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The Normal Pregnancy. Tintinalli Chapter 104. Pregnancy Prevention. 7% of women who state they can not be pregnant are pregnant Failure rate with PROPER oral contraceptives are less than 1/100, but ~30% are not compliant IUD pregnancy rate 0.8% Tubal Ligation is variable, but < 0.75%.
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The Normal Pregnancy Tintinalli Chapter 104
Pregnancy Prevention • 7% of women who state they can not be pregnant are pregnant • Failure rate with PROPER oral contraceptives are less than 1/100, but ~30% are not compliant • IUD pregnancy rate 0.8% • Tubal Ligation is variable, but < 0.75%
Pregnancy • Gravidity – number of pregnancies • Parity – number of pregnancies carried to viability (not increased by multiple births) • After GP – list term pregnancies / pre-term pregnancies / abortions / living children • Trimesters: • 1st 0-14 weeks • 2nd 14-28 weeks • 3rd 28-40 weeks
Pregnancy Physiology • Cardiovascular: 40% increase in blood volume; 43% increase in CO; 17% increase in HR; 20% decrease SVR; Diastolic BP decreases by 10-15 by second trimester; EKG may show a slight left axis; Small pericardial effusion is normal • Respiratory: 40% increase in tidal volume, leaves little functional residual capacity; PCO2 drops to average of 30mmHg • GI: GERD due to delayed gastric empting, poor intestinal motility, and decreased lower esophageal tone; gallbladder empting is slowed • Urinary:2nd trimester GFR increases 50%; BUN & Cr decrease; ureteral & kidney dilation due to uterus compression
Pregnancy Physiology Continued • Hematopoietic: plasma volume and erythrocytes increase with a Hb decrease, but above 11g/dL; Leukocytes range from 5000-12,000; immune system weakens in 2nd trimester; autoimmune diseases may improve; coagulation factors increase; platelets may decrease • Endocrine: carbohydrate metabolism changes leading to hyperinsulinemia and fasting hypoglycemia; altered glucose response leads to postprandial hyperglycemia; Free thyroxine and TSH are not altered in pregnancy • Uterus: weight increases from 70 –1100 grams; volume increases from 10 – 5000 mL; expands out of the pelvis by 12 weeks • Beasts: tenderness; increased nodularity, nipple size, and pigmentation
History and PE • Get HX of contraception; LNMP; Hx of prenatal care; past medical HX • FHT: normal between 120-160 • Pelvic Exam: note condition of the cervix; wet prep and GC cultures; note size of the uterus • Uterus Size • 12 weeks at pelvic rim • 20 weeks at umbilicus • After 20 weeks, centimeters above symphysis determines gestational age
Diagnosis • HCG – produced by the trophoblast after implantation • Commercial Tests: false negative rate of <1% when greater than 1 week after conception • HCG increase 66% every 1.4-2 days • Transabdominal US: gestational sac @ 5.5-6 wks • Transvaginal US: gestational sac @ 4-5 wks; fetal pole @ 5.5-6 wks; cardiac activity @ 6 wks
Issues During Pregnancy • Abdominal Pain • Vascular congestion of pelvic tissue and round ligament cause sharp pain during movement • Braxton-Hicks – irregular, palpable contractions during late pregnancy • Appendicitis – most common non-OB related surgery in pregnancy; displacement of appendix occurs due to enlarging uterus • Threatened Abortion & Ectopic Pregnancy (Early) & abruption/uterine rupture/premature labor (Late)
Issues During Pregnancy • Syncope: anemia, electrolyte imbalance, dehydration, PE, arrhythmias (PACs & PVCs increase) • Medication Use: don’t know, look it up • Most teratogenesis during 4-12 weeks (organogenesis) • Before 4 wks, drugs cause an all or none response • Most information obtained from animal studies • A – no risk per human controlled studies • B – studies have not shown risk, but no human controlled studies • C – No studies available or animal studies revealed risk, but no human studies • D – evidence of human fetal risk, but the benefits of use may be acceptable • X – Studies show risk, and are contraindicated in pregnancy
Issues During Pregnancy • Medicaitons continued • Antimicrobials: ceph., PCNs, erythro/azithromycin, Nitro are safe • Bactrim should be avoided in the first trimester • Analgesics: acetaminophen is safe, NSAIDS should be avoided in third trimester • Gastro: Promethazine & Prochlorperazine, metoclopramide, and odansetron are safe; OTC antacids and cime/ranitidine are safe • Immunizations: Live viruses should be avoided (MMR, polio, & varicella); Inactivated viruses can be given (Influenza); Td is safe to give
Preventive Medicine in Pregnancy • Multivitamin is recommended (iron / folic acid / Zinc) • Caffeine – small risk of spontaneous abortion if consumption of > 500mg/day • Illicit drugs – multidisciplinary approach • Nicodine – only 20% quit by the 1st prenatal evaluation; higher rates of spontaneous abortion; abruption, preterm labor, low birth weight; if stopped by 16 wks, the risk is removed • EtOH – fetal alcohol syndrome can occur with consumption at any trimester, but 1st is the most dangerous; no safe amount identified
Fever/Chills Refractory Emesis Visual Disturbance Abdominal Pain Headache Anasarca Vaginal bleeding & fluid loss Abnormal vaginal discharge Signs & Symptoms that need prompted Evaluation
Resources • Tintinalli Chapter 104