# Clinical Cases: Reproductive Pharmacology

## Case 1: Medical Abortion with Mifepristone and Misoprostol

### Clinical Image
![Mifepristone](case_01_image.jpg)
*Source: [Wikipedia - Mifepristone](https://en.wikipedia.org/wiki/Mifepristone) - CC BY-SA 4.0*

### Case Presentation
A 26-year-old G2P1 woman presents requesting pregnancy termination. Her last menstrual period was 7 weeks ago, and she has a positive home pregnancy test. She has one child and is certain she does not want to continue this pregnancy due to personal circumstances. Transvaginal ultrasound confirms an intrauterine pregnancy at 6 weeks 5 days gestation with a yolk sac and embryonic pole measuring 5 mm without cardiac activity visualized. She has no contraindications to medical abortion (no suspected ectopic pregnancy, inherited porphyria, chronic adrenal failure, or concurrent long-term corticosteroid use). She is counseled about her options including surgical aspiration versus medication abortion. She prefers medication abortion due to its non-invasive nature and the ability to complete the process at home. She is prescribed mifepristone 200 mg orally, taken in the clinic, which competitively blocks progesterone receptors, leading to decidual necrosis and pregnancy detachment. She is instructed to take misoprostol 800 mcg buccally 24-48 hours later at home. Misoprostol causes uterine contractions. She is counseled about expected bleeding (heavier than a period with clots) and cramping, and provided with pain medication and a 24-hour contact number. She follows up 1 week later. Ultrasound shows an empty uterus, confirming complete abortion. Serum hCG has appropriately declined. She is counseled about contraception and chooses a hormonal IUD, which is placed at the same visit.

### Key Learning Points
- Medical abortion using mifepristone (anti-progestin) plus misoprostol (prostaglandin) is highly effective (>95% complete abortion rate) for pregnancies up to 10-11 weeks gestation
- Mifepristone blocks progesterone receptors, causing decidual necrosis and detachment of the pregnancy; misoprostol causes cervical softening and uterine contractions to expel the pregnancy
- Contraindications to medical abortion include confirmed or suspected ectopic pregnancy, IUD in place, chronic corticosteroid use, inherited porphyrias, and allergy to the medications
- Follow-up to confirm complete abortion is essential; failure (ongoing pregnancy or incomplete abortion) requires repeat medication or surgical intervention

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## Case 2: Management of Preterm Labor with Tocolytics and Antenatal Corticosteroids

### Clinical Image
![Nifedipine](case_02_image.jpg)
*Source: [Wikipedia - Nifedipine](https://en.wikipedia.org/wiki/Nifedipine) - CC BY-SA 4.0*

### Case Presentation
A 29-year-old G1P0 at 28 weeks gestation presents with regular, painful uterine contractions every 4 minutes for the past 3 hours. She denies rupture of membranes, vaginal bleeding, or fever. Cervical examination reveals 3 cm dilation and 70% effacement. Fetal heart rate tracing is reassuring. Fetal fibronectin test is positive. The diagnosis is preterm labor at 28 weeks. The patient is admitted for tocolysis and antenatal corticosteroid administration. Nifedipine (calcium channel blocker) is chosen as the tocolytic agent, given as a loading dose of 20 mg orally followed by 10-20 mg every 4-6 hours. Nifedipine is preferred for its efficacy and favorable maternal side effect profile compared to beta-agonists. Betamethasone 12 mg IM is administered, with a second dose to be given in 24 hours to promote fetal lung maturity and reduce neonatal respiratory distress syndrome, intraventricular hemorrhage, and necrotizing enterocolitis. Magnesium sulfate 4 g IV bolus followed by 1-2 g/hour is also started for fetal neuroprotection to reduce the risk of cerebral palsy. Over the next 24 hours, contractions decrease significantly with nifedipine, and cervical change arrests. She receives both doses of betamethasone. Tocolysis is discontinued after 48 hours. She is discharged on activity restriction and progesterone supplementation. She goes on to deliver at 36 weeks following spontaneous labor.

### Key Learning Points
- Tocolytic agents (nifedipine, indomethacin, magnesium sulfate, terbutaline) are used to delay delivery for 48 hours to allow administration of antenatal corticosteroids, not to prevent preterm birth long-term
- Nifedipine (calcium channel blocker) is often considered first-line tocolytic due to efficacy and favorable side effect profile; indomethacin is limited to <32 weeks due to risk of premature ductus arteriosus closure
- Antenatal corticosteroids (betamethasone or dexamethasone) significantly reduce neonatal morbidity and mortality when given between 24-34 weeks gestation
- Magnesium sulfate is given for fetal neuroprotection at <32 weeks; its antidote for toxicity is calcium gluconate

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## Case 3: Ovarian Hyperstimulation Syndrome Following Gonadotropin Therapy

### Clinical Image
![Ovarian Hyperstimulation](case_03_image.jpg)
*Source: [Wikipedia - Ovarian hyperstimulation syndrome](https://en.wikipedia.org/wiki/Ovarian_hyperstimulation_syndrome) - CC BY-SA 3.0*

### Case Presentation
A 28-year-old woman with PCOS is undergoing her first IVF cycle. She responded vigorously to gonadotropin stimulation, with 28 follicles seen on monitoring ultrasound and estradiol level of 4,500 pg/mL. Due to her high response, a GnRH agonist trigger was used instead of hCG trigger to reduce OHSS risk, and all embryos were cryopreserved (freeze-all cycle) rather than performing fresh transfer. Despite these precautions, 5 days after oocyte retrieval, she presents with abdominal distension, bloating, nausea, and decreased urine output. Physical examination reveals a distended abdomen with shifting dullness consistent with ascites. Weight has increased 4 kg since retrieval. Laboratory studies show hematocrit 48% (elevated due to hemoconcentration), creatinine 1.3 mg/dL (mildly elevated), and sodium 128 mEq/L (low). Ultrasound shows enlarged ovaries (12 cm bilaterally) with multiple cysts and significant ascites. The diagnosis is moderate-to-severe ovarian hyperstimulation syndrome (OHSS). She is admitted for IV fluid resuscitation and close monitoring of fluid balance, renal function, and coagulation parameters. Thromboprophylaxis with low-molecular-weight heparin is initiated given the hypercoagulable state. Therapeutic paracentesis is performed, removing 2 liters of ascitic fluid with symptomatic improvement. Over 5 days, her symptoms gradually resolve as hCG levels (from the agonist trigger) decline. She is discharged and undergoes successful frozen embryo transfer 2 months later.

### Key Learning Points
- OHSS is a potentially life-threatening iatrogenic complication of ovarian stimulation characterized by ovarian enlargement, third-spacing of fluid, hemoconcentration, and hypercoagulability
- Risk factors include PCOS, young age, low body weight, high antral follicle count, elevated estradiol levels, and large number of retrieved oocytes
- Prevention strategies in high-risk patients include GnRH agonist trigger (instead of hCG), freeze-all cycles (avoiding hCG from pregnancy), and dopamine agonists
- Management is supportive: IV fluids for intravascular volume depletion, paracentesis for tense ascites, thromboprophylaxis, and monitoring for complications (VTE, renal failure, respiratory compromise)