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Obstetrics
History taking & examination Obstetrics = study and management of normal and abnormal pregnancy Gynaecology = study of diseases of female genital tract + reproductive system Gravidity = pregnancy Parity = woman who has given birth to potentially viable infant (alive/dead) >500g & gestational age >24wks Primipara (1), multiparous (2-4), nulliparous (0), grand multipara (>5, separately)
4 pregnancies, 2 miscarriages = gravida 4, para 2 à multigravid multiparous woman Gravida = pregnant woman Parturient = woman in labour Puerpera = woman given birth within last 42d Obstetr ic history – present pregnancy
• Date of LMP = first day of the last menstrual period • Length of menstrual cycle = time between first day of period and first day of next period
o 21-35d (usually 28d) o Proliferative phase can vary hugely (between menstruation & ovulation)
• EDD – subtract 3months/add 7d (28d cycle, ± if longer/shorter) o Need to know: usual length of menstrual cycle & LMP
• Contraceptive hx o Hormonal contraception maybe assc. w/ delay in ovulation in 1st cycle after use
• Menarche Symptoms of pregnancy
• Onset of 2º amenorrhea in previously regular menstrual cycle • N+V within 2wks of amenorrhea
o Any time of day (not just morning sickness) o Often precipitated by sight/smell of food o Usually 1st 3 months (may be entire duration) o Hyperemesis gravidarum = severe & persistent vomiting leading to dehydration & electrolyte
imbalance § In-patient IV fluid replacement + electrolyte correction
• 3-4L Hartmann’s solution + 5% dextrose/day • Frequency of micturition
o Increased diuretic response to water loading in upright position (declines in 3rd trimester) • Excessive lassitude
o Early-12wks • Breast heaviness & tenderness • Foetal movements (‘quickening’)
o 20wks primigravidae, 18wks multigravidae. May have none/earlier. • Pica = abnormal desire for particular food • Pseudocyesis
o Condition where S+S develop in absence of pregnancy Previous obstetr ic history
• Previous miscarriages o Duration of gestation
• Previous viable pregnancies • Stillbirths/neonatal deaths • Previous births
o Induction of labour o Duration of labour o Presentation of delivery o Method of delivery
• Gestational age & sex of infants o Birthweight o Condition of baby at birth
• Previous antenatal • Postnatal complications
o Need for special care baby unit o Postpartum haemorrhage o Infections of genital tract o UTI
Obstetrics
o DVT o Perineal complications – breakdown of perineal wounds etc.
Hx
• PMHx o Diabetes o Cardiac disease o HTN o Renal disease o Endocrine disorders i.e. thyrotoxicosis, Addison’s o Infectious disease i.e. HIV, HCV, HBV, TB, syphilis
• FHx o Inherited conditions known
Obstetr ic examination
• General examination including CVS o Height - ?small pelvis (1st visit) o Weight o BP – L lateral supine position (avoids IVC compression by gravid uterus) OR same position each
time § Supine hypotensive syndrome
• IVC compression late pregnancy à syncope + nausea • Assc. postural hypotension
• Flow murmurs common o Soft systolic bruits over apex o Mammary soufflé = internal mammary vessels murmur in 2nd ICS (disappears with stethoscope
pressure) • Head & neck
o Chloasma = brown discoloration 2º to pigmentation over forehead & cheeks (fades after) o Mucosal pallor (conjunctival) o Oral hygiene
§ Hypertrophic gingivitis • Breasts & nipples (if clinically indicated)
o Montgomery’s tubercles o Pigmentation of areola of nipples
• Abdominal o Striae gravidarum = stretch marks o Linea alba à linea nigra (pigmented) o Hepatosplenomegaly o Uterus >12wks
• Limbs & skeletal o Oedema o Varicose veins o Posture
§ Kyphosis § Increased lumbar lordosis à back ache/sciatic pain
• Upper trunk posterior disposition to compensate foetus weight • Pelvic if indicated
o Thick plug of viscid cervical mucus occludes cervical os o Bony pelvis variants
§ Gynacoid pelvis = normal, sacrum evenly curved, maximum space for foetus head § Android pelvis = flattened sacrum
o False pelvis = pelvic area above the iliopectineal line o True pelvis = below pelvic brim
§ Sacrum posteriorly, ischial bones + sacrosciatic notches + ligs. Laterally, pubic rami + obturator fossae + membranes anteriorly
Abdominal palpation
• Palpate fundus • Measure symphysial-fundal height • Feel for presenting part • Determine lie = relationship of long axis of foetal to long axis of uterus
o Transverse (presents w/ shoulder), oblique or longitudinal (breech [podalic] vs head [cephalic])
Obstetrics
• Assess station of presenting part • Determine position of presenting part • Auscultation of foetal heart
Obstetrics
Normal pregnancy and antenatal care • Basic aims of antennal care
o Ensure optimal maternal health o Detect & treat disorders à ensure health mother & infant
Routine screening tests
• Haematological Ix to detect: anaemia, haemoglobinopathies in susceptible groups o 1st visit, 28wks, 36wks
• Blood groups + prevention of Rhesus disease o Screening for Rh Ig in Rh- women 1st visit o Give anti-D antibodies
Infection screening
• Rubella • HIV
o Can avoid mother-child vertical transmission by caesarean, avoiding breastfeeding and antiretroviral therapy
• HBV • Syphilis
Screening for foetal anomalies
• Why? o Early detection o Terminal of pregnancy (if appropriate)
• Structural anomalies (in order): CVS, craniospinal, renal, GI ß USS detection • Neural tube defects
o Serum a-fetoprotein testing 15-19wks § Glycoprotein made in foetal yolk sac & in foetal liver § Enters amniotic fluid via foetal urine
o Any doubt/not clear result à amniocentesis à a-FP + acetyl cholinesterase test § Acetylcholinesterase = not normally found in amniotic fluid, released when foetal CSF has
access to amniotic sac o RFx
§ PMHx of affected child • Reduced by PO 5mg folic acid (pre conception – 12wks gestation)
• Down’s syndrome (trisomy 21) o Biochemical & USS tests
§ Biochemical: maternal serum a-FP (low), hCG (raised), serum unconjugated oestiol (low) = TRIPLE TEST
§ 15-20wks § USS: nuchal translucency = measures fluid behind foetal neck
• Amniocentesis o If abnormality à within 15-17wks o 10-15ml aspirated transabominally w/ spinal needle (USS guidance) o 0.5-1% risk of miscarriage o 2-5% failure rate in foetal cell culture process
• Chorion villus sampling o Transcervical/transabdominally o <12wks o Result within 2-3d o Higher rate pregnancy loss
Screening for maternal disorders
• Gestational diabetes o Assc w/ increased intrauterine foetal death o At booking & 28wks o Screening programmes:
§ Selection by history • PMHx gestational diabetes • IGT • 10 relative with diabetes • Unexplained stillbirth
Obstetrics
• Macrosomic infant wt >4kg • BMI >35 • Rptd glycosuria • Full GGT: 75/100g glucose loading dose • Fasting glucose >4.5mmol/L
§ Universal screening • Modified GGT: 50g glucose + 1 hour à >7.7mmol/L
• UTIs Antenatal education
• Diet in pregnancy o Energy requirements o Protein, fat & CHO o Minerals & vitamins
§ Vitamin A + B: kidney, liver, dark green veg § Vit B2: whole grain + cereals § Vit B5: fish, lean meat, poultry, nuts § Ascorbic acid: citrus fruits, brussel sprouts + broccoli § Folic acid: green veg, nuts + yeast
• Social habits o Exercise & coitus
§ Ok to continue these unless high risk or Hx of foetal loss/premature rupture of membranes/antepartum haemorrhage
o Smoking § Adverse effect on foetal growth & development (CI) § CO à shifts oxygen dissociation curve to LHS à impaired tissue O2 delivery
• Conc up to 7.6% § Nicotine à uteroplacental vasoconstrictor (minimal) § Reduced birth wt & crown-heel length § Increased perinatal mortality § Pre-eclampsia
• Found that smoking reduces risk of developing • BUT if it does develop – significantly higher risk of perinatal loss
o Alcohol § Foetal alcohol syndrome
• Cause: excessive (<8U/d) alcohol consumption during pregnancy • Features
o Growth retardation o Various structural defects
§ Facial defects o Joint anomalies o Cardiac defects
o Other substance abuse § Heroin addiction
• IUGR • Perinatal death • Preterm labour • 50% neonatal withdrawal
§ Cocaine • Maternal
o Cardiac arrhythmias o CNS damage
• Placental abruptions • IUGR • Preterm labour
§ ?Teratogenic effect of marijuana substance 9-tetrahydrocannibol • Breast care
o Encourage breastfeeding! o CI:
§ Damage/grossly inverted nipples
Obstetrics
§ Certain drugs (concentrated in breast milk) § Maternal infections: HIV
o Breast care § Washed daily + carefully dried antenatally (colostrum may leak esp 3rd trimester) § Soft cream § Appropriate maternity bra
Common disorders
• Vomiting o Advice
§ Small frequent meals § Avoid highly spiced food § Sweetened drink before starting work/activity in AM
o 10mg metoclopramide BD/TD o OR 50mg Cyclizine TD o Extreme: ACTH/prednisolone injections
• Abdominal pain • Heartburn
o Worse on lying flat & after spicy food o Tx: antacids (gaviscon), metoclopramide, ranitidine
• Constipation o Progesterone à slows bowel motility o Tx: increased dietary fibre, bulk-forming laxatives (lactulose), mild stimulants (senokot, milk of
Magnesia) • Backache
o Don’t exclude more serious causes!!! • Syncopal episodes • Varicosities • Carpal tunnel syndrome
Obstetrics
Antenatal disorders HTN in pregnancy
• Commonest complication of pregnancy in UK o Severe assc. w/ convulsions, proteinuria, sever HTN + oedema, cerebral haemorrhage, renal &
hepatic failure o HTN = sBP >140 or dBP >90 on 2 occasions >20wks o Proteinuria = >0.3g/L in 24hr urine collection
§ Poor prognosis for infant o Oedema = Development of pitting oedema/wt gain >2.3kg/wk
• Summary of classifications:
o Gestational HTN o Pre-eclampsia o Eclampsia o Chronic hypertensive diseases = HTN present prior to pregnancy (?pathological cause) o Superimposed pre-eclampsia/eclampsia on pre-existent forms of HTN = pre-eclampsia in woman
with chronic HTN/renal disease o Unclassified hypertensive disease = random basis, insuffienct info to classify otherwise
• Gestational HTN = HTN alone after 20wks/within 24hrs postpartum in previously normotensive • Pre-eclampsia = HTN + proteinuria >20wks
o Pathogenesis of pre-eclampsia uncertain, contributing factors: § Increase in platelet A2 receptors (reduce sensitivity to AT2), § Endothelial dysfunction (reduced NO & EDRF vasodilator effect) § Decreased antioxidants (lipid peroxides damage endothelium)
o Vasoconstriction in placental bed à release trophoblastic material into peripheral circulation à DIC 2º to thromboplastins within material
o 2 key features: § Arteriolar vasoconstriction of vascular beds § DIC
• Pathological lesions in vascular beds of : o Placenta – gross infarction 2º to reduced uteroplacental blood flow à IUGR
?foetal death § Defective trophoblastic invasion of spiral arterioles à reduced
dilation o Kidney – Na + H20 retention in ECF
§ Glomerular lesion – reduced GFR § Tubular changes – hyperuricaemia 2º to impaired uric acid
secretion o Liver
o RFx: § FHx of pre-eclampsia
o S+S: § Asymptomatic § Symptoms
• Frontal headache • Blurring vision • Epigastic pain
o Mgt § Bed rest § Anti HTN pharmacological tx
• HELLP syndrome o Severe triad of manifestations of pre-eclamsia
Haemolysis Elevated Liver enzymes Low Platelet count
o Tx: termination once controlled • Treatment options
o Bed rest – increase renal & uteroplacental blood flow à diuresis o Diuretics
§ Generally worsen condition as fluid retention is extracellular § Indications:
• Oedema relief
Obstetrics
• Previous essential HTN • Immediately postpartum oliguria (osmotic diuretics mannitol)
o Sedatives § Reduce cerebral excitability & decrease convulsion risk § 10-20mg diazepam Q6H
• Long term risk of floppy baby syndrome o Hypothermia + hypotonia in foetus o 2º to transport of diazepam + it’s metabolite (desmethyl diazepam) across
placenta o ? use Mg Sulphate instead
§ Antihypertensives • Methyldopa • Hydralazine • B-blockers: atenolol, oxyprenolol, metoprolol • Combined a- & b-blockers: labetalol • CCB: nifedipine • Selective serotonin receptor blockers: ketanserin • ACUTE: IV bolus 5mg hydralazine OR 20mg labetalol
• Eclampsia = pre-eclampsia + convulsions to 48hrs post-partum o Serious risk of: IU death, maternal death (cerebral haemorrhage/hepatic/renal failure) o Mgt
§ Control of fits • IV bolus 10mg diazepam (further 10mg if LOC not compromised/resp depression) • Mg sulphate 4g IV 20ml of 20% over 20mins (20!!)
o Supresses convulsions o Inhibits muscular activity o Reduces platelet aggregation à reduced DIC o Monitor blood Mg as risk of complete respiratory arrest
§ Reversal by Ca gluconate 1g over 2-3mins § Control of BP
• Hydralazine IV 5-10mg over 5 mins (rpt at 15mins) OR • Labetalol IV bolus 20mg (can increase)
§ Deliver infant by induction of labour/caesarean • Important to monitor post-partum as risk carried for 1wk post
Anaemia
• UK Hb <11g/dl o <12g/dl in 1st trimester
• Usually caused by: o Not enough dietary iron o Impaired iron absorption
§ Gastric achlorhydia, malnutrition, chronic diarrhoea, hookworm § Ix: MCV, HCHC, serum iron + iron-binding, folate, vitB, others (rarer causes)
o Mgt: PO iron/folic acid Diabetes
• Classified into: o Potential = no evidence of chemical diabetes + FHx/PMHx macrosomic baby/Hx of unexplained
foetal death o Latent/gestational = develop clinical diabetes during pregnancy & over diabetes later in life o Chemical = IGT alone (increased risk of perinatal mortality + morbidity) o Clinical = insulin-dependent diabetes
• Control by diet (gestational diabetes)/short acting insulin • White’s classification of diabetes:
Obstetrics
• GTT using 75mg loading dose:
o Normal § Fasting <6 § 2hr <7.8
o Gestational IGT § Fasting 6-7 § 2hr 7.8-11.1
o Diabetes § Fasting >7 § 2hr >11.1
• Maternal complications o Hyperglycaemia à ketoacidosis & diabetic coma à maternal & foetal death risk o Hydramnios à unstable lie + premature rupture of membranes o Pre-eclampsia o Dystocia (esp shoulder) = difficult childbirth
• Foetal complications o Macrosomia + increased fat deposition à large babies o Poor diabetic control à increased IU death o Foetal acidosis during labour
• Neonatal complications o Hypoglycaemia (esp 1st 48hrs) o RDS o Congenital abnormalities
Thyroid disease
• Hypothyroidism o Mostly AA (i.e. Hashimoto’s) o Low free t4, raised TSH
• Graves disease o May cause:
§ Foetal malformation § Low birthweight § Premature labour
o Risk of thyroid crisis à mortality 25% o High t3, low TSH/flat response to TRH o Ig can cross placenta à foetal thyroid disease o Tx: pharmacological tx
§ Carbimazole, methimazole, propylthiouracil (PTU: drug of choice as crosses placenta slow) § Look out for foetal thyroid suppression
Cardiac disease
Obstetrics
• NYHA classes 3 + 4 prognosis poor – consider termination
Low risk condit ions Moderate r isk High r isk Septal defects PDA Pulmonary lesions Tricuspid lesions
MS AS Marfan’s (w/o cardiomyopathy) PMHx MI Coarctation
Eisenmenger’s syndrome Pulmonary HTN Marfan’s involving aorta + CM
• Antibiotic cover in labour • Encourage vaginal delivery - ?anticoag w/ valve replacement
Respiratory disease
• Assess asthma control with pulmonary function tests • Tx as non-pregnant
Epilepsy
• AED teratogenic but hazards of epilepsy>risk of therapy o Congenital heart defects o Orofacial clefts o Microcephaly o Intrauterine growth restriction o Developmental delay o (Phenytoin) vitamin K dependent clotting probs
• 1st priority à control fits AA disorders
• Antiphospholipid antibodies o SLE o Myeloproliferative disorders o Assc. w/:
§ Increased risk of IUGR § Stillbirth § Miscarriage § Thrombosis
o Tx: heparin + low dose aspirin Liver disease
• Intrahepatic cholestasis of pregnancy o S+S
§ Unexplained pruritis § Late-onset jaundice § Dark urine, pale stools
o Hypoprothrombinaemia à risk of obstetric haemorrhage o Risk of: stillbirth & foetal distress in labour o Tx: PO dexamethasone (pruritis) + self resolves 4-7d post partum
• Acute fatty liver of pregnancy o Microvascular fatty infiltration of liver o Death ß hepatic encephalopathy, genital tract haemorrhage + DIC
Obstetrics
o Tx: mgt of hypoglycaemia, coagulopathy + acidosis • Acute viral hepatitis
o HBV hepatitis à infant given Ig IM at birth + vaccinated in 1st month (stops vertical transmission) § Hepatitis B carrier state à may reactivation during pregnancy § Rpt vaccination 6mnths
Renal disease
• Treat bacteriuria w/ AB to prevent acute pyelonephritis o Commonly Escherichia coli
§ Tx: amoxicillin/cefurozime + supportive • Moderate-severe chronic renal disease usually worsens during pregnancy & doesn’t improve post-delivery • Renal disease à increased intrauterine growth restriction, preterm delivery + perinatal loss • Avoid lithotripsy in pregnancy (renal calculi)
Obstetrics
Antepartum haemorrhage Antepartum haemorrhage = vaginal bleeding >24wks Vaginal bleeding maybe due to:
• Haemorrhage (placental site + uterine cavity) • Lesions (vagina/cervix) • Foetal bleeding (vasa praevia)
Main causes of uterine bleeding:
• Placenta praevia • Abruptio placentae/accidental haemorrhage • Uterine rupture • Unknown aetiology
Placenta praevia
• Placenta praevia = all/part of placenta implants in lower uterine segment .’. lies in presenting part • Incidence 1% (quite constant, unaffected by social/nutritional factors) • RFx:
o Multiparous o Previous caesarean section o Larger placental area
§ Multiple pregnancy § Placenta membranacea
• Pathophysiology o Delay in blastocyst implantation o Formation of lower segment à separation of placenta à cervix effaces à bleeding o Blood from venous sinuses in lower segment o Vasa praevia = foetal blood loss where one of placental vessels lies across cervical os
• Classification
o Marginal = placenta encroaches/covers internal cervical os before cervical dilatation occurs o Central = placenta fully covers on even with dilatation
§ Spontaneous delivery extremely rare! Possible in other types o Lateral = encroaches on lower uterine segment not reaching internal os
Obstetrics
• S+S
o Symptoms: painless PV bleeding, lower abdominal discomfort (if + minor placental abruption) o Signs: vaginal bleeding, malpresentation of foetus, uterine hypotonus o Usually >28wks
• Dx o Clinical
§ Sudden recurrent painless vaginal bleeding § ?Profuse haemorrhage at onset of labour when cervix dilates
o Abdominal examination § Displaced presenting part § Flaccid uterus
o Confirmed by USS/MRI • Mgt
o Conservative until 37wks § Hospital admission for major degrees
• Avoid vaginal examination unless (risk of haemorrhage): o Serious doubt of Dx o Bleeding in established labour
§ Blood held + cross matched § Caesarean section unless marginal
• Prognosis for foetus – good • Risk of: postpartum haemorrhage + placenta accreta = placental implantation over site of previous uterine
scar Placental abruption
• Abruptio placentae = haemorrhage resulting from premature separation of placenta • Incidence 0.5-1% • RFx:
o Social deprivation o Dietary deficiencies (esp. folic acid) o Pre-existing:
§ Pre-eclampsia § Essential HTN § (Abruption may also cause these…)
o Male foetus o PMHx of abruption
• Worse prognosis in smokers • Types
Obstetrics
Vaginal bleeding Haemorrhage à cervical os >36wks Longitudinal lie ?Increased uterine activity
Haemorrhage between placenta + uterine wall Abnormally large fundal size Hypertonic uterus Pain & shock ?Ridgid + tender uterus Couvelaire uterus = haemorrhage penetrates through uterine wall + uterus appears bruised
Interval where blood concealed Then appears vaginally
• S+S:
o Painful vaginal bleeding o Increased uterine activity
• Differential Dx: o Placenta praevia
§ Painless haemorrhage, unstable lie, hypotonic uterus o Acute hydramnios
§ Enlarged, tender & uterus § No haemorrhage
o Acute abdomen § Perforated ulcer § Volvulus of bowel § Strangulated inguinal hernia § ^ may stimulate concealed placental abruption
• Dx: clinical + USS • Mgt: replace blood loss
o Check for DIC o Deliver infant if abruption severe o Prognosis for foetus – poor
• Maternal complications o Afibrinogenaemia o Couvelaire uterus o Post partum haemorrhage o Hypovolaemia from blood loss o Renal tubular/cortical necrosis o Scar dehiscence + uterine rupture
Unexplained causes
• Ruptured uterus • Carcinoma of cervix – terminate if early, tx lesion if late • Cervical polyp – removal • Cervical erosions – best untreated • Vaginitis
o Vaginal moniliasis/trichomoniasis à blood stained d/c • Vasa praevia
Congenital abnormalities and infections in pregnancy Congenital abnormalit ies
• 25-30/1000 of stillbirths
Obstetrics
• 20% neonatal deaths • Commonest
o Neural tube defects § Anencephaly = cephalis end of neural tube fails to close § Microcephaly = significantly smaller head size 2º to failure of brain growth § Spina bifida with/without:
• Myelo-meningocele = bones of spine don’t completely form resulting in incomplete spinal canal
• Encephalocele = sac-like protrusions of the brain & meninges through the skull • Holoprosencephaly = prosencephalon (forebrain) fails to divide into 2 hemispheres • Hydranencephaly = brain’s cerebral hemispheres absent & remaining cranial
cavity full of CSF o Congenital HD
§ ASD § VSD § PS § AS § Coarctation § Transpositions § Tetralogy of Fallot § Dx: detailed USS 4-chamber scans (18wks)
o Severe mental retardation o Down’s syndrome o Hare lip/cleft palate
• Abdominal wall defects o Exomphalos = bowel extrudes outside abdominal cavity o Ectopia vesicae = bladder is everted + opens on to the surface of abdominal wall
• Cerebral palsy o Cerebral palsy = disorder of movement + posture caused by non-progressive insult to immature
brain o Complex aetiology
§ Disorders of development § IU infections § Disturbance of normal foetal nutrition § Oxygenation before/during labour § Post-natal events: kernicterus, meningitis, trauma § Intrapartum asphyxia (<15%)
o S+S: § Persistence of infantile behaviour § Infantile reflexes § CNS matures à handicap increases
• X-linked diseases (i.e. Duchenne’s muscular dystrophy, haemophilia) • Chromosomal defects
o Down’s syndrome incidence increases with maternal age § Non-disjunction at meiosis § S+S:
• Typical abnormal facial features • Mental retardation (varying degrees) • Congenital heart disease
• Most structural defects demonstrated by USS • Metabolic disorders may need foetal blood sample (i.e. PKU) • Chromosomal defects need amniocentesis confirmation • Chorion villus sampling also Dx defects
Maternal infections affecting the foetus
• Incidence of defects 2º to maternal rubella infection varies depending on gestational age at time of infection o Infection in 1st 14 wks à foetal infection o Microcephaly o 4-12wks: lens à cataracts, infection o Deafness
Obstetrics
o 5-12wks: heart à congenital heart disease, foetal growth restriction, thrombocytopenia, hepatosplenomegaly + vasculitis
o Osteitis o S+S:
§ Fine macular rash § Lymphadenopathy (cervical LN) § Mild pyrexia
o Dx: § Throat swab/blood culture – virus isolation § Infant: cord blood measurements of similar Ig titres as mother à in utero infection
• HBV transmission by contamination by faeces, amniotic fluid inhalation • Herpes Simplex
o HSV1: 50% genital tract infections, eyes, mouth, CNS o HSV2: STI o Increased risk of miscarriage o Foetal infection
§ Skin vesicles, brain, liver, adrenals manifestations o Caesarean section delivery recommended with maternal active herpes (type 2) infections
§ 40% incidence of neonatal infection • CMV à microcephaly + mental retardation
o 1º infection at birth: § Growth restriction § Jaundice § Hepatosplenomegaly § Rash § Chorioretinitis § Intracranial calcification § Encephalitis/microcephaly
• Toxoplasmosis affects 2/1000 births (infection of Toxoplasma gondii domestic cats) o Tx: spiramycin, pyrimethamine, sulfadiazine, folinic acid
• Chlamydiosis à neonatal conjunctivitis + trachoma o Dx: immunoassay o Tx: 7-14d erythromycin
• Varicella zoster à miscarriage risk + embryopathy • Listeriosis à miscarriages + still births (avoid raw meat + soft cheese) • Parvovirus (parvovirus B19) à severe anaemia, myocarditis à gross hydrops + foetal death • Decrease vertical HIV transmission by drug tx, caesarean delivery + avoiding breastfeeding
o Foetal AIDS § Intrauterine growth retardation § Microcephaly § Prominent forehead § Blue sclera
• Malaria worse in pregnancy – prophylaxis essential
Obstetrics
Assessment of foetal wellbeing Use of USS in pregnancy
• USS based on transmission of sound frequencies of order 2-20 MHz into human tissue o Measurements of returning echoes from diff density surfaces o Doesn’t penetrate gaseous medium – no good in bowel + lung
• Pregnancy dating – most accurate 1st trimester o 1st trimester: crown-rump length o 2nd trimester: biparietal diameter, head circumference, femur length + abdominal circumference o 3rd trimester: limited options!
• Multiple pregnancies o Early Dx o Chorionicity = whether or not multiple foetus share placenta
§ Dichorionic lambda sign = triangular projection of thick septum between 2 chorion sacs
• Difficult to view ectopic pregnancy:
o Absence of gestation sac in uterus o An adnexal mass w/w.o. foetal pole o Fluid in pouch of douglas o +ve pregnancy test
• Hydatiform mole
Obstetrics
o Molar pregnancy classical appearance – snowstorm appearance (uterus filled with echoes) o Haemorrhage in molar tissue may ?miscarriage + foetal resorption
• Early embryonic demise o Foetal clearly identified & grows normal rate until death o Foetal heartbeat no longer seen o Rpt scan 1wk
• Anembryonic pregnancy o Absence of foetal development à empty foetal sac o Rpt scan 1wk
Screening for abnormalit ies
• Structural o Neural tube defects o Renal tract anomalies
§ Bladder visual >14wks • Genetic • Down’s syndrome
o ‘Double bubble’ sign of duodenal atresia o Cardiac abnormalities: VSD, echogenic foci in ventricle wall o Nuchal translucency = increase in thickness + translucency in skin over the neck
• Nuchal translucency Placental imaging
• Site & density • 15-20% low-lying 2nd trimester • 1% at term
Assessing foetal growth
• Cephalometry = measuring foetal biparietal diameter • Head circumference, biparietal diameter • Abdominal circumference • Femur length
Assessment of foetal wellbeing
• Biophysical profile (5, 4 USS) o Amniotic fluid volume o Foetal breathing o Gross body movements o Foetal HR o Foetal tone
• Effective at predicting normality • Amniotic fluid filled volume • Abnormal maximum depth <2cm • Amniotic fluid index 8-18cm
Obstetrics
Umbil ical artery Doppler
• Abnormal findings • Absent end diastolic flow • Reversed end diastolic flow • Increased resistance index
Antepartum cardiotocography
• Loss of baseline variability • Variable decelerations • Computer based analysis reduces observer bias • Better predictor of foetal acidosis
Obstetrics
Normal labour
Labour/parturition = process where the products of conception expelled from uterine cavity >24th week gestation Premature labour = labour <37th week gestation Prolonged labour = labour >24/12hrs. Increased foetal & maternal morbidity & mortality.
• Normal labour o Labour resulting in vaginal delivery
§ <24h in primigravida § <12hr in multigravida
• 3 stages o 1st stage: onset à full dilatation of cervix (can’t palpate) o 2nd stage (expulsion): full dilatation à delivery (expulsion of foetus) o 3rd stage (placental): delivery à expulsion of the placenta
• Onset of labour o Regular painful contractions
§ Pain – compression of nerve fibres in cervical zone/hypoxia of compressed myocytes § Lower abdomen + lumbar backache § >IU pressure 25 mmHg
o Clinical features: § Increasing strength/freq contractions à progressive cervical dilatation § A vaginal ‘show’ = passage of blood stained mucous § Rupture of foetal membranes (variable)
Init iat ion of labour
• Complex interaction of foetal + maternal factors • Principal parts
o Progesterone-oestradiol interaction § Prog à suppresses uterine activity § Oestrodiol à increases
o Increased foetal cortisol – reduces placental prog, increases oestrone + oestradiol o Local activity of prostaglandins – increase myometrial activity o Oxytocin release – enhances myometrial activity
• Effects on myometrium by: relaxin, activin A, follistatin, hCG and CRH • Ripening of cervix
o Increased hyaluronic acid (hydrophilic) + reduced fibronectin affinity for collagen – softening + ripening of cervix
Uterine activity
• Retraction = contractions produce effacement + dilatation of the cervix as a result of shortening of myoemetrial fibres (upper uterine segment) + stretching and thinning (lower uterine segment)
o Lower segment gets longer & thinner • Increasing strength/freq contractions à progressive cervical dilatation
o Initiated by pacemaker in L uterine conus à spreads down via myometrium • Normal resting tonus increases slightly during labour • Contractions à shortening of myometrial cells
o Gap junctions (made of connexins) – co-ordinated contractions • Progressive effacement and dilatation of cervix
o False labour = painful contractions not assoc. w/ above • Fundal dominance necessary for progression
Obstetrics
o Fundal dominance = first contractions stronger & longer in fundus of uterus (compared to lower seg)
The passages
• Softening of pelvic ligaments • Increased distensibility of pelvic floor • Often results in:
o Perineal tear o Vaginal wall tear o Disruption of external anal sphincter
The mechanism of normal labour
• Foetal head adapts by: o Descent throughout labour (measure indicates progress of labour) o Flexion – minimise diameter @ presentation
§ Chin up to foetal thorax § Occipitoposterior (unflexed) à suboccipitobregmatic (flexed)
o Internal rotation – as head reaches pelvic floor § Towards pubic symphysis
o Extension – with delivery of head § Crowning = maximal distension of perineum + introitus in final expulsion of head
o Restitution – after head delivered its rotated to be in line with shoulders o External rotation – shoulders descent into pelvis o Delivery of shoulders
§ Anterior shoulders 1st – delivered by traction § Posterior shoulder – lift head anteriorly over perineum
The 3rd stage
• Following delivery o Placenta sheds of uterine wall (2º to uterine muscle contraction) o Uterus expels placenta à lower segment/vault of vagina o Oxytocic drugs given with delivery of the anterior shoulder o Assisted delivery of placenta o Check placenta
• Classical signs of placental separation: o Lengthening of cord o Elevation of uterine fundus (globular à tent shaped)
Obstetrics
o Show of blood • 4th stage?
o Time between expulsion & 6hrs post-partum
Management of labour
• Observation + use of partogram o Partogram = single piece of paper showing progression of labour graphically
• Examination o Full general examination o Obstetrical examination of abdo o Vaginal examination (aseptic) o Important things to note:
§ Cervix – consistency, dilatation, effacement (CDE) § Membrane status (ruptured/intact)
• Colour of amniotic fluid if ruptured § Nature & presentation of presenting part & relationship to ischial spine § Bony pelvis assessment (esp. pelvic outlet)
• Fluid balance + nutrition in labour o Signs of dehydration in labour:
§ Tachycardia § Mild pyrexia § Loss of tissue turgor
• Pain relief o Narcotic agents
§ Pethidine IM 50-150mg Q2-3H • SE: N+V, respiratory depression (maternal + foetal) • Give + phenothiazines à reduce N
o Inhalation analgesia § Entonox (50/50 nitrous oxide + oxygen)
o Non-pharmacological methods § Psychoprophylaxis
• Controlled respiration (antenatal classes) • Education about regulation of expulsive efforts in 2nd stage of labour
§ TENS = transcutaneous electrical nerve stimulation • 2 TENS electrode pairs T10-L1 + S2-S4
§ Massage & relaxation o Regional analgesia
§ Epidural • Fine catheter à lumbar (L3-4) epidural space à local anaesthetic agent injected • Addition of opioid reduces anaesthetic dose .’. reducing SE • Classic complications
o Hypotension o Abnormal foetal HR o Accidental dural puncture o Postdural headache
• CI o Maternal refusal o Coagulopathy
Obstetrics
o Local/systemic infection o Uncorrected hypovolaemia o Inadequate/inexperienced staff
§ Spinal anaesthesia § Paracervical blockade § Pudendal nerve blockade
Foetal monitoring in labour
• Foetal cardiotocography • Basal heart rate
o Measure every 15mins with Pinard fetal stethoscope (1st stage) o After every contraction (2nd stage)
• Transitory changes o Accelerations = increases in HR >15bpm for >15s. Associated with foetal movement (good sign) o Decelerations = decreases of >15bpm for >15s o Normal = 110-160bpm o Tachy = 160-180 (moderate), >180 (severe) o Brady = 100-110 (mod), <100 (severe)
• The foetal electrocardiogram o Relationship between T + QRS height related to acidosis o Relationship between PR interval + RR interval related to asphyxia
• Foetal acid-base changes o Scalp blood sampling (amnioscope) o 7-7.25 1st stage = mild acidosis (n = 7.25-7.35) o <7.20 = significant acidosis ?delivery
Management of the 2nd stage
• Cervical dilatation o Latent phase = onset-3cm dilatation (2/3 labour time) o Active phase = latent-full dilatation reached
• Delivery of the head • Controlled descent • Minimising perineal damage
o Squatting during 2nd stage carries increased risk of perineal tear if labour uncontrolled • Water births
o Flotation à support of pregnant uterus o Delivery shouldn’t be in bath due to risk of bath water inhalation 1st breath
• Baby should cry within 1minute of birth if not… o Aspirate Nasopharynx & inflate lungs with O2 (facemask) o Still delayed?
§ Endotracheal intubation + ventilation • Clamping the cord
o Clamped twice & cut between the two clamps • Evaluation of Apgar score (1, 5 and 10 minutes)
Management of the 3rd stage
• Recognition of placental separation • Assisted delivery of placenta w/ cord traction • Routine use of oxytocic agents (Syntometrine: 0.5mg ergometrine + 5 IU oxytocin) with crowning of the
head o Causes contraction of uterus – minimise postpartum haemorrhage
• Brandt-Andrews technique
Obstetrics
o Uterus contracted à cord traction applied with R hand, monitor fundal descent + apply counterpressure on uterus (L hand?)
Repair of perineal damage
• 4 degrees of perineal damage o 1st degree = vaginal and perineal skin damaged o 2nd degree = posterior vaginal wall + underlying levator + perineal muscles (not anal sphincter) o 3rd degree = anal sphincter involvement o 4th degree = anal sphincter + rectal mucosa involvement
• 3rd + 4th degree tears should be repaired by experienced obstetrician in OT • Follow repair, check:
o No retained swabs o No rectal suture (if left potential to form à rectovaginal fistula) o Vagina not abnormally constricted
Obstetrics
Abnormal labour – instrumental & operative Preterm labour
• Labour occurring <37wks • Occurs 6% pregnancies • Causes:
o Spontaneous onset of premature labour (commonest) o Antepartum haemorrhage o Multiple pregnancy o Infection
§ Chorioamnionitis • Bacterial mechanism: proteases à tissue degradation • Phospholipase A2 + phospholipase C à arachidonic acid à prostaglandins • Toxins à inflammation of decidua + membranes à prostaglandins + cytokines
o Polyhydramnios o Socioeconomic
§ Poverty § Maternal age <20y, >35y § Heavy stressful work § Marital status § Cigarette smoking § Substance abuse
o Obstetric intervention (baby safer outside) § Severe pre-eclampsia § Intrauterine growth restriction § Antepartum haemorrhage
• Factors: o Hydramnios o Multiple pregnancy o Incompetent cervix o Premature rupture of membranes (PROM) o Infection o PMHx preterm delivery
• Chances of survival 34wks = survival at term • Prevention à tx of infection, Mg sulphate + 17-alpha-hydroxyprogesterone caproate • Tx: corticosteroids + tocolysis
o CI >34wks, APH, infection, cervix >5cm o Delays delivery by 48hrs (allows foetal lung surfactant production) o Allows time to transfer/give steroids o May cause pulmonary oedema
• Drug tx for preterm labour (inhibit uterine activity) o B-blockers – inhibit actin-myosin interaction
§ SE: palpitations, tremor, ischaemic arrhythmia, pulmonary oedema, sudden death § Potentially hypokalaemia + hyperglycaemia
o Prostaglandin Synthetase inhibitors § In-utero closure of ductus arteriosus – monitor foetal circulation
o Magnesium sulphate – changes calcium uptake in SMC § Risks: respiratory depression, cardiac arrest, pulmonary oedema, paralysis, tetany,
hypotension, paralytic ileus o Slow CCBs (not licensed during pregnancy in UK) o Corticosteroids – enhancing surfactant production o Oxytocin antagonists
• Assc. increased risk of breech presentation o Delivery à caesarean section (if breech)
Premature rupture of membranes
• Rupture of membranes <37wks • Factors:
o Tensile strength of foetal membranes o Surrounding tissues support o Intra-amniotic fluid pressure
• Causes: o Infection
Obstetrics
o Multiple pregnancy o Polyhydramnios o Smoking
• Usually then à labour (within 48hrs) • Conservative tx: monitoring for S+S infection <36wks • May à chorioamniotitis
Prolonged pregnancy
• 10% pregnancies • Associated with increase in perinatal mortality >42wks • Ass. Increased incidence of meconium • Post-maturity = condition of the infant with characteristic features (signs of IU malnutrition)
o Clinical § Dry, peeling + cracked skin (esp hands + feet) § Absence of vernix caseosa + lanugo (fine hair) § Loss of SC fat § Meconium stained skin
o Complications § Increased perinatal mortality § Intrapartum foetal distress § Increased operative delivery rate § Meconium aspiration
• Mgt: o Routine induction >41wks o Increased monitoring
Induction
• Indications: o Pre-eclampsia o Prolonged pregnancy o Placental insufficiency & IUG Restriction o Antepartum haemorrhage o Rhesus isoimmunisation o DM o CKD
• Bishop’s score used to assess cervix à predicts likely outcome of labour induction o >6 indicated labour, <5 needs cervical ripening
• Methods o Forewater rupture = using finger to separate foetal membranes from lower segment & then ruptured
using instruments o Hindwater rupture = rupture of membranes behind presenting part o Medical induction of labour following amniotomy o Medical induction of labour + cervical ripening
Breech presentation
• Occurs 3% pregnancies (term) o 3 types
§ Frank breech = legs extended along foetal trunk, flexed at hip, extended at knees. Buttock presentation.
§ Flexed breech = legs flexed at hips + knees. Both feet presentation. § Footling breech = One thigh flexed + one extended. Single foot presentation.
• Associated with: o Preterm delivery o Multiple pregnancy o Foetal abnormality
§ Neurological impairment of foetal limbs o Placenta praevia o Uterine abnormalities
• Mgt o External cephalic version @ 38wks – foetal HR monitoring o Elective caesarean section o Criteria for vaginal delivery:
§ Foetal weight 1.5-4kg
Obstetrics
§ Flexed/frank breech Rare presentations
• Face presentation
• Brow presentation • Unstable lie, assc. with:
o High parity o Polyhydramnios o Uterine anomalies o Low-lying placenta
• Mgt of unstable lie: o Exclude fixed causes o Hospitalisation at 37wks o Stabilising induction at term o Be prepared for cord prolapse
Cord prolapse
• Cord prolapse = when any part of cord is in front of/alongside the presenting part • Predisposing factors:
o Multiple pregnancy o Malpresentation o Polyhydramnios
• Anticipate where pp high • Tx:
o Head-knee position – minimises pressure on cord o Urgent c-section
Occipitoposterior posit ion
• 10-20% cephalic presentation • Assc. with: backache, prolonged labour • Tx:
o Adequate analgesia o Syntocinon o C-section o Rotational forceps
Abnormalit ies of uterine action
• 90% primigravidae delivery within 16hrs • Dx partogram • Mgt:
o Pain relief o Fluid replacement o Mobilise if hypotonic uterus o Stimulate w/ oxytocin o Ruptured membranes o Operative delivery if lack of progress/foetal distress
Read up on instrumental delivery i f relevant
Obstetrics
Obstetrics
Multiple pregnancy Prevalence of mult iple pregnancy
• Monozygous twin rates constant o Monozygotic = twins arising from 1 fertilised egg
• Dizygotes rates increasing o Dizygotic = twins derived from 2 fertilised eggs
Determination of chorionicity
• Monochrorionic – always same sex • Dichorionic – same/different sex • Familial factors – dizygotic twins • Increasing age + parity – dizygotic twins • Ovulation induction + IVF
Complications
• Miscarriage • Antepartum haemorrhage • Polyhydramnios • Pre-eclampsia • Preterm labour • Increased perinatal mortality • Foeto-foetal transfusion = syndrome where 1 foetus transfuses the other through interlinked vascular
channels o Donor twin – oliguric, growth restricted + oligohydramnios o Recipient twin – polyhydramnios, risk of hydrops fetalis + cardiomegaly o Tx: serial amnioreduction, selective feticide, laser ablation of communicating vessels
• Conjoined twins • Other congenital abnormalities
Management
Obstetrics
• Treatment of complications • Management of IUG restriction
o USS measurements Management of labour & delivery
• Dependent on presentation o In order:
§ Cephalic/cephalic § Cephalic/breech § Breech/cephalic § Breech/breech
• Previous obstetric history • High caesarean section rates
Complications of labour
• Locked + conjoined twins • Perinatal mortality • Cerebral palsy rates increases
Obstetrics
The puerperium Puerperium = 6wks post completion of 3rd stage of labour Physiological changes
• Uterine involution o Catabolism of muscle fibres. Autolysis + atrophy. o Back to non-pregnant size within 6wks
• Lochial loss • Endometrial regeneration
o Lochia = uterus discharge o Lochia rubra = initial bloody (fresh/altered) discharge for 2-14d
§ Menstruation occurs within 6wks unless lactating o Lochia alba = slight white discharge following rubra
• Reduction of CO • Fluid loss – 2L in 1st week
Endocrine changes
• Oestrogen/progesterone – non-pregnant levels by 7th postnatal day • hCG undetectable 10d
Lactation & breastfeeding
• Colostrum • Milk flow 2-3d • Suckling process • Lactation suppression
o Can give oestrogens – thromboembolic disease risk Psychological changes
• Puerperal depression Puerperal pyrexia
• Genital tract infection • UTI • Breast infection (mastitis) • Wound infection • Thromboembolism
o Thrombophlebitis o Phlebothrombosis
• Perineal damage o Incontinence/urinary retention o Anal sphincter dysfunction
• Breakdown of episiotomy wound
Obstetrics
Psychiatric disorders of childbirth Importance of psychiatr ic disorders
• Substantial morbidity • Effective tx • Adverse consequences • Predict risk • Regular health contact • Prevention
Risk factors for mild postnatal depression
• Young • Single • Short interval • Early deprivation • Chronic life difficulties • Society adversity trend • Lack of confidence • Past psychiatric history • Question TOP index pregnancy • Antenatal admission, non-serious conditions • Life events • Prior social services involvement
Adverse sequelae of postnatal depression
• Immediate: o Physical morbidity o Suicide/infanticide o Prolonged psychiatric morbidity o Social attachments mother-infant o Emotional development
• Later: o Social-cognitive affects in the child o Psychiatric morbidity in the child o Marital breakdown
Risk factors for serious mental i l lness
• Primiparity • Past psychiatric history • FHx psychiatric history
Puerperal psychosis
• Severe affective disorder • 1/3 pt are manic, 2/3 are suffering depressive psychosis • Mgt issues: admission w/ baby • RFx: FHx/personal Hx, emergency c-secion • Abrupt onset (80% in 1st 2 wks) • Vigorous tx • Rapidly changing clinical picture • Delire triste = • Good prognosis
Severe major postnatal depression
• Classical biological syndrome: o Early morning wakening o Mood worse in morning o Impaired appetite, concentration & interests
• Overt guilt/worthlessness o Anomie o Ruminative worry o Anxiety
Obstetrics
• Onset in 1st 2wks: o Postpartum more gradual
• Tx: o Antidepressants/counselling
• 2 peaks of presentation: o 2-4wks o 10-14wks
• Good prognosis • Early presentation often missed (atypical) • Risk 1:2 of next baby
Mild postnatal depression
• ‘Problems with mothering’ • Vulnerable at risk • Insidious onset in 1st week + symptoms of:
o Anxiety o Phobias
• Present 3months-1yr • ‘Understandable’ • Treatment:
o Counselling o Social support
• Unhappy & tearful i.e. depressed Prevention of mental i l lness
• Counsel women with chronic severe mental illness about pregnancy • Manic-depressive illness: consider restarting treatment after delivery • Maintain chronic schizophrenic medication throughout pregnancy • PMHx: puerperal psychosis/severe postnatal depression – close contact in 1st week • Consider prophylaxis post-delivery • Assess all women @ 6wks postnatal check
Psychotropic medication in pregnancy
• Balance risk to foetus of maternal medicine vs. risk to foetus of maternal relapse • Teratogenic:
o Mood stabilisers o Lithium o Carbamazepine o Sodium valproate
• Antidepressents: tapered & preferably stopped before delivery • More info on older drugs • Only use medication in pregnancy if ABSOLUTELY necessary • Close psychiatric + obstetric liaison
Deciding to breastfeed
• Tricyclic antidepressants: YES o Trazadine: NO o Doxepin: NO
• SSRIs: o Fluoxetine: NO o Fluvoxamine, paroxetine + sertraline: probably YES (older babies)
• MAOIs: NO • Lithium: NO • Carbamazepine valproate: YES • Phenothiazine: YES (moderate/oral) NO (high dose) • Atypical antipsychotics: NO • Benzodiazepines, alcohol, cannabis: BEST AVOIDED
Time Action RFx
Booking clinic Full FHx & personal Hx Severe postnatal depression
Obstetrics
Psychiatric disorder Refer to PMHx
Puerperal psychosis Previous serious psych disorder Previous baby, previous loss, infertility Multiple antenatal admissions High anxiety C-section Maternal danger Baby admitted to special care baby unit Maternal readmission Early maternal disturbance Screen for postnatal depression
Antenatal clinic Vigilance Delivery Vigilance Postnatal Vigilance Postnatal examination 6 weeks
