ABSTRACT
The epidemiology of multiple pregnancy is complex and depends on various factors including age, race, genetic and environmental factors, season of conception and, more recently, iatrogenic factors. In recent years, twinning rate increased dramatically especially in countries where ovulation induction and assisted reproductive technologies are widely used. Multiple pregnancies are most frequent in Nigeria where majority of them are dizygotic. The lowest frequency of twinning is observed in Japan where almost 70% of multiples are monozygotic. This paper discusses genetic, environmental and sociocultural factors which are related to the "epidemic" of multiples.
Subject(s)
Pregnancy, Multiple/statistics & numerical data , Age Distribution , Asian People , Black People , Culture , Europe/epidemiology , Female , Humans , Japan/epidemiology , Maternal Age , Nigeria/epidemiology , Ovulation Induction , Pregnancy , Pregnancy, Multiple/genetics , Reproductive Techniques , Risk Factors , Seasons , United States/epidemiology , White PeopleABSTRACT
Multiple pregnancies are not physiologic in humans and the understanding of the pathogenesis of this phenomenon is not fully established. Embriology of multiple pregnancy has been extensively investigated and this paper presents the phases of embrional development of monozygotic and dizygotic twins.
Subject(s)
Embryonic and Fetal Development/physiology , Pregnancy, Multiple/physiology , Twins, Dizygotic , Twins, Monozygotic , Female , Humans , PregnancyABSTRACT
Before ultrasound was aggressively introduced into everyday obstetrical practice, diagnosis, prophylaxis and active pre- and perinatal management were at best inadequate, but more often nonexistent. Twin pregnancies were complicated by high perinatal morbidity and mortality. The use of classical radiography was limited due to proven teratogenic and carcinogenic properties. Introduction of ultrasound dramatically changed the obstetrician's approach to twin pregnancy management. This paper discusses in detail the recent advances in ultrasound diagnosis of twin pregnancy.
Subject(s)
Pregnancy, Multiple , Ultrasonography, Prenatal/methods , Female , Gestational Age , Humans , Pregnancy , Pregnancy TrimestersABSTRACT
Multiple pregnancies are considered high risk. This qualification is associated with the multitude of conditions which are known to complicated these pregnancies. Early diagnosis of these complications is the fundamental element of clinical managements. In numerous cases therapeutic protocols are widely known and in many others intensive monitoring and appropriate management may save the fetus from early and late complications. This paper will discuss the most common prenatal and perinatal complications associated with multiple pregnancies as well as the most widely accepted therapeutic protocols.