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Back to Basics! The essence of OBSTETRICS in two hours Susan Aubin, MD, FRCSC Assistant Professor Department of Ob/ Gyn The Ottawa Hospital/University of Ottawa Special Thanks to: Karine J. Lortie , MD, FRCSC. OVERVIEW Introduction Early pregnancy Antenatal care Teratogens
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Back to Basics! The essence of OBSTETRICS in two hours Susan Aubin, MD, FRCSC Assistant Professor Department of Ob/Gyn The Ottawa Hospital/University of Ottawa SpecialThanks to: Karine J. Lortie , MD, FRCSC
OVERVIEW • Introduction • Early pregnancy • Antenatal care • Teratogens • Fetal growth and wellbeing • Medical complications • Breech • Multiple pregnancy • Labour
RISK SPECTRUM IN PREGNANCY LOW RISK (75%): normal obstetrics MEDIUM RISK (20%): pre-post dates breech twins maternal age, etc.. HIGH RISK (5%): genetic disease serious obstetric maternal complications
RISK IN PREGNANCY Definition of Outcome Measures • Perinatal mortality rate • all stillbirths (intrauterine deaths) > 500 grams plus all neonatal deaths per 1,000 total births • Neonatal death • death of a live-born infant less than • 7 days after birth (early) or less than 28 days (late) • Live birth • an infant weighing 500 grams or more exhibiting any sign of life after full expulsion, whether or not the cord has been cut and whether or not the placenta is still in place
PERINATAL MORTALITY RATE • ONTARIO: 5/1000 • Developing: 100/1000
PERINATAL MORTALITY • Prematurity • Congenital anomaly • Sepsis • Abruption • Placental insuffienciency • Unexplained stillbirth • Birth asphyxia • Cord accident • Other ie. isoimmunization
MATERNAL MORTALITY RATE • ONTARIO: 5/100 000 • Developing: 1000/100 000
MATERNAL MORTALITY • Direct Deaths • Indirect deaths: < 42 days from delivery • Causes: • Hypertensive disorders • Pulmonary embolism • Anesthesia • Ectopic pregnancy • Amniotic fluid embolus • Hemorrhage • Sepsis
EARLY PREGNANCY Dating: 40 weeks from LMP 280 days, Naegle’s rule (-3 months + 7 days) Affected by cycle length Hegar’s sign: soft uterus Chadwicks sign: blue cervix
Hormones BhCG: A subunit similar to TSH, LH, FSH Measurable 8 days post conception Role: stimulate CL progesterone 100,000 • Others use: • Zone 2000-6000 • Mole • Ectopic • Ovarian cysts Level doubling time 2 days 5,000 16 weeks 8 days 8 weeks
Other placental hormones • HPL = human placental lactogen (growth hormone) • prolactin • progesterone • estrogen
Maternal physiology • RBC • plasma volume by 50%, GFR, CrCl (creatinine), glucosuria • cardiac output (highest 1st hour after delivery) • HR by 20% • SV • Placental flow: 750ml/min at term
Antenatal care Antepartum history: age: >40 offer amniocentesis Parity/gravidity Medical, surgical history Family, social history Meds, allergies Routine tests: CBC (Hg), Type and Screen, prenatal antibodies VDRL, Rubella, Hep B, HIV Urine culture Pap smear, +vag swabs, cervical cultures Offer IPS GBS swab at 35 weeks
Antenatal Care Other testing: Dating ultrasound, 18 weeks morphology ultrasound Hb electrophoresis (Thalassemia, sickle cell, etc.) Chicken pox, parvovirus, TSH 28 weeks glucose screening test Genetic testing: CVS Amniocentesis Scheduled visits: 0-28 weeks: q4 weeks 28-36 weeks: q2 weeks 36+ weeks: q1 week
Scheduled visits SFH (cm): (+ 2 # of weeks) Sensitivity of 60% 12 weeks: symphysis pubis 20 weeks: umbilicus 36 weeks: siphisternum presentation Symptoms, fetal movement + urine dip: glucose, protein Blood pressure, maternal weight
MATERNAL WEIGHT • wksgain • 0 - 20 4 kg • 21 - 28 4 kg • 29 - 40 4 kg • Average 12 kg • Weight Gain: • Underweight: 35-45 lbs (15-20 kg) • Normal BMI: 25-35 lbs (11-15 kg) • Overweight: less than 25 lbs (10 kg)
Genetic testing • IPS: • First Trimester screening (10.6 – 13.6 weeks) • Nuchal translucency • PAPP-A, (BhCG) • Second Trimester screening (15-16 weeks) • BhCG, estriol, AFP, Inhibin A • 87% detection rate, 2% false positive rate • MSS: (Quad test) • 15-19 weeks • BhCG, estriol, AFP, Inhibin A • 77% detection rate, 5% false positive rate
NT Suchet I, Tam W. The ultrasound of life. Interactive fetal ultrasound teaching program on DVD, 4th Edition, 2004.
Screening patterns Down’s syndrome: low PAPP-A, AFP, estriol, high BhCG Trisomy 18: low PAPP-A, AFP, BhCG, estriol, Inhibin A, high NT Trisomy 13: high AFP, low BhCG/estriol NTD: high AFP Low estriol – associated with many congenital anomalies
Which of the following statements best describes the foramen ovale: It shunts blood from right to left It connects the pulmonary artery with the aorta It shunts deoxygenated blood into the left atrium It is an extra cardiac shunt It is functional after birth
Risk Classification System for Drug Use in Pregnancy Category Description A Taken by a large number of pregnant women. No increase in malformation. B Taken by only a limited number of pregnant women and women of childbearing age. No increase in malformation. Studies in animals wither show no increase or are inadequate. C Have caused or may be suspected of causing harmful effects on the human foetus or neonate without causing malformations. These effects may be reversible. D Have caused an increased incidence of human foetal malformations or irreversible damage. X Drugs that have such a high risk of causing permanent damage to the foetus that they should not be used in pregnancy.
Dating Scan Gestational sac: 5wks Fetal pole: 6wks Fetal heart: 7 wks Limb buds: 8 wks crown rump length
Morphology scan 18- 20 weeks BPD HC AC Femur length
Info from U/S • Estimated fetal weight • Twins discordance • Behavioral states (BPP) • Presentation • Placenta (previa)
Anomalies: ultrasound 18 - 20 weeks • Spina Bifida • Anencephaly • Cardiac • Renal • Diaphragmatic hernia • Limbs • Facial • Chromosomal • Late > 20 weeks • Renal • Microcephaly • Hydrocephalus • Ureteral valves
Interventions • amniocentesis, l/s ratio (lung maturity) • cvs • cordocentesis, transfusion • paracentesis • Shunts: bladder, ascites, kidney, head • Liver biopsy, skin • Fetal reduction
DEFINITION OF I.U.G.R • < than 2500 grams • < than 5th centile for GA • Approx. 4-7% of infants
BPD AC
BPD AC
CAUSES OF IUGR • Maternal: • Malnutrition • Drugs • Substance Abuse • Diseases • Infections • Fetal: • Chromosomal Abnormality • Congenital Abnormality • Multiple Gestation • Congenital Infection
CAUSES OF IUGR • Placental: • Perfusion • Abnormalities: • Abnormal Cord Insertion • Abruption • Circumvallate placentation • Placental Hemangioma • Placental Infections • Twin to Twin Transfusion
IMMEDIATE NEONATAL MORBIDITY IN IUGR • Birth asphyxia • Meconium aspiration • Hypoglycemia • Hypocalcemia • Hypothermia • Polycythemia, hyperviscosity • Thrombocytopenia • Pulmonary hemorrhage • Malformations • Sepsis
CAUSES OF FETAL OVERGROWTH • Maternal diabetes • Maternal obesity • Excessive maternal weight gain
EVALUATION OF WELL-BEING
FETAL ACTIVITY • Kick counts: • “count to ten “ chart • towards term • 10 movements in 2 hours over 12 hours
BIOPHYSICAL PROFILE • Graded (0 or 2 pts; max 10) • NST (normal) • Movement (2) • Tone (2) • AFI (amniotic fluid volume) • Breathing (30 seconds) DOPPLER • What is it? • Uteroplacental waveforms • Umbilical artery • Carotid artery • Descending aorta