How Can Pregnancy Continue After Pprom Usmle

Summary

Pregnancy begins with the fertilization of the ovum and its subsequent implantation into the uterine wall. The duration of pregnancy is counted in weeks of gestation from the first day of the last menstrual period and on average lasts 40 weeks. Presumptive signs of pregnancy include amenorrhea, nausea and vomiting, and breast enlargement and tenderness. Preconception counseling assists in the planning of pregnancy through education and risk assessment to help ensure best possible outcomes. Pregnancy can be confirmed definitively via positive serum or urine hCG tests and detection of the embryo on ultrasound. Ultrasound is also used to determine the gestational age and date of delivery. Women experience several physiological changes during pregnancy (e.g., increased plasma volume, venous stasis, increased insulin secretion, increased oxygen demand), which can lead to symptoms and conditions that may require treatment (e.g., peripheral edema, insulin resistance, hypercoagulability, dyspnea). Regular check-ups should be performed to detect potential high-risk pregnancies as well as fetal and maternal complications.

See also "Prenatal care" and "Maternal complications during pregnancy."

Definitions

Gravidity, parity, and duration of pregnancy ^[1]

• Gravidity : the number of times a woman has been pregnant, regardless of pregnancy outcome
• Parity : the number of pregnancies that a woman carries beyond 20 weeks of gestation and ends with the birth of an infant weighing > 500 g
• Fetal age ^[2]
  • Counted as completed weeks of gestation and completed days (0–6) of the current week of pregnancy
  • Gestational age: estimated fetal age (in weeks and days) calculated from the first day of the last menstrual period
  • Conceptional age: the age (in weeks and days) of the fetus calculated from the day of conception (fertilization)
• Duration of pregnancy
  • Normal duration of pregnancy: 40 weeks (280 days)
  • Postterm pregnancy: a pregnancy that extends beyond 42 weeks' gestation or the estimated date of delivery plus 14 days
  • Periviable birth: live birth occurring between 20–25 weeks of pregnancy
  • Preterm birth: live birth before the completion of 37 weeks ( < 37 0/7 ) of pregnancy
  • Postterm birth: live birth after 42 weeks ( > 42 0/7 ) of pregnancy
• Trimesters of pregnancy

Clinical signs of early pregnancy

Diagnosis of pregnancy

Human chorionic gonadotropin (hCG)

• Site of production: placental syncytiotrophoblast
• Structure
• Function
• Pregnancy test : measurement of human chorionic gonadotropin ( β-hCG )
  • Urine β-hCG test (e.g., home pregnancy test)
    • Qualitative test (less sensitive than serum pregnancy test)
    • β-hCG can be detected in urine 14 days after fertilization
  • Serum β-hCG test

Interpretation of β-hCG findings

Overview
β-hCG findings		Description
Normal		β-hCG concentration doubles every 2.5 days for the first 4 weeks of pregnancy. Peaks at 8–10 weeks of gestation (peak value ∼ 100,000 mlU/mL ) Decreases during the second trimester Reaches a steady level during the third trimester At β-hCG level of 1,500–2,000 mlU/mL the gestational sac will be visible with transvaginal ultrasound (if β-hCG < 1000 mlU/mL , repeat β-hCG and transvaginal ultrasound after 2–3 days ) [5]
Low	Maternal	Ectopic pregnancy Abortion
	Fetal	Edwards syndrome Patau syndrome
High	Maternal	β-hCG secreting tumors Hydatidiform mole Choriocarcinoma Multiple pregnancies
	Fetal	Down syndrome
False-positive		Recent mononucleosis infection IgA deficiency : due to heterophilic antibody formation Antibodies crossreact with serum beta-hCG test Urine β-hCG test should be performed as antibodies do not cross the glomerular membrane.

Physiological changes during pregnancy

Cardiovascular system ^{[8] [9]}

• ↑ Progesterone → ↓ vascular tone → ↓ peripheral vascular resistance (↓ afterload)
  • ↑ Cardiac output by up to 40% (↑ preload)
  • ↑ Stroke volume (by 10–30%)
  • ↑ Heart rate (by ∼ 12–18 bpm) → ↑ uterine perfusion
  • ↓ Mean arterial pressure
• Innocent systolic murmur
• The apex beat is displaced upward.
• ↑ Plasma volume → ↓ oncotic pressure → edema of lower limbs
• Varicosities
• Aggravation of preexisting valvular diseases

A physiological systolic murmur may be heard due to increased cardiac output and increased plasma volume .

Respiratory system ^[10]

• ↑ Oxygen consumption (by approx. 20%)
• ↑ Intraabdominal pressure through uterine growth → dyspnea (the diaphragm is displaced upwards → ↓ total lung capacity , residual volume, functional residual capacity, and expiratory reserve volume)
• Progesterone stimulates the respiratory centers in the brain → hyperventilation (to eliminate fetal CO₂ more efficiently) → physiological, chronic compensated respiratory alkalosis

Renal system ^{[9] [11]}

• ↑ Renal plasma flow → ↑ GFR → ↓ BUN and creatinine
• ↑ Aldosterone → ↑ plasma volume and hypernatremia
• ↑ Progesterone and intraabdominal pressure → dilation of kidney, pelvis, and calyceal systems → reduced tone and peristalsis
• ↑ Glucose levels in urine: Increased glomerular filtration results in overload of the glucose carrier responsible for its resorption.
• Mild proteinuria: Increased GFR and glomerular permeability to albumin increases protein excretion.

Endocrine system ^{[9] [12] [13]}

• Progesterone
• Human placental lactogen: a hormone synthesized by syncytiotrophoblasts of the placenta, which promotes the production of insulin-like growth factors.
• Thyroid hormones
• ↑ SHBG and corticosteroid-binding globulin
• ↑ Triglycerides and cholesterol (due to increased lipolysis and fat utilization)
• Hyperplasia of lactotroph cells in the anterior pituitary → physiological enlargement of the pituitary gland ( up to 40% increase from pregestational volume)

Hematologic system ^{[9] [14] [15]}

• ↑ Plasma volume → ↓ hematocrit , especially towards the end of pregnancy ( 30–34^th week of gestation) → dilutional anemia ( hemoglobin value rarely drops below 11 g/dL )
• Hypercoagulability is due to an increase in fibrinogen, factor VII, and factor VIII and a decrease in protein S ; (reduces the risk of intrapartum blood loss).
• ↓ Platelet count
  • Etiology
  • Diagnostics: peripheral blood smear to exclude pseudothrombocytopenia, repeat CBC using citrate or heparin, and comparison with previous platelet counts.
  • Management: no treatment is required for mild gestational thrombocytopenia ( 100,000–150,000/μL ) or gestational pseudothrombocytopenia.
• ↑ RBC mass (increases from 8–10^th week of gestation until the end of pregnancy)
• ↓ Iron and folate levels due to increased vitamin and mineral requirements
• ↑ WBC count
• ↓ Albumin
• ↑ Alkaline phosphatase (placental isoenzymes)

Physiological hypercoagulability during pregnancy leads to an increased risk of thrombosis. Patients with thrombophilia should receive adequate thrombosis prophylaxis.

Gastrointestinal system ^[9]

• ↑ Salivation
• ↓ Lower esophageal sphincter tone → gastroesophageal reflux
• ↓ Motility → constipation
• Gallbladder stasis → gallstones
• Hemorrhoids

Pelvic girdle pain ^[17]

• Etiology: increased pressure from the uterus , lumbar lordosis , and relaxation of the ligaments supporting the joints of the pelvic girdle
• Clinical features: lower back pain
• Diagnosis: positive pelvic pain provocation tests (e.g., posterior pelvic pain provocation test , FABER test , active straight leg raise )
• Management
  • Nonpharmacological: heat therapy , manual therapy (e.g., massage, spinal manipulation ), braces, physical therapy
  • Pharmacological: acetaminophen

Round ligament pain

Skin

• Spider angioma
• Palmar erythema
• Striae gravidarum : scarring that manifests as erythematous, violaceous, and/or hypopigmented linear striations on the abdomen
• Hyperpigmentation: chloasma, linea nigra, hyperpigmentation of the nipples

Reproductive system

• Uterus: increase in size
• Vulva and vagina
  • Vaginal discharge
  • Formation of varicose veins
• Mammary glands increase in size

Nutrition during pregnancy

Physical activity during pregnancy

High-risk pregnancy

Early identification of high-risk pregnancies is vital in order to prevent the occurrence of maternal and fetal complications. They require regular prenatal care to monitor and support the pregnant mother (see "Prenatal care").

Postterm pregnancy

• Definition: Pregnancy that progresses beyond 42 weeks ( 294 days ) since the first day of the last menstrual period or beyond 14 days of the estimated delivery date. ^[33]
• Etiology: unknown
• Risk factors
• Management
• Complications

Fetal complications during pregnancy

Oligohydramnios ^[35]

• Definition: amount of amniotic fluid is less than expected for gestational age
• Etiology
  • Fetal anomalies
    • Urethral obstruction (e.g., posterior urethral valves )
    • Bilateral renal agenesis
    • Autosomal recessive polycystic kidney disease (ARPKD)
    • Chromosomal aberrations (e.g., trisomy 18 )
    • Intrauterine infections (e.g., congenital TORCH infections)
    • In multiple pregnancies: twin-to-twin transfusion syndrome
  • Maternal conditions
    • Placental insufficiency
    • Late or postterm pregnancies (> 42 weeks of gestation)
    • Premature rupture of membranes
    • Preeclampsia
  • Idiopathic
• Diagnosis ^[36]
• Treatment
  • Amnioinfusion: infusion of fluid into the amniotic cavity through amniocentesis
  • Treat underlying cause: See "Preeclampsia," "Premature rupture of membranes," and "Placental insufficiency."
  • Delivery is advised if the fetus is close to term.
• Complications
  • Intrauterine growth restriction (due to diminished mobility of the fetus)
  • Birth complications (e.g., umbilical cord compression)
  • Potter sequence
    • Etiology
    • Pathophysiology: oligohydramnios → intrauterine compression and decreased amniotic fluid ingestions → ↓ space for fetal development → internal and external deformations
    • Clinical features
      • Pulmonary hypoplasia (cause of death due to severe neonatal respiratory insufficiency)
      • Craniofacial abnormalities (e.g., prominent epicanthal and infraorbital folds, flattened nose, receding chin, low set ears)
      • Wrinkling of the skin
      • Limb anomalies (e.g., bowed legs, clubbed feet)

P otter babies cannot P ee.

POTTER sequence: P ulmonary hypoplasia (lethal), O ligohydramnios (origin), T wisted facies, T wisted skin, E xtremity deformities, and R enal agenesis (classic form).

Polyhydramnios ^[37]

• Definition: excessive amniotic fluid volume expected for gestational age that results in uterine distention.
• Etiology
  • Typically idiopathic ( ∼ 70% of cases) ^[38]
  • Fetal anomalies
    • Gastrointestinal (e.g., esophageal atresia, duodenal atresia and stenosis): reduced swallowing and absorption of amniotic fluid
    • CNS: anencephaly ; ( leads to impaired swallowing of amniotic fluid , leakage of cerebrospinal fluid, and increased urination due to lack of fetal ADH), meningomyelocele (due to leakage of cerebrospinal fluid) ^[39]
    • Pulmonary: cystic lung malformations
    • Multiple pregnancy: twin-to-twin transfusion syndrome
    • Fetal anemia ^[40]
    • Chromosomal aberrations
    • Intrauterine infections (e.g., congenital TORCH infections)
  • Maternal conditions
    • Diabetes mellitus
    • Rh incompatibility (e.g., hemolytic disease of the newborn)
• Diagnostics
• Management
• Complications

Related One-Minute Telegram

Interested in the newest medical research, distilled down to just one minute? Sign up for the One-Minute Telegram in "Tips and links" below.

References

1. Anthony J, Osman A, Sani M. Valvular heart disease in pregnancy. Cardiovasc J Afr. 2016; 27 (2): p.111-118. doi: 10.5830/cvja-2016-052 . | Open in Read by QxMD
2. Soma-Pillay P, Nelson-Piercy C, Tolppanen H, Mebazaa A. Physiological changes in pregnancy. Cardiovasc J Afr. 2016; 27 (2): p.89-94. doi: 10.5830/cvja-2016-021 . | Open in Read by QxMD
3. LoMauro A, Aliverti A. Respiratory physiology of pregnancy. Breathe. 2015; 11 (4): p.297-301. doi: 10.1183/20734735.008615 . | Open in Read by QxMD
4. Ghamrawi R, Kattah AG, Garovic VD. Isolated Proteinuria of Pregnancy: A Call for Action. Kidney International Reports. 2019; 4 (6): p.766-768. doi: 10.1016/j.ekir.2019.04.012 . | Open in Read by QxMD
5. Magon N, Kumar P. Hormones in pregnancy. Nigerian Medical Journal. 2012; 53 (4): p.179. doi: 10.4103/0300-1652.107549 . | Open in Read by QxMD
6. Cignini P, Cafà EV, Giorlandino C, Capriglione S, Spata A, Dugo N. Thyroid physiology and common diseases in pregnancy: review of literature.. Journal of prenatal medicine. 2012; 6 (4): p.64-71.
7. Chandra S, Tripathi AK, Mishra S, Amzarul M, Vaish AK. Physiological Changes in Hematological Parameters During Pregnancy. Indian Journal of Hematology and Blood Transfusion. 2012; 28 (3): p.144-146. doi: 10.1007/s12288-012-0175-6 . | Open in Read by QxMD
8. Bremme KA. Haemostatic changes in pregnancy.. Best Pract Res Clin Haematol. 2003; 16 (2): p.153-168.
9. Reese JA, Peck JD, Deschamps DR, et al. Platelet Counts during Pregnancy. N Engl J Med. 2018; 379 (1): p.32-43. doi: 10.1056/nejmoa1802897 . | Open in Read by QxMD
10. Kanakaris NK, Roberts CS, Giannoudis PV. Pregnancy-related pelvic girdle pain: an update. BMC Med. 2011; 9 (1). doi: 10.1186/1741-7015-9-15 . | Open in Read by QxMD
11. Tunzy, Gray. Common Skin Conditions During Pregnancy. American Family Physician. 2007 .
12. Probable signs of pregnancy. https://brooksidepress.org/ob_newborn_care_1/?page_id=288&cn-reloaded=1. Updated: July 30, 2016. Accessed: September 2, 2020.
13. Cohen LS. Diagnostic Ultrasound in the First Trimester of Pregnancy. The Global Library of Women's Medicine. 2009 . doi: 10.3843/glowm.10094 . | Open in Read by QxMD
14. Tezuka et al.. Embryonic Heart Rates: Development in Early First Trimester and Clinical Evaluation. Gynecol Obstet Invest. 1991; 32 (4): p.210-212. doi: 10.1159/000293033 . | Open in Read by QxMD
15. ISUOG. ISUOG Practice Guidelines: performance of first-trimester fetal ultrasound scan. Ultrasound in Obstetrics & Gynecology. 2012; 41 (1): p.102-113. doi: 10.1002/uog.12342 . | Open in Read by QxMD
16. Hart TD, Harris MB. Preeclampsia revisited. US Pharm. 2012; 37 (9): p.48-53.
17. American College of Obstetricians and Gynecologists.. ACOG Committee Opinion No. 764.Medically indicated late-preterm and early-term deliveries.. American Journal of Obstetrics and Gynecology.. 2019 .
18. Dubil EA, Magann EF. Amniotic fluid as a vital sign for fetal wellbeing. Australasian Journal of Ultrasound in Medicine. 2013; 16 (2): p.62-70. doi: 10.1002/j.2205-0140.2013.tb00167.x . | Open in Read by QxMD
19. Mousavi AS, Hashemi N, Kashanian M, Sheikhansari N, Bordbar A, Parashi S. Comparison between maternal and neonatal outcome of PPROM in the cases of amniotic fluid index (AFI) of more and less than 5 cm. J Obstet Gynaecol (Lahore). 2018; 38 (5): p.611-615. doi: 10.1080/01443615.2017.1394280 . | Open in Read by QxMD
20. Salhan S. Textbook of Obstetrics. JP Medical Ltd ; 2016
21. Taskin S, Pabuccu EG, Kanmaz AG, Kahraman K, Kurtay G. Perinatal outcomes of idiopathic polyhydramnios. Interventional Medicine and Applied Science. 2013; 5 (1): p.21-25. doi: 10.1556/imas.5.2013.1.4 . | Open in Read by QxMD
22. Sahni M, Ohri A. Meningomyelocele. StatPearls. 2020 .
23. Hamza A, Herr D, Solomayer E, Meyberg-Solomayer G. Polyhydramnios: Causes, Diagnosis and Therapy. Geburtshilfe Frauenheilkd. 2013; 73 (12): p.1241-1246. doi: 10.1055/s-0033-1360163 . | Open in Read by QxMD
24. Committee on Obstetric Practice. ACOG Committee Opinion No. 650: Physical Activity and Exercise During Pregnancy and the Postpartum Period. ACOG Comm Opin. 2015 . doi: 10.1097/AOG.0000000000001214 . | Open in Read by QxMD
25. Galal M, Symonds I, Murray H, Petraglia F, Smith R. Postterm pregnancy.. Facts, views & vision in ObGyn. 2012; 4 (3): p.175-87.
26. Alkmark M, Keulen JKJ, Kortekaas JC, Bergh C, van Dillen J, Duijnhoven RG, Hagberg H, Mol BW, Molin M, van der Post JAM, Saltvedt S, Wikström AK, Wennerholm UB, de Miranda E. Induction of labour at 41 weeks or expectant management until 42 weeks: A systematic review and an individual participant data meta-analysis of randomised trials.. PLoS medicine. 2020; 17 (12): p.e1003436. doi: 10.1371/journal.pmed.1003436 . | Open in Read by QxMD
27. Alcohol use in pregnancy. https://www.cdc.gov/ncbddd/fasd/alcohol-use.html. Updated: April 30, 2020. Accessed: August 28, 2020.
28. Dietary guidelines for Americans 2015-2020. https://health.gov/sites/default/files/2019-09/2015-2020_Dietary_Guidelines.pdf. Updated: December 1, 2015. Accessed: August 28, 2020.
29. Soneji S, Beltrán-Sánchez H. Association of Special Supplemental Nutrition Program for Women, Infants, and Children With Preterm Birth and Infant Mortality. JAMA Network Open. 2019; 2 (12): p.e1916722. doi: 10.1001/jamanetworkopen.2019.16722 . | Open in Read by QxMD
30. Bibbins-Domingo et al.. Folic Acid Supplementation for the Prevention of Neural Tube Defects. JAMA. 2017; 317 (2): p.183-189. doi: 10.1001/jama.2016.19438 . | Open in Read by QxMD
31. Viswanathan M, Treiman KA, Kish-Doto J, Middleton JC, Coker-Schwimmer EJ, Nicholson WK. Folic Acid Supplementation for the Prevention of Neural Tube Defects: An Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.. JAMA. 2017; 317 (2): p.190-203. doi: 10.1001/jama.2016.19193 . | Open in Read by QxMD
32. McNulty B, McNulty H, Marshall B, et al. Impact of continuing folic acid after the first trimester of pregnancy: findings of a randomized trial of Folic Acid Supplementation in the Second and Third Trimesters.. Am J Clin Nutr. 2013; 98 (1): p.92-8. doi: 10.3945/ajcn.112.057489 . | Open in Read by QxMD
33. Cantor et al.. Routine Iron Supplementation and Screening for Iron Deficiency Anemia in Pregnancy: A Systematic Review for the U.S. Preventive Services Task Force. Ann Intern Med. 2015; 162 (8): p.566. doi: 10.7326/m14-2932 . | Open in Read by QxMD
34. Calcium. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/. . Accessed: June 6, 2019.
35. Mahadevan S, Kumaravel V, Bharath R. Calcium and bone disorders in pregnancy. Indian J Endocrinol Metab. 2012; 16 (3): p.358–363. doi: 10.4103/2230-8210.95665 . | Open in Read by QxMD
36. Calcium and bone disorders in pregnancy..
37. Stagnaro-Green A et al. Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and Postpartum. Thyroid. 2011; 21 (10): p.1081-1125. doi: 10.1089/thy.2011.0087 . | Open in Read by QxMD
38. Weight gain during pregnancy. https://www.cdc.gov/reproductivehealth/maternalinfanthealth/pregnancy-weight-gain.htm. Updated: January 17, 2019. Accessed: August 28, 2020.
39. Obstetrics Data Definitions. https://www.acog.org/practice-management/health-it-and-clinical-informatics/revitalize-obstetrics-data-definitions. Updated: January 1, 2014. Accessed: August 27, 2020.
40. Spong CY. Defining "Term" Pregnancy. JAMA. 2013; 309 (23): p.2445. doi: 10.1001/jama.2013.6235 . | Open in Read by QxMD
41. Ferri FF. Ferri's Clinical Advisor 2017. Elsevier ; 2016 : p. 1345-1346
42. Callahan TL, Caughey AB. Blueprints Obstetrics and Gynecology. Lippincott Williams&Wilki ; 2013
43. Medical Embryology, the Placenta: Decidual Formation.
44. Smith JA, Refuerzo JS, Ramin SM, Lockwood CJ, Barss VA. Treatment and Outcome of Nausea and Vomiting of Pregnancy. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/treatment-and-outcome-of-nausea-and-vomiting-of-pregnancy.Last updated: January 3, 2017. Accessed: June 16, 2017.
45. Ehsanipoor RM, Satin AJ, Lockwood CJ, Barss VA. Normal and Abnormal Labor Progression. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/normal-and-abnormal-labor-progression.Last updated: June 7, 2017. Accessed: June 16, 2017.
46. Refuerzo JS, Smith JA, Ramin SM, Lockwood CL, Barss VA. Clinical Features and Evaluation of Nausea and Vomiting of Pregnancy. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/clinical-features-and-evaluation-of-nausea-and-vomiting-of-pregnancy.Last updated: January 3, 2017. Accessed: July 7, 2017.
47. American College of Obstetricians and Gynecologists. Practice Bulletin No. 142: Cerclage for the Management of Cervical Insufficiency. Obstet Gynecol. 2014; 123 (2): p.372-379. doi: 10.1097/01.AOG.0000443276.68274.cc . | Open in Read by QxMD
48. Ressel GW. ACOG Releases Bulletin on Managing Cervical Insufficiency. Am Fam Physician. 2004; 69 (2): p.436-439.
49. Norwitz ER, Saade GA, Miller HS, Davidson CM. Obstetric Clinical Algorithms. Wiley-Blackwell ; 2016
50. Berghella V, Lockwood CJ, Barss VA. Cervical Insufficiency. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/cervical-insufficiency.Last updated: January 4, 2017. Accessed: July 7, 2017.
51. Tao Le, Vikas Bhushan, Deol M, Reyes G. First Aid for the USMLE Step 2 CK, Tenth Edition. McGraw-Hill Education ; 2018
52. Ciobanu et al.. Thrombocytopenia in Pregnancy. Maedica. 2016; 11 (1): p.55-60.
53. Valenti O, Di Prima FA, Renda E, et al. Fetal cardiac function during the first trimester of pregnancy.. Journal of prenatal medicine. 2011; 5 (3): p.59-62.

montgomerywhimpaincy.blogspot.com

Source: https://www.amboss.com/us/knowledge/Pregnancy

Share this post