Multiple births always attract attention and there is generally a great deal of fascination about the concept of more than one baby being born at the same time. But for parents of quadruplets, their initial responses can be far from what can be called exuberance, at least in the early stages. The practicalities of raising four babies to adulthood can seem utterly overwhelming, which is why experienced parents of higher order multiples (HOM) say it can help to just take things slowly at first and to allow the news to settle in, one steady day at a time.
The most common form of multiples are twins. Statistically 90% of all multiple births are made up of twins and the remaining 10% being shared between triplets, quadruplets and more. The most common variety of quadruplets is formed when four separate eggs are fertilised by four separate sperm. There are however, a range of possibilities when it comes to the different combinations of quadruplets and how they are conceived. Quadruplets may be identical, non identical or a combination of both.
As well as the four separate eggs and sperm variety, there is also the possibility that:
- One fertilised egg splits into four identical embryos.
- One fertilised egg splits into three identical embryos and another separate egg is fertilised by a separate sperm. This means there are identical triplets plus one.
- One set of Identical (monozygotic) twins occurs plus another two entirely separate embryos or another set of identical twins.
- Another possibility is that a set of non identical/fraternal twins are conceived plus a monozygotic pair form making a total of four embryos.
Quadruplet pregnancy is usually diagnosed on ultrasound. This is the most common time for parents to be told that four babies have been conceived and implanted. Seeing four little embryos on the screen can help the idea become a reality, but it’s very normal for expectant parents to leave the ultrasound rooms in a state of shock. If they have had fertility assistance then there is an increased risk of multiple birth so the possibility may already have been raised and discussed. Although rare, it is not unknown for quadruplets to be naturally conceived.
Tell us again how lucky we are
Different cultures view multiple births in diverse ways. For the Mayans, identical twins were seen as a blessing from God and a sign that they shared one soul which had been split between the two. In Roman culture twin boys were also viewed as a blessing, but unfortunately this belief did not extend to twin girls. They were seen as too much of a burden and the expense of raising two dowries instead of one overshadowed the “specialness” of two babies. Within Greek and other European mythology, twins and other higher order multiples all feature, with their existence being attributable to the blessing or alternately, a curse from an almighty God.
In some ancient cultures, multiple births were seen as an outward sign that a woman had been unfaithful to her husband and the existence of more than one baby was indisputable proof of this. Without any means of disproving this theory the poor women and their babies were often left to fend for themselves.
It goes without saying that we have much to be thankful for in terms of our current understanding of science and reproductive biology. But no matter how smart we have become and irrefutable evidence now supports our knowledge, there is still a little mystery and specialness surrounding multiple births.
Are quads as common as they used to be?
In the 1980s-1990s, multiple pregnancies were generally more common than at the present time. This decrease is thought to be due to overall advances in technology surrounding fertility assistance as well as the increased likelihood of these pregnancies being successful.
In the early days of assisted reproductive technology the general approach was to implant as many fertilised eggs as possible and therefore increase the chances of at least one of them implanting. But since there has been a greater understanding of the processes involved, as well as changes in the legislation surrounding the numbers of embryos which can be implanted, this has meant a reduction in the number of quadruplets being born.
There is an increased likelihood of quadruplets when:
- A mother has a family history of multiple births. If she is a multiple herself or her mother and/or sisters naturally conceived multiple babies, then she is more likely to as well. This is because there is a genetic link of hyper ovulation amongst the women in some families.
- Couples have had fertility assistance. Medication which increases the number of eggs supported towards maturity will increase the chances of multiple conception.
- Women whose diet is high in dairy foods and yams/sweet potato.
- Women are of African, especially Nigerian, descent.
- Women are already breastfeeding an older baby or toddler; they are more likely to conceive with multiples. But lactation and frequent breastfeeding can also have a contraceptive effect by stopping ovulation so this is a very individual process.
- Couples have regular sex during the woman’s fertile phases. This increases the overall chances of conception occurring.
- A woman conceives in her first cycle after ceasing the contraceptive pill. This is a time when her body is going through a readjustment phase of ovulation and menstruation and it can take a few months for her body to align back to a and normal reproductive cycle.
- Women are taller and have a higher Body Mass Index (BMI). Though this can also have a reverse effect, as women who are overweight can also have problems with regular ovulation.
- Women are older when they conceive rather than in a younger age group. Research has shown that women who are over 35 years are more likely to conceive with multiples. This tendency is thought to be due to what is known as a “fertility spike”, which occurs in women just before they enter peri-menopause. From a biological perspective, this is probably due to the naturally occurring phenomenon of nature maximising the number of babies which can be born whilst women are still fertile.
- A woman has had many previous pregnancies. The more babies she has had and the more times she has ovulated the more likely she is to naturally conceive with multiples. This includes quadruplets.
Risks of quadruplet pregnancy
To the mother:
- Miscarrying one or all of the quadruplets. Genetic abnormalities account for a large percentage of early stage miscarriage. Even in a singleton pregnancy, the chances of miscarriage are 10-25% and these odds are increased for multiples.
- Increased risks of pregnancy complications overall including gestational diabetes, hypertension, placenta praevia, ante and post partum haemorrhage and anaemia.
- Uterine rupture and placental abruption.
- Need for caesarian section delivery. A normal vaginal delivery is not advisable for the birth of quadruplets as it is too stressful and risky for both the mother and her babies.
- Access to tertiary level neonatal services is essential. Women who are pregnant with quadruplets and who live in rural or regional areas are usually advised to relocate in their second or third trimester (at the latest) so they are close to the major city maternity hospital where their quads will be born.
- Restrictions around lifestyle, work, household and care of older children if there are any. The usual recommendations around working during pregnancy and taking maternity leave are usually different in the case of multiple pregnancy.
- Greater likelihood of having post natal depression and psychological adjustment disorders after the babies are born. Additional stress on the parent’s relationship is inevitable and the need for practical, financial and emotional support is great.
To the babies:
- Premature birth is always a risk factor in multiple births.
- Intra-uterine growth retardation and low birth weight. The average weight for a preterm individual quadruplet is around 1.3kgs but many weigh less than this and do not exceed 1kg when they are born.
- Cerebral palsy and jaundice. May need blood transfusions if there has been incompatibility issues or in cases of anaemia and extreme jaundice.
- Breathing difficulties, problems maintaining their temperature and blood sugar levels.
- A generalised higher risk of physiological problems including hernia.
- Greater risk of developmental problems and global delays, including gross and fine motor skills, speech and language development, social and emotional development and visual acuity.
For more support:
The 2008 twin birth rate in the United States was 32.6 per 1,000. This is up very slightly from 2007, when the twin birth rate was 32.2 per 1,000. The twinning rate rose sharply between 1980 and 2004 (from 18.9 to 32.2) but has been fairly stable in the years since.
In 2008, 138,660 infants were born in twin deliveries.
This number is down slightly from 2007(138,961). This number mirrors the decrease in overall births in the United States, which declined about 2%.
- 138,660 twins were born in 2008
- The twin birth rate in 2008 was 32.6 per 1,000 births.
- 138,961 twins were born in 2007
- The twin birth rate in 2007 was 32.2 per 1,000 births.
- 137,085 twins were born in 2006
- The twin birth rate in 2006 was 32.2 per 1,000 births.
Higher Order Multiples
Overall, the rate of triplet and higher order multiple births (quadruplets, quintuplets, sextuplets and septuplets) was slightly decreased in 2008. The 2008 rate was 147.6 per 100,000 births compared to 148.9 in 2007, 153.5 in 2006, 161.8 in 2005 and 176.9 in 2004. The number of triplets born in 2008 decreased: 5,877 down from 5,967 in 2007 and 6,118 in 2006. The number of quadruplet and higher order multiple births also decreased. Quadruplets: 345 in 2008, down from 369 quads in 2007, but up from 355 in 2006. The number of quints (or higher) decreased almost by half: 46 born in 2008, down from 91 quints or higher in 2007, but only 67 in 2006.
In 2008, the number of higher order multiple deliveries were 6,268, the lowest number in more than a decade. The number of higher order multiple deliveries by type were:
- 5,877 triplets
- 345 quadruplets
- 46 quintuplets or higher
In 2007, the number of higher order multiple deliveries were:
- 5,967 triplets
- 369 quadruplets
- 91 quintuplets
- 0 sextuplets or septuplets
Twinning Rates by Race
Among the three largest racial/origin groups in the United States, the twinning rates in 2008 are as follows:
- Non-Hispanic White: 36.6 per 1,000
- Non-Hispanic Black: 36.8 per 1,000
- Hispanic: 22.3 per 1,000
For triplets and other higher order multiples, the rates for 2008 are:
- Non-Hispanic White (198.1 per 100,000)
- Non-Hispanic Black 91.3 per 100,000
- Hispanic 80.1 per 100,000
Impact of Fertility Treatments
Assisted reproducive therapies (including in vitro, ovulation-inducing drugs and artificial insemination) account for 17 percent of all twins and 40 percent of all triplets born in 2007.
- 17 percent of twins are the result of fertility treatments.
- 40 percent of triplets are the result of fertility treatments.
Maternal Age Factors
Older women are much more likely to give birth to twins or triplets. In 2008, 6% of all births to women 40-44 years old, and 22% of births to women 45 or older was a twin, compared with less than 2% of births to teenage mothers.
- 22 percent of births to women over age 45 were twins.
- Only 2 percent of teen mothers had twins.
Preterm Birth Rates
A trend towards shorter pregnancies with multiples was observed in 2007. The percentage of twins delivered preterm (prior to 37 weeks) rose to 60.4% in 2006. This compares to 11.1% for single birth babies.
In 2007, multiples were more likely to be born small. More than half (57 percent) of all twins and nearly all triplets (96 percent) were identified as LBW (low birth weight) babies, as compared to 6 percent of singleton babies.
- Less than 40% of twins were born at 37 weeks or later.
- More than 12% were born prior to 32 weeks gestation.
- 36.33% of triplets were born prior to 32 weeks.
- About 80% of quads and higher were born befoer 32 weeks.
Highest and Lowest Multiple Birth Rates By State
For the years 2006- 2008, the state with the highest multiple birth rate (for twins, triplets and other multiple births) was New Jersey. The lowest twin birth rate was reported in New Mexico. The state with the lowest triplet+ birth rate is Alaska.
| U.S. Multiple Birth Rates 1995 - 2006 | |||||||
| Year | Twins | Triplets | Quadruplets | Quintuplets or More | Twin Birth Rateper 1,000 total births | Triplet Birth Rate(per 100,000 total births) | Quadruplet and Higher Birth Rate(per 100,000 total births) |
| 2008 | 138,660 | 5,877 | 345 | 46 | 32.6 | 147.6 (triplet+) | N/A |
| 2007 | 138,961 | 5,967 | 369 | 91 | 32.2 | 138.2 | 10.7 |
| 2006 | 137,085 | 6,118 | 355 | 67 | 32.1 | 143.4 | 9.89 |
| 2005 | 133,122 | 6,208 | 418 | 68 | 32.2 | 150.0 | 11.7 |
| 2004 | 132,219 | 6,750 | 439 | 86 | 32.2 | 164.2 | 12.8 |
| 2003 | 128,665 | 7,100 | 468 | 85 | 31.5 | 173.8 | 13.5 |
| 2002 | 125,134 | 6,898 | 434 | 69 | 31.1 | 171.5 | 12.5 |
| 2001 | 121,246 | 6,885 | 501 | 85 | 30.1 | 171.0 | 14.6 |
| 2000 | 118,916 | 6,742 | 512 | 77 | 29.3 | 166.1 | 14.4 |
| 1999 | 114307 | 6,742 | 512 | 67 | 28.9 | 170.3 | 14.6 |
| 1998 | 110,670 | 6,919 | 627 | 79 | 28.1 | 175.5 | 17.9 |
| 1997 | 104,137 | 6,148 | 510 | 79 | 26.8 | 158.4 | 15.2 |
| 1996 | 100,750 | 5,298 | 560 | 81 | 25.9 | 136.1 | 16.5 |
| 1995 | 96,736 | 4,551 | 365 | 57 | 24.8 | 116.7 | 10.8 |
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