Alvin N. Eden, MD
The incidence of twin births has increased dramatically over the last twenty years. The more widespread use of fertility drugs in the treatment of infertility (ovarian stimulating- medications) as well as more and more successful in-vitro fertilizations are the major reasons for this increase. In 1980, before fertility drugs and newer technology were available, the incidence of twins births was about one in sixty, according to the 2005 National Vital Statistics Report from the Centers for Disease Control and Prevention. The current incidence is one in thirty births.
There are two types of twins, identical (monozygotic, one egg) and fraternal (dizygotic, two eggs). There is no genetic influence with identical twins. Fraternal twins run in families, occur more often beyond the second pregnancy and in older women. The current increased incidence of twins is therefore due to the increase in fraternal twins.
Currently, it is estimated that 90% of twins are detected before delivery. Elevated levels of serum alphafetoprotein and human chorionic gonadotropin (HCG) are clues to multiple births, and confirmation is obtained by ultrasound.
At the time of delivery of twins it is not always possible to determine if the twins are identical or fraternal. Even if the placentas are separated the twins are not necessarily fraternal. Further, an apparently single placenta may be present with fraternal twins. Therefore in many cases of twins it will take time to be certain whether or not they are identical. Obviously, if the twins are of different gender, a boy and a girl, they cannot be identical.
If there is some urgency in finding out if the twins are identical, detailed blood typing, DNA fingerprinting and tissue (HCA) typing can be done. But usually there is no rush to know. In a few months the answer will become clear with identical twins. The following is required:
1. Both are the same sex
2. Features, including ears and teeth, must be alike
3. Hair must be identical in color, texture and distribution
4. Eyes are same color
5. Skin of both must be same color and texture
6. Hands and feet must be of similar size
7. Should be very close in height and weight
If you are one out of the thirty mothers who gives birth to twins, the most important thing to remember is that each of your babies, even if he is identical to the other, is a separate, different and distinct human being. The parents of fraternal twins realize this because their twins look different. But often, in my experience, many parents of identical twins don't think of their two look-a-likes as two separate little people.
It is important to remember that each twin grows and develops at his own pace, and he should never be compared to the other.
The reality of being a parent of twins is that you will have twice as much work (as well as twice as much fun as they get older). Some good advice is to try to take care of both twins together whenever possible. For example, try to feed and bathe them at the same time. In some cases you can breastfeed them both at the same time, one on each breast. If this method is successful, it's a good idea to alternate the position of the twins with each feeding, so you don't play favorites. However, keeping track may be difficult.
I once had a breastfeeding mother of twins who solved the problem of position by designating her twin girls A and B and her breasts A and B. She established alternating schedules, either an A and A and B and B feeding or an A and B and B and A feeding. I didn't believe her but she insisted her system was foolproof and worked. In my experience, most mothers cannot follow this simultaneous twin feeding system. If your breast milk supply is not adequate for both babies or if you find it too difficult to breastfeed both during the same feeding period, simply breastfeed one twin and formulafeed the other, again alternating with each feeding. Most mothers of twins find that this combination feeding method works best. My best advice is to accept all the help you can get, especially during the first few months.
Some final thoughts. From the twins' point of view, it's pretty nice to have a built-in sibling, friend and companion right from the start. Certainly you will face some jealousy issues through the years. But on the whole, having twins really is a great experience.
Twin parenting indeed can be very tiring. When you find that it all seems too much for you to handle, just think about the poor mother who has triplets.
Dr. Eden is the chairman of the Department of Pediatrics, Wyckoff Heights Medical Center, Brooklyn, New York and a Clinical Professor of Pediatrics, Weill Cornell Medical Center, New York, NY. His latest book, Positive Parenting, is now available.
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