In the Journals

Maternal weight gain tied to poor birth outcomes in twin pregnancies

Photo of Lisa Bodnar
Lisa M. Bodnar

In twin pregnancies, very high and very low maternal weight gain were both associated with poor birth outcomes, according to findings published in Obstetrics and Gynecology.

“Twin pregnancies have high rates of complications, so it is important to identify factors that we can modify during pregnancy to lessen these risks,” Lisa M. Bodnar, PhD, MPH, RD, professor in the department of epidemiology at the University of Pittsburgh Graduate School of Public Health, told Healio Primary Care.

Bodnar explained that in addition to higher risk for infant death and preterm birth, women who are pregnant with twins are more likely than those with singleton pregnancies to have diabetes, preeclampsia and cesarean deliveries.

Although recommendations have previously been made on maternal weight gain in twin pregnancies, they were informed by a study with a population that included only mothers of infants that weighed at least 2,500 g (5.5 pounds) at 36 weeks’ gestation, according to the researchers.

In twin pregnancies, very high and very low maternal weight gain were both associated with poor birth outcomes, according to findings published in Obstetrics and Gynecology.

To provide more data on the effect of weight gain during twin pregnancies, Bodnar and colleagues conducted a population-based study of 54,836 liveborn twins in Pennsylvania between 2003 and 2013. The twins were born alive before 39 weeks' gestation.

The researchers found that across all prepregnancy BMI groups, gestational weight gain z score was negatively associated with having infants who were small for gestational age and positively associated with having infants who were large for gestational age and cesarean delivery.

Very low weight gain in normal weight women and very high weight gain in women without obesity were both associated with an increased risk for infant death.

The risk for adverse birth outcomes was highest among underweight or normal-weight women who gained less than 14 kg (31 pounds) or more than 27 kg (60 pounds), overweight women who gained less than 11 kg (24 pounds) or more than 28 kg (62 pounds), and women with obesity who gained less than 6.4 kg (14 pounds) or more than 26 kg (57 pounds).

Bodnar said the findings are only starting ranges, and the research team will continue to work to provide more robust data and refine ideal weight gain ranges.

“We are not saying that gaining within these weight ranges is necessarily best for the health of the mother and her babies, but simply that gaining above or below them carries greater risk of poor health,” she said. “Ongoing conversation with patients about weight gain while pregnant is an important part of prenatal care.”– by Erin Michael

Disclosures: Bodnar reports no relevant financial disclosures. Please see study for all other authors’ relevant financial disclosures.

Photo of Lisa Bodnar
Lisa M. Bodnar

In twin pregnancies, very high and very low maternal weight gain were both associated with poor birth outcomes, according to findings published in Obstetrics and Gynecology.

“Twin pregnancies have high rates of complications, so it is important to identify factors that we can modify during pregnancy to lessen these risks,” Lisa M. Bodnar, PhD, MPH, RD, professor in the department of epidemiology at the University of Pittsburgh Graduate School of Public Health, told Healio Primary Care.

Bodnar explained that in addition to higher risk for infant death and preterm birth, women who are pregnant with twins are more likely than those with singleton pregnancies to have diabetes, preeclampsia and cesarean deliveries.

Although recommendations have previously been made on maternal weight gain in twin pregnancies, they were informed by a study with a population that included only mothers of infants that weighed at least 2,500 g (5.5 pounds) at 36 weeks’ gestation, according to the researchers.

In twin pregnancies, very high and very low maternal weight gain were both associated with poor birth outcomes, according to findings published in Obstetrics and Gynecology.

To provide more data on the effect of weight gain during twin pregnancies, Bodnar and colleagues conducted a population-based study of 54,836 liveborn twins in Pennsylvania between 2003 and 2013. The twins were born alive before 39 weeks' gestation.

The researchers found that across all prepregnancy BMI groups, gestational weight gain z score was negatively associated with having infants who were small for gestational age and positively associated with having infants who were large for gestational age and cesarean delivery.

Very low weight gain in normal weight women and very high weight gain in women without obesity were both associated with an increased risk for infant death.

The risk for adverse birth outcomes was highest among underweight or normal-weight women who gained less than 14 kg (31 pounds) or more than 27 kg (60 pounds), overweight women who gained less than 11 kg (24 pounds) or more than 28 kg (62 pounds), and women with obesity who gained less than 6.4 kg (14 pounds) or more than 26 kg (57 pounds).

Bodnar said the findings are only starting ranges, and the research team will continue to work to provide more robust data and refine ideal weight gain ranges.

“We are not saying that gaining within these weight ranges is necessarily best for the health of the mother and her babies, but simply that gaining above or below them carries greater risk of poor health,” she said. “Ongoing conversation with patients about weight gain while pregnant is an important part of prenatal care.”– by Erin Michael

Disclosures: Bodnar reports no relevant financial disclosures. Please see study for all other authors’ relevant financial disclosures.