This chapter explores the maternal and fetal complications, advances in prenatal diagnosis, and management of complications unique to multiple gestations. Tidal volume and oxygen consumption in multiple gestations are increased, as is the normal alkalosis seen in singleton pregnancy. Hypertensive disorders increase by at least twofold in twin gestations. Hemorrhagic complications occur more frequently with twins. Growth of singletons and twins is comparable until 27 weeks gestation. The uterus accommodates the larger volume imposed by twins by overdistension, and beyond a certain limit, premature labor can result. Preterm deliveries (less than 37 weeks' gestation) occurred in 10.6% of singleton pregnancies against a phenomenal rate of 61.2% of live births in multiple gestations. Diagnosis of multiple gestations, establishing chorionicity, identifying anomalies, foreseeing possible maternal and fetal complications, prevention and treatment of preterm labor, and management of growth restriction are some of the areas of medicolegal concerns in multiple gestations.

Gamete intrafallopian transfer (GIFT) involves a direct transfer of human gametes, sperm and oocytes into the fallopian tubes. Zygote intra-fallopian transfer (ZIFT) involves the transfer of embryos at the pronucleus stage into the fallopian tubes. In in vitro fertilization (IVF), the four- to eight-cell embryo is transferred 48-72 hours after oocyte collection and thus reaches the uterine cavity some two to three days earlier than would occur in a natural cycle. Centres offer comprehensive assisted conception, including IVF, GIFT and ZIFT. IVF-embryo transfer has become acceptable, with improvements in vaginal ultrasound, oocyte retrieval techniques and ambulant care with local sedation and analgesia. In women aged above 40 years, a flexible number of oocytes transferred during GIFT maximizes the chance of achieving singleton pregnancy. ZIFT is indicated for couples who have had repeatedly failed IVF cycles. GIFT/ZIFT is considered for patients who have cervical stenosis or in utero exposure to diethylstilbestrol.