Module 2: Antenatal risk selection

One of the most important aims of antenatal care is to detect and treat any conditions which may threaten the wellbeing of the mother or her baby.  As we have discussed, antenatal screening for increased risk of adverse outcomes is important and we use to reduce the risk of complications to the mother or fetus if possible.

Of course, for some women and their babies, it would be even better if they had pre-pregnancy advice. Fetal abnormalities can be reduced by pre-pregnancy treatment with folic acid and achieving good glycaemic control for diabetic women before a pregnancy and also by changing medications where women are using teratogenic drugs such as some epilepsy treatments.  

However in New Zealand approximately 50% of pregnancies are unplanned so pre-pregnancy risk reduction is not optimised. We have already discussed the importance of a booking visit, which allows screening to take place and risk factors to be identifed early. In some cases, advice and treatment at this early stage will increase the chance of a healthy pregnancy. 

There are two components to risk selection:

1. the risk factor

   1. modifiable (eg: smoking)

   2. non-modifiable (eg: age, ethnicity)

2. the adverse outcome that the risk factor increases the risk of (eg: stillbirth, pre-eclampsia, preterm birth)

Once you have completed an assessment of a pregnant women, you will be able to list risk factors, and identify the adverse outcomes that the risk factors could contribute to. The duty of antenatal care providers is to inform pregnant women of their risk factors and to modify the risk or encourage the woman to modifiy the risk if possible. A major area of research in obstetrics is risk reduction, and this research has led to actions that reduce risk such as prescribing aspirin to women whose pregnancy is at increased risk of either pre-eclampsia or an small for gestational age (SGA) infant.

In this section we will look first at some risk factors (smoking, drugs, alcohol, domestic violence, obesity, medical conditions) and then some complex adverse outcomes (diabetes, SGA, pre-eclampsia, venous thrombo-embolism (VTE), spontaneous pre-term birth, and still birth) and some ways that the risk of these outcomes can be reduced.

Objectives

Readings