PCC SOM 2026 Clinical Pathology PDF

PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION FAMILY AND COMMUNITY MEDICINE LECTURE LECTURER: Dr. Arlene L. Quitasol TOPIC OUTLINE i. NORMAL PHYSIOLOGY a. Sex Steroids b. Regulation of Male Reproduction c. Regulation of Female Reproduction d. Pregnancy ii. LABORATORY EVALUATION OF REPRODUCTIVE F...

PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION FAMILY AND COMMUNITY MEDICINE LECTURE LECTURER: Dr. Arlene L. Quitasol TOPIC OUTLINE i. NORMAL PHYSIOLOGY a. Sex Steroids b. Regulation of Male Reproduction c. Regulation of Female Reproduction d. Pregnancy ii. LABORATORY EVALUATION OF REPRODUCTIVE FUNCTION a. Male Evaluation b. Female Evaluation c. Assisted Reproductive Technology iii. LABORATORY EVALUATION OF PREGNANCY I. Normal Physiology Reproductive function and pregnancy are regulated by the complex interaction of a variety of hormones Synthesized and secreted by the: Testis: testosterone Ovary: estradiol and progesterone Pituitary: follicle-stimulating hormone [FSH] and luteinizing hormone [LH] Hypothalamus: gonadotropin-releasing hormone Placenta: human chorionic gonadotropin [hCG], estrogens, progesterone SEX STEROIDS Once in the blood, most of the hydrophobic sex steroids become reversibly and noncovalently bound to plasma proteins Low-affinity, nonspecific binding to hydrophobic sites on albumin High- affinity binding to specific transport proteins that are synthesized by the liver SEX HORMONE–BINDING GLOBULIN (SHBG) Transports androgens and estrogens CORTICOSTEROID-BINDING GLOBULIN (CBG) Transports progesterone (as well as glucocorticoids) In blood: 1% to 2% of the sex steroids are free (unbound) About half of the remainder are bound to SHBG or CBG About half are bound to albumin Free fraction Biologically active Can exit the vascular system (by diffusion) and interact with target cells REGULATION OF MALE REPRODUCTION GONADOTROPIN-RELEASING HORMONE (GNRH) Decapeptide Synthesized and secreted by neuroendocrine cells of the hypothalamus (arcuate nucleus) Binds to specific cell membrane receptors on gonadotrophs in the anterior pituitary, resulting in the synthesis and secretion of two protein hormones: FOLLICLE-STIMULATING HORMONE (FSH) LUTEINIZING HORMONE (LH) FSH and LH Similar to thyroid-stimulating hormone (TSH) in that all three consist of two subunits and all share the same α subunit Each has a different β subunit conferring their functional specificity SEMINIFEROUS TUBULES OF THE TESTIS Contain cells in various stages of spermatogenesis (spermatogonia, spermatocytes, spermatids), along with Sertoli cells and Leydig cells NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 1 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION SERTOLI CELLS Induced by FSH Synthesize and secrete androgen-binding protein into the lumen of the seminiferous tubule Maintains the high testosterone concentration required for normal spermatogenesis INHIBIN ✓ Synthesized and secreted by Sertoli cells ✓ Dimeric protein composed of an α and β subunit ✓ Interacts with gonadotrophs in the anterior pituitary, where it also has a negativefeedback effect by decreasing the synthesis and secretion of FSH, but not LH ✓ Androgens also stimulate inhibin production, which locally helps regulate spermatogenesis LEYDIG CELLS Induced by LH to synthesize testosterone Testosterone ✓ Some enters the general circulation and is transported to other target tissues, such as skeletal muscle = where it has an anabolic effect ✓ Transported to the hypothalamus and anterior pituitary = where it has a negativefeedback effect (decreases and helps control the synthesis and secretion of GnRH, FSH, and LH) REGULATION OF FEMALE REPRODUCTION GnRH from the hypothalamus Increases the synthesis and secretion of FSH and LH from the anterior pituitary Regulatory process in the female is cyclic and is referred to as the MENSTRUAL CYCLE MENSTRUAL CYCLE Begins with menses, or shedding of the uterine endometrium (Day 1) FSH FOLLICULOGENESIS Process of follicular selection and maturation Occurs during FOLLICULAR PHASE Cohort of about 10-12 antral follicles are recruited to begin further growth and development within the ovaries From this cohort, one to two (usually) antral follicles are selected to become the dominant follicle, continuing to grow and develop Other recruited follicles undergo regression, or atresia As the follicle grows, increasing amounts of estradiol are synthesized and secreted from the granulosa cells via FSH-induced aromatase activity ESTRADIOL Acts to restore the endometrium via cell proliferation and growth Negative-feedback effect on the hypothalamus and the anterior pituitary decreasing FSH levels during the latter part of the follicular phase Near the end of the follicular phase Estradiol levels are at their highest:200 to 300 IU Feedback effect on the hypothalamus and anterior pituitary switches from negative to positive Causes a surge in the secretion of GnRH, FSH, and particularly LH, which culminates in ovulation LH SURGE Causes final oocyte maturation with the completion of meiosis in the ovaries before the follicle bursts, releasing the oocyte into the fallopian tubes Owing to disruption of the growing follicle Estradiol synthesis and secretion drop dramatically Disrupted follicle begins to differentiate into the corpus luteum → thus begins the LUTEAL PHASE of the ovarian cycle Corpus luteum synthesizes estradiol and progesterone as a result of the action of LH Combination of the two steroids Acts on the uterine endometrium to cause development of numerous exocrine glands, producing the secretory phase of the uterine endometrial cycle Secretory Phase (Uterine Endometrial Cycle) NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 2 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION Prepares the endometrium for implantation should fertilization and early development occur LH levels decline gradually during the luteal phase Indicating restoration of negative-feedback regulation of the hypothalamus and anterior pituitary by estradiol and progesterone INHIBIN Male: selective negative-feedback effect on FSH Female: 2 Forms INHIBIN A ▪ From corpus luteum ▪ Reaches peak in midluteal phase INHIBIN B ▪ Synthesized and secreted by the developing follicles ▪ Reaches a peak in the early- to midfollicular phase and a second peak at ovulation Normal fertile cycle (sa ppt ni Doc); Infertile cycle (book) Corpus luteum begins to regress near the end of the luteal phase Results in a decrease in estradiol and progesterone synthesis and secretion Because these steroids are required for maintenance of the secretory endometrium, it begins to deteriorate and is ultimately shed during menstruation With the drop in estradiol and progesterone ▪ negative feedback effects decrease ▪ FSH and LH rise to begin another cycle PREGNANCY If the oocyte is fertilized during its transit down the fallopian tubes o Develops into a multicellular blastocyst by the time it reaches the uterus Around the time of implantation (about 7–9 days after ovulation) and before the corpus luteum begins to regress o Increasing amounts of an LH-like hormone, human chorionic gonadotropin (hCG), are found in maternal blood hCG Synthesized and secreted by the syncytiotrophoblast cells of the developing placenta Dimeric protein hormone that has the same α subunit as LH, FSH, and TSH, but a different β subunit β-subunit of hCG is very similar to that of LH, but larger Can interact with LH receptors on luteal cells Interaction prevents regression of the corpus luteum and allows it to continue synthesis and secretion of estradiol and progesterone, both of which are required for appropriate maintenance of the uterine endometrium throughout pregnancy First trimester of pregnancy hCG increases from 100,000 mIU/mL Increase is responsible for the similarly dramatic increases in the levels of estradiol and progesterone End of the first trimester hCG levels begin to plateau at first and then decline significantly Estradiol and progesterone continue to increase because, by this time, the placenta has assumed most steroid synthesis, including significant amounts of estrone and estriol HUMAN PLACENTAL LACTOGEN (HPL) Synthesized in large quantities by the placenta during the last two trimesters Structurally similar to both prolactin and growth hormone and has both lactogenic and growthpromoting activities Parallels the steady increase in placental mass PARTURITION Process by which the fetus is expelled from the internal environment of the maternal uterus to the external environment Occurs as a result of a change in the activity of the uterine myometrium (smooth muscle) from irregular, long-lasting, lowfrequency contractions to regular, highintensity, high-frequency contractions Parturition is followed by lactation NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 3 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION Initial development of the mammary gland occurs at puberty Estradiol: causes growth and branching of the ducts Progesterone: causes formation of the alveoli During pregnancy High concentrations of estrogens and progesterone cause further branching of the ducts and growth of the alveoli Secretory capability of the alveolar epithelial cells Induced by: ▪ Prolactin: increases during pregnancy ▪ HPL (Human Placental Lactogen) At parturition Decrease in estrogen and progesterone eliminates their inhibitory effects on milk secretion, which still requires prolactin Milk ejection Requires oxytocin, acting as part of a neuroendocrine reflex This reflex is initiated by the suckling stimulus, which generates nerve impulses that travel from the nipple to the hypothalamus -→ cause secretion of oxytocin from neuroendocrine cells in the posterior pituitary Oxytocin travels to the mammary gland, where it stimulates the contraction of smooth muscle cells surrounding the alveoli, causing milk ejection II. LABORATORY EVALUATION OF REPRODUCTIVE FUNCTION Male and female reproductive disease states typically categorized according to: hormone deficiency or excess primary (gonad) or secondary (pituitary) dysfunction PRIMARY DISEASE STATES - gonadal steroid levels are inversely related to pituitary gonadotropin levels SECONDARY DISEASE STATES directly related (e.g., both high or both low MALE EVALUATION Usually begins with SEMEN ANALYSIS cost-effective relatively simple procedure Normal results: further evaluation is often unnecessary Abnormal results: hormone analyses are performed, which include FSH, LH, and testosterone levels SEMEN ANALYSIS Used to select donors for therapeutic insemination Monitor the success of surgical procedures, such as varicocelectomy and vasectomy Consists of MICROSCOPIC MACROSCOPIC components ✓ physical (e.g., volume) ✓ chemical (e.g., pH) properties 1. Sample Collection Collect semen after 2 to 5 days of sexual abstinence to ensure that the sperm count will be at its highest and improve the reliability of the test Longer periods of abstinence → result in a higher sperm concentration but reduced sperm motility Laboratory should provide a sterile plastic (polypropylene) container with a screw top Specimen should be delivered to the laboratory within 1 hour of collection and kept warm during transportation 2. MACROSCOPIC EXAMINATION Performed after liquefaction usually occurs in less than 20 minutes at room temperature Failure to liquefy may indicate inadequate prostate secretion Semen should be thoroughly mixed before examination and its viscosity recorded Volume of ejaculate can be measured by weighing the collection cup before and after specimen collection NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 4 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION Appearance: Yellow hue: pyospermia Rust color: small bleedings in the seminal vesicle pH ranges from 7.2 to 7.8 pH of 8.0 or higher acute infection in the prostate, seminal vesicle, or epididymis pH of 7.0 or lower contamination with urine obstruction in the ejaculatory ducts specimen consists of mainly prostatic fluid 3. Microscopic Examination Performed to obtain estimates of: Sperm concentration Motility Morphology Agglutination Other cellular elements, such as polygonal cells of the urethral tract and round cells such as spermatogenic cells and leukocytes, can also be observed when sperm are counted in a hemocytometer Because sperm motility and velocity are temperature dependent, these parameters must be assessed on a microscope with a warm stage At least four different fields of two specimen aliquots should be counted and the mean of the eight separate readings recorded Total sperm count is then calculated by: multiplying the dilution factor (normal concentration range, 15–50 million/mL) by its volume (normal range, 2–5 mL) TOTAL MOTILITY Normal range: 40% or above Expressed as the percentage of sperm that move, including twitch PROGRESSIVE MOTILITY Normal range: 32% or above Expressed as the percentage of sperm that move in a forward, linear motion If motility is less than 30% ▪ a viability stain of eosin Y with nigrosin as a counterstain In bright-field microscopy Dead sperm: stain red Live sperm: will exclude the dye and appear unstained In samples with no visible sperm, such as post vasectomy semen, the entire sample should be centrifuged and the pellet examined for intact or damaged sperm fragments ▪ analysis should be repeated in 4 to 6 months Grading Interpretation Grade 4 sperm that move rapidly in a straight line with little yaw and lateral movement Grade 3 they move more slowly Grade 2 sperm move even more slowly and with substantial yaw Grade 1 sperm have no forward progression Zero Progression denotes absence of any motility Agglutination Occurs when motile sperm stick to one another in an orientation that is reproducible within a given specimen, such as head-to-head, tail to tail, midpiece to midpiece, or mixed ways, depending on the specificity of sperm antibodies Suggests an immunologic cause of infertility, and a description of the type of agglutination should be recorded Can usually be distinguished from clumping due to bacterial infection or tissue debris, which typically involves nonspecific orientation of the sperm Morphology ROUND CELLS should be differentiated into two classes: Immature germ cells with a single or double highly condensed nucleus with a relatively large area of cytoplasm Polymorphonuclear leukocytes, which are smaller than the germ cells and have a lower nuclear/cytoplasmic ratio NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 5 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION PEROXIDASE STAINING Identifies the polymorphonuclear leukocytes in the presence of lymphocytes and other cells that normally occur in semen Bacterial contamination should be noted If no sperm are seen in association with a low semen volume, a fructose test should be performed to confirm the presence of fluid from the seminal vesicle However, the significance of a fructose test result has declined over the years because of the availability of more direct diagnostic tools, such as transrectal ultrasonography Sperm Morphology can predict fertility MEN WITH PROVEN FERTILITY (WHO) These men were defined as men who were known to help their partners conceive in the previous 12 months. More than 4% of the sperm in a semen specimen should exhibit normal morphology Morphologically abnormal sperm usually have multiple defects TERATOZOOSPERMIC INDEX Average number of defects per sperm Significant predictor of sperm function both in vivo and in vitro Strict morphology score of greater than 4% of normal indicates excellent fertilizing capacity Scores between 0% and 3% predict probable inability to fertilize Wide variability in the size of the acrosomal cap most obvious characteristic of abnormal sperm Abnormal Sperm Acrosomal cap > one-third of the head surface Retention of a cytoplasmic droplet greater than one-half of the head size Tail less than 45 μm long Direct relationship between acrosome size and the frequency of fertilization or pregnancy IMMUNOLOGIC TESTS Sperm antibody binding to head or tail antigens is considered specific for immunologic infertility Antibodies are usually: ✓ IgA (most clinically significant) or IgG ✓ IgM (rare) Increased risk of men developing sperm antibody is associated with: ✓ Vasectomy ✓ Repeat prostate gland infections ✓ Obstruction of the ducts ✓ Cryptorchidism ✓ Varicocele ✓ Testicular biopsy ✓ Trauma ✓ Torsion ✓ Cancer ✓ Genetic predisposition In women, sperm antibody is usually associated with intense mucosal inflammation of the genital tract ACCESSORY GLANDS Seminal vesicle, prostate, and epididymis function can be evaluated by analyzing unique constituents of each Prostate secretions: Acidic and contain acid phosphatase Seminal fluid that is more alkaline than normal (pH >8.0) and that has reduced acid phosphatase suggests prostate dysfunction NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 6 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION FRUCTOSE Measure of seminal vesicle secretory function In azoospermia caused by the congenital absence of vasa deferentia, a low fructose level may indicate an associated dysgenesis of the seminal vesicles, as in some patients born with cystic fibrosis Ejaculatory duct obstruction, or agenesis of the vasa deferentia and seminal vesicles ▪ May result in the production of semen with: ✓ Low volume ✓ Low Ph ✓ Lack of coagulation ✓ Absence of characteristic semen odor NEUTRAL α-GLUCOSIDASE ▪ Originates solely from the epididymis ▪ Diagnostic value for distal ductal obstruction when considered with hormonal and testicular finding Hormone Analysis PRIMARY TESTICULAR FAILURE Decreased testosterone Increased LH and FSH Acquired or due to a genetic disease SECONDARY TESTICULAR FAILURE Decreased testosterone Decreased or inappropriately normal LH and FSH indicates hypothalamic-pituitary disease If normal testosterone, LH, and FSH levels accompany oligospermia or azoospermia Seminal fluid fructose should be evaluated ✓ Absence of fructose = Congenital absence of vasa deferentia and seminal vesicles ✓ Presence of fructose = Ductal obstruction or spermatogenic failure, which can be distinguished using testicular biopsy Seminiferous tubule failure Oligospermia accompanied by normal testosterone and LH along with increased FSH Increase in FSH is likely due to reduced negative feedback inhibition by decreased Sertoli cell inhibin GYNECOMASTIA Breast development in males Thought to be due to a relative imbalance of androgen (decreased) and estrogen (increased) acting at the mammary gland Measuring serum testosterone, estradiol, LH, hCG, prolactin, and TSH can reveal an endocrine abnormality or hormonesecreting tumor FEMALE EVALUATION Can be simplified to confirmation of ovulation and normal female reproductive anatomy Abnormal menstrual cycle pattern is one of the best predictors of anovulation. AMENORRHEA Absence of menstrual flow by age 16 years, or by age 14 years if no breast development occurs Patients who have not exhibited menses by age 16 years Often due to a genetic and/or anatomic abnormality Endocrine abnormality is still a possible cause ▪ Presence or absence of secondary sexual characteristics (e.g., breast development) is an important indicator in the evaluation Patients who have a history of menstruation but have not experienced menses for more than 3 months Endocrine abnormality is a more likely cause A stepwise approach to evaluating amenorrhea is based on: Measuring hCG, PRL, TSH, free thyroxine (FT4), FSH, LH, and androgen levels Assessing estrogen status 1. hCG is measured to exclude the most common cause of secondary amenorrhea—pregnancy NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 7 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION Although a result of greater than 5 mIU/ mL is typically indicative of pregnancy, an elevated result can also be obtained with trophoblastic disease or an hCG-secreting tumor. 2. PRL, TSH, and FT4 are measured to exclude the endocrine disorders Increased prolactin + normal TSH and FT4 Prolactinoma Further evaluated by imaging techniques Hyperprolactinemia Can be caused by primary hypothyroidism indicated by high TSH and low FT4 Low TSH and FT4 Secondary hypothyroidism patient should be evaluated for panhypopituitarism (a deficiency of all anterior pituitary hormones) Hyperthyroidism (increased FT4) ca also be associated with amenorrhea 3. If hCG, PRL, TSH, and FT4 are all normal, then endogenous estrogen status is evaluated with the Progestin Withdrawal Test Progestin Administered orally for 5 to 10 days or in one intramuscular injection (progestin dissolved in oil) Presence of withdrawal bleeding within 7 days after treatment indicates: Outflow tract is intact Sufficient estrogen was present at the outset to stimulate endometrial growth Absent withdrawal bleeding = Genital tract should be evaluated using imaging techniques 4. Serum FSH and LH levels should be determined Elevated FSH and LH Indicate primary ovarian failure Low or inappropriately normal FSH and LH Indicate secondary ovarian failure Hypothalamic-pituitary origin and can result from a variety of clinical disorders, including Sheehan syndrome, eating disorders, weight loss, and stress If withdrawal bleeding is present, then Step 5 is followed 5. Androgen excess should be evaluated Elevated testosterone (>150 ng/mL) Tumor or polycystic ovarian syndrome Increased DHEAS Adrenal tumor 17-OH progesterone Androgen precursor Increase in serum levels can indicate congenital or adult-onset adrenal hyperplasia due to 21- hydroxylase deficiency Abnormalities are accompanied by hirsutism (i.e., male pattern of hair growth in females) INFERTILITY WORKUP Evaluation of the ovulatory function is an important step BASAL BODY TEMPERATURE One of the methods used to confirm ovulation A rise in progesterone after ovulation increases basal body temperature by 0.4° F to 0.8° F When the diagnosis of ovarian failure is suspected Level of FSH in the early follicular phase (on day 3) should be determined because, as mentioned earlier, it will be elevated Concentrations greater than 10 mIU/ Ml Associated with diminished ovarian reserve ▪ Defined by low numbers of normal oocytes and the presence of poorquality oocytes ▪ Serum levels of Anti-Mullerian Hormone (AMH) have also been considered to be able to accurately predict ovarian reserve ANTI-MULLERIAN HORMONE (AMH) Recently been added as a new diagnostic assay during the initial female infertility evaluation Secreted by preantral and small antral follicles within the ovaries As AMH is released inhibits FSH-induced aromatase activity AMH is absent faster rates of primordial follicular recruitment have been observed, resulting in premature ovarian failure NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 8 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION AMH levels increased Results in disease states such as polycystic ovary syndrome (PCOS) CLOMIPHENE CITRATE CHALLENGE TEST More extensive testing of ovarian reserve Clomiphene Citrate o Nonsteroidal estrogen receptor modulator o Stimulates production of GnRH which, in turn, stimulates the release of FSH and LH. In this test, serum FSH levels are determined on day 3 of the menstrual cycle Clomiphene citrate o Administered on days 5 through 9 (or days 3–7) of the cycle Serum levels of FSH and estradiol o Measured again on day 10 Women with a poor cohort and aging follicles cannot generate enough estradiol or inhibin B to suppress FSH o Therefore, FSH remains high ASSISTED REPRODUCTIVE TECHNOLOGY (ARTs) INFERTILITY Defined as 1 year of unprotected intercourse without conception Initial treatments may include: Artificial insemination with washed and concentrated sperm Ovulation induction with clomiphene citrate or letrozole, a nonsteroidal aromatase inhibitor If these are unsuccessful, then one of several ARTs may be attempted ARTs involve techniques of direct manipulation of oocytes that are performed to control as much of the reproductive process as possible to achieve pregnancy Much of this external control requires significant monitoring through laboratory analyses Indications for ART include: Male infertility Ovarian failure Unexplained infertility PCOS, tubal disease Uterine factor Endometriosis NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh ART can also be applied in infertile couples requiring donation Involves two distinct groups of patients: Females without gonadal function because of: ✓ gonadal dysgenesis ✓ premature menopause (which may occur spontaneously or after surgical castration or castration induced by chemotherapy or radiotherapy) ✓ resistant-ovary syndrome Women with functional ovaries who do not wish to use their own oocytes to become pregnant because of: ✓ risk of transmitting chromosomal abnormalities to the offspring (e.g., if there is a history of autosomal dominant disease or X-linked disease, or when both partners are carriers of an autosomal-recessive disease) Most common form of ART is IVF Other forms involve: gamete intrafallopian transfer zygote intrafallopian transfer tubal embryo transfer ✓ all performed with the use of laparoscopy ✓ rarely practiced III. LABORATORY EVALUATION OF PREGNANCY Patient’s first visit to an obstetrician Early in the first trimester Clinical laboratory tests are routinely ordered to identify disorders that can be treated or prevented Simple, inexpensive blood and urine tests Carried out for anemia, red cell alloimmunization, and suspected viral or bacterial infection Sometimes, the clinical history, physical examination, or test results indicate additional studies for genetic disease, disorders of coagulation or thrombosis, causes of spontaneous abortion, and other conditions Page 9 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION hCG and Early Pregnancy Elevated hCG in maternal serum and urine Reliable indicator of pregnancy. Discovery of monoclonal antibodies (late 1970s) Led to the development of the current generation of quantitative hCG immunoassays which typically use a pair of monoclonals to measure either the β subunit of hCG or the intact hCG α-β dimer These assays can quantify hCG as low as 1 to 2 mIU/mL Serum hCG increases above the reference interval (typically 4–6 mIU/mL) by implantation, 6 to 12 (mean, 9.1) days after ovulation Urine hCG levels Commonly measured by qualitative immunoassay test kits Detection limits of approximately 20 mIU/mL. Can detect elevated urine hCG 2 to 3 days later than serum methods Serum hCG Increases dramatically during the first trimester Reaching a peak at about 16 weeks’ gestation Throughout pregnancy Intact hCG is the predominant form present Small quantity of free β subunit is present in the first trimester Free α subunit appears in the second trimester and steadily increases in the last trimester Increased levels of hCG Germ cell tumors Gestational trophoblastic disease Tumor production Includes significant amounts of free β subunit, in addition to intact hCG False-positive hCG Due to interference by heterophilic Ig antibodies; it is characterized by large molecular weight and is not filtered by renal glomeruli NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Serum concentrations of hCG are typically less than 150 mIU/L with negative urine test Quantitative measurements of hCG Indicated when a patient presents with: ✓ Early gestational vaginal bleeding or abdominal pain that may suggest the presence of ectopic pregnancy or spontaneous abortion A simple protocol using only ultrasound and quantitative hCG examinations allows more accurate diagnosis and sound management than are obtained by clinical judgment alone Because hCG concentrations rise quickly in normal early pregnancy, serial measurements can be used to ensure that an intrauterine implantation has occurred Doubling of hCG in 2 days Provides a greater than 80% probability of intrauterine implantation of the fertilized ovum Increases in serum hCG of less than 53% in 2 days Abnormal pregnancy with 99% sensitivity hCG concentrations exceed discriminatory zone values of 1500 to 2000 mIU/mL Intrauterine gestational sac becomes visible on ultrasound examination in a normal singleton pregnancy Multiple gestations Higher hCG levels than singletons hCG levels may rise above 2000 mIU/mL before ultrasound findings of intrauterine gestational sac are obtained Ectopic pregnancy Absence of an intrauterine gestational sac Failure to double the serum hCG Presence of an adnexal mass Progesterone measurements may provide additional information about abnormal pregnancy Normal Intrauterine Pregnancy ✓ Serum levels higher than 20 ng/mL Abnormal Pregnancy ✓ Low serum progesterone ✓ Less than 5 ng/mL (specificity of 100%) Page 10 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION Recurrent abortion Caused by the antiphospholipid syndrome Diagnosed by the presence of anticardiolipin and specific phospholipid antibodies in the first trimester Defined as three or more: ✓ Due to inherited thrombophilia ✓ Diagnosed by detection of factor V Leiden gene mutation, β2 glycoprotein, antithrombin III, prothrombin gene mutation, levels of proteins C and S, and activated protein C activity NEURAL TUBE DEFECTS Most common congenital malformations in the United States and worldwide Incidence approximately 1 per 1000 pregnancies Data suggest a decline in these rates due to increased education regarding the benefits of folic acid consumption Result from failure of the neural tube to close by the 27th day after conception ANENCEPHALY o Comprises 50% of NTDs o Involves absence of the calvarium, cranial vault, and cerebral hemispheres o It is incompatible with life SPINA BIFIDA o Abnormalities of the caudal portion of the neural tube o Present as a lumbar (or cervical) meningomyelocele, with herniation of meninges, spinal cord, and nerve roots Severity of complications such as: o paralysis or muscle weakness o fecal and/ or urinary incontinence o intellectual impairment ▪ dependent on the vertebral level and extent of spina bifida, which may be open in 80% of cases (referring to whether the defect is completely uncovered or is covered only by a very thin membrane) or closed (covered by skin or a thick membrane) Distinction is important because maternal serum screening will detect only open defects a) Folic Acid Prevention Folic acid is a major preventive agent against NTD Many clinical studies have established that folic acid supplementation before conception reduces the recurrence of fetal NTDs American College of Obstetrics and Gynecology (ACOG, 2017) recommends that all women capable of becoming pregnant should take 400 μg of folic acid daily— supplementation should begin 1 month prior to pregnancy and through the first 12 weeks of pregnancy, at least Women at high risk of NTDs should supplement with higher doses of folic acid b) Screening for Neural Tube Defects: αFETOPROTEIN (AFP) Maternal serum marker for NTDs Produced initially by the fetal yolk sac and later by the fetal liver Most abundant protein in fetal serum Concentration increases in both fetal serum and amniotic fluid until about 13 weeks’ gestation, after which the liver gradually shifts to production of albumin AFP becomes elevated because: o fetal serum from exposed neural membranes and blood vessels leaks into amniotic fluid (AF) Second trimester o maternal screening is performed o maternal serum (MS) AFP levels increase by approximately 15% per gestational week MS AFP increase, while AF levels are decreasing is due to combined changes in transfer to MS and maternal clearance Measurable increase serves as the basis of midtrimester MS AFP screening for open NTD Clinical factors must be considered when patient specific results are calculated Laboratories routinely adjust for the following factors: i. Maternal weight: MS AFP concentration decreases with increasing maternal weight NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 11 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION Although the fetus itself produces a constant amount of AFP, the maternal blood volume will vary according to the weight of the mother Failure to adjust for maternal weight causes increases in both false-positive and false negative results and affects the sensitivity and specificity of the test ii. Race: African American women o have MS AFP values that are approximately 10% to 15% higher than those of white women iii. Insulin-dependent Diabetes Mellitus MS AFP levels in otherwise normal women with IDDM are approximately 20% lower than in the general population iv. Multiple Gestation Multiple gestation (e.g., twins) will yield higher MS AFP levels because each fetus contributes its own AFP to the maternal blood MS AFP level is approximately proportional to the number of fetuses Down Syndrome All women should be offered screening for fetal chromosomal abnormalities before fetal age 20 weeks, regardless of maternal age First-trimester screening Performed between 12 and 13 weeks, include: nuchal translucency measurement combined with two maternal serum analytes: free β subunit of hCG with pregnancy-associated plasma protein A (PAPP-A) and maternal age An increase in the size of nuchal translucency Refers to a fluid collection at the back of the fetal neck in the first trimester Characteristic of fetal chromosomal and structural aberration Women with increased risk of aneuploidy or advanced maternal age (age 35 years or greater at NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh the time of delivery) on first-trimester screening should be offered: Genetic counseling Diagnostic testing ✓ chorionic villous sampling ✓ second-trimester amniocentesis In 2012, ACOG released guidelines for noninvasive fetal testing called CELL-FREE FETAL DNA Done on maternal plasma Used as a screening test Indications: ✓ maternal age 35 years or greater at delivery ✓ increased risk for aneuploidy on another screening test ✓ history of previous pregnancy with aneuploidy ✓ parental balanced robertsonian translocation with increased risk of fetal trisomy 13 or 21 Other approaches to screening for fetal chromosomal abnormalities include: Second-trimester triple screen with MS AFP, hCG, and unconjugated estriol (uE3) performed between 15 and 20 weeks Detection rate of triple screen can be improved from 69% to 81% by adding the inhibin A (quadruple screen) dimeric protein produced by placenta and fetus SEQUENTIAL SCREENING Patient is informed about first-trimester results Early diagnostic testing (chorionic villous sampling) ✓ offered after a positive result ✓ patients with negative results may undergo additional second trimester screening and may benefit from its higher sensitivity Advantage of integrated and sequential screening: ✓ lower false-positive rate that leads to fewer diagnostic procedures All patients who elected to have only first-trimester screening for chromosomal abnormalities should Page 12 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION undergo neural tube defect screening in the second trimester Erethroblastic Fetalis Severe hemolytic disease in a fetus marked by anemia accompanied by normoblastic hyperplasia (erythroblastosis) may be followed by congestive heart failure (hydrops) and intrauterine death Detection of fetal blood in maternal circulation has conventionally been identified by KLEIHAUER-BETKE TESTING in the setting of incompatibility (i.e., Rh-negative mother carrying an Rh-positive fetus) Flow cytometry has been reported as an effective alternative HEMOGLOBIN (Hb) Released by hemolysis Catabolized to unconjugated bilirubin Fetus with hemolytic disease does not develop hyperbilirubinemia or become jaundiced because the placenta normally removes the bilirubin However, some bilirubin appears in the amniotic fluid Measurement of amniotic fluid bilirubin levels ✓ using spectral analysis at 450 nm (ΔOD450) ✓ introduced to clinical practice by Liley in 1961 ✓ accepted method of assessing the severity of erythroblastosis in utero Gestational Diabetes Any glucose intolerance in a pregnant woman is termed gestational diabetes regardless of the state of glucose tolerance antepartum or postpartum Prompt diagnosis and treatment of gestational diabetes may help to avoid maternal and fetal complications: Preeclampsia Fetal congenital malformation Fetal macrosomia (abnormally large body size) Fetal demise Patient who is a known diabetic HbA1c level assessment should be ordered preconception and maintained at a level of 6.0% or below for healthy pregnancy outcomes. Fetal Lung Maturity Fetal lung maturation is marked by production of surface-active phospholipid compounds called SURFACTANT o Decreases surface tension within the alveolar space during inspiration o Allows continuous and effective gas exchange o Prevents alveolar collapse during expiration o Produced by type II pneumocytes in the form of lamellar bodies Deficiency of surfactant o Leads to neonatal respiratory distress syndrome (RDS) o Disorder that results in hypoxia, acidemia, and vascular protein transudation into alveolar air spaces (hyaline membrane disease) Fetal lung maturity testing o Performed before scheduled delivery at less than 39 weeks and uncertain gestational age Third trimester o Fetal respiratory activity allows the passage of surfactant into amniotic fluid, and its quantity may be evaluated using tests of amniotic fluid samples Before 35 weeks’ gestation, the major component of surfactant is α-palmitic β-myristic lecithin. After that time o Dipalmitic lecithin predominates o Phosphatidyl glycerol (PG) appears about a week later PG increases until term and maintains alveolar stability LECITHIN/SPHINGOMYELIN (L/S) RATIO TEST o First practical chemical test to assess fetal pulmonary status o Estimates the ratio of lecithin to sphingomyelin in amniotic fluid NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 13 | 16 PCC SOM 2026 o CLINICAL PATHOLOGY P.01 INTRODUCTION Concentrations of sphingomyelin remain constant throughout the pregnancy, and levels of lecithin are increasing o Densitometric quantification determines the L/S ratio. o L/S ratios greater than 2.0 usually indicate maturity; ratios less than 1.5 indicate immaturity Preeclampsia Syndrome characterized by: Hypertension of 140 mmHg or greater systolic or 90 mmHg or greater diastolic on two separate occasions four hours apart, or 160 mmHg or greater systolic or 110 mmHg or greater diastolic minutes apart Proteinuria greater than 0.3 g/L in a 24-hour urine specimen that occurs after 20 weeks’ gestation in previously normotensive women Protein/creatinine ratio greater than or equal to 0.3, or Urine protein dipstick of +1 when other resources are unavailable is diagnostic If there is an absence of proteinuria, then the presence of new-onset elevation of BP along with: Thrombocytopenia of 100,000/μL or less Renal insufficiency defined as serum creatinine of 1.1 mg/dL or doubling of serum creatinine in the absence of other renal disease Elevated liver aminotransferases of twice the normal concentrations Pulmonary edema Cerebral or visual defects is diagnostic Life-threatening manifestations of preeclampsia that remain a cause of maternal mortality are: Eclampsia HELLP syndrome (hemolytic anemia, elevated liver enzymes, low platelet count) ECLAMPSIA New-onset grand mal seizures in women with preeclampsia May result in intracranial hemorrhage Cause of preeclampsia remains unknown Pathophysiologic abnormalities include: Abnormal trophoblastic invasion by the placenta, resulting from an imbalance between proangiogenic and angiogenic factors Impaired uteroplacental flow causes intrauterine growth restriction, oligohydramnios, and placental abruption (abruptio placenta). Interaction of various vasoactive agents—such as prostacyclin, thromboxane A2, nitric oxide, and endothelins Causes the vasospasm that leads to depleted intravascular volume and hepatic and renal changes Hematologic changes Hemoconcentration Thrombocytopenia Hemolysis Hepatic involvement Elevation of aminotransferases, usually twice above the normal limit Lactate dehydrogenase (LD) is increased primarily because of: Hepatic disease (mostly LD5) Hemolysis with increases in LD1 and LD2 Hyperbilirubinemia Presence of hemolysis as well Proteinuria in preeclampsia Glomerular type (mostly albumin) Urine sediment contains hyaline and finely granular casts Mild to moderate increases in urea and creatinine are noted, as is a marked increase in uric acid. Premature Rupture of Membranes Rupture of membranes before the onset of labor Followed by a variety of complications, including: Chorioamnionitis Fetal pulmonary hypoplasia Placental abruption Neonatal respiratory distress Diagnosis of membrane rupture is made upon visualization of fluid passing from the cervical canal on the sterile speculum examination Amniotic fluid: Constitutes part of the posterior vaginal fluid pool NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 14 | 16 PCC SOM 2026 CLINICAL PATHOLOGY P.01 INTRODUCTION Identification of the amniotic component is optimally carried out within 2 hours of membrane rupture pH Vaginal secretions= acidic (pH, 4.5–5.5) Amniotic fluid= alkaline (pH of 7.0 to 7.5) Vaginal pool aspirate tested with nitrazine paper to estimate pH visually Nitrazine test ✓ usually performed at the bedside ✓ have an overall accuracy of about 90% in the absence of bloody show, vaginal discharge, or prolonged membrane rupture Aliquot of the aspirated fluid Applied to a glass microscope slide Dried for 5 minutes Examined microscopically for arborization (ferning) ✓ which indicates the presence of amniotic fluid in the vaginal fluid pool Alternative method Rapid immunoassay of proteins present in amniotic fluid Test for placental α-1 microglobulin Currently marketed as the AmniSure test Preterm Labor In 1991, Lockwood and colleagues discovered an association between the presence of fetal fibronectin (fFN) in cervical secretions and the risk of preterm delivery FETAL FIBRONECTIN (fFN) Glycoprotein produced by fetal membranes found in the choriodecidual junction amniotic fluid Released as cervical secretions at up to 20 weeks’ gestation Responsible for the cellular adhesiveness of placenta and membranes to the decidua Disruption of the chorion from the decidual layer of the uterus leads to the release of intact or degraded chorionic components of the extracellular matrix into the cervical and vaginal secretions fFN Enzyme Immunoassay U.S. Food and Drug Administration– approved test for assessment of the risk for preterm delivery in women between 24 and 35 weeks’ gestation Purposes of the test: ✓ To identify asymptomatic women who are at risk for preterm delivery ✓ To predict the risk of delivery in symptomatic women with preterm contractions Specimen is collected During sterile speculum examination with a swab from the posterior fornix of the vagina or the region of the external cervical os for 10 seconds Concentrations of fFN in the cervicovaginal fluid greater than 50 ng/mL are considered positive A meta-analysis of many studies on patients with symptoms suggestive of preterm labor showed that cervicovaginal fFN is an effective predictor of preterm delivery Intrapartum Assessment of Fetal Status Goal of intrapartum fetal surveillance: To recognize whether the fetus with a nonreassuring fetal heart tracing on external monitoring is acidotic and at risk for neurologic impairment or death Episodes of hypoxemia are transient and well tolerated by the fetus Prolonged or repeat episodes May lead to hypoxic-ischemic encephalopathy Available tests can help to ensure fetal well-being and reduce false-positive findings on external fetal heart monitoring Noninvasive and preferred tests, such as: digital scalp stimulation vibroacoustic stimulation of the fetus ▪ followed by the presence of reassuring fetal heart monitoring, indicate that the fetus is not acidotic Direct method for evaluation of fetal acid-base status is FETAL SCALP BLOOD SAMPLING Performed using the amnioscope with a light source NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh Page 15 | 16 PCC SOM Blood is collected from a punctured fetal scalp and is transferred in a heparinized capillary tube pH value of less than 7.20 identifies fetal acidosis Use of fetal scalp pH assessment is decreasing in many institutions because of the difficulty involved in obtaining and processing samples and in obtaining standardized laboratory equipment. Fetal Lactate Concentrations With the use of rapid enzymatic assays Blood samples are collected by using techniques similar to those used in fetal scalp pH Umbilical Cord Sampling Most objective tool for determining intrapartum fetal status and obtaining information related to obstetric management Immediately after delivery arterial blood is drawn from a segment of clamped umbilical cord to a heparinized capillary syringe analyzed for cord blood pH and blood gas values. ACOG (2006b) recommends analysis of umbilical cord blood in neonates with low Apgar scores to differentiate hypoxia from metabolic acidemia and other causes of low Apgar scores Significant metabolic acidosis defined by umbilical cord blood pH values of less than 7.0 base deficits of 12 mmol/L or greater are predictive of adverse neurologic outcomes and are included in the criteria for an acute intrapartum hypoxic event CheckPoint! Identif lang NOTE TAKER: Agullana, Martinez, Mabanta, Namuhmuh 1. Contain cells in various stages of spermatogenesis (spermatogonia, spermatocytes, spermatids), along with Sertoli cells and Leydig cells Interacts with gonadotrophs in the anterior pituitary, where it also has a negative-feedback effect by decreasing the synthesis and secretion of FSH, but not LH Inhibin 2. Synthesized and secreted by the syncytiotrophoblast cells of the developing placenta Process by which the fetus is expelled from the internal environment of the maternal uterus to the external environment Parturition 3. Used to select donors for therapeutic insemination and Monitor the success of surgical procedures, such as varicocelectomy and vasectomy 4. Total Motility Normal Range? 5. cells with a single or double highly condensed nucleus with a relatively large area of cytoplasm 6. Absence of menstrual flow by age 16 years, or by age 14 years if no breast development occurs 7. Most common congenital malformations in the United States and worldwide 8. Fetal lung maturation is marked by production of surface-active phospholipid compounds called? 9. Detection of fetal blood in maternal circulation has conventionally been identified by 10. Defined as 1 year of unprotected intercourse without conception SEMINIFEROUS TUBULES OF THE TESTIS hcg Semen Analysis >40% Immature Germ Cells Amenorrhea Neural Tube Defects Surfactant KLEIHAUER-BETKE TESTING Infertility P.01 INTRODUCTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 2026 CLINICAL PATHOLOGY Page 16 | 16