In this episode of the podcast, Penny has a rant about one of her pet peeves – the ever changing due date – and gives lots of tips on how to determine the estimated due date (EDD) with the greatest accuracy.
Take home messages:
The only way to know the exact EDD for certain is an IVF pregnancy with a known implantation date.
The next most accurate method is an ultrasound measurement of crown-rump length between ~7 and 13+6 weeks (or maybe even up to 23 weeks, if you believe the Canadians). Dates based on LMP are fraught with assumptions and risks of error.
Transabdominal measurements are just as good as transvaginal scans at determining the EDD.
The margin of error increases the later the scan is done – about 5 days in first trimester, 7-10 days up to 20 weeks, 2 weeks in late second trimester, and up to 3 weeks in third trimester.
International organisations agree that ultrasound should be offered universally between 8 and 13+6 weeks and an EDD based on first trimester crown-rump length should be the definitive date. Note, however, that in practice, some radiologists will leave the EDD as per the LMP if it’s within 5-7 days.
Offering universal early dating scan reduces the rate of interventions in the post-dates period.
Check for inaccurate dates written on request forms, or typos on reports.
Never use HCG to determine gestational age.
Don’t be fooled into adjusting the due dates based on growth parameters later in pregnancy!
Australasian Society of Ultrasound Medicine recommendations:
Earliest measurement of gestational age in pregnancy should be the definitive assessment
If the first scan is after the first trimester –> if the ultrasound measurements are within one week of EDD as determined by LMP date, the scan confirms the LMP date.
If the first scan is 14 – 20 weeks and differs from the LMP date by more than one week, a new EDD is assigned, if the different measurement parameters are in agreement.
Today on the podcast we pick the brain of Dr Matthew Coates, a psychiatrist with experience in perinatal mental health. We talk about the common dilemmas of antidepressant prescribing in pregnancy and how to pick the post-natal patient with genuine mental illness as well as breastfeeding and neonatal issues. We also take a look at the more serious end of the spectrum of psychosis and mania in pregnancy and the post-partum period.
Take home messages:
Pre-conception planning is important for patients on psychotropic medications.
The ideal choice of antidepressants in pregnancy is the one that works for the patient. SSRIs have been better studied than SNRIs. Dosages may need to be increased in the third trimester.
Use non-drug strategies such as psychological therapies.
Patients with bipolar 1 and psychosis should be jointly managed with a psychiatrist.
Consider the effects of psychotropic medications on the neonate when planning for delivery.
Post-partum psychosis is a psychiatric emergency. Engage perinatal psychiatric services urgently.
We’re back on the podcasting bandwagon, and this episode Penny is joined by self-proclaimed twit and legendary Aussie GP obstetrician, Ewen McPhee (@Fly_texan), to discuss what they learned at the recent RCOG World Congress.
We cover a range of topical issues including:
An update of GDM diagnosis and management
NIPT for aneuploidy screening
The use of progesterone for threatened miscarriage
Pre-term labour – screening and treatment
Menopausal hormone therapy
Fertility, the place of AMH and the legal and ethical dilemmas of fertility preservation
Future therapies for pre-eclampsia
If this has whet your appetite, why not come along to RCOG World Congress 2016 in Birmingham, or RANZCOG 2016 Annual Scientific Meeting in Perth.
We have two special guests on the podcast this week: Paul Jones and Dan Finnigan are Canadian family doctors with extra training in emergency and obstetrics.
The guys have created a mobile obstetric app called “Simply Obstetrics”. Check it out here. In part one of the podcast we discuss the perils of rural and remote obstetrics and how the app can come in handy for those isolated or “occasional” birth attendants.
In part two we get into the meaty clinical topic of episiotomies and protection of the perineum.
Our top take home messages:
Episiotomies should be used selectively not routinely, as the use of routine episiotomy results in increased risk of major sphincter injury
The mediolateral approach is associated with less risk of sphincter injury compared to midline approach
The threshold for cutting an episiotomy should be much lower with instrumental deliveries, particularly forceps (NNT = 7)
We prefer the use of “hands on” technique for delivery, with controlled delivery of the fetal head and warm compresses to the perineum