For information about medications in pregnancy, I recommend a comprehensive textbook such as: Drugs in Pregnancy and Lactation, 2015, 10th edition: Gerald G Briggs and Roger K Freeman. Lippincott Williams & Wilkins Publishers.

Mothersafe; the telephone and in person teratology service run from RHW is an excellent resource for drugs and exposures advice.

Phone: 9382 6539 (Sydney Metropolitan Area)
Phone: 1800 647 848 (Non-Metropolitan Area)
Alternatively, the in-depth answers on Micromedex database are very helpful.

MIMS and the A,B,C,D,X categories are not adequate for counselling individual patients



  • Thyroid function in early pregnancy
  • Universal screening is not recommended but is often performed
  • For women with no personal or family history of thyroid disease, an estimate of TSH between 8-10 weeks gestation should be interpreted based on individual laboratory normal ranges
  • Prior to 8 weeks, the normal ranges are closer to non-pregnant levels ie TSH does not fall into the pregnant range immediately.
  • If an abnormal TSH is detected, initial management should follow this algorithim. Subsequent management will depend on individual counselling.


TSH Further tests Treatment Recommend appointment
<0.5 Check free T3 and T4, TPO, TG and Thyroid receptor antibodies Nil Within 4 weeks
2.6-5.0 Check free T3 and T4 TPO TG antibodies Nil Within 4 weeks
2.6-5.0 with PH or FH of thyroid disease Check free T3 and T4, TPO, TG antibodies Commence oroxine 50mcg per day Within 4 weeks
>5.0 Check free T3 and T4, TPO, TG antibodies Commence oroxine 50mcg-75mcg per day Within 2-3 weeks

Assuming a normal range for 8-14 weeks pregnancy of 0.5-2.5Iu/L

  • Women with pre-existing thyroid disease:
    • Hypothyroid:
      • Check FT3, FT4 and TSH at 7-8 weeks gestation and arrange an appointment around this time
      • An increase in thyroxine dose is required for the majority of women
    • Thyrotoxicosis
      • Avoid radio-iodine for 6 months prior to pregnancy
      • Check free T4, free T3 and TSH in early pregnancy and refer within 2-3 weeks.


  • Normal BP in pregnancy is less than 140/90 mm Hg and often much lower
  • A manual sphygmomanometer should be used to measure BP in pregnancy as automated monitors are less reliable
  • New onset hypertension before 20 weeks gestation is almost always chronic hypertension or white coat hypertension
  • New onset hypertension after 20 weeks gestation may be either chronic hypertension or a pregnancy related form of hypertension; either gestational hypertension or pre-eclampsia
  • For women with pre-existing hypertension prior to pregnancy:
    • Refer for preconceptual counselling to set up a management plan for pregnancy and breastfeeding
    • Cease ACEI or angiotensin receptor blockers and diuretics as soon as pregnancy is confirmed
    • Other antihypertensive agents ie beta blockers, calcium antagonists, methyldopa, prazosin, hydralazine may be continued if required but seek specialist advice if needed
    • Arrange review within 2-4 weeks
  • After 20 weeks, all women with BP >140/90 mm Hg need prompt assessment
    • Check urine dipstick; if proteinuria ≥2+, refer for urgent assessment (within 24 hours)
    • Otherwise: check FBC, UEC, LFT, urate, urine protein:creatinine ratio and refer within 1 week
    • Consider commencing antihypertensive treatment whilst awaiting assessment
  • Gestational hypertension and pre-eclampsia can occur for the first time post-partum
    • If BP >140/90 mm Hg within 6 weeks of pregnancy, consider antihypertensive treatment and refer if not settling



Refer for preconceptual counselling to set up a management plan for pregnancy and breastfeeding

  • Pregnancy is associated with a significantly increased risk of thromboembolism
  • Chronic anticoagulation
    • All woman on chronic anticoagulation therapy will need to continue treatment
    • Cease warfarin and NOACs (rivaroxaban, epixaban, dabigatran) as soon possible after confirmation of pregnancy
    • Commence therapeutic LMWH eg enoxaparin 1mg/kg bd
    • Refer for specialist advice as soon as possible
  • Women with a past history of venous or arterial thromboembolic events eg stroke, TIA
    • Refer for specialist advice
    • If in doubt, especially with recurrent episodes, or if referral is delayed, consider commencing prophylactic LMWH eg enoxaparin 40mg sc daily ( VTE) or aspirin 100mg nocte (arterial)
  • Women with known thrombophilia or family history of significant thromboembolism
    • Refer for specialist advice , ideally pre-conception


  • Nausea and vomiting that improves with eating is common in pregnancy
  • Encourage any intake desired but ensure adequate fluids (not necessarily water)
  • Consider simple treatments tabled below
Treatment Dose
Ginger 400mg 1-2 tabs tds
Pyridoxine 25mg tds
Metoclopramide 25mg tds

Hyperemesis Gravidarum:

  • More severe cases of nausea and vomiting in pregnancy may be associated with dehydration, weight loss and electrolyte disturbances
  • Women are often depressed and overwhelmed by this condition but it is not psychosomatic
  • High recurrence risk
  • Refer for preconceptual counselling to set up a management plan for early pregnancy
  • Commence treatment as above
  • Add ondansetron 4mg tablets bd (6-am and 1-2pm)
  • Add doxylamine 6.25-25 mg nocte
  • Treat constipation aggressively
  • Refer early for specialist advice


Pre-existing Type 1, Type 2, Insulin resistance and carbohydrate intolerance

  • Refer for pre-conception counselling and at 6-8 weeks once pregnancy is confirmed
  • Aim for HbA!C < 6-7% prior to pregnancy
  • Recommend high dose folate 5mg/day
  • Tight blood sugar control is required during the first trimester to reduce the risk of congenital malformation during the critical first 10-12 weeks of pregnancy
  • Continue usual treatment including oral hypoglycemics until pregnancy is confirmed but cease at time of positive pregnancy test in all except those with Type 2 diabetes on metformin
  • Most women with pre-existing type 1 or 2 will need insulin in pregnancy

Previous gestational diabetes

  • These women have a 70-80% risk of recurrence, often earlier in their pregnancy
  • Counsel regarding healthy eating [] , appropriate weight gain targets and regular exercise
  • Consider intermittent home BGL monitoring (early morning before breakfast and 1 or 2 hours post prandial) from early pregnancy as an alternative to OGTT if high risk
    • Target BGL: early morning before breakfast <5.0 and post prandial 1 hour <8.0 or 2 hours <7.0 mmol/L
    • If abnormal, assume recurrent GDM and refer (without OGTT)
  • OGTT to be performed at 12-14 weeks and if normal, repeated at 26 weeks
    • Abnormal if F ≥5.0 mmol/l
    • 1 hr ≥10.0 mmol/l
    • 2 hr ≥8.5 mmol/l
  • Refer promptly to diabetes educator and A/Prof Lowe once the diagnosis is confirmed


Suite 5, Level 7
Prince of Wales Private Hospital
Barker Street
Randwick NSW 2031

t:(02) 9650 4957
f:(02) 9650 4903

Email: Rachel Hoskins

Info for Health Professionals - Disclaimer


This website contains general information about certain medical conditions and treatments. The information is not advice, and should not be treated as such. You must not rely on the information on this website as an alternative to medical advice regarding your patient’s condition.

If you have any specific questions about any medical matter please contact A/Prof Lowe or arrange an appointment.