There is a racial variation in the natural incidence of twins - 1 in 50 among Africans  1in 80 among Caucasians  and 1 in 150 among Asians, least among Mongoloid Races. With the proliferation of Assisted Reproductive Technology, there has been a marked increase (20 %) in the incidence of twins. The risk is about 5 percent with fertility tablets and 20 percent with fertility injections( gonadotrophins) and in vitro fertilization and embryo transfer ( IVF and ET) when 3to 4 embryos are transferred  to increase the success rate

“Two for the price of one”  and “ instant family” may sound like a good thing until one realize that twin pregnancy is associated with an increase in all obstetric complications except  post maturity. Hyperemesis, miscarriage, pre mature  partum bleeding, fetal growth restriction, fetal death, abnormal presentation, fetal malformation and post partum bleeding are all increased. As for the baby, peri natal mortality is 4 times that of singleton births and cerebral palsy is 6 times that of singleton births.

 For optimal outcome, an early referral and care by an obstetrician, and  delivery at a well equipped hospital with anaesthetic and paediatric support is essential.

Twins  may result from the division of one fertilized egg  ( mono ovular-identical twins) or from two fertilized eggs (binovular–fraternal twins). Mono ovular twins may be present in two sacs (diamniotic-96% ) or one sac ( mono amniotic- 4%), depending on the time of separation.

Fetal anomalies, growth restriction and death are more common among mono ovular twins. The risk of cord entanglement and fetal death is very high in mono amniotic twins.

When the uterus is large for dates and multiple fetal parts are felt, one would suspect a twin pregnancy. Before the introduction of the Ultrasound Scan, many a twin pregnancy was a surprise diagnosis after the delivery of twin 1. Routine obstetric ultrasound  of all pregnant women at 18 week gestation with earlier scans  for those who are large for dates will not only detect twins but also indicate the type and screen for fetal anomalies.

All pregnant women should have obstetric ultrasound exam. Twin pregnancy is a high-risk pregnancy and an early referral to an obstetrician  is advised. The Mother will require additional pre natal vitamins and iron and more frequent assessment for the early detection of maternal or fetal complications. Serial Ultrasound  will be required to assess the fetal well being. Delivery should be in a well equipped hospital as discussed earlier. After delivery, the mother will require extra time in the hospital to adjust to the demands of the twins and establish breast feeding.

8 Week Ultrasound Diamniotic Twins

Twice The Joy