Jasmin Jaber\'s Obstetrics Notes PDF

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Jasmin Jaber 2015 1. History Taking in Obstetrics (background, dating a pregnancy, risk factors, gravidity, parity) Background Establish general facts age, date of birth, number of previous pregnancies, etc. Make sure the patient is comfortable, respect their wishes if they want another person prese...

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Jasmin Jaber 2015

1. History Taking in Obstetrics (background, dating a pregnancy, risk factors, gravidity, parity) Background - Establish general facts – patient’s age, date of birth, number of previous pregnancies, etc. - Make sure the patient is comfortable, respect their wishes if they want another person present - Social history  Marital status, employement, type of housing  Enquiry about domestic violence, smoking/drinking habits, illicit drug use - Obstetric history  List previous pregnancies in order and discuss the outcome of each one  Recurrent miscarriage/preterm delivery, congenital abnormalities, FGR  Methods of delivery - Gynecological history  Regularity of periods, contraception history, previous PID, previous cervical smear, previous treatment for any cervical changes  Previous ectopic pregnancies or recurrent miscarriages (APL syndrome), previous terminations of pregnancy, previous gynecological surgery, donor egg or sperm use - Medical and surgical history - Drug history - Family history Dating the Pregnancy - Dated from the last menstrual period (LMP) - Median duration is 280 days (40 weeks) – used to get the estimated date of delivery (EDD), assuming that  The cycle is 28 days long  Ovulation occurs on the 14th day  It was a normal cycle (not after stopping OCP or close to a previous pregnancy) - The EDD is calculated by taking the date of LMP, counting forwards 9 months, and adding the difference between the cycle length and 28 to compensate - Ultrasound scan may be used Gravidity – total number of pregnancies, regardless of outcome Parity – number of any live births at any gestation or stillbirths after 24 weeks

Jasmin Jaber 2015

2. Examining the Obstetric Patient (abdominal, internal examination and special situations) Maternal Weight and Height - Measured at the initial examination  Women with BMI 30 there is risk for gestational diabetes and hypertension - Blood pressure evaluation  If hypertension is diagnosed, investigate for an underlying cause (renal, endocrine, or vascular disease) - Urinary examination  Screen midstream urine for asymptomatic bacteruria  High risk of ascending UTI in pregnancy – increasing the risk for pregnancy loss/premature labor General Medical Examination - Cardiovascular - Breast - Abdomen  In semi-recumbent position  Inspection  Shape or the uterus, look for asymmetry  Fetal movement  Scars  Striae gravidarum  Palpation  Symphysis-fundal height measurement  Fetal lie  Pole over pelvis – longitudinal  Leading pole doesn’t lie over the pelvis – oblique  Fetus lying directly across the abdomen – transverse  Presentation  Head down – cephalic  Bottom/feet down – breech  Engagement  Palpate the fetal head during labor – if the whole head can be felt and easily moveable, it is ‘free’ = 5 5 palpable

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As the head descends into the pelvis, less can be felt – if the head is no longer moveable, it is ‘engaged’ = 1 5 or 2 5

Auscultation  Pinard stethoscope – position it over the fetal shoulder Pelvis (under certain circumstances)  Excessive/offensive discharge  Vaginal bleeding without placenta previa  To perform a cervical smear  To confirm rupture of membranes Other  Fundoscopy – in case of hypertension or headache  Check for signs of pre-eclampsia (papilloedema, peripheral edema)

Jasmin Jaber 2015

Bishop score

Dilation of cervix (cm) Consistency of cervix Length of cervical canal Position Station of presenting part

0 0 Firm >2 Posterior 3

Score 1 1 or 2 Medium 2-1 Central 2

2 3 or 4 Soft 1-0.5 Anterior 1 or 0

3 >5 4.5Kg  Previous gestational diabetes  First-degree relative with diabetes  Family origin from a high-prevalence area - Pre-eclampsia and preterm birth  Measure blood pressure and urinalysis  Blood testing and ultrasound are not routine - Fetal growth and well-being  Symphysis-fundal height (SFH) measurement should be done with a tape measure at every antenatal visit from week 25  Not recommended if there are no concerns about fetal growth Visit Initial contact Booking (by 10w)

Dating scan (10-14w) 16w 18-20w 25w 28w

31w 34w 36w 38w 40w 41w

Purpose Information giving, folic acid supplementation, food hygiene Lifestyle issues and screening tests offered Information giving Identification of women needing additional care Offer screening tests, dating scans, Down’s syndrome screening Calculate BMI, measure BP, test urine Accurately determine gestational age, finalize EDD and detect multiple pregnancies Review test results, offer quadruple test if not yet screened for Down’s Ultrasound for structural anomalies Information giving; BP, urine dip, SFH measurement Information giving; BP, urine dip, SFH Second screen for anemia and red cell antibodies; anti-D prophylaxis if RhDnegative Information giving; BP, urine dip, SFH Information about labor and birth; BP, urine dip, FSH 2nd dose of prophylactic anti-D Information about breastfeeding, vitamin K for the newborn, caring for the baby, and post-natal issues; Palpation for fetal presentation; BP, urine dip, SFH Information on prolonged pregnancy; Palpation for fetal presentation; BP, urine dip, SFH Information on prolonged pregnancy; Palpation for fetal presentation; BP, urine dip, SFH Membrane sweep and formal induction of labor; Palpation for fetal presentation; BP, urine dip, SFH

Jasmin Jaber 2015

12. Diagnostic Ultrasound in Pregnancy- Clinical Applications of US and Scanning Schedule Diagnostic Ultrasound in Pregnancy - Ultrasound uses very high frequency sound waves between 3.5 and 7.0 MHz emitted from a transducer - Transvaginal US is useful in early pregnancy, examining the cervix in later pregnancy, and identifying the lower edge of the placenta - Transabdominal US is used after week 12 - Doppler US allows assessment of fetal and placental condition; velocity of blood within placental vessels can be examined Clinical Applications - Diagnosis and confirmation of viability in early pregnancy  Gestational sac can be visualized at weeks 4-5; yolk sac at weeks 5-6  The heart beat can be visualized around week 6  Missed miscarriage – fetus can be identified, but absent fetal heart beat  Blighted ovum – empty gestational sac  Ectopic pregnancy – no gestational sac within the uterus, present of an adnexal mass with or without a fetal pole, or fluid in the pouch of Douglas - Determination of gestational age and assessment of fetal size and growth  Up to week 20, there is little variation in the mean values of fetal length, head size, and long bone length  Crown-rump length can be used up to 13 weeks + 6 days  Head circumference is used from weeks 14-20  Biparietal diameter and femur length can also be used  The earlier the measurement is made, the more accurate the prediction  In later pregnancy, measuring fetal abdominal and head circumference can be used to assess size and growth; combined with femur length and BPD to get an estimate of fetal weight (EFW)  Gestational age cannot be accurately calculated after week 20 Multiple Pregnancies - In monochorionic twins, the dividing membrane is made of 2 layers of amnion; in dichorionic twins it is 2 layers of chorion and 2 layers of amnion – thicker membrane in dichorionic – seen on ultrasound in the first trimester - Chorionicity can also be determined by seeing the ‘lambda’ sign or ‘twin peak’ in dichorionic membranes – weeks 9-10 - Confirming fetal presentation, checking for growth restriction, fetal anomalies, placenta previa, or twin-to-twin transfusion syndrome Diagnosis of Fetal Abnormality - Spina bifida, hydrocephalus, skeletal abnormalities (achondroplasia), abdominal wall defects (exomphalos, gastroschisis), cleft lip/palate, and congenital cardiac abnormalities - A ‘normal’ scan does no guarantee a normal baby, as detection rates vary between 40 and 90%; repeat scans are required - 1st trimester ‘soft’ markers such as absence of fetal nasal bone and increased nuchal translucency are used Placental Localization - US is used to identify the lower edge of the placenta to exclude/confirm placenta previa - At week 20, it is possible to identify a low-lying placenta, which may progress to placenta previa Amniotic Fluid Volume Assessment - Oligohydramnios/polyhydramnios

Jasmin Jaber 2015

Assessment of Fetal Well-being - Evaluating fetal movements, tone, breathing - Doppler ultrasound can be used to assess placental function and identify blood flow redistribution (sign of hypoxia) Measurement of Cervical Length - Transvaginal scanning

Jasmin Jaber 2015

13. The Routine Ultrasound Scan in Early and in Mid. Trimester Pregnancy – the Importance The Early Pregnancy Scan (11-14 weeks) - Confirm fetal viability - Provide accurate estimation of gestational age - Diagnose multiple gestations and chorionicity - Identify markers indicating risks of chromosomal abnormality - Identify gross structural abnormalities The 20 Week Scan (18-22 weeks) - Provide an accurate estimation of gestational age if the previous scan wasn’t performed - Carry out detailed fetal anatomical survey to detect structural abnormalities or markers of chromosomal abnormalities - Locate the placenta; identify a low-lying placenta - Estimate amniotic fluid volume Ultrasound in the Third Trimester - Assess fetal growth and well-being

Jasmin Jaber 2015

14, Ultrasound in the Assessment of Fetal Well-being (CTG, NST and Stress Test, Biophysical Profile, Doppler Investigation) Amniotic Fluid Volume - Oligohydramnios – reduced amniotic fluid volume - Polyhydramnios – excessive amniotic fluid volume - Maximum vertical pool is measured after a survey of the uterine contents – if less than 2 cm, suspect oligohydarmnios, and if more than 8 cm suspect polyhydramnios - Amniotic Fluid Index (AFI) is measured by dividing the uterus into 4 quadrants, a vertical measurement is taken of the deepest cord free pool in each quadrant and the result summated  Should be 10-25 cm in the 3rd trimester (25 – polyhydramnios) Cardiotocograph - Continuous tracing of the fetal heart used to assess fetal well-being - Special features of a CTG  Baseline rate  Normal fetal heart rate at term is 110-150 bpm  Falls with advancing gestational age  Tachycardia  fetal/maternal infection, acute fetal hypoxia, anemia  Baseline variability  Long-term fluctuations in heart rate occurring 2-6 times per minute  Abnormal if 10 bpm, and more than one acceleration seen in a 20-30 minute tracing Biophysical Profile - 30 minute-long ultrasound scan which observes fetal behavior, measures amniotic fluid volume, and includes a CTG - Fetal breathing movements, gross body movements, flexor tone and accelerations in fetal heart rate are signs that would be missing in case of fetal hypoxia - Each of the variables, amniotic fluid volume, and CTG are assigned a score of either 2 (normal) or 0 (suboptimal), and a fetus can get a score between 0-10 - 0, 2, or 4 are considered abnormal; 8 or a 10 are considered normal; a score of 6 requires a repeat within a few hours Parameter Non-stress CTG Fetal breathing movements Fetal body movements Fetal tone Amniotic fluid volume

Score 2 Reactive >30 seconds of breathing in 30 minutes >3 in 30 minutes One episode of limb flexion Largest cord-free pocket over 1 cm

Score 0 38.5°C), systemic disturbance, shock  Treat with IV fluids and antibiotics, and opiate analgesics Assess renal function and monitor the baby with CTG

Abdominal Pain in Pregnancy - Pregnancy-caused conditions  Early pregnancy (24 weeks)  Labor  Placental abruption  HELLP syndrome  Uterine rupture  Chorioamnionitis - Pregnancy-unrelated conditions  Uterine/ovarian  Torsion/fibroid degeneration  Ovarian cyst accident  Urinary tract  UTI – acute cystitis/pyelonephritis  Renal colic  Gastrointestinal  Medical gastric/duodenal ulcer  Acute appendicitis/pancreatitis/gastroenteritis  Intestinal obstruction/perforation  Medical  Sickle cell disease  DKA  Acute intermittent porphyria  Pneumonia  Pulmonary embolus  Malaria

Jasmin Jaber 2015

21. Venous Thromboembolism in Pregnancy -

Pregnancy is associated with a 6-10-fold increase in the risk of venous thromboembolic disease (VTE) compared to the non-pregnant state Pregnancy is a hypercoagulable state - ↑ clotting factors 8, 9, 10, and fibrinogen levels; ↓ in protein S and AT III  Predisposition to embolism, further exacerbated by venous stasis

Thrombophilia - Hereditary  Deficiencies of protein C, protein S, and ATIII  Abnormal procoagulant factors  Factor V Leiden  Prothrombin mutation G20210A - Acquired  Antiphospholipid syndrome – combination of lupus anticoagulant with or without anti-cardiolipin antibodies; history of recurrent miscarriage/thrombosis Diagnosis of Acute Venous Thromboembolism - Deep vein thrombosis  Unilateral pain in the calf with varying redness or swelling  Compression ultrasound has a high sensitivity and specificity  Venography – injection contrast medium and using x-rays – excellent visualization of veins above and below the knee - Pulmonary embolus  Mild breathlessness or inspiratory chest pain in a women who is not cyanosed but may be slightly tachycardic (>90 bpm) with a mild pyrexia (37.5°C)  Check ECG, chest x-ray, and arterial blood gases – unreliable on their own  Check lower limbs for evidence of DVT  Ventilation perfusion (V/Q) scan or computed tomography pulmonary angiogram should be performed  D-dimer can be elevated in pregnancy and is not clinically useful Treatment of VTE - Warfarin – prolongs prothrombin time; crosses the placenta and causes limb and facial defects in the 1st trimester and fetal intracerebral hemorrhage in the 2nd and 3rd trimesters - LMWHs – does not cross the placenta - Graduated elastic stockings Prevention of VTE in Pregnancy and Postpartum - Antenatal  High risk – prophylaxis with LMWH  Intermediate risk – prophylaxis with LMWH  Low risk – mobilization & avoidance of dehydration - Postnatal  High risk – at least 6 weeks postnatal prophylactic LMWH  Intermediate risk – at least 7 days postnatal prophylactic LMWH  Low risk – mobilization & avoidance of dehydration

Jasmin Jaber 2015

22. Breech Presentation, Oblique and Transverse Lie at Term Malpresentation – presentation that is not cephalic; becomes a problem if the baby is not cephalic by week 37 Breech Presentation - Extended (frank) - Flexed (complete) - Footling – foot presents at the cervix; risk of cord and foot prolapse

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Predisposing factors  Maternal  Fibroids  Congenital uterine abnormalities  Uterine surgery  Fetal/placental  Multiple gestation  Prematurity  Placenta previa  Abnormality – anencephaly/hydrocephalus  Fetal neuromuscular condition  Oligo-/polyhydramnios Antenatal management  External cephalic version  Performed with a tocolytic  Guided by ultrasound, breech is elevated from the pelvis with one hand, while the other hand applies gentle pressure to flex the fetal head and bring it down to the pelvis  Relatively safe; should not last more than 10 minutes  Fetal heart trace performed before and after  Contraindications – fetal abnormality, placenta previa, oligo/polyhydramnios, multiple gestation, previous C-section, pre-eclampsia  Vaginal breech delivery  Prerequisites  Presentation should be either extended or flexed  No evidence of feto-pelvic disproportion and EFW >3500 g

Jasmin Jaber 2015

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No evidence of hyperextension of the fetal head and no fetal abnormalities  Delivery of the buttocks  Full dilation and descent of the breech occur naturally  Buttocks will lie in the anterior-posterior diameter  When anterior buttock is delivered and the anus is over the fourchette, an episiotomy can be cut  Delivery of the legs and lower body  If legs are flexed, they will deliver spontaneously  If extended, Pinard’s maneuver may need to be used – using a finger to flex the leg at the knee and extend at the hip, anteriorly then posteriorly (+ contractions and maternal effort)  Delivery of the shoulders  Baby will be lying with the shoulders in the transverse diameter of the pelvic mid-cavity  Anterior shoulder rotates into the anterior-posterior diameter, the spine or the scapula will become visible  A finger can then be gently placed above the shoulder to help deliver the arm  When the posterior shoulder reaches the pelvic floor, it will also rotate anteriorly; delivery of the second arm occurs when the spine is visible  Delivery of the head  Mauriceau-Smellie-Veit maneuver – baby lies on the obstetrician’s arm with one finger in the mouth and one on each maxilla  First downward then upward movement, may need to apply forceps  Complications  Baby might get ‘stuck’ – interference with oxytocic agents or trying to pull the baby out increases the risk of obstruction Elective cesarean section

Other Fetal Malpresentations - Transverse lie – when the fetal long axis lies perpendicular to the maternal long axis  shoulder presentation - Oblique lie – when the long axis of the fetal body crosses the long axis of the maternal body at a 45° angle - Risk of cord prolapse following spontaneous rupture of the membranes and prolapse of the hand, foot, or shoulder - Usually, the woman is multiparous with a lax uterus and abdominal wall musculature – gentle version of the baby’s head will restore cephalic presentation - Diagnosis may be made by abdominal inspection  Abdomen appears asymmetrical  SFH less than expected  Fetal head or buttocks may be in iliac fossa on palpation  Palpation over the pelvic brim reveals an ‘empty’ pelvis - Any lie other than longitudinal cannot be delivered vaginally – high risk of morbidity or mortality if C-section is not performed

Jasmin Jaber 2015

23. Rh Isoimmunization, Substance Abuse in Pregnancy Rhesus Iso-immunization - ABO blood group – 4 different permutations (O, A, B, AB) - Rhesus system – C, D, E antigens - Mismatch between fetus and mother means that when fetal red cells pass across to the maternal circulation, the maternal immune system becomes sensitized to the fetal red blood cells – may give rise to hemolytic disease of the fetus and newborn (HDFN) - Etiology  Rhesus system is coded on 2 genes both on chromosome 1 – one codes for polypeptides C/c and E/c, the other for D polypeptide (Rh antigen)  Ag expression is dominant – those with negative phenotype are either homozygous for the recessive gene or have the gene deleted  Only anti-D and anti-c cause HDFN, but anti-D is much more common  HDFN occurs in 3 stages  Rh-negative mother must conceive baby who is Rh-positive  Fetal cells gain access to the maternal circulation  Maternal antibodies gain transplacental access and immune destruction of red cells in the fetus  Rhesus disease does not affect the first pregnancy; the primary response is weak and mainly consists of IgM; in consequent pregnancies, IgG is produced  Rh antigens can be detected as early as 30 days of gestation; if IgG antibodies cross from the mother to the fetal circulation in sufficient amount, fetal hemolysis can occur  severe anemia that can lead to death unless a transfusion is performed - Preventing iso-immunization  IM administration of anti-D Ig to the mother within 72 hours of exposure for fetal red cells (sensitization)  In the 1st trimester, fetal blood volume is low – standard dose of anti-D is given; in the 2nd and 3rd trimesters a larger dose is given and a Kleihauer test done  Test of maternal blood to determine the proportion of fetal cells present – allows calculation of extra anti-D Ig required - Management of rhesus disease in sensitized women  Rhesus disease gets worse with successive pregnancies, management depends on the clinical scenario  The father of the next baby is Rh-negative – no risk that the baby will be Rh-positive and no chance of disease  The father of the next baby is Rh-positive – he may be heterozygous, determining the...