Endocrinology in pregnancy Flashcards
What hormone will a follicle release?
Oestradiol
What will the corpus luteum release?
Progesterone
When is hCG reelased?
When the ferilised follice (corpus lutem) is implaned
What hormones does the placenta release?
Human placental lactogen (hPL)
Placental progesterone
Placental oestrogens
What will the pituitary release during pregnancy?
Prolactin
When is the peak of LH in the menstrual cycle?
During ovulation - commonly day 14
When is the peak of FHS in the menstrual cycle?
Ovulation - day 14
How long does the luteal phase last?
14 days
How long does the follicular phase last?
14 days but can be very variable
When is the peak of progesterone in the menstrual cycle?
In the luteal phase around day 21
What are the 3 phases of the menstrual cycle?
Menses
Proliferative phase
Secretory phase
What hormones lead to increased insulin resistance in a pregnant woman?
Progesteron
hPL
What can increased insulin resistance lead to?
If predisposed then can lead to gestational diabetes
When does gestational diabetes tend to start?
In the 3rd trimester as the placental hormones are at their highest level
When does foetal organogenesis start?
At 5 weeks
What complications in pregnancy can happen due to gestational diabetes?
Macrosomia - >90th centile, over 4kg
Polyhydraminos
Intrauterine death
What complications in pregnancy can happen due to pre-existing diabetes in pregnancy?
Congenital malformation Prematurity Intra-uterine growth retardation Macrosommia Polyhydraminos Intrauterine death
What complications can occur in the neonate from a diabetic pregnancy?
Respiratory distress - immature lungs
Hypoglycaemia - fits
Hypocalcaemia - fits
What CNS defects are more common in diabetic pregnancies?
Anencephaly
Spina bifida
What skeletal abnormalities are more common in diabetic pregnancies?
Caudal regression syndrome
What genital and GI abnormalities are more common in diabetic pregnancies?
Urteric duplication
UTI
Why does maternal diabetes lead to macrosomia?
Maternal hyperglycaemia
Foetal hyperglycaemia
Foetal hyperinsulinaemia
Results in macrosomia and neonatal hypoglycaemia
Why does foetal hyperinsulinaemia lead to increased growth?
In the 3rd trimester, the foetus produces its own insulin which is a major growth factor
What pre-pregnancy advice would you give to diabetic mothers?
Good sugar control 3 months pre-conception
Limit risk of congenital malformation
What is the advice surrounding folic acid in diabetic mothers?
Folic acid 5mg instead of the 400 micrograms for the geneal pop
What is the advice around eye checks in diabetic mothers?
Regular eye checks (10/20/30 weeks gestation) as there is accelerated retinopathy
What drugs should be stopped during pregnancy for diabetic mothers?
Avoid ACEI and statins
Change tablets to insulin if T2DM
If hypertensive - change to labetalol, nifedipine or methyldopa
What are the aims for blood sugar control in pregnant diabetics?
Pre-meal <4-5.5 mmol/l
2h post meal <6.5-7 mmol/l
What is the management for pregnant diabetics?
Diabetic diet and lifestyle Good blood sugar control Monitor HbA1c Monitor BP Maintain good glucose levels during labour - IV insulin and IV dextrose
What drug treatments for diabetes are approved in pregnancy?
T1: insulin
T2: metformin and insulin
GDM: lifestyle, metformin, may need insulin
When should the blood sugars be checked in a women with diabetes with GDM?
6 weeks post natal fasting glucose or GGT to ensure they have resolution of DM and to ensure they dont have T2DM
What is the risk factor for developing T2DM ifi you have gestational diabetes?
50% after 10-15 years
80% for those who are obese
How can diabetes be prevented after GDM?
Keep weight as low as poss
Healthy diet - low refined surgar, predominant starch, low saturated fat, low energy foods
Aerobic exercise
Annual fasting glucose
What can hypo and hyperthyroidism do to the menstrual cycle?
Anvovulatory cyles - reduced fertility
What happens to the demand for thyroxine during pregnancy?
Maternal thyroxine important for neonatal development (esp CNS)
Increased demand on the thyroid during pregnancy as the plasma protein binding increases
What will happen to the size of the thyroid gland during pregnancy?
Increase in size
Increased T4 production to maintain normal conc
What happens in pregnancy to a women with pre-existing hypothyrodism?
Unable to compensate for increased demand
Increase thyroxin dose by 25 micograms as soon as pregnancy is suspected
Check TFTs monthy for the first 20 weeks then 2 months until term
Average dose is increased by 50% by 20 weeks
What is the target TSH in pregnancy?
<3 mU/I
What are the risks of untreated hypothyrodism in pregnancy?
Increased abortion Preeclamsia Abruption Postpartum haemorrhage Preterm labour Foetal neuropsychological development
What is the link between TSH and hCG?
hCG increases the need for thyroxine therefore supressing TSH
What will the thyroid function tests be like in hyperemesis gravidarum?
hGC HIGH, 50% have a low TSH and a high fT4
What is the hCG effect of thyroid tests in pregnancy?
fT4 increased in 14% of pregnancies
Low TSH (0.1-0.4) of pregnancies
Mimics hyperthyrodism biochemically
What are the signs and symptoms of gestational hCG-associated thyrotoxicosis?
Hyperemesis gravidarum - increased hCG and decreased TSH
Not TRab antibody positive
Resolves by 20 weeks
Only treat if it persists beyond 20 weeks
What effects does hypertyrodism have on conception, pregnancy and labour?
Infertility due to anovulatory cycle
Spontaneous miscarriage
Stillbirth
Thyroid crisis in labour
What effect will maternal hyperthyrodism have on the neonate?
Transient neonatal htyrotoxicosis - thyroid receptor antibodies cross the placenta causing an overactive thyroid in the foetus
What are the symptoms of hyperthyrodism in pregnancy?
N+V
Tachycardia
Warm and sweaty
Lack of wt gain
How should hyperthyrodsim be managed in pregnancy?
Supportive - if hyperemesis it will settle. Graves may also settle during pregnancy
Beta blockers if needed
What is the pharma management of hyperthyrodism in pregnancy?
Low soe anti-thyroid drugs
Propylthiouracil in 1st trimester
Carbimazole in 2/3rd trimester
Why should you never use carbimazole in pregnancy?
Teratogenic - scalp abnormalities, GI abnormalities, chanal and oesophageal atresia
What are the issues with propylthiouracil?
Risk of liver toxicity
When should TRAb antibodies be checked in pregnancy?
3rd trimester
If present should alert neonatologist
What is the treatment if the baby has hyperhyrosidm?
Low does carbimazole until settles - is transient
What is post-partum thyroditis?
Normal thyroid level at delivery but development of thyroditis 6/8 weeks post partum and then 4/6 months of hypothyrodism until it settles at around a year
Why shouldnt carbimazole be given in post-partum thyroditis?
Makes the hypo crash MUCH worse
What blood test should you do in post-natal depression?
Thyroid levels - hypothyrodism can cause depression
What will happen if the post partum mother still needs levothyroxine after 1 year post partum?
Persistent hypothyrodism - likley need levothyroxine lifelong
