Research is one of the primary goals of Multiples of America. By developing our own organizational surveys, we learn more about our multiples, our clubs and ourselves. By partnering with the scientific community, we allow outside researchers to tap our membership for participants to learn more about our multiples’ medical, educational, or social nature and that research can have an impact on the greater good. Whether you are a member or a non-member, we invite you to take part in our organizational surveys and/or contact the outside researchers and tell them you saw them on our website. Also, be sure to check out the section entitled Multiple Information for facts on twinning and current statistics on the incidence of multiple births.
Multiples of America Research Surveys
|Current Research Surveys:
Multiples of America
What is MBDB? It is the Multiple Birth Data Base form. This form is to be filled out by a parent of multiples and will be used to enter information about you and your multiples into a CONFIDENTIAL, computerized data base maintained by the National Organization of Mothers of Twins Clubs, Inc. Complete this form only once. If you have more than one set of multiples, please fill out a separate form for each set. http://www.surveymonkey.com/NOMOTCMBDB.
Updates Needed– If you are a member who filled out the Multiple Birth Data Form before 2000, the Research Department is requesting for those Multiples of America members to take the time to fill this form out again. This is due to the fact that these files are not compatible with the new system currently being used on Survey Monkey. If there is a question on when you filled out this form, please contact the Research Vice President or Chairman.
NOMOTC anuncia orgullosamente una versión en español de la Base de Datos de Parto Múltiple que está ubicado online en
Les animamos a miembros y también los que no son miembros a ayudar NOMOTC a construir nuestra base de datos con respecto a niños de parto múltiple.
Partnering with the Scientific Community
One of the goals of Multiples of America is to cooperate with and participate in outside research studies which involve multiples and/or their families.
These items can now be found by members on the “Outside Research Studies” page
For more information about the Research Department send an email to ResearchVP@multiplesofamerica.org
Expecting multiples is a wonderful but challenging experience. Being prepared is the key to maintaining a healthy outlook. Multiples of America produces an annual pamphlet, Your Multiples and You (available in English and Spanish), which is filled with tips for preparing for multiples, tips for new parents, feeding tips and tips for maintaining a healthy pregnancy, as well as nutritional and educational information. Click here to locate a parents of multiples club and receive a free copy of Your Multiples and You.
Higher Order Multiple Pregnancy
Higher Order Multiple (HOM) pregnancies are generally more high risk situation. According to the March of Dimes, the following are the average gestations seen in HOM pregnancies:
- Triplets – 32 weeks
- Quadruplets – 30 weeks
- Quintuplets and higher – 29 weeks
- Most preterm HOMs are generally under 2,500 grams (5.5 pounds) which is considered low birthweight.
The medical community continues to make great advances in managing care of both mother and babies, but there can be variations in level of experience and care, especially in areas that do not see many HOM births. Expectant parents need to educate themselves about the HOM pregnancy and learn about seeking out a medical team (physician, hospital, nutritionist, etc.) with experience in managing triplet, quad or higher pregnancies
- using protocols such as electronic fetal monitoring, special medications to halt or slow down contractions, strict bedrest, etc.
- knowing the signs of preterm labor or other complications
- preparing for caesarean birth (almost all HOM births are by C-section)
- preparing for breastfeeding triplets or more by consulting a lactation expert and newborn nurses
If you are a lover of data and statistics then check out our Multiple Births Statistics section. Here you will find the most up-to-date data on birth occurrences, ages, birth rate increases or decreases, and much more.
Go there now >>
Just for Parents
We continually scour the web to find sites and resources relating to the art of Parenting Multiples.
Go there now >>
Provided is a quick link to other resources on the Internet which may be of interest to parents of multiples. The directory is categorized by topic. The sites in this section are not affiliated with Multiples of America and we assume no responsibility for the accuracy of the information presented at these sites. We’ve taken the time to also give you a general synopsis of what is on the website to further fine tune your search.
Go there now >>
Unusual Types of Twins
In addition to all the different combinations of identical and fraternal multiples, there are some rare types of twins.
Mirror-image twins occur only in identical twins. In approximately 23 percent of identical twins the egg splits later than usual, most often day seven or beyond. The original right half of the egg becomes one individual and the original left half becomes the other. These twins will often have “mirror images” of their features, such as hair whorls that run clockwise in one and counter clockwise in the other, a birthmark on the right shoulder of one and the left shoulder of the other, etc. There is no specific test for determining if twins are mirror-image. The determination is made by observation only, and the twins must be monozygotic, or identical.
One twin will be right-handed, while the co-twin is left-handed. This may be a partial explanation for the fact that a little over one third of identical twins are left-handed, double the rate in the general population. In extreme cases, all of the internal organs are reversed in one of the twins, with the heart on the right, the liver on the left and the appendix on the left.
Polar Body Twins (Half Identical)
Polar body twinning is very unusual and very rare. The process is quite complicated. The polar body appears when the egg has been developing, even before fertilization. It is a small cell that does not function and will usually degenerate and die. It is thought that in some cases, when the egg is old, the splitting off of the polar body takes place in an abnormal way. It then becomes larger, receives more nourishment, and does not die as it usually does. Instead, it acts as a second egg. The polar body and the egg share identical genes from the mother, but they may then be fertilized by two separate sperm from the father. This will result in twins who share half their genes in common (from the mother) and the other half different (from the two sperm). They share some features of identical twins and some features of fraternal twins and thus are called half-identical twins.
Mixed Chromosomes or Chimerism
Another form of twinning that has been identified is called chimerism. This is thought to occur if two separate sperm fertilize two separate eggs which then fuse, producing individuals with different sets of chromosomes. Some have been identified that have more than one distinct red blood cell type and individuals who are both XX and XY (the sex chromosomes – XX being female and XY being male.) This phenomenon might also be associated with fused placentas causing intermixing of the circulations. It is very rare, and fewer than twenty-five cases have been identified. It is more common in other mammals, such as calves.
Twins can have different fathers. One well-known case was described in 1810 in the United States. A woman had both a white and a black lover, and she became pregnant and gave birth to twins, one white and the other black. Each twin had a different father. This is called superfecundation. It happens when the mother ovulates more than one egg and has more than one partner during her fertile period. One egg is fertilized with sperm from one partner, and the other egg from sperm of the second partner. These types of twins are always fraternal or dizygotic.
Superfetation occurs when a women ovulates more than one egg but the eggs are released at different times, sometimes up to 24 days apart, and they are fertilized when they are released. The resulting twin pregnancy has different conception dates, so the babies may be quite different in size. Days or weeks may separate the births. It is quite an unusual event. In some cases, the births of twins may be weeks or months apart due to deliberate medical intervention. This is called interval birth.
More Than Two
Higher order multiples can be triplets which consist of three babies; quadruplets (or quads) which are four babies; quintuplets (or quints) which are five babies; sextuplets which are six babies; or septuplets which are seven babies. These are all referred to as higher order multiples (HOMs) or supertwins. Higher order multiples can be any combination of the two basic twin types.
There can be different types of quadruplets just as there are different types of triplets. There can be any combination of fraternals and identicals within the four. According to data from the Triplet Connection and Raising Multiples aka Mothers of Supertwins (MOST), close to 60 percent of the families registered with these organizations have a combination of identical and fraternal children. Many of the other higher order multiples result from multiple ovulations and thus are fraternal. Identical quads, where all four are genetically identical, is extremely rare.
Multiple Birth Facts
The average person has many misconceptions regarding twins and higher order multiples. You will find answers to both the most common questions as well as more obscure questions. Either way this section should cover all the basics on multiples.
Types of Twins
There are two basic types of twins: monozygotic, commonly referred to as identical twins and dizygotic, referred to as fraternal twins. There are also other rare and unusual types of twins, such as polar body twins. The specific cause of twinning is still a mystery.
Identical, or monozygotic, twins develop from one fertilized egg (mono=one, zygote=egg). This egg divides into two individuals who will share all their genes in common. No one knows what causes the egg to divide in half. These twins are genetic clones of each other. They will therefore always be the same sex and have identical features, eye and hair color. Their handprints and footprints are similar, but the fingerprints are different. This type is what most people think of when they think of twins.
Fraternal, or dizygotic, twins develop from two eggs (di=two, zygote=egg) that are fertilized separately by two different sperm. This usually happens when the mother produces more than one egg at ovulation. These two fertilized eggs develop separately and have their own unique genes. They are no more alike than genetic single-birth brothers and sisters. Dizygotic, or fraternal, twins may be the same sex or opposite and may appear similar or look completely different. They may have different hair and eye colors and be different sizes. Some may not even appear to be related!
Tips for Parents of Twins, Triplets, Quads, or More
Accept all offers of help! Try to schedule and coordinate all volunteers to make the optimum use of their time – this would be a good job to delegate to a friend or relative.
If your children have medical issues, consider notifying local fire/ambulance services to make sure they have your address and know how to get to your house in case of an emergency.
Discuss with your medical team if your children should receive flu shots and/or the RSV vaccine at the beginning of flu and cold season. Ask family, friends and volunteers if they could provide backup help should one or more of your children become very sick.
Talk to your medical team and experienced parents about setting up a sleep schedule for the babies and try to develop (and stick with) a schedule that will work for your family. Caring for two, three, four, five or more newborns is physically exhausting – the sooner you can set up a system that works for your family, the sooner you will get some sleep and the saner your life will be.
Set up your house for convenience and organization.
Invest in a good stroller for outings. Talk to other parents of twins and higher order multipless for their equipment recommendations, including the type of vehicle they drive. You will need a larger vehicle for two, three or more car seats and probably various accessories.
Check into special promotions and free products offered to families of twins and higher order multiples. Generally, companies ask that you submit copies of each child’s birth certificate to qualify. Ask for discounts everywhere, including your pediatrician.
Keep a positive attitude and be prepared for occasional negative comments from passersby especially for parents of higher order multiples. Decide how you will answer questions about whether you took fertility drugs, if you’re having more children, and how you do it. Talk to other parents of HOMs – they can fill you in on what to expect and provide some good responses.
Take lots of photos/videos, jot down lots of notes. Try to remember as much of the fun stuff as you can – your days will go by quickly and your children will be grown before you know it!