Preface

Chapter 6 **Multiple Pregnancy in Women of Advanced**

Laura Pérez Martín and Duna Trobo Marina

**Section 5 Unique Complication in Multiple Pregnancy 123**

Chapter 7 **Complications in Monochorionic Pregnancies 125**

Chapter 10 **Time and Mode of Delivery in Twin Pregnancies 211**

Stelios Fiorentzis, Styliani Salta, Michail Pargianas, Artemis Pontikaki, Dimitrios P. Koutsoulis, Christodoulos Akrivis, Dimitrios

Marcelo Santucci Franca, Tatiana E. N. K. Hamamoto and Antônio

Eduardo Félix Martins Santana, Vivian Melo Corrêa, Isabela Bottura

**Reproductive Age 99**

Bruno Rodrigues Toneto

Chapter 8 **Quadruplets and Quintuplets 159**

Akrivis and Ioannis Kosmas

and José Pedro Parise Filho

Chapter 9 **Preterm Birth in Twins 187**

Fernandes Moron

**Section 7 Delivery 209**

**Section 6 Preterm Birth 157**

**VI** Contents

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 to the subject matter.

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" (Fiona Langdon, Roger Hart).

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 weeks until the third trimester.

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‐ chological aspects during prenatal care.

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‐ tín, Duna Trobo Marina).

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 in Monochorionic Pregnancies" (Bruno Toneto). The pathophysiology of most of these com‐ plications is related to placental angioarchitecture such as twin to twin transfusion syn‐ drome (TTTS). Fetoscopic laser treatment for TTTS represents one of the best applications for fetal surgery, showing great results. Fetoscopic laser photocoagulation has drastically improved the survival rate of fetuses with TTTS when compared to serial amnioreduction.

The chapter "Quadruplets and Quintuplets" (Stelios Fiorentzis et al.) shows that preterm birth occurs in nearly 100% of high-order pregnancy twins and in 50% of twins as demon‐ strated in the chapter "Preterm Birth in Twins" (Marcelo Santucci et al.). Perinatal morbidity and mortality in multiple pregnancy is very elevated when compared to singleton pregnan‐ cy. The incidence of twins is only 2–3% of all pregnancies, but it is responsible for 15% of all preterm births with less than 32 weeks. Therefore, several strategies have been proposed to minimize this risk, such as follow-up of cervical length to prevent preterm birth, pessary, progesterone, and tocolysis to postpone birth to use corticosteroids in fetal pulmonary ma‐ turation, and magnesium sulfate use for neuroprotection.

After all the intense prenatal care, good assistance during delivery is essential, which brings us to the final stop on this journey: the chapter "Time and Mode of Delivery in Twin Preg‐ nancies" (Eduardo Santana et al.).

Throughout our 10 chapters the book contemplates the most relevant aspects of the multiple pregnancy scenario. Authors from all over the world, who have contributed to this book, know their subjects deeply and offer readers the best from their research experiences.

The book gives the reader a state-of-the-art update on multiple pregnancy.

I would like to thank my wife, Camila, and our children João and Pedro for their support, understanding and love during the journey to complete this mission that will help women with multiple pregnancy all over the world.

> **Julio Elito Jr.** Associate Professor of the Department of Obstetrics Federal University of São Paulo (UNIFESP) São Paulo, Brazil

**Section 1**

**Epidemiology**

**Section 1**
