Weight generally correlates to gestational age; however, infants may be underweight for other reasons than a preterm delivery. Neonates of low birth weight (LBW) have a birth weight of less than 2,500 g (5 lb 8 oz) and are mostly but not exclusively preterm babies as they also include small for gestational age (SGA) babies. Weight-based classification further recognizes Very Low Birth Weight (VLBW) which is less than 1,500 g, and Extremely Low Birth Weight (ELBW) which is less than 1,000 g. Almost all neonates in these latter two groups are born preterm. About 75% of nearly a million deaths due to preterm deliver would survive if provided warmth, breastfeeding, treatments for infection, and breathing support. Complications from preterm births resulted in 740,000 deaths in 2013, down from 1.57 million in 1990. Society and culture
Economics
Preterm birth is a significant cost factor in healthcare, not even considering the expenses of long-term care for individuals with disabilities due to preterm birth. A 2003 study in the U.S. determined neonatal costs to be $224,400 for a newborn at 500–700 g versus $1,000 at over 3,000 g. The costs increase exponentially with decreasing gestational age and weight. The 2007 Institute of Medicine report Preterm Birth found that the 550,000 premature babies born each year in the U.S. run up about $26 billion in annual costs, mostly related to care in neonatal intensive care units, but the real tab may top $50 billion.
It is typically used after other antinausea drugs have failed.There appears to be a low risk of harm to the baby with use during pregnancy, though there may be an increase in heart problems among the babies.Ondansetron is in pregnancy category B in the US. It is not known if ondansetron is excreted in breast milk. Cyclic vomiting syndrome
Ondansetron is one of several antiemetic drugs used during the vomiting phase of cyclic vomiting syndrome. Gastroenteritis
Trials in emergency department settings support the use of ondansetron to reduce vomiting associated with gastroenteritis and dehydration. A retrospective review found it was used commonly for this purpose, being administered in over 58% of cases. Its use reduced hospital admissions, but was also associated with higher rates of return visits to the emergency department. Furthermore, people who had initially received ondansetron were more likely to be admitted on the return visit than people who had not received the drug. However, this effect may simply be due to the agent being used more frequently in people who present with more severe illness. Its use was not found to mask serious diagnoses. Special populations
Children
Ondansetron has rarely been studied in people under 4 years of age. As such, little data is available to guide dosage recommendations. Elderly
It is not necessary to adjust the dosage for people under 75 years of age. The use of ondansetron has not been studied in people older than 75 years of age, and it is not known if dosage should be adjusted for this group.