**Preface XI**





Preface

to the subject matter.

(Fiona Langdon, Roger Hart).

weeks until the third trimester.

tín, Duna Trobo Marina).

chological aspects during prenatal care.

Multiple pregnancy is a challenge for obstetricians. There have been many innovations in diagnosis and management over the past few years. This book offers an immersion into multiple pregnancy. Each chapter presents the reader with various important issues related

The first chapter, "Historical Studies of Hellin's Law" (Johan Fellman), is about the epidemi‐ ology of multiple pregnancy. The incidence is approximately 2–3%. Currently, there is a ten‐ dency for women to postpone pregnancy. Therefore, we can see an increase in women of advanced reproductive age becoming pregnant, who are more likely to have twins. The eti‐ ology of this phenomenon is well demonstrated in the chapter "Twinning as an Evolved Age-Dependent Physiological Mechanism: Evidence from Large Brazilian Samples" (Varella Marco et al.). The incidence of twins has increased since 1980 as a result of assisted repro‐ duction techniques. However, several attitudes to avoid it are being implemented, as shown in the chapter "Judicious Fertility Treatment to Minimise the Risk of Multiple Pregnancy"

The early diagnosis of chorionicity is crucial for a good follow-up as presented in the chap‐ ter "Early Pregnancy Ultrasound Assessment of Multiple Pregnancy" (Antasaklis Panagiotis et al.). Once the chorionicity is defined, prenatal and follow-up can be planned. The screen‐ ing of twin-to-twin transfusion syndrome (TTTS) starts at 16 weeks, with an ultrasono‐ graphic follow-up every two weeks. On the other hand, dichorionic pregnancies have a lower risk than monochorionic and therefore the follow-up could be performed every four

Prenatal care of twins has several challenges due to a more intense adaptive mechanism. In multiple pregnancies the risks of nausea, vomiting, abortion, anemia, pre-eclampsia, gesta‐ tional diabetes, fetal anomalies, preterm birth, and other diseases are increased. The chapter "Prenatal Attachment in Twin Pregnancy" (Chiara Ionio et al.) highlights medical and psy‐

Maternal morbidity and mortality are higher in multiple pregnancy when compared to sin‐ gleton pregnancy. Maternal advanced age plus the morbidities associated with it increase by approximately three times the risk of maternal mortality. This topic is addressed in the chapter "Multiple Pregnancy in Women of Advanced Reproductive Age" (Laura Pérez Mar‐

Multiple pregnancy has serious complications, which are greater than in singleton pregnan‐ cy. Monochorionic pregnancies present several unique complications that contribute to the high rate of perinatal mortality. These aspects are presented in the chapter "Complications

