Introduction to Obstetrics and Gynecology
Core concepts, key terminology, and foundational principles for medical students and health‑care professionals.
1. Scope of the Specialty
| Discipline |
Primary Focus |
Typical Clinical Settings |
| Obstetrics |
Pregnancy, childbirth, and the postpartum period |
Antenatal clinics, labor & delivery units, maternal‑fetal medicine centers |
| Gynecology |
Health of the female reproductive system (uterus, ovaries, cervix, vagina, vulva) |
Outpatient gynae clinics, surgical suites, cancer centers |
- Combined practice: Most physicians are trained in both fields (OB‑GYN) and manage women’s health across the lifespan—from menarche to menopause and beyond.
- Sub‑specialties: Maternal‑Fetal Medicine, Reproductive Endocrinology & Infertility, Gynecologic Oncology, Urogynecology, Minimally Invasive Surgery.
2. Basic Anatomy & Physiology
| Structure |
Function |
Clinical Relevance |
| Ovaries |
Produce oocytes; secrete estrogen & progesterone |
Disorders of ovulation, ovarian cysts, tumors |
| Fallopian Tubes |
Transport oocyte; site of fertilization |
Ectopic pregnancy, tubal factor infertility |
| Uterus |
Implantation & support of embryo/fetus; menstrual shedding |
Fibroids, adenomyosis, uterine malformations |
| Cervix |
Passage for sperm; barrier to pathogens; dilates during labor |
Cervical dysplasia, incompetent cervix |
| Vagina |
Birth canal; microbiome reservoir |
Vaginal infections, prolapse |
| Placenta |
Nutrient/gas exchange; hormone production |
Placental insufficiency, previa, abruption |
| Mammary Glands |
Lactation |
Mastitis, breast cancer |
- Hormonal regulation: Hypothalamic‑pituitary‑gonadal axis (GnRH → LH/FSH → ovarian steroids).
- Menstrual cycle: Follicular (estrogen‑dominant), ovulation, luteal (progesterone‑dominant), menses.
3. Obstetric Care Continuum
| Phase |
Objectives |
Typical Interventions |
| Preconception |
Optimize health before pregnancy |
Folate supplementation, chronic disease control, vaccination |
| Prenatal (Antenatal) |
Monitor fetal growth, maternal wellbeing, detect complications |
Routine visits (every 4 wks → every 2 wks → weekly), ultrasound, labs (CBC, glucose tolerance, TORCH) |
| Intrapartum (Labor & Delivery) |
Safe progression of labor, fetal monitoring, manage emergencies |
Cervical exam, partogram, electronic fetal monitoring, analgesia, operative delivery |
| Postpartum |
Support recovery, lactation, mental health |
Uterine involution assessment, contraception counseling, postpartum depression screening |
- Key milestones: First‑trimester dating scan, anatomy scan (18‑22 wk), glucose tolerance test (24‑28 wk), group B Strep screening (35‑37 wk).
4. Common Gynecologic Conditions
| Condition |
Pathophysiology |
Presentation |
First‑line Management |
| Dysmenorrhea |
Prostaglandin‑mediated uterine contractions |
Crampy pelvic pain during menses |
NSAIDs, hormonal contraception |
| **Polycystic Ovary Syndrome (PCOS |
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