertility
Characteristics
- Proliferates within the uterus without myometrial infiltration or hematogenic dissemination
- May undergo malignant transformation to an invasive mole
Complete mole
Pathophysiology
Clinical features
Pathophysiology:
- Hydropic degeneration of chorionic villi with concomitant proliferation of cytotrophoblasts and syncytiotrophoblasts → death of the embryo
Clinical features:
- Vaginal bleeding during the first trimester
- Uterus size greater than normal for gestational age
- Pelvic pressure or pain
- Passage of vesicles with grape-like appearance
- β-hCG-mediated endocrine conditions:
Theca lutein cysts
Preeclampsia (before the 20th week of gestation)
Hyperemesis gravidarum
Hyperthyroidism: Very high amounts of hCG may lead to
hyperthyroidism because the α-subunit of hCG structurally resembles TSH
Partial mole
Clinical features
- Vaginal bleeding
- Pelvic tenderness
- No change in uterine size
- β-hCG-mediated endocrine conditions (less common)
Choriocarcinoma
Definition
Aetiology
Pathophysiology
Clinical features
Def
- highly malignant GTN characterized by invasive, highly vascular, and anaplastic trophoblastic tissue without villi
- Has the tendency to metastasize to the lungs, vagina, CNS, liver, pelvis, GI tract, and kidneys
Aetiology
Choriocarcinoma is preceded by:
- Hydatidiform mole
- Spontaneous abortion or ectopic pregnancy
- Term or preterm gestation
Pathophysiology:
- Malignant transformation of cytotrophoblastic and syncytiotrophoblastic tissue
- Destructive growth into myometrium without chorionic villi → risk of haemorrhage and early metastasis (lung, vagina, brain, liver)
Clinical features:
- depend on disease extension and metastases location
- Postpartum vaginal bleeding and inadequate uterine regression after delivery
Additional symptoms according to the site of metastasis e.g.:
- Dyspnea, cough, or hemoptysis from metastases in the lungs
- Seizures, headaches from metastases in the brain
- Visible vascular lesions from metastases to the vagina
- β-hCG-mediated endocrine conditions (e.g., hyperthyroidism, theca lutein cysts)
Invasive mole
Definition
Aetiology
Pathophysiology
Clinical features
Def
- form of GTD characterised by malignant transformation of incomplete or complete mole
Aetiology:
- risk of progression to an invasive mole depends on the type of initial hydatidiform mole
- Complete mole: 15–20% risk of subsequent invasive mole
- Incomplete mole: < 5% risk of subsequent invasive mole
Pathophysiology:
- Trophoblasts infiltrate the myometrium → increased risk of uterine perforation, intraperitoneal haemorrhage, or infection
- Hematogenic dissemination leads to metastatic growth (including in the brain, lungs, and liver).
Clinical features:
- Often detected on routine posttreatment surveillance following a hydatidiform mole
- Less likely to cause haemorrhage from a metastatic site than choriocarcinoma
Problems that arise form inaccurate determination of GA (gestational age)
- Poor scheduling of antenatal care visits and targeted investigations/interventions
- Misdiagnosis of preterm labour or post-term pregnancy hence intervention for these conditions
- Missed diagnosis of fetal growth aberration (small- or large-for-gestational age, intra-uterine growth restriction)
** Early dating of pregnancy central to optimising management of pregnancy –> ideal is the first trimester else no later than 24w**
Define:
- Large for gestational age (LGA)
- Small for gestational age (SGA)
- Intrauterine growth restriction (IUGR)
Large for gestational age (LGA): expected fetal weight > p90 for the specific gestational age
Small for gestational age (SGA): expected fetal weight < p10 for the specific gestational age
Intrauterine growth restriction (IUGR): failure of the fetus to achieve its full genetic growth potential
(p=percentile)
