Dr. MSc. Raul Hernandez Canete Multiple Gestation Dr. MSc. Raul Hernandez Canete

Type of multiple gestation Results from the ovulation and subsequent fertilization of more than one oocyte: Dizygotic (the fetuses are genetically different) Result from the splitting of one embryonic mass to form two or more genetically identically fetuses (Monozygotic).

Dizygotic twins: Diamniotic and Dichorionic. Monozygotic Twins: - Monochorionic, Monoamniotic - Monochorionic , Diamniotic - Dichorionic, Diamniotic.

Monozygotic twins: Single embryonic mass splits into two within three days of fertilization: Diamniotic and Dichorionic. When embryonic splitting occurs after the 3rd day following fertilization: Monochorionic and Diamniotic Embryonic splitting after the 9th day following fertilization: Monoamniotic and Monochorionic. Splitting after 12th days: Conjoined Twins.

Zygosity and Chorionicity Zygosity refers to whether the twins have come from the same ovum or from different ova, in other words whether they are identical or non-identical. Chorionicity refers to the number of placentae.

Incidence (by Clinical Obstetrics and Gynaecology, Drife/Magowan, 2004) 54/1000 in Nigeria 4/1000 in Japan 12/1000 in UK Identical twins: 3/1000 Preterm delivery: 40% The incidence is higher after ovulation induction

Etiology: Familial factors (dizygotic +; monozygotic is rare). Parity and maternal age: increase with the parity and maternal age(dizygotic). Ovulation induction In vitro fertilization and embryo transfer

Clinical features: Increased uterine size Hyperemesis gravidarum Early oedema At physical exam two poles and two different fetal heart

Diagnosis: History (Assisted conception, family history, increased symptoms of pregnancy, abdomen larger than expected for gestation) Clinical examination USG

Complications of twin pregnancy: Miscarriage APH Polyhydramnios Preeclampsia Anemia Gestational diabetes Preterm labour IUGR Fetal abnormalities and chromosomal defects IUFD Twin to Twin transfusion syndrome

Management of pregnancy Early booking Proper antenatal care Health education USG Prevention of anemia Assessment of fetal wellbeing Prevention of preterm delivery Early diagnosis of complications

Management of Twin delivery: IV line To identify the presentation < 34 weeks: Caesarean section CTG if is possible Work in team Oxytocin infusion could be necessary after delivery of the first twin. No ARM until advanced cervical dilatation.

Cont……. External version of the second twin is if necessary, if it fail: breech extraction No more than 30 mtes between delivery of the first baby and the second. First twin in breech and second in cephalic presentation have risk of locked twins Be ready for possible post partum hemorrhage