The grades of evidence (I-III) and levels of recommendation (A-C) are defined at the end of the "Major Recommendations" field.
The following recommendations are based on limited or inconsistent scientific evidence (Level B):
- Tocolytic agents should be used judiciously in multiple gestations.
- Women with high-order multiple gestations should be queried about nausea, epigastric pain, and other unusual third-trimester symptoms because they are at increased risk to develop hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome, in many cases before symptoms of preeclampsia have appeared.
- The higher incidence of gestational diabetes and hypertension in high-order multiple gestations warrants screening and monitoring for these complications.
The following recommendations are based primarily on consensus and expert opinion (Level C):
- The National Institutes of Health recommends that women in preterm labor with no contraindication to steroid use be given one course of steroids, regardless of the number of fetuses.
- Cerclage, hospitalization, bed rest, or home uterine activity monitoring have not been studied in high-order multiple gestations, and, therefore, should not be ordered prophylactically. There currently is no evidence that their prophylactic use improves outcome in these pregnancies.
- Because the risks of invasive prenatal diagnosis procedures, such as amniocentesis and chorionic villus sampling, are inversely proportional to the experience of the operator, only experienced clinicians should perform these procedures in high-order multiple gestations.
- Women should be counseled about the risks of high-order multiple gestation before beginning assisted reproductive technology (ART).
- Management of discordant growth restriction or death of one fetus in a high-order multiple gestation should be individualized, taking into consideration the welfare of the other fetus(es).
Definitions:
Grades of Evidence
I: Evidence obtained from at least one properly designed randomized controlled trial.
II-1: Evidence obtained from well-designed controlled trials without randomization.
II-2: Evidence obtained from well-designed cohort or case–control analytic studies, preferably from more than one center or research group.
II-3: Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled experiments also could be regarded as this type of evidence.
III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees.
Levels of Recommendations
Level A — Recommendations are based on good and consistent scientific evidence.
Level B — Recommendations are based on limited or inconsistent scientific evidence.
Level C — Recommendations are based primarily on consensus and expert opinion.