First Prenatal Visit: Screening & Assessment

1. Gestational Age Determination

• Calculate the Estimated Date of Delivery (EDD) using Nagle's Rule: first day of LMP, subtract 3 months, add 7 days
• Adjust for cycles shorter or longer than 28 days
• If LMP is uncertain or uterine size is discrepant, order early ultrasonography (more accurate for dating than late US after 24 weeks)
• Any irregular bleeding or abdominal pain warrants ultrasound to confirm viability and intrauterine location

2. History & Risk Assessment

• Complete obstetric history (gravida/para)
• Current pregnancy history to date
• Medical conditions and surgical history
• Nutrition update

• Smoking, alcohol, drug use
• Social support systems
• Physical work demands and activity level
• Stress assessment

• Family history of genetic disorders
• Previously affected fetus or child
• History of recurrent miscarriage - if present, offer genetic counseling

3. Physical Examination

4. Laboratory Screening - Recommended for ALL

5. Laboratory Screening - Recommended for SOME (Risk-Based)

6. Genetic Screening Offers (First Trimester)

• Cell-free fetal DNA (cfDNA/NIPT) - at 10 weeks' gestation or later: screens for trisomies 21, 18, 13, and sex chromosome aneuploidies
• First-trimester combined screening (nuchal translucency US + PAPP-A + free beta-hCG): 10-13 weeks
• CVS (chorionic villus sampling): offered to high-risk women (advanced maternal age, abnormal screen, family history) for definitive diagnosis
• All women should be offered prenatal serum marker screening for neural tube defects and aneuploidy

7. Counseling & Education Topics

• Teratogen avoidance: smoking, alcohol, illicit drugs, prescription/OTC/herbal medications
• Nutrition and weight gain (individualized)
• Folic acid supplementation (reduces neural tube defects - ideally started preconception)
• Exercise in pregnancy (continue moderate intensity; avoid supine position after 1st trimester, hyperthermia, high-impact activity)
• Infection prevention: hand washing, food safety (listeria, toxoplasma)
• Immunizations: influenza, Tdap (offered later in pregnancy)
• Sexual activity: generally safe except in placenta previa, preterm labor
• Workplace exposures and hot tub/sauna use
• Breastfeeding preparation
• Frequency and schedule of future prenatal visits
• Danger signs requiring immediate reporting (bleeding, severe headache, decreased fetal movement, etc.)

8. Later Pregnancy Testing (Scheduled at First Visit)

• Textbook of Family Medicine 9e (Rosen et al. Expert Panel recommendations), pp. 479-480
• Tietz Textbook of Laboratory Medicine, 7th Edition, p. 2412

Uterine Evacuation: Methods

Overview of Main Categories

1. Instrumental/Surgical evacuation - via the vaginal route
2. Medical (pharmacological) - using drugs to stimulate uterine contractions
3. Major surgical procedures - hysterotomy/hysterectomy (rarely)

I. SURGICAL METHODS

1. Vacuum/Suction Aspiration (MVA & EVA)

• Uses a hand-held modified 50-mL syringe and flexible plastic cannula
• No electricity required; sedation or anesthesia often not needed
• As effective as electric vacuum through 10 menstrual weeks
• Advantages: portable, safe, less hemorrhage, less risk of uterine perforation
• Products of conception are aspirated into the syringe

• Electric vacuum pump creates negative pressure of 0.4-0.6 kg/sq.cm
• Cervix dilated; 9 mm cannula used between 8-12 weeks
• Cannula moved gently over all uterine surfaces; aspiration takes 3-5 minutes
• Contents broken up by suction and collected in a connected bottle
• Advantages: less hemorrhage, diminished perforation risk vs. sharp curettage

• Metal or plastic dilators (mechanical)
• Osmotic dilators (laminaria - seaweed; Dilapan-S - hydrophilic polymer)
• Misoprostol 400 mcg vaginally/buccally 3-4 hours before procedure

2. Dilation and Curettage (D&C)

• Cervix dilated; uterine contents removed by a sharp/blunt curette
• Most commonly used above 8 weeks gestation (first trimester)
• Has largely been replaced by vacuum aspiration for safety reasons
• Sharp curettage is more painful and carries higher risk of endometrial damage (Asherman syndrome) compared to vacuum aspiration

3. Dilation and Evacuation (D&E)

• Overnight osmotic dilator placement to achieve adequate dilation
• Specialized forceps + large-bore vacuum cannula to extract fetus and placenta
• Ultrasound guidance is helpful
• At later gestations (>18-20 weeks): feticidal agents may be used first - intra-amniotic or intrafetal digoxin (1.5 mg) or intracardiac potassium chloride

II. MEDICAL METHODS

1. Mifepristone + Misoprostol (First-line regimen)

• Mifepristone 200 mg orally: blocks progesterone receptor → decidual necrosis, cervical softening, uterine sensitization to prostaglandins
• Followed 24-48 hours later by Misoprostol 800 mcg buccally/vaginally: stimulates uterine contractions
• Efficacy: 96-99% complete abortion; up to 70 days (10 weeks) gestation
• FDA approved; can be self-administered at home
• Common side effects: nausea, vomiting, diarrhea, headache, dizziness, fatigue

• Ectopic pregnancy
• IUD in place (must remove first)
• Chronic adrenal failure
• Concurrent long-term corticosteroid therapy
• Hemorrhagic disorder
• Inherited porphyrias

2. Misoprostol Alone

• Used when mifepristone is unavailable
• Vaginal misoprostol 800 mcg, repeated in 24 hours if needed
• Complete abortion rate ~91% up to 56 days of amenorrhea (less effective than combination)

3. Methotrexate + Misoprostol

• Antifolate methotrexate arrests trophoblast proliferation
• Alternative when mifepristone is unavailable
• Takes longer to act than the mifepristone/misoprostol regimen

4. Prostaglandins Alone

• PGE2 (dinoprostone) and PGF2α (carboprost) - induce uterine contractions
• Can be given IV, orally, or intra-amniotically
• Intra-amniotic injection of 25 mg prostaglandin F2α used for second-trimester evacuation
• Primarily used in later gestation or as labor-induction method

5. Oxytocin

• IV oxytocin infusion combined with cervical dilation
• Used in labor induction for mid/late-trimester evacuation
• Direct injection of 10 units into the uterus is an older method

6. Amniotic Fluid Replacement (Hypertonic Saline)

• Useful after 12 weeks or in cases of intrauterine fetal death
• Amniotic fluid removed and replaced with equal volume of 20% saline or 50% glucose
• Abortion typically occurs within 24-48 hours
• Largely replaced by safer pharmacological methods

III. SURGICAL (MAJOR) METHODS

Hysterotomy

• Abdominal or uterine incision to remove contents
• Preferred after 14 weeks when other methods are not feasible or have failed
• Higher morbidity than D&E; now rarely performed
• Essentially a mini-cesarean section

Comparison by Gestational Age

Complications of Uterine Evacuation

• Berek & Novak's Gynecology, pp. 779-784
• Kaplan & Sadock's Comprehensive Textbook of Psychiatry, p. 7836
• Essentials of Forensic Medicine and Toxicology, 36th ed., pp. 9437-9496
• Tintinalli's Emergency Medicine, p. 3392