Mother and infant complications are worse in triplet and quadruplet pregnancies than in twin pregnancies, according to a report in the American Journal of Obstetrics & Gynecology.

“Triplets and quadruplets aren’t just ‘one more baby’ - the risks for all adverse outcomes increase on a log scale,” Dr. Barbara Luke from the Miller School of Medicine, University of Miami, told Reuters Health.

Luke and colleagues used data from the National Center for Health Statistics to calculate estimates of maternal and infant risk in 12,193 triplet and 778 quadruplet pregnancies compared with 316,696 twin pregnancies.

The average pregnancy was 3.5 weeks shorter for triplet pregnancies and 5.4 weeks shorter for quadruplet pregnancies compared with twin pregnancies, the researchers found. Significantly more triplet births (16.9 percent) and quadruplet births (28.3 percent) than twin births (5.6 percent) occurred before 29 weeks of pregnancy.

Compared with twin pregnancies, triplet and quadruplet pregnancies were associated with significantly higher risks of gestational or pre-gestational diabetes, pregnancy-associated high blood pressure, incompetent cervix, delayed labor, cesarean delivery, premature rupture of membranes, excessive bleeding during labor and delivery, and infant death, the investigators report.

Mothers of triplets and quadruplets were more likely to be older, white, and to have had fewer previous pregnancies compared with mothers of twins.

Non-modifiable factors that affect the outcome of three or more births include maternal height; previous full-term pregnancy; normal-weight pregnancy; placement of the placenta; and number of fetuses. The modifiable factors include maternal nutrition and gestational weight gain, which can “significantly influence length of gestation, birthweight, and adequacy of birthweight-for-age,” Luke pointed out.

The type and content of prenatal care for women with a multiple pregnancy needs a different focus than woman pregnant with one baby, she said. “Early and adequate weight gain should be paramount, as well as prevention of infection and dehydration.”

Luke added, “Work leave (and often household help) is critical, to ensure that the pregnant woman has adequate rest at home. Patient education is central to this type of care - more frequent and longer prenatal visits, to educate the woman and her family about signs and symptoms of complications, and to teach from the fetal growth ultrasounds and the labs for monitoring of nutritional status.”

SOURCE: American Journal of Obstetrics & Gynecology, April 2008.