84 Fetal growth rates and very preterm birth of twins

Nutrition for Multiples

In 2012 there were 135,943 infants of multiple pregnancies born in the United States, nearly a 2-fold increase since 1980, with twins accounting for 96% of all multiple births. To date, most perinatal morbidities associated with multiple births have proven resistant to technological or pharmaceutical interventions. Maternal nutrition can have a profound effect on the course and outcome of multiple pregnancy, with the goal of achieving optimal intrauterine growth and birthweights, and minimizing prenatal and perinatal complications for the mother and her children.

Risk factors for adverse outcomes in spontaneous versus assisted conception twin pregnancies

OBJECTIVE

To evaluate risk factors for adverse outcomes in spontaneous vs. assisted conception twin pregnancies.

DESIGN

Historical cohort study.

SETTING

Four academic tertiary medical centers.

PATIENT(S)

Women with twin pregnancies, including 2,143 spontaneous and 424 assisted conception; 2,492 nonreduced and 75 reduced.

INTERVENTION(S)

None (observational).

MAIN OUTCOME MEASURE(S)

Preeclampsia, preterm premature rupture of membranes, birth <32 weeks and <30 weeks, low birth weight, very low birth weight, and slowed midgestation fetal growth (<10th percentile between 20 and 28 weeks).

RESULT(S)

Among nonreduced pregnancies, assisted conception was not significantly associated with any adverse outcomes; among nulliparas, the risk for preeclampsia was increased regardless of method of conception; among spontaneous conceptions, the risks for preterm premature rupture of membranes, low birth weight, very low birth weight, and slowed midgestation fetal growth were increased. Among all pregnancies, fetal reduction increased risks for birth <32 weeks and <30 weeks, low birth weight, very low birth weight, and slowed midgestation fetal growth. Among nulliparas with assisted conceptions, fetal reduction increased the risks for birth <30 weeks, very low birth weight, and slowed midgestation fetal growth.

CONCLUSION(S)

These findings indicate that in twin pregnancies, assisted conception is not a risk factor for adverse outcomes, but rather specific factors that are more common among these pregnancies, such as nulliparity and fetal reduction, increase risks.

The association between maternal factors and perinatal outcomes in triplet pregnancies

OBJECTIVE

The purpose of this study was to evaluate the associations between maternal factors and outcomes in triplet pregnancies.

STUDY DESIGN

This was a historic cohort study of 194 triplet pregnancies of >or=24 weeks of gestation that were delivered from 1983 through 2001 from five medical centers.

RESULTS

In analyses that were limited to pregnancies with all live-born triplets (178 pregnancies), women with a previous good outcome (>2500 g + >37 weeks of gestation) had longer gestations (+7.9 days, P =.03), better rates of fetal growth (+4.9 g/wk, P <.0001), and higher birth weights (+153 g, P <.0001). Maternal weight gains of <36 pounds by 24 weeks of gestation were associated with lower birth weights (-197 g, P <.0001), and fetal growth rates at <or=25th percentile were associated with a shorter length of gestation (-36.7 days, P <.0001).

CONCLUSION

Previous obstetric outcome and weight gain by 24 weeks of gestation were associated significantly with fetal growth rate and birth weight; fetal growth rate, in turn, was associated significantly with length of gestation.