Healthy lifestyle choices can increase the likelihood a woman will have a normal pregnancy outcome, according to a new study by a collaboration of scientists from the UK, Ireland and New Zealand. Pregnancy complications, including high blood pressure, preterm births, low gestational weight, can cause serious problems for the mother and her baby.

The researchers gathered information from 5,628 healthy women who delivered singletons and had no previous pregnancies. Of the participants, 3,196 were from Australia while 2,432 were from the UK and Ireland. The scientists assessed the women at 15-20 weeks gestation to identify any factors linked to lowered risk for complications during pregnancy.

By the end of the pregnancies, 61 of the participants had an uncomplicated pregnancy, meaning the pregnancy did not have any significant complications, lasted more than 37 weeks and resulted in the birth of a live baby who was not small for gestational age. The most common complications were babies who were small for gestational age, premature birth, the development of high blood pressure during pregnancy, and preeclampsia, which is a condition where a pregnant woman develops both high blood pressure and high levels of protein in her urine.

The researchers in this new study identified lifestyle behaviors that increased the risk for these types of pregnancy complications. Poor body mass index (BMI), high blood pressure, misuse of drugs, and binge drinking within the first trimester appears to be detrimental to women and can cause them to experience complications during pregnancy.

Some risk factors for pregnancy complications cannot be altered. These risk factors include high blood pressure prior to pregnancy associated with contraceptive use, family history of high blood pressure during pregnancy, and bleeding during pregnancy. Women who do not have a history of hypertension outside of pregnancy can reduce their risk for complications by exercising regularly, reaching and maintaining a healthy weight, reducing salt intake and alcohol consumption, and consuming a healthy diet.

The scientists also named lifestyle choices that appear to reduce the risk of complications, such as normalizing weight during maternity, increasing fruit intake before pregnancy, reducing blood pressure, and stopping drug misuse.

Source: Chappell, Lucy C., et al. "Exploration and confirmation of factors associated with uncomplicated pregnancy in nulliparous women: prospective cohort study." BMJ 2013; 347. Web. 5 Dec 2013.