W

omen who are pregnant for the first time

are largely unaware that the four main

complications of pregnancy – pre -

eclampsia, preterm birth, intrauterine

growth restriction and gestational

diabetes – occur in one-quarter of first pregnancies. Worry-

ingly, the number of these pregnancy complications is rising, and

they contribute to poor health outcomes for mothers and babies

in both the short and long term.

Currently there are no effective screening tools in clinical

practice that can accurately predict any complications of preg-

nancy in women who are pregnant for the first time. While

there are models to predict some of these complications in

women who have previously given birth, they rely heavily on

previous pregnancy history and their use is still confined to a

small number of UK hospitals. Furthermore, their accuracy is

modest at best.

However, our research group has used data from nearly 3000

pregnant women in Adelaide and Auckland, their partners and

babies to develop robust models to predict risk for each of the

four pregnancy complications with low false positives and nega-

tives. These will be offered as a genetic test, for which a small

blood or saliva sample is required from both the pregnant

woman and her partner at 12–15 weeks gestation.

We have already identified specific gene variants in both the

pregnant woman and her partner that, when combined with a

number of clinical, family history, dietary and lifestyle factors,

predict risk. Some of these factors are highly modifiable.

In this article we will reveal what some of these factors are

and offer strategies to reduce women’s risk.

Risk Factors

We are all predisposed to some sort of disease, such as heart

disease, high blood pressure or some cancers. These tend to

run in families, and this implicates genetic variants in their aeti-

ology. We have identified a number of gene variants in both

pregnant women and their partners that contribute to the risk

of pregnancy complications.

Gene variants that associate with many diseases, including

pregnancy complications, are often said to have low penetrance.

This simply means that not all people who carry these variants

actually get the disease.

26 | JAN/FEB 2016

Which Pregnant

Women Are at Risk?

CLAIRE ROBERTS & TINA BIANCO-MIOTTO

A new screening test can identify the risk of pregnancy complications based on a genetic test

in conjunction with lifestyle factors.

Pregnancy Complications Explained

Preeclampsia High blood pressure first occurring after 20 weeks gestation in conjunction with protein excretion

in the urine (consistent with impaired kidney function).

Preterm Birth Birth before 37 weeks of gestation. (Full term is 37–41 weeks, with the estimated date of delivery

40 weeks from the start of the last menstrual period.)

Intrauterine growth restriction A baby that did not grow to its full genetic potential (often defined as being the lightest 5% or 3%

of babies corrected for gestational age).

Gestational diabetes mellitus Diabetes first diagnosed during pregnancy.