Twins Days in Twinsburg

Twinsburg, Ohio (http://www.twinsburg.com/) is a small town just south of Cleveland. Every year in the first weekend of August, starting in 1976, the town has hosted the Twins Days Festival where twins and parents of twins from around the world meet to socialize and have fun together. The festival organizers maintain a very informative web page at http://www.twinsdays.org/. The most recent festival was held 31 July to 2 August 1998 and the next festival will be held on 6-8 August 1999. The official attendance count for the 1998 meeting was 2,642 sets of twins and other multiples. This count was based on the number that paid the $8.00 USD registration fee, but unofficial counts exceeded 3,000 sets. In past years, the twins have come from all 50 of the United States and from 10-15 other countries including Austria, Romania, Russia, Hungary, Poland, the United Kingdom, Canada, and Korea.

Excepting the obvious methodological limitation that ascertainment of twins is not systematic, the Twins Days Festival provides an excellent resource for researchers. There are few places where researchers can have face-to-face contact with a large number of twins in a short period of time. Unfortunately, I could find no information about research on the Twins Days web page, so I spoke with Sandy Miller (no relation), one of the festival organizers, about opportunities for researchers.

According to Ms. Miller, researchers may apply to the Twins Days organizing committee for a $1,000 USD grant. The application is reviewed by a panel of researchers whose decision to fund the research is based on the merit of the proposal and on the their perception of the level of interest the research will generate among the twins at the festival. The research is usually medical but it could be behavioral. They try to limit the total number of research projects to six, so fewer than six grants would be funded. A research pavilion is erected on the festival grounds to protect researchers against rain and to house booths for the research projects. The costs of conducting research at the festival include a $600 USD fee to cover the cost of the pavilion, the booth and electricity. It should be possible to plug computers into electrical outlets at the research pavilion. In past years, some researchers have parked vans outside the pavilion to provide additional research space. Ms. Miller has worked with Twins Days for 17 years and she has known many researchers, but she only knows of two researchers who paid twins to participate in research. Sandy Miller and others are currently in the process of setting up a twins museum in Twinsburg that may hold all of the published papers that used data collected at the festival. The Twins Days Festival organizers (including Sandy Miller) can be reached at (303) 425-3652 or by e-mail to info@twinsdays.org.

Risks of anticoagulant use in IVF pregnancies

A 38-year-old woman, nine weeks pregnant with triplets as a result of in vitro fertilization (IVF), died from massive cerebral swelling following a surgical attempt to stop a brain hemorrhage. The woman had been undergoing anticoagulant therapy with heparin and aspirin--a tactic that is often used to reduce risk of miscarriage in IVF pregnancies. Because of concern that her death may have been related to her use of anticoagulant drugs, the United States' Centers for Disease Control (CDC) assisted state and local health departments in a two-year investigation of the case. A summary report of the investigation was published as part of the 15 May 1998 Morbidity and Mortality Weekly Report (MMWR; pp. 368-371) which can be found at the following URL: http://www.cdc.gov/epo/mmwr/preview/mmwrhtml/00052611.htm

Treatment with heparin and aspirin (both anticoagulant drugs) has proven effective for women with elevated antiphospholipid antibodies (APA) and a history of early pregnancy loss. The drugs modify the effect of APA on platelet activity and thereby reduce risk of placental thrombosis. Heparin and aspirin are also effective in reducing risk of thromboembolism in surgical patients, but the same studies that demonstrate a salutary effect on thromboembolism risk also establish an adverse effect on risk of hematoma formation and serious bleeding (see the MMWR report for references).

The CDC report concluded that it was not possible to demonstrate a causal relation of anticoagulant therapy and hemorrhage from this single case. (According to the report, "This case is the first reported pregnancy-related death associated with use of heparin and aspirin for infertility." p. 370) However, the report noted that "Because the potential for bleeding exists with heparin and aspirin, the risks for and benefits of anticoagulation therapy to improve success rates in IVF patients require vigorous scientific investigation before being accepted as routine practice." (p. 370). They also note that although the U.S. Food and Drug Administration (FDA) has not approved either heparin or aspirin (alone or in combination) for use by IVF patients, this use is apparently quite common in the United States (74% of respondents in a July 1997 survey of medical practices that provide assisted reproductive technology admitted at least one use of heparin/aspirin combination therapy). Sadly, the pregnant IVF patient whose death triggered the investigation did not have an elevated APA, the major putative indicator for anticoagulant therapy.

Exercise and the twin pregnancy

A paper in the October 1998 issue of the American Journal of Public Health (vol. 88, pp. 1528-1533), by researchers at Columbia School of Public Health, reported on correlates of exercise in a sample of 557 U.S. middle class mothers-to-be. The researchers noted that, in the United States, about 40% of pregnant women engage in regular exercise. They found that low- moderate levels of exercise had no association with gestational length and that heavier levels of exercise were associated with lower risk of pre-term birth and with quick deliveries.

This should be encouraging news for pregnant women who enjoy exercise, but what about exercise in twin pregnancies? I know of no systematic epidemiological research on exercise in twin pregnancies, but an interesting case study of a female distance runner was published in the 18 April 1998 issue of The Lancet (vol. 351, p. 1182). The 33-year-old woman was a champion runner whose best marathon (26.2 miles or 42.2 km) time was 2 hours, 36 minutes. She was pregnant with twins, yet she ran 107 km (66 miles) per week until three days before giving birth by elective cesarean section in her 36th week of pregnancy. She started training again eight days later. This athlete's exercise regimen was surely so demanding that it would not appeal to most pregnant women. In fact, the authors of the article warned that such high levels of exercise should not be undertaken by female athletes who were not well- conditioned before pregnancy. Also, this woman's health was monitored closely by a team of physicians throughout her pregnancy. Still, the favorable outcome shows that vigorous exercise (but with heart rate less than 150 beats per minute) needn't be prohibited in twin pregnancies.

Clone Watch
Martha Stewart: The first human Dolly?

As far as science has been able to determine, all genetically-identical pairs of humans are monozygotic (MZ) twins. Most people seem fascinated by MZ twins and amazed by their similarities and differences. From my observations, genetic identity seemed to be regarded as a greater good than the mere genetic half-similarity enjoyed by siblings and dizygotic twins. When Ian Wilmut announced in February 1997 that he had succeeded in cloning a lamb named Dolly from a mammary gland cell of an adult ewe, shouldn't we have been surprised when he also announced that he "would find it offensive" to clone a human being and that he fervently hoped no one would try it? (To be precise, Wilmut's method of nuclear somatic transfer clones only the nuclear DNA and not the extranuclear DNA of the adult animal). The President of the United States had a similar negative reaction. When Dr. Richard Seed, a physicist, promised in January 1998 to clone a human, Bill Clinton responded that this was "profoundly troubling news."

I wondered why the notion of human cloning had so offended Wilmut and troubled the President. My curiosity was partially sated by a New York Times article of 14 February 1998 reporting that Wilmut was uncomfortable with the unusual family relationships that cloning would create. He was quoted as saying that if he were cloned, "my wife would grow up not just with me but with a copy of me. ...How would my wife respond to a teen-age copy of me?... How would I respond to a teen-age copy of me?" Perhaps Dr. Wilmut was a difficult teenager.

Despite Dr. Wilmut's concerns, several people have announced plans to clone themselves. A man calling himself Rael (http://www.rael.net/) and claiming to be "the last embassador [sic]" to Earth of an extra-terrestrial species, announced his plan soon after the Dolly result was made public. Rael leads the Raelian Religion and claims 35,000 members in 84 countries. Richard Seed announced in September 1998 he would attempt to clone himself, and that his post-menopausal wife would carry the embryo. Rael has created a company called Clonaid (http://www.clonaid.com/) that intends to fund human cloning projects, including Richard Seed's project (http://www.rael.net/web/aclone2.html). I do not know if Seed plans to work with Rael, nor do I know if either of them seriously intends to attempt human cloning.

In a strange twist, Martha Stewart (http://www.marthastewart.com/), the well-known expert on all things domestic, was quoted in the September 1998 issue of Nature Genetics (vol. 20, no. 1) saying, "Cloning hasn't worked yet, but I'll be the first. The first human Dolly will be me." (p. 11). The journal gave no further information on Stewart's plans. She is often the brunt of jokes about her excessive domesticity, and this may be a joke of her own, or maybe she truly wishes to have a second Martha to hang hand-made Christmas tree ornaments while she serves the cranberry steamed pudding.

"Twins born apart" are doing well

We hear often of "twins reared together" and "twins reared apart," but what of twins born apart? In fact, unless they are conjoined, twins are never born at exactly the same time and the separation in time of birth is sometimes surprisingly large. The Associated Press carried a story on 11 October 1998 announcing the fourth birthday of the first-born member of a record-holding pair of twins. Timothy was born prematurely on 15 October 1994, but his twin sister, Celeste, was born full-term on 18 January 1995. According to the Associated Press report, this 95 day separation in birth date is a record for twins.

At birth, Timothy weighed only 1 lb., 14 oz. (850 g.) and required a three month hospital stay. He lagged behind Celeste in developmental milestones for the first six months of his life, but he has since caught up in every domain. Now Celeste is jealous of Timothy because he gets his birthday presents three months before she gets hers!