Obstetrics and Gynecology/Ectopic Pregnancies, Spontaneous Abortion, and other First Trimester Complications
Spontaneous Abortion[edit | edit source]
Solitary Spontaneous Abortion[edit | edit source]
Spontaneous abortion (SA) is defined as the expulsion or extraction of an embryo or fetus <500g in mass or before 20 weeks gestation. It may also be recognized by first trimester bleeding: recognize, however, that up to 30% of pregnancies encounter some form of first trimester bleeding but less than half of these will be complicated by SA.
Classification[edit | edit source]
- Threatened abortion: presents with cramping and bleeding, with a closed cervical canal
- Inevitable abortion: fully dilated cervical canal in the presence of cramping and escalating blood loss
- Incomplete abortion: fully dilated cervical canal, cramping, bleeding, and some tissue passage, but with retention
- Missed abortion: in utero fetal demise in the absence of tissue passage
- Septic abortion: cramping, pain, discharge, bleeding, fever, and malaise.
Epidemiology[edit | edit source]
- SA complicates >15% of recognized pregnancies.
- 80% of SAs occur in the first trimester. Very few complicate the second and third trimesters.
Etiology[edit | edit source]
- 60% of SA in the first trimester are due to abnormal karyotypes. By and large, up to 60% of SA are due to embryonic viability issues.
- Few, up to 20% of SAs may be due to maternal factors such as maternal age, uterine abnormalities, infection, lifestyle factors (smoking, alcohol, and cocaine are major factors), and concurrent maternal disease.
- The rest of SAs may have unknown etiologies.
Clinical Presentation[edit | edit source]
- The major presenting factors are cramping, bleeding, and a history of amenorrhea.
- The patient may have passed tissue
- The cervical canal may be dilate
- The uterus must be enlarged
- Infection for septic abortions (rare in the developed world, especially in those countries with legalized abortion)
Management[edit | edit source]
See management for recurrent abortions, because management strategies are similar.
Recurrent Abortion[edit | edit source]
Definition and Clinical Presentation[edit | edit source]
- Primary recurrent abortion: absence of any pregnancy greater than 20 weeks in duration.
- Secondary recurrent abortion: three or more miscarriages in the context of a previous pregnancy lasting longer than 20 weeks.
Classification[edit | edit source]
Recurrent abortions can be classified into those occurring before 6 weeks, and between 6-10 weeks gestation.
Before 6 weeks:
- Biochemical abortions occur before 4 weeks of gestation in the context of an Ultrasound negative and Beta-HCG positive pregnancy
- Anembryonic abortions occur between the 4th and 5th weeks of gestation. It involves passage of a gestational sac with diameter greater than 8mm.
- Yolk sac abortions occur between the 5th and 6th weeks and involve passage of a gestational sac with yolk sac. The total mass must be greater than 16mm.
Between 6-10 weeks:
- Embryonic abortions occur between 6 and 10 weeks of gestation and involve passage of a circulatory arrested embryo with crown rump length greater than 5mm.
- Fetal miscarriages occur between 10 and 20 weeks of gestation, but resemble embryonic abortions in other respects.
Epidemiology[edit | edit source]
- 1-2% of couples experience recurrent abortions
Etiology[edit | edit source]
- The risk of subsequent abortion increases exponentially with the number of prior abortions experienced by a couple.
Management[edit | edit source]
- Grief counseling
- Measure Rh status. If mother is Rh negative, administer Rho(D) Intravenous Immune Globulin.
- Conservative approach: typically expulsion of fetal remains within 2 - 4 weeks.
- Misoprostol (Prostaglandin E1 analogue): side effects include pain, diarrhea, fever, and bleeding.
- Dilatation and curretage: indicated for hemodynamic instability, infection. Side effects include perforation, adhesions, trauma, and infection.
Ectopic pregnancies[edit | edit source]
Ectopic pregnancies are defined as the presence of gestational tissue outside of the uterine cavity. Ectopic pregnancies are life-threatening emergencies.
Epidemiology[edit | edit source]
- Ectopic pregnancies affect 2% of all pregnancies, and approximately 10% of individuals with first trimester bleeding.
- Ectopic pregnancy is the leading cause of first trimester mortality.
Etiology[edit | edit source]
- Half of all ectopic pregnancies occur in the context of absent risk factors.
- A major risk factor for ectopic pregnancy is previous incidence of pelvic inflammatory disease.
- Ectopic pregnancy recurs in 15% of women and this risk increases proportionally with the invasiveness of the initial treatment.
- On the same note, tubal manipulation increases the risk for ectopic pregnancy.
- Infertility (related to tubal manipulation)
- Age under 18 (at sexual debut) or over 35.
Clinical Presentation[edit | edit source]
- Abdominal pain
- Bleeding
- Amenorrhea
- If ruptured, the ectopic pregnancy may cause intraperitoneal hemorrhage.
Diagnosis[edit | edit source]
- Clinical diagnosis, however, lab tests and imaging may be used to confirm.
- Beta-HCG will increase at a rate less than 50% per 48h.
- 15% of ectopic pregnancies will have a normal doubling time, and 15% of normal pregnancies will be associated with doubling times <15%.
- Progesterone measured in light of clinical findings may be helpful:
- <15.9 pmol/L predicts EP or SA
- >63.6 pmol/L predicts viable pregnancy located in the intrauterine cavity.
- Ultrasound
Management[edit | edit source]
- Conservative "watch and wait" approach: indicated by absent rupture, B-HCG <1500 U/L, declining change in B-HCG within 48h. B-HCG should be followed weekly until they extend below 5U/L. During this time, sexual intercourse is contraindicated.
- Methotrexate: indicated for persistent ectopic pregnancy (BHCG >5000 and/or rising 2 days later), and works best for ectopic pregnancies <35mm in diameter.
- Patient must be hemodynamically stable with no active bleeding
- Patient must have stable hematological and hepatic function
- Alcohol, folic acid, and intercourse are contraindicated during methotrexate therapy.
- Hysterosalpingography should be conducted 3 months after methotrexate therapy and subsequent pregnancies should be delayed for an additional three months after methotrexate cessation.
- Surgery: indicated for persistent ectopic pregnancy, in a hemodynamically unstable female
- Patients with impending rupture of ectopic pregnancy are indicated for surgery
- Patients who are not able to comply with treatment should be operated upon
- Laparoscopy is indicated to provide definite diagnosis if required.
- Surgery is indicated if medical therapy has failed.
- Laparotomy should be favoured against laparoscopy if complex, hemodynamically unstable, complex reoperative. Salpingostomy if contralateral tube damaged/missing; salpingectomy if high-grade hemorrhage, overwhelming tubal damage, or recurrent ectopic pregnancies in one tube.
Molar Pregnancy[edit | edit source]
Epidemiology[edit | edit source]
- Molar pregnancies occur in 1/1000 pregnancies
- Molar pregnancies occur more often in Asian women
- Molar pregnancies occr at the extremes of age in pregnancy (under 20, over 40)
Choriocarcinoma[edit | edit source]
- Choriocarcinomas arise in 1/40000 pregnancies
- 50% of choriocarcinomas arise from normal pregnancies
- 25% of choriocarcinomas arise from hydatidiform moles
- 25% of choriocarcinomas arise from ectopic pregnancies/abortions
Placental Site Trophoblastic Tumor[edit | edit source]
- Very rare
Etiology, Risk Factors, and Pathophysiology[edit | edit source]
Hydatidiform Mole[edit | edit source]
- Complete moles arise when an empty ovum is fertilized by more than one sperm cell. This creates a situation in which the entire genome is paternal.
- Incomplete (partial) moles arise when a normal ovum is fertilized by more than one sperm cell. This creates a polyploid zygote.
Invasive Mole[edit | edit source]
Risk factors for individuals with hydatidiform moles developing invasive moles include
- Uterine size grossly disproportional to gestational age.
- Bilateral thecal-lutein cysts.
- Uterine bleeding following evacuation of hydatidiform mole by dilatation and curettage.
- Age >40 years old.
- Penetration of molar tissue into the uterine wall and specifically the venous drainage of the uterus/adenexae. This results in embolization of molar tissue.
Choriocarcinoma[edit | edit source]
- From a complete hydatidiform mole, the risk of developing choriocarcinoma is 2-3%.
- Biphasic proliferation of the cyto- and syncytiotrophoblasts in the absence of chorionic villi.
- Invasion of the uterine vasculature and embolization to
- Lungs
- Brain
- Liver
- Lymph nodes
- Skin
- Kidney
- GI tract
- Vagina
Placental Site Trophoblastic Tumor[edit | edit source]
- Placental site trophoblastic tumors (PSTTs) are composed mainly of intermediate trophoblast which produces human chorionic somatomammotropin and little hCG.
Clinical Presentation and Diagnostic Approach[edit | edit source]
Hydatidiform Mole[edit | edit source]
Complete moles typically present with
- Abnormal bleeding between the 6th and 16th week of gestation.
- Higher than expected HCG levels.
- Larger than expected uterus.
- Pre-eclampsia and hyperemesis gravidarum.
- Bilateral thecal-lutein cysts.
Diagnosis of a complete hydatidiform mole may be done with ultrasound: absent embryo with "snowstorm" pattern.
Incomplete (partial) moles present with
- Missed/incomplete abortion
- Smaller HCG rise than in complete moles
Diagnosis of an incomplete (partial) mole is done through documentation of a missed abortion on ultrasound.
Invasive Mole[edit | edit source]
Invasive moles typically present with metastases to the
- Lung
- Broad ligament of the uterus
- Vagina
- Vulva
- Cervix
Diagnosis of invasive mole is done via
- Observation of persistent or rising HCG titres following removal of molar tissue.
Choriocarcinoma[edit | edit source]
- Bleeding (from vagina or from metastases)
Diagnosis of choriocarcinoma is done by clinical evaluation and biopsy, although the latter is often not useful.
Placental Site Trophoblastic Tumour[edit | edit source]
- Present as missed abortions
Pathology and Histology[edit | edit source]
Hydatidiform Moles[edit | edit source]
- Complete moles are characterized by diffuse trophoblastic hyperplasia with villus thickening, and absent vasculature/embryoblast.
- Partial moles are characterized by focal trophoblastic hyperplasia, villous swelling, scalloping of the villi, and an embryo and/or present.
Management[edit | edit source]
Hydatidiform Mole[edit | edit source]
- Dilatation and curettage is the management of choice for complete and partial hydatidiform moles. With respect to the former, there is an 80% cure rate, with the other 20% developing invasive disease requiring chemotherapy. Fewer than 5% of partial moles develop invasive disease requiring chemotherapy.
- Overall, 5-15% of patients will develop invasive molar disease and require chemotherapy.
- Weekly monitoring of the HCG should be done until negative for three consecutive weeks. After this point, monthly monitoring of HCG should be conducted for 6 months.
- Regular pelvic exams should be conducted and the patient should be advised to use contraception (oral contraceptive pill, if possible) for 6 months.
Invasive Mole[edit | edit source]
- Prior to chemotherapy, the following lab tests should be recorded
- CBC, Creatinine, Liver Enzymes and Liver Function Tests, CT scan of the head, thorax, and abdomen
- Therapy delivered will be different based on patient risk profiling: either non-metastatic, low-risk metastatic, and high-risk metastatic (see table below).
- Non-metastatic invasive moles receive methotrexate or actinomycin-D
- Low risk patients receive methotrexate and/or actinomycin-D
- High risk patients receive surgery, chemotherapy, and radiotherapy
Low-Risk Metastatic | High-Risk Metastatic |
---|---|
<4mo since last pregnanc | >4mo since last pregnancy |
Pretherapy hCG <40000 | Pretherapy hCG >40000 |
No prior chemotherapy | Prior chemotherapy |
Brain and/or liver mets | Brain and/or liver mets |
No antecedent term pregnancy | Antecedent term pregnancy |
Choriocarcinoma[edit | edit source]
- Same treatment as invasive mole
Placental Site Trophoblastic Tumours[edit | edit source]
- Dilatation and curettage
- Total abdominal hysterectomy