Obstetrics - Collated from sources such as Passmed, Zero to Finals, AMBOSS, BMJ best practice PDF

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Collated from sources such as Passmed, Zero to Finals, AMBOSS, BMJ best practice...

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Obstetrics

History 

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Obstetric Hx - Planned? - Natural conception or assisted? - Gravidity - Parity – grand multiparity = >6 pregnancies - EDD  1st day of LMP + 280 days (40 weeks) - Any abnormalities on scans - Growth on scans - Happy with foetal movements? - Rhesus status - Any abnormal blood test results - Any complications e.g. hospital admissions, HTN, pre-eclampsia - If miscarriage, was it spontaneous, medical or surgical? Delivery - Mode of delivery - Gestational age - Complications - Birth weight - Group B Strep swab +/-? Obstetric Hx for previous pregnancies Gynae Hx - Smear Hx - Any gynae surgery e.g. surgical evacuation of uterus - Contraception Medical and Family Hx - DM, HTN, autoimmune conditions - Thrombophilia, clotting disorders, VTE Drug Hx - Anti-epileptics - Anti-hypertensives e.g. ACEi or ARB’s (need to be stopped) - Folic acid supplementing? - Aspirin prophylaxis? - Allergies Social Hx - Smoker/drinker/IVDU - Occupation - Support at home - Siblings/child care issues

Exam      

Hands Radial pulse – higher than norm (80-90) Capp refill Peripheral oedema – some degree is normal, but may be a sign of pre-eclampsia Would do BP ideally Face

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Jaundice – obstetric cholestasis Oedema – pre-eclampsia Conjunctival pallor – anaemia Mention fundoscopy – look for papilloedema seen in pre-eclampsia

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Legs Pedal oedema Varicose veins Reflexes – (PET = hyperreflexia)

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Positioning Early pregnancy  bed elevated to 15-30o Late pregnancy >28 weeks  Left lateral position to avoid IVC compression

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Inspect Abdomen Shape of abdomen – “abdomen is distended, consistent with pregnancy” Any foetal movements? Cutaneous signs of pregnancy: - Linea nigra - Striae gravidarum (recent stretch marks, purple) - Striae albicans (older, silver/white) Symphysis-fundal height >20 weeks should be gestational age in wks +/- 2cm Fundal height: - Umbilicus  20 weeks - Xiphoid process  36 weeks Low measurement (4.5kg) - Maternal high BMI - Multiple pregnancy - Cysts or fibroids - Molar pregnancy

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Fundal palpation – fundal and pelvic grip (find baby’s back)

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Presenting part – face ladies’ feet - Cephalic - Breech

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Foetal lie - Longitudinal – vertical (can be cephalic or breech) - Oblique – diagonal - Transverse – horizontal - ‘ROP’ = right occiput posterior

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Engagement - How many fifths palpable is the head? 0/5 = fully engaged

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Foetal heartbeat Pinard stethoscope or Doppler US Auscultate over anterior shoulder Normal HR = 110-160 bpm

Further investigations:  BP  Urinalysis, checking for proteinuria (pre-eclampsia)  Weight and height measurement  Speculum exam if necessary

Antenatal care   

*If 35 years old managed by a consultant Yolk sac can be seen from 4-5 weeks. The corpus luteum looks like a cyst in the ovary Foetal pole is seen from 7 weeks

10 weeks: Booking scan  Confirm intrauterine, live foetus by seeing foetal pole & foetal heart activity on USS  Multiple pregnancy?  Identify women who will need extra care e.g. renal disease, HIV or HBV, obesity, epilepsy, endocrine disorders, DM, cardiac disease, chronic HTN, recurrent miscarriage  Check blood group and Rhesus status  Screening bloods  Measure mum’s height and weight – calculate BMI  BP and urine dipstick  Urine culture to detect asymptomatic bacteriuria (8-12 wks)  Dating scan using CRL 16 weeks  Discuss screening results  Investigate Hb if 24 weeks it’s a still birth Should feel foetal movements regularly by 24 weeks

25 weeks for Nulliparous women  Additional appointment for new mums  Measure and plot symphysis-fundal height  BP and urine dipstick  Answer any questions 28 weeks

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2nd screening for anaemia and blood group Anti-D prophylaxis 1st dose BP and urine dipstick Symphysis-fundal height Give info on antenatal classes

31 weeks for Nulliparous women  Additional appointment for new mums  BP and urine dipstick  Answer questions  Discuss screening results from 28-week check 34 weeks: Routine check & birth plan  Anti-D prophylaxis 2nd dose  Same as 31 weeks (routine check) 36 weeks: Routine check   

Routine BP/dipstick/measurement Check foetal lie Offer External Cephalic Version (ECV) if breech and nulliparous o 37 wks if multiparous - Can be done in early labour IF membranes are intact - Success rate = 50% (30-80%) - Baby can return to breech position in 100kg or BMI >30 Persistent glycosuria (>2 episodes) Previous stillbirth or unexplained neonatal death Previous gestational diabetes  need OGTT ASAP rather than the normal 24-28wks First degree relative with diabetes Congenital anomaly Previous macrosomic baby >4.5kg Screening is via an oral Glucose Tolerance Test (GTT) at 24-28 weeks’ gestation Fasting glucose >5.6 mmol/L or 2-hour Glucose >7.8 mmol/L = Gestational diabetes Steroids are diabetogenic so take extra care when prescribing for prematurity etc

Mx: o BG maintained between 4-7 mmol/L o Regular glucose monitoring 4x / day: fasting, pre-meal, one-hour post-meal and bedtime Targets for self-monitoring:  Fasting = 5.3  1 hr post-prandial = 7.8  2 hrs post-prandial = 6.4 o o o o o o o o o o

Metformin is the tx of choice for T2DM pt’s and Gestational diabetes pt’s Unless fasting glucose is >7mmol/L at diagnosis, in which case Insulin should be started immediately Glibenclamide is an alternative only if Metformin isn’t tolerated and Insulin is refused Need 5mg of Folic acid and 75mg Aspirin from 12 wks-birth to reduce risk of NT defects and PET Use IV dextrose and Insulin sliding scale during labour to control glucose levels Delivery when on Insulin is via IOL at 37/8 weeks Delivery whilst on Metformin is via IOL at 39 wks Delivery with just diet control can be as close to term as possible To address the high risk of hypoglycaemia at birth, monitoring BG and early feeding are mandatory All women should be seen 6 weeks post-delivery & pre-pregnancy insulin should be re-started if indicated. Breast feeding reduces Insulin requirement so dose may need to be adjusted

Multiple pregnancy

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Identical Monozygotic twins are from one fertilised egg splitting. They’re always same sex Fraternal, aka Dizygotic twins (80%) are two eggs fertilised by two sperm producing genetically unique children. They’re DCDA Monozygotic twins can either by MCMA or DCMA – depends on the day of division of the zygote: o Day 3 division = DCDA o 4-8 = MCDA o 9-13 = MCMA o >13 = conjoined Multiple pregnancy is associated with increased rates of hyperemesis, anaemia, PET, spontaneous miscarriage, malformations, IUGR, prematurity, PPH Factors increasing likelihood of having twins: Higher maternal age Multiparity FHx Ethnicity – black African women have the highest incidence IVF Twin to Twin Transfusion syndrome (TTTS) is seen in 15% of MC twins – where one twin (the ‘donor’) receives less of the placental blood flow than the recipient. It usually occurs mid-pregnancy and detection of TTTS is the main aim of USS between 16-24 weeks (it’s for TTTS to present >26 wks) >24wks the aim of USS is to check for IUGR Gestation for twins is around 37 wks, continuing pregnancy past 37+6 increases risk of still birth For DCDA (37 wks) or MCDA (36 wks) NVD is safe provided: Pregnancy continues past 32 wks uncomplicated The first twin’s presentation is cephalic There’s no major discordance in twin size (EFW discordance >25% CI NVD) All MCMA twins are delivered via LSCS between 32-33+6 wks due to the high risk of cord entanglement

Bleeding in pregnancy  **Any bleeding could be a sensitisation event so remember to check rhesus status and give Anti-D if Rh –‘ve Bleeding Hx:  Volume?  Has it happened before? – repeated episodes indicate praevia  Was it provoked? –after vaginal exam indicates praevia, or post-coital indicates cervical pathology e.g. ectropion or polyp  Is it painful? – indicates abruption Main differentials for early pregnancy: o Implantation bleed – normal o Miscarriage o

Ectopic

Miscarriage    

A miscarriage is the spontaneous loss of a pregnancy before the foetus reaches viability (2 beats) Hyperreflexia Breathlessness Complications of pre-eclampsia include: - Eclampsia  Seizures - HELLP syndrome: Haemolysis, Elevated Liver enzymes, Low platelets - Acute renal failure - IUGR or foetal death

Investigations:  Serial BP monitoring – looking every 15 minutes for an hour  Bloods: FBC – check for platelets, U+E’s, LFT’s, Protein-creatinine ratio (PCR) – to confirm proteinuria

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MSU for proteinuria CTG and ask about foetal movements

Mx:  Identify women at high risk of developing pre-eclampsia early and give prophylactic Aspirin 75-150mg from 12 weeks – birth  High risk = 1 of the ‘high risk’ factors or at least 2 of the moderate factors High risk: o Past pregnancy with pre-eclampsia o CKD o Chronic HTN o Thrombophilia o Auto-immune disease e.g. SLE or APLS o DM Moderate risk: o Primigravidae

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o >40 years o FHx of pre-eclampsia o BMI >35 o Multiple pregnancy or molar pregnancy Urine dipstick and monitor BP at every antenatal visit The mainstay of management is delivery, which cures PET or eclampsia If likely to need delivery 36 weeks IOL is used and delivery is usually via LSCS MgSO4 is used to prevent seizures, and continued for 48hrs post-partum or 24 hrs after the last seizure as 40% of seizures occur post-partum - Can’t use MgSO4 alongside Nifedipine as there’s a risk of extreme Hypotension - Need to monitor urine output whilst on MgSO4 as its excreted by the kidneys, so dose needs to be reduced if there’s oliguria If seizures persist in Eclampsia, use Diazepam to control them -

Ergometrine, an oxytocic drug sometimes used in the 3rd stage of labour, cannot be used in PET pt’s as it exacerbates HTN

hCG      

Produced by syncytiotrophoblasts then the placenta Promotes maintenance of the corpus luteum which produces Progesterone Can be detected via blood test at conception + 10 days, or urine test 12-14 days after conception >25 mIU/mL = pregnant (1500 iu/L pregnancy should be identifiable by transvaginal USS

Low hCG: o Miscarriage – levels return to non-pregnant range after 4-6 weeks o Ectopic High hCG: o Molar pregnancy (aka hydatidiform moles)

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Multiple pregnancy Tumour marker in non-pregnant people e.g. Seminoma, choriocarcinoma, teratoma High levels of hCG stimulates the Thyroid to produce T3 and T4, which negatively feedback to reduce TSH levels  high thyroxine, low TSH can be seen

Molar pregnancy       

Hydatidiform mole = abnormality of early trophoblast development Complete mole  formed from paternal genetic material Partial mole  shows a foetus as part of the same conception More common in Asian population Can see exaggerated sx of pregnancy e.g. Hyperemesis gravidarum from the high hCG Painless vaginal bleeding Gestational hypertension Big uterine size for gestational age Diagnosed on USS – grape-like vesicles – ‘snow storm appearance’, missing the foetal pole in a complete mole Complications are haemorrhage or malignant change into a choriocarcinoma

Mx:  Surgical evacuation of the uterus  Follow up with weekly hCG tests till levels normalise  If hCG is still high after 10 weeks  specialist care  Advise not to become pregnant again for up to 1 year after, due to the increased risk of choriocarcinoma Hyperemesis gravidarum      1. 2. 3.    

Most common between 8-12 wks and can persist up to 20 wks Related to high beta hCG levels Biggest risk factor = multiple pregnancy Other associations are trophoblastic disease, hyperthyroidism, nulliparity and obesity Smoking decreases incidence of hyperemesis In order to diagnose the following are needed: 5% pre-pregnancy weight loss Dehydration Electrolyte imbalance Ketones can be present in urine, indicating dehydration Hyponatraemia, Hypochloraemia and Hypokalaemia can be seen with a metabolic alkalosis due to loss of stomach acid Pregnancy Unique Quantification of Emesis (PUQE) can be used to classify the severity of nausea and vomiting of pregnancy (NVP) Wernicke’s encephalopathy is a complication of severe hyperemesis, px with diplopia and ataxia

Mx: o Antihistamines  promethazine or cyclizine - Ondansetron and Metoclopramide are 2nd line o If dehydrated may need IV fluids o If Wernicke’s has developed  IV Vit B and C (Pabrinex)

Amniotic Fluid

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Aka ‘liquor’ Present from the formation of the gestational sac at around 4 weeks Consists of maternal plasma and foetal urine It’s absorbed via foetal swallowing or absorption by the foetal bowel Polyhydramnios is too much amniotic fluid - >8cm pool depth on USS Oligohydramnios is too little amniotic fluid - 35 weeks IOL is used to deliver  If it’s caused by foetal anaemia, blood transfusion into the umbilical vein at cordocentesis is used – this will reduce hydrops fetalis Oligohydramnios  o o o o o o o

Causes of Oligohydramnios: Things which impede foetal urine secretion, as this is the main component of amniotic fluid past 12 wks e.g. Rupture of membranes NSAID or ACEi use Foetal renal problems e.g. agenesis, dysplasia or cystic kidneys Foetal hypoxia – because other systems are prioritised in an emergency situation over the kidneys IUGR Pre-eclampsia

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Post-term gestation It’s a marker of a high-risk pregnancy – can result in IUGR, foetal asphyxia or intrauterine death Less fluid means less room in the gestational sac and therefore less foetal movements  fixed flexion deformities. Reduced foetal breathing movements  Lung hypoplasia – the physical appearance of a baby with pulmonary hypoplasia is Potter’s syndrome

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Mx:  Exclude foetal anomalies, IUGR, ROM  Supportive measures until delivery is possible Amniotic Fluid Embolism 

When amniotic fluid gains access to circulation and is carried to the lung

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Usually during labour but can be immediately post-partum Lungs have an anaphylactic type reaction  vasoconstriction and increase in pulmonary arterial pressure, triggering the compliment cascade and leakage of fluid into intravascular spaces Linked with IOL and high maternal age Causes Hypoxia and Left ventricular failure Diagnosed from a triad of features: 1. Collapse – production of pink, frothy sputum 2. Cyanosis 3. DIC Other sx: Sudden breathlessness Tachycardia Hypotensive Chills or sweating Convulsions occur in 20% Mortality is 85%

Mx:  ABCDE  Mx left ventricular failure with vasopressor therapy e.g. Dopamine or Dobutamine  Mx DIC with transfusions of red cells, platelets and FFP with haematologist advice

Liver abnormalities in pregnancy   

There’s increased Hepatic production of clotting factors during pregnancy, increasing risk of VTE Obstetric Cholestasis is the most common Liver abnormality in pregnancy Others include HELLP syndrome and AFLP

Obstetric Cholestasis    

Widespread pruritis in absence of rash – esp involving palms of hands and soles of the feet + Abnormal LFT’s and/or raised bile acids Raised bilirubin is seen in >90% of cases If there’s pruritis with normal LFT’s, they should be repeated every 2 weeks for change Look for raised LFT’s above normal limit for pregnancy:

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Other evidence of cholestasis e.g. pale stool, dark urine Risk factors incl previous hx of obstetric cholestasis, FHx, multiple pregnancy, Hep C or Gallstones Increases risk of premature birth

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Resolves after birth – measure LFT’s after 10 days post-partum (because they increase normally in the first 10 days of puerperium) LFT’s should be monitored weekly until delivery

Mx: o No specific management o Topical emollients o Ursodeoxycholic acid – reduces elevated ALP by encouraging bile flow o Usually there’s IOL at 37 wks due to risk of still birth with prolonged pregnancy Acute fatty Liver of Pregnancy (AFLP)         

Rare disorder where mum or foetus has a genetic disorder causing defective beta-oxidation of fatty acids, causing fat to accumulate in the Liver, Kidney or placenta Usually diagnosed late in pregnancy or post-delivery Affects multiple pregnancies more than single pregnancies and male foetus > female Severe disease can cause PET Sx: N+V Abdominal or epigastric pain Excessive fatigue LOA Jaundice Usually diagnosed late due to its rarity and non-specific sx Investigations: Abnormal clotting ALT usually >500 u/l Increased serum Ammonia Hypoglycaemia High serum uric acid In comparison to HELLP, AFLP is more of a clotting problem than a platelet problem and BP isn’t affected as much Once established, mx is with delivery via LSCS

Rashes in pregnancy

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Atopic eruption of pregnancy (AEP): Aka eczema in pregnancy, prurigo, pruritic folliculitis, popular dermatoses >70% occurs before the 3rd trimester Can be an exacerbation of pre-existing atopic dermatitis e.g. eczema Dry skin with: Rough erythematous patches (Eczematous type  E-type AEP) on face, neck, elbows and back of knees Or itchy bumps (Prurigo  P-type AEP) across abdomen, extensor surfaces of arms and legs Usually controlled with moisturisers and steroid creams e.g. Hydrocortisone No adverse effects to pregnancy Polymorphic eruption of pregnancy (PEP):

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Pruritis with erythematous, polymorphous papules which can form plaques Starting on the abdomen then moving to buttocks/thighs with periumbilical sparing Regular emollients + topical steroid + oral anti-histamine e.g. Chlorphenamine + antipruritic e.g. Menthol can be used Crusting/scaling is seen in 6 wks post-partum If there’s inadequate response oral steroids can be used short-term No adverse effects to pregnancy

Pemphigoid gestationis (PG):  Burning sensation and pruritis, followed by periumbilical urticarial papules coalescing into plaques  Causes a widespread bullous eruption, affecting the face in 10% of cases  Severe PG is early onset and blisters develop  Associated with premature labour, and small babies due to placental failure  Mild cases can be tx with topical steroids and oral anti-histamines  Majority of cases need oral steroids  Can improve if tx during pregnancy but will usually recur at delivery or when menstruation restarts  Breastfeeding reduces duration of post-partum PG  Refractory PG postpartum can be tx with Dapsone or Cyclophosphamide  10% of babies develop transient blisters from maternal transfer of IgG antibodies

Infection in pregnancy    

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Chorioamnionitis UTI Candida Group B Strep (GBS) - Can be px on one swab but not on another - Swabs offered at 35-37 weeks - 50% mortality after pneumonia - Having a previous pregnancy with GBS +’ve swab predisposes to another - If GBS +’ve early on in pregnancy, tx with intrapartum IV Benzylpenicillin only - If mum has a hx of a previous pregnancy where baby developed GBS infection post-birth, give prophylactic intrapartum Abx Endometritis

Chorioamnionitis        -

Chorioamnionitis is an intrauterine infection of the placenta and amniotic fluid which can trigger...