2002n-499 birthandbabycare care childbirth childcareandupbringing childdevelopment complications congresses diseasesintwins family fetalmonitoring fitness health high-risk infantcare multiple multiplebirth newborninfants parenting popularworks pregnancy pregnancycomplications pregnancyoutcome prenatal prenatalcare psychology quadruplets relationships research triplets twins ultrasonography women'shealth wq235i591980t wq235l533e2000 wq235n748h1991 wq235t8352002