Risk Factors for Premature Birth and How to Reduce Your Risk

Premature birth – the birth of a baby before 37 weeks of gestation – is influenced by a complex interplay of medical, lifestyle, and socio-demographic factors. In many cases, the exact cause of preterm labour is not known. However, understanding the key risk factors can help families and healthcare providers take steps to reduce the likelihood of early delivery.

In Australia, approximately 8.7% of babies are born prematurely each year. While not all premature births can be prevented, awareness of risk factors and access to appropriate care can make a meaningful difference.

Certain medical conditions and pregnancy-related factors are associated with a higher risk of preterm birth. These include:

• Previous premature birth – having had a prior preterm delivery is one of the strongest predictors of a subsequent premature birth
• Short cervical length – a shortened cervix detected during mid-pregnancy ultrasound is associated with increased risk
• Multiple pregnancies – carrying twins, triplets, or higher-order multiples significantly increases the chance of early delivery
• Pre-eclampsia and high blood pressure – these conditions can necessitate early delivery for the safety of mother and baby
• Preterm prelabour rupture of membranes (PPROM) – when the amniotic sac breaks before 37 weeks
• Infections – urinary tract infections, bacterial vaginosis, and other infections during pregnancy can trigger preterm labour
• Chronic health conditions – diabetes, kidney disease, and autoimmune disorders can increase risk
• Placental complications – including placenta praevia and placental abruption

• Smoking during pregnancy – tobacco use is a well-established risk factor for preterm birth
• Alcohol and substance use – consuming alcohol or using recreational drugs during pregnancy increases risk
• Inadequate nutrition – poor dietary intake, low pre-pregnancy weight, or insufficient weight gain during pregnancy
• High levels of stress – chronic psychological stress can affect hormonal balance and contribute to preterm labour
• Physical demands – prolonged standing, heavy lifting, or physically demanding work may increase risk in some cases

Premature birth does not affect all communities equally. Social determinants of health play an important role:

• Maternal age – mothers younger than 20 or older than 39 are at higher risk
• Socioeconomic disadvantage – limited access to healthcare, nutrition, and support services increases risk
• First Nations Australians – Aboriginal and Torres Strait Islander women experience preterm birth at approximately twice the rate of non-Indigenous women
• Rural and remote communities – geographic isolation can limit access to specialist maternity and neonatal care
• Pregnancies conceived through IVF – assisted reproduction is associated with a higher incidence of preterm birth

While not all premature births can be prevented, several evidence-based strategies can help reduce the risk:

Regular antenatal care

Attending regular check-ups allows healthcare providers to monitor the health of both mother and baby. Routine tests for blood pressure, blood sugar levels, growth, and infections can help identify and manage conditions early.

Cervical length screening and progesterone treatment

Cervical length measurement at the mid-pregnancy scan is a useful predictor of preterm birth. In cases where a shortened cervix is detected, treatment with progesterone has been shown to reduce the incidence of preterm delivery.

Healthy lifestyle choices

Quitting smoking, avoiding alcohol and recreational drugs, eating a balanced diet, and maintaining a healthy weight all contribute to a healthier pregnancy and reduced risk of premature birth.

Midwife-led continuity of care

Research indicates that women who receive midwife-led models of care are less likely to experience antenatal hospitalisation, loss of the baby, or early spontaneous birth. Continuity of carer – seeing the same midwife throughout pregnancy – is associated with improved outcomes.

Emotional and social support

Having adequate support from partners, family, friends, and healthcare providers can positively influence pregnancy outcomes. If you are experiencing stress, anxiety, or difficult circumstances, speaking with your healthcare team about available support services is an important step.

When to seek medical advice

If you are pregnant and experiencing any signs of preterm labour – such as regular contractions before 37 weeks, pelvic pressure, lower back pain, or changes in vaginal discharge – it is important to contact your healthcare provider or hospital immediately.

Early intervention can sometimes delay or prevent premature delivery, giving your baby more time to develop.

Understanding risk to support better outcomes

Knowing the risk factors for premature birth is an important step in supporting healthier pregnancies and better outcomes for mothers and babies. While some factors cannot be changed, many can be managed with the right care, support, and information.

Running for Premature Babies is committed to supporting families affected by prematurity. By giving today, you can help fund urgently needed neonatal equipment that supports hospitals and saves the lives of sick and premature babies.