MEDICAL DISORDERS OF PREGNANCY

MAC HILL

MHIL0004@STUDENT.MONASH.EDU

KEY TOPICS TO COVER OTHERS TO KNOW OF

• Hypertension and pre-eclampsia
• Diabetes
• Pre-existing
• Gestational(GDM)
• Nausea, vomiting and hyperemesis gravidarum
• SGA/IUGR

• Management of various STIs
• Intrahepatic cholestasis of pregnancy

BP>140/90 and pregnant

Other organ involvement

No other organ involvement

Pre-eclampsia

Eclampsia

Chronic hypertension

Gestational hypertension

BP only or other issues?

Gestation

Seizures

(+HELLP syndrome)

DEFINITIONS – NO OTHER ORGAN INVOLVEMENT

• Chronic hypertension – BP>140/90 detected before pregnancy or at <20/40
• Gestational hypertension – BP>140/90 first detected at >20/40
• These tend to be more benign and less likely to have severe risks to the mother or baby, so treatment is only definitely indicated if BP≥160/110
• Severity can be classified as below:

DEFINITIONS – WITH ORGAN INVOLVEMENT

• Pre-eclampsia* – BP>140/90 at >20 weeks + ≥1 of:
• Proteinuria
• Renal involvement e.g. high creatinine
• Liver involvement e.g. high ALT/AST, RUQ pain
• Neurological signs/symptoms e.g. clonus, hyperreflexia, visual changes, headache
• Haematological changes e.g. DIC, low plt
• Uteroplacental dysfunction e.g. IUGR
• Eclampsia – BP>140/90 with onset of seizures or coma
• HELLP syndrome – Hypertension, Elevated Liver enzymes, Low Platelets

*if <20/40 with pre-eclampsia criteria, categorised as early pre-eclampsia

PRE-ECLAMPSIA

• Thought to be a disease of abnormal placentation leading to
• Vasoconstriction
• Platelet activation with local(rarely disseminated) intravascular coagulation
• Endothelial dysfunction
• Blood flow is impaired through the placenta(and hence fetus) and to the maternal kidneys, liver and brain

ASSESSMENT OF THE HYPERTENSIVE PATIENT

• History
• Gestation
• Pre-existing hypertension
• Headache
• Vision changes
• Pulmonary/peripheral oedema
• Epigastric/RUQ pain
• N+V
• Oliguria
• RFM or concerns about fetal wellbeing

EXAM AND INVESTIGATIONS

• Exam
• Check BP again
• Look for oedema
• Listen to chest for APO
• Palpate for RUQ tenderness
• SFH if appropriate for gestation
• UMN signs
• Clonus
• Hyperreflexia

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• Investigations
• Urine for proteinuria and PCR
• Pre-eclampsia screening bloods
• FBE
• UEC
• LFT
• Uric acid
• ±Coags e.g. with abnormal LFTs, falling Hb, low platelets
• ±increased US scans and Dopplers

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MANAGEMENT OVERVIEW

• Varies depending on the type of hypertension
• Especially monitoring and frequency of review
• Aim systolic BP 130-140 to avoid maternal hypotension + fetal compromise
• Monitor mum and baby for progression, whether from benign hypertension to pre-eclampsia or for harm to fetus e.g. IUGR

• Be aware of when you need to consider early delivery to keep mum or baby safe
• Gestation >37 weeks
• Uncontrolled hypertension
• Organ dysfunction(renal, hepatic, haematological)
• Neurological complications including eclampsia
• Pulmonary oedema
• Placental abruption
• Concerns about fetus e.g. RFM, non-reassuring CTG

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MONITORING

MAINTENANCE ANTIHYPERTENSIVE AGENTS

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EMERGENCY MANAGEMENT OF PRE-ECLAMPSIA

• Needed if women have a BP≥160/110 or progress to eclampsia, aiming to stabilise the mother and reduce BP to 130-140/80-90

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NAUSEA, VOMITING AND HYPEREMESIS GRAVIDARUM

DEGREES OF SEVERITY

• Morning sickness with nausea and vomiting is common
• Up to 75% of all pregnancies involve some degree of N+V
• HEG is seen in <1% of all pregnancies and is defined as excessive N+V preventing fluid and food intake, in turn split into 3 tiers
• No volume depletion
• Volume depletion and electrolyte imbalances
• Volume depletion, electrolyte imbalances, ketosis and >5% weight loss

MECHANISM AND EFFECTS OF HEG

• Increasing levels of beta-hCG are thought to have a role, and beta-hCG rises at its greatest rates in early pregnancy
• Hence HEG is mainly seen between weeks 5 and 16 of pregnancy
• Symptoms usually settle after the first trimester
• Inability to contain intake leads to
• Hypokalaemia
• Hypochloraemia and acidosis
• Hyponatraemia

DIAGNOSIS

• Requires exclusion of other causes
• GIT e.g. cholecystitis, gastro
• Neurological e.g. migraines
• Genitourinary e.g. UTI/pyelo
• Metabolic disease e.g. hyperthyroidism
• Psychological e.g. eating disorders
• Molar pregnancy

• History and exam consistent with hypovolaemia ±ketosis if severe
• Investigations exclude other diseases and assess volume effects
• Urine MCS
• FBE
• UEC given ?volume depletion
• TFTs
• Serum beta-hCG and pelvic US ?molar
• ±other as needed e.g. biliary US, thiamine if protracted

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Hydration Status

Well-hydrated

Dehydrated, not tolerating oral intake, ketotic

• Conservative management including
• Avoiding specific foods/odours
• Small frequent meals
• Ginger, B6, acupressure, whatever works for them
• Antiemetics
• First-line includes: prochlorperazine, doxylamine, promethazine or metoclopramide
• If these fail, chlorpromazine
• If that fails, ondansetron

• Admission to hospital for IV rehydration with NaCl and electrolyte replacement
• ±Dietitian referral if severe e.g. losing weight, refractory, considering NGT
• Vitamin supplementation, including B1 if protracted to prevent WKE
• Parenteral antiemetics
• Same as the first-line for conservative management, but swap doxylamine for ondansetron
• If ongoing, hydrocortisone IV, then oral prednisolone

DIABETES IN PREGNANCY

WHY DO WE CARE?

• Any diabetes in pregnancy increases the risk of many adverse outcomes
• The better the glycaemic control is before and during pregnancy, the lower the risk is to the mother and the fetus

DETECTING GDM OR OVERT DIABETES

• We screen for GDM universally at 24-28 weeks gestation with the OGTT
• If high-risk, screening is then first performed at the booking visit
• Random BSLs for all women at booking

• High-risk groups
• PCOS
• Obese(BMI>35)
• Past GDM
• Past macrosomia
• Family history of GDM or overt DM
• Age>40 years
• Steroid/antipsychotic use

DIABETES IN PREGNANCY – ANTENATAL CARE

• May be manageable on diet and exercise alone or require medication
• Only insulin and metformin can be used as hypoglycaemics in pregnancy, usually basal-bolus
• HbA1c is measured at the first visit and then every 4-6 weeks

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• Other key interventions
• See relevant specialists(eye, renal etc)
• Increased folate dose(2.5-5mg)
• Diabetes education e.g. nurse educator, dietitian review to help count carbs
• Monitor BSLs at least 4x/day
• Usual antenatal care otherwise e.g. normal bloods, PET screening etc

MATERNAL AND FETAL MONITORING

DELIVERY TIMING AND INTRAPARTUM MANAGEMENT

• Aim to maintain BSLs during labour between 4-7mmol/L
• Achieved using a SC insulin sliding scale every 2-4 hours
• IV insulin infusion + dextrose if control is poor on SC alone
• Can usually deliver vaginally, may recommend elective C/S if the baby is macrosomic(>4500g)

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POSTPARTUM AND FOLLOW-UP

• Pre-existing DM
• Monitor baby for hypoglycaemia
• T1DM usually returns to their antepartum regimen at a lower dose
• T2DM on OHGs can usually stay on these, mainly metformin
• For follow-up, these women need standard DM management e.g. eye checks, glycaemic control monitoring

• Gestational DM
• Monitor baby for hypoglycaemia
• GDM requiring medication should have their BSLs monitored for 48 hours
• GDM without medication usually doesn’t need ongoing monitoring
• For follow-up, ensure they don’t have ongoing hyperglycaemia/DM with an OGTT at 6 weeks post-partum

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FGR AND SGA

A DISTINCTION BETWEEN FGR/IUGR AND SGA

• The names tell you what you need to know
• A baby which is pretty small is SGA as long as nothing else bad is happening
• A baby which has had a pathological process restrict its growth has had FGR
• May be environmental(e.g. placental), fetal or maternal issues
• A small baby is one with EFW or AC<10^th centile on US scans
• Severe SGA/IUGR is when either of these is below the 3^rd centile
• NB SFH can be used as a clinical marker but is not as good as US scans

RISK FACTORS/CAUSES

• Causes external to the fetus cause asymmetric FGR as the fetus, usually associated with uteroplacental insufficiency
• Intrinsic causes lead to symmetrical FGR as the fetus is uniformly affected

SURVEILLANCE IF AT RISK

• Minor risk factors
• UA Doppler at 20-22 week morph scan
• If abnormal UA, serial US at 28, 32 and 36 weeks
• If normal UA, consider another US at 34 weeks
• If the fetal scan becomes abnormal, manage as for SGA/FGR

• Major risk factors
• Serial US at 28, 32 and 36 weeks
• If normal serial US, assess vessels(UA and MCA), EFW/AC and AFI every 4 weeks
• If abnormal at any point, manage as for SGA/FGR

FETAL WELLBEING

• Vessels can be assessed for pressure index, changes from normal suggest placental insufficiency
• Umbilical artery(UA)
• Normally has low pressure as the placenta should have low resistance
• High pressure can lead to A/REDV
• Middle cerebral artery(MCA)
• Normally high resistance, resistance drops if hypoxic to compensate
• Ductus venosus(DV)
• Dilates to bypass liver, taking blood straight to the IVC, if hypoxic

OTHER SCANS

• US biometry is basically measuring the fetus, assess HC, AC, BPD and FL to calculate EFW
• Falling AC and increasing HC:AC ratio suggest poor supply to the baby and asymmetry
• Growth scans like this should be performed serially to assess for falling centiles, ≥2 weekly
• Amniotic fluid index(AFI) assesses fluid around the baby
• Interested in oligohydramnios as a sign that there’s inadequate renal perfusion due to redistribution of blood supply to the brain/vasoconstriction/inadequate supply again
• Biophysical profile monitors fetal behaviour and movements

ASSESSMENT FOR FGR/SGA

• The following is if there’s no particular risk of SGA already noted
• Increased monitoring is required in women with more risk factors
• If difficult to assess SFH (e.g. large fibroids, twins, BMI>35), use serial USS for fetal growth and wellbeing
• Initial at 28 weeks, repeat at 34-36 weeks

WHAT NOW?

MCQS

MCQ 1

A 29 year old G1P0 lady presents for a routine antenatal visit at 25 weeks. On exam, she is noted to have a blood pressure of 145/97. She denies any other symptoms and has only trace protein on urine dipstick. All blood tests including FBE , LFTs and coagulation profile are normal. Which of the following options is the least appropriate for her ongoing management?

A. 2 weekly US scans for fetal growth and vessels

B. Screening for proteinuria at future antenatal visits

C. Pre-eclampsia screening bloods every 4 weeks

D. Start oral labetalol

E. Counselling on the signs and symptoms of pre-eclampsia

MCQ 2

A 35 year old G2P1 with no past history of diabetes is found to have a fasting BSL of 6mmol/L(normal <5) but normal 1 and 2 hour BSLs at her screening OGTT at 26 weeks. Which of the following is true?

A. This patient does not have diabetes and can be managed as normal

B. This patient does not have diabetes but must be closely monitored for GDM

C. This patient is at an increased risk of overt diabetes in future

D. This patient has gestational diabetes and will need to deliver by C/S

E. This patient has gestational diabetes and will be on insulin until post-delivery

MCQ 3

A 24 year old G3P1 is referred for fetal growth scan and Dopplers at 31 weeks’ gestation following a measured SFH of 27cm, only 1cm larger than her previous measurement at 26 weeks. Her last scan was at 22 weeks and previous US scans showed adequate interval growth with no anatomical abnormalities. Her newest results show:

-Head circumference on the 15^th centile(down from 40^th)

-Abdominal circumference on the 3^rd centile(down from 35^th)

-UA PI is on the 96^th centile without UA AREDV, MCA PI is on the 4^th centile and the CPR is on the 3^rd centile.

Oligohydramnios is also noted. Which of the following is true?

A. An immediate C/S should be performed

B. This fetus is SGA and can be managed as a normal pregnancy with a small fetus

C. These results are likely to be evidence of fetal infection

D. These results suggest asymmetric FGR and induction of labour should now be considered

E. A possible cause for this change is pre-eclampsia

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KEY RESOURCES

• bettersafercare.vic.gov.au – a few guidelines about various conditions with flowcharts
• PROMPT – the source of all truth
• RANZCOG guidelines
• Obstetrics and Gynaecology: An Evidence-Based Guide(textbook)
• Royal Women’s Hospital guidelines on pre-existing DM in pregnancy