Anatomy of the Female Reproductive System

Internal Organs

1. Ovaries

• Paired gonads, almond-shaped, ~3 × 2 × 1 cm
• Located in the ovarian fossa on the lateral pelvic wall
• Attached to the uterus by the ovarian ligament and to the pelvic wall by the suspensory (infundibulopelvic) ligament
• Functions: Oogenesis (egg production) and secretion of estrogen and progesterone
• Cortex contains follicles at varying stages of development (primordial → mature Graafian follicle)

2. Fallopian Tubes (Uterine Tubes)

• Two muscular tubes, ~10 cm long, extending from the uterine cornua to the ovaries
• Parts (medial → lateral):

  Segment	Features
  Intramural (interstitial)	Passes through uterine wall; narrowest part
  Isthmus	Thick-walled, narrow lumen
  Ampulla	Widest; usual site of fertilization
  Infundibulum	Funnel-shaped; bears fimbriae that sweep the ovum

• Lined by ciliated columnar epithelium that facilitates ovum transport

3. Uterus

• Hollow, pear-shaped muscular organ, ~7.5 × 5 × 2.5 cm (nulliparous)
• Parts:
  • Fundus — dome above the fallopian tube openings
  • Body (corpus) — main part; contains the triangular uterine cavity
  • Isthmus — narrow junction between body and cervix
  • Cervix — lower cylindrical part; projects into the vagina
• Layers of the uterine wall:

  Layer	Description
  Perimetrium	Outer serosal (peritoneal) covering
  Myometrium	Thick smooth muscle; contracts during labor
  Endometrium	Inner glandular lining; undergoes cyclic changes

• Supports: Held in place by the broad, round, cardinal (Mackenrodt's), and uterosacral ligaments; normal position is anteverted and anteflexed
• Blood supply: Uterine artery (branch of internal iliac)

4. Cervix

• Lower cylindrical segment, ~2.5–3 cm long
• Ectocervix: Covered by stratified squamous epithelium (visible on speculum exam)
• Endocervix: Lined by mucus-secreting columnar epithelium
• Transformation zone (squamocolumnar junction): Clinically important site where most cervical cancers arise
• Internal os opens into the uterine cavity; external os opens into the vagina

5. Vagina

• Fibromuscular canal, ~8–10 cm long, connecting cervix to the external genitalia
• Upper third from Müllerian ducts; lower two-thirds from urogenital sinus
• Lined by stratified squamous epithelium (non-keratinized)
• Forms fornices (anterior, posterior, and lateral) around the cervix — the posterior fornix is deepest and lies adjacent to the rectouterine pouch (Pouch of Douglas)
• Functions: Birth canal, menstrual outflow, copulation

External Genitalia (Vulva)

Blood Supply Summary

Lymphatic Drainage

Nerve Supply

• Sympathetic: T10–L2 (uterus, tubes, ovaries)
• Parasympathetic: S2–S4 (pelvic splanchnic nerves)
• Somatic: Pudendal nerve (S2–S4) — external genitalia

Key Anatomical Relations

• Anteriorly: Bladder and urethra
• Posteriorly: Rectum; Pouch of Douglas (rectouterine pouch) lies between uterus and rectum — clinically important for ectopic fluid/blood
• Laterally: Ureters run ~1 cm lateral to the cervix ("water under the bridge" — ureters pass beneath the uterine artery), making them vulnerable during hysterectomy

Chronic Hypertension in Pregnancy

Definition

• A pre-existing diagnosis of hypertension, OR
• SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg on 2 occasions at least 4 hours apart before 20 weeks' gestation

Classification of Hypertensive Disorders of Pregnancy

Risks & Complications

• Superimposed preeclampsia (most important complication; risk 15–25%)
• Placental abruption
• Stroke / hypertensive crisis
• Renal deterioration
• Cardiac failure (in severe/long-standing HTN)

• Intrauterine growth restriction (IUGR)
• Preterm birth
• Placental insufficiency
• Perinatal mortality (increased)

Pre-pregnancy & Early Pregnancy Evaluation

1. Identify secondary/remediable causes of hypertension
2. End-organ assessment — renal function, proteinuria (baseline), cardiac evaluation, fundoscopy
3. Transition off teratogenic antihypertensives (especially ACE inhibitors and ARBs) before conception or as soon as pregnancy is confirmed
4. Baseline proteinuria — helps differentiate pre-existing renal disease from later-developing preeclampsia

Blood Pressure Targets in Pregnancy

Targets balance maternal safety (preventing stroke, end-organ damage) with fetal perfusion (avoiding uteroplacental insufficiency from over-aggressive lowering). (Harrison's, p. 13634; Management of Elevated BP Guidelines, p. 60)

Antihypertensive Drug Management

First-Line Agents (Safe in Pregnancy)

Contraindicated in Pregnancy

Management Guidelines Summary

Monitoring During Pregnancy

• Frequent antenatal visits — every 2–4 weeks (more frequent if poorly controlled)
• BP monitoring: Home BP monitoring (HBPM) and/or ambulatory BP monitoring (ABPM) to exclude white-coat and masked hypertension (more common in pregnancy)
• Urine protein at each visit — early detection of superimposed preeclampsia
• Fetal surveillance: Serial growth ultrasounds (every 4 weeks from 28 weeks), umbilical artery Doppler, non-stress tests
• Labs: Renal function, LFTs, CBC, uric acid

Delivery Planning

Postpartum Considerations

• BP often rises 3–6 days postpartum — close monitoring required
• Resume or initiate antihypertensives as needed; most are compatible with breastfeeding (labetalol, nifedipine, methyldopa)
• ACE inhibitors (e.g., enalapril, captopril) are acceptable postpartum and in breastfeeding
• Evaluate for secondary causes postpartum if not done previously
• Long-term: chronic hypertension persists — ongoing cardiovascular risk management