Chapter 31: Pregnancy

Pregnancy establishes a foundation by detailing the complex endocrinological shifts driven by the placenta, particularly the vital roles of human chorionic gonadotropin (hCG), progesterone, and estrogen in sustaining gestation and facilitating systemic anatomical changes. The text systematically categorizes the clinical diagnosis of pregnancy into presumptive, probable, and positive signs, while meticulously outlining the multisystemic transformations occurring across all three trimesters. First-trimester discussions cover the embryonic-to-fetal transition, cardiovascular vasodilation, and subjective symptoms like nausea and fatigue. Second-trimester assessments emphasize dermatologic phenomena such as the linea nigra and striae gravidarum, along with gastrointestinal shifts and the onset of fetal quickening. Third-trimester evaluations focus on peak hemodynamic volume, respiratory adjustments, postural lordosis, and cervical effacement as the body prepares for parturition. The text provides a thorough guide to gathering subjective maternal histories, encompassing gynecological, obstetric, and nutritional backgrounds, while addressing contemporary psychosocial factors such as teen pregnancy disparities, advanced maternal age risks, substance use disorders including neonatal abstinence syndrome, and the specific perinatal needs of transgender and gender-diverse individuals. In terms of objective physical examination, the chapter details specialized clinical techniques, including the calculation of the expected date of delivery using Nägele's rule, the measurement of fundal height to monitor fetal growth, and the application of Leopold maneuvers to determine fetal lie, presentation, and engagement. Pelvic examination findings are clearly defined, noting crucial vascular and anatomical indicators such as Chadwick's, Goodell's, and Hegar's signs. Furthermore, the text reviews essential diagnostic screening tools like ultrasound and cell-free DNA testing, concluding with a critical analysis of abnormal pathological findings, notably preeclampsia, HELLP syndrome, postpartum hemorrhage, and fetal size discrepancies like intrauterine growth restriction and fetal macrosomia, ensuring a robust knowledge base for prenatal clinical practice.