Antenatal Problems 1 Flashcards
What is hyperemesis gravidarum?
Excessive vomiting in pregnancy causing severe dehydration, weight loss or electrolyte disturbance / ketosis
What are some risk factors for hyperemesis gravidarum?
- Multiple pregnancies
- Molar pregnancies
Due to higher levels of hCG
What are some signs/symptoms of hyperemesis gravidarum?
Usually 1st trimester
- Vomiting
- Weight loss
- Muscle wasting
- Dehydration
- Ptyalism (inability to swallow saliva)
- Hypovolaemia
- Electrolyte imbalance
- Behaviour disorders
- Haematemesis (mallory-weirs tears)
What are some maternal complications of hyperemesis gravidarum?
- Liver and renal failure
- Hyponatraemia and rapid reversal of hyponatraemia leading to central pontine myelinosis
- Thiamie deficiency can lead to Wernicke’s encephalopathy
- Can be fatal if untreated
What are some fetal complications of hyperemesis gravidarum?
- IUGR
- Fetal death in cases of Wernicke’s encephalopathy
What investigations are done in hyperemesis gravidarum?
- Urinalysis = detect ketones
- MSU to exclude UTI
- FBC = raised haemaocrit
- U&Es to exclude hypokalaemia or hyponatraemia
- LFTs = transaminases may be abnormal and albumin may be low
- US to diagnose multiple pregnancies or a molar pregnancy
How common is hyperemesis gravidarum?
Rare (0.1-1%)
Ddx of hyperemesis gravidarum?
- GI cause eg gastroenteritis / ileus
- Metabolic cause eg diabetic keoacidosis
- Neurological cause eg migraine
What is the treatment hyperemesis gravidarum?
- Admit if not tolerating oral fluids
- IV fluids (NaCl or Hartmanns but avoid dextrose containing fluids as can precipitate Wernickes encephalopathy)
- Daily U&Es (replace K+ if needed)
- NBM for 24hrs then introduce light diet as tolerated
- Antiemetics if IV fluids and electrolyte treatment not helping:
= metoclopramide 10mg/8hr PO/IM/IV OR = cyclizine 50mg/8hr PO/IM/IV OR = Prochloperzaine 12.5mg IM/IV TDS or 5mg PO TDS
- Thiamine (either thiamine hydrochloride 25-50mg PO TDS or thiamine 100mg IV infusion weekly)
- If vomitng unresponsive to fluids and antiemetic, consider a trial of corticosteroids:
= prednisolone 40-50mg PO daily in divided doses
OR
= hydrocortisone 100mg/12hr IV
- May need psychological support
What is SGA?
Small for gestational age = an infant born with a birth weight less than 10th percentile
Severe SGA = less than 3rd centile
Can either be constitutionally small or IUGR
What are some intrinsic factors affecting fetal growth?
Maternal factors:
- Maternal height and weight
- Parity (nulliparity smaller)
- Ethnic group (asian smaller vs Caucasian or Afro-carribean)
Fetal factors:
- Sex (F smaller)
- Multiple pregnancy
- Genes/inherited conditions
What are some extrinsic factors affecting fetal growth?
Maternal:
- Social class
- Nutritional status
- Altitude (lower oxygen = smaller baby)
- Pre-existing disease
- Pregnancy-related disease eg DM/HTN
Fetal - Nutrition = most common problem is antiphospholipid syndrome - Teratogens - Infective = viral: rubella, CMV, Hep A, B = protozoan: toxoplasmosa Others = listeria, syphilis
What are the risks of SGA?
Inc risk:
- Cerebral palsy
- Preterm delivery (iatrogenic and spontaneous)
- Maternal risk greater as pre-eclampsia may exist and CS is more often used
- May be reduced fetal movements
How may SGA present?
- Serial measurements of symphysis fundal height may be reduced or slow down
What investigations should be done for SGA?
- USS makes diagnosis = gestation most accurately determined by USS before 20wk as assumption all foetuses are similar size until that point.
Natural variation in size after this point makes accurate dating difficult and estimate required from menstrual dates
- BP and urinalysis for pre-eclampsia
- To determine which SGA are IUGR = serial USS and umbilical artery doppler
- Infection or chromosomal abnormalities are investigated using fetal blood sampling or amniocentesis
- CTG only abnormal when severe compromise of fetal distress is present
What are the most reliable measurements between:
8-10 weeks
16-20 weeks
8-10 weeks = crown-rump length
16-20 weeks = biparietal diameter
How should SGA be managed?
- Fortnightly growth checks
- The small but consistently growing fetus with normal umbilical artery doppler values does not need intervention
If fetal compromise at term:
- SGA with abnormal doppler values should be delivered beyond 36wk by induction / CS
What is LGA?
Large for gestational age = macrocosmic
Excessive intrauterine growth beyond a specific threshold regardless of gestiantional age. Usually >4000 - 4500g (above 95th percentile)
(approx 1.7% babies)
What are some causes of LGA?
- Gestational DM (most common)
- Gestational trophoblastic disease
- Fetal abnormality
- Intrauterine infection
- Constitutional
- Excessive maternal weight gain during pregnancy can increase fetal weight
How does gestational DM increase fetal weight?
Mother’s increased blood glucose circulates to the baby which in response produces insulin = fetal pancreatic cell hyperplasia leads to hyperinsulinaemia and fat deposition
What is polyhydramnios?
Increased liquor (increased amniotic fluid)
What must normal in order for an LGA to be considered constitutional?
- Normal maternal blood glucose
- Normal placenta
- Normal liquor volume
What are some risks of LGA?
- Infants at greater risk of perinatal morbidity and long term metabolic complications
- Dystocia (obstructed labour) esp shoulder dystocia
- Birth trauma (perineal tearing, blood loss or damage to coccyx
- Glucose regulation problems:
1) hypoglycaemia of baby after delivery
2) Inc incidence of birth defects
3) Resp distress - Left colon syndrome = self-limiting condition where temporary bowel obstruction occurs
- Hyperbilirubinaemia
What can shoulder distocia cause?
May result in the collar bone being broken or damage to brachial plexus
What investigations should be done for LGA?
- Glucose tolerance test (check for gestational DM)
- If polyhydraminos is found in the absence of gestational DM, fetal infection may be cause so check IgM and IgG to toxoplasma, rubella, CMV and herpes
- USS
- CTG
- Umbilical artery doppler not useful unless pre-eclampsia or IUGR develop
What is the management of LGA?
- Position adjustment during birth to reduce need for episiotomy
- Induction may be required esp if gestational DM
What is prolonged pregnancy?
Pregnancy that exceeds >42wks gestation (294 days)
What happens beyond 41 weeks?
Placental function may decline, reducing supply of oxygen and nutrients to fetus
Increased risk of meconium aspiration and neonatal hypoglycaemia
How common is prolonged pregnancy?
Common (3-10%)
Recognised cause of increased morbidity and mortality
What are some risk factors for prolonged pregnancy?
- One previous prolonged pregnancy = 30% risk of another
- History of two = 40% risk of another
When are EDD unreliable?
- Uncertainty of LMP
- Irregular periods
- Recent use of COCP
- Contraception during lactational amenorrhoea
What are some risks of prolonged pregnancy?
- Increased risk of intrapartum and early neonatal death
- Meconium aspiration and assisted ventilation
- Oligohydraminos
- Macrosomia, shoulder dystocia and fetal injury
- Cephalhaematoma
- Fetal distress in labour
- Neonatal hypothermia, hypoglycaemia, polycythaemia and growth restriction
What interventions may be done in prolonged pregnancy?
- Induction of labour
- Operative delivery
What investigations should be done in prolonged labour?
Confirm EDD (most accurate is 1st trimester USS)
Assess RF which may be an indicator to induce close to EDD:
- Pre-eclampsia
- DM
- Antepartum haemorrhage
- IUGR associated with placental insufficiency
Fetal monitoring:
- USS assessment of growth and amniotic fluid volume
- CTG after 42wk
- Report reduced fetal movements
How should prolonged pregnancy be managed?
Offer ‘stretch and sweep’ at 41wks
- During internal examination, sweep a finger around the cervix
- This should separate membranes of amniotic sac from the cervix which will stimulate prostaglandin release which may kick-start labour
Offer IOL between 41-42wks:
- Reduce perinatal mortality and risk of CS
What is a cephalhematoma?
One of the most common cranial injuries that an infant may suffer esp during a forceps-assisted delivery or vacuum extraction. Can result from prolonged labour
= Swelling of an infants scalp as a result of haemorrhaging or collection of blood between infant’s skull, most commonly parietal or occipital bone and periosteum (a tough thin tissue that surrounds the bone)
Goes away weeks-months