Saturday, October 4, 2008

Malaria Prophylaxis

Every year more than 125 million people visit over 100 countries endemic for Malaria. Each year up to 30,000 travelers are estimated to contract Malaria and late or wrong Malaria diagnosis in their home country may make things worse for them. Fever occurring in a traveler within three months of leaving a Malaria-endemic area is considered a medical emergency and should be investigated urgently. Malaria is contracted by the bite of a female anopheles mosquito. It is not contagious, and cannot be transmitted from person to person.

Malaria prophylaxis is the prevention of Malaria. Malaria is thought to be one of the oldest infectious diseases, evolving around 10,000 years ago. The development of new antimalarial drugs spurred the World Health Organization in 1955 to attempt a global Malaria eradication program. This was successful in much of Brazil, the US and Egypt but ultimately failed elsewhere. Efforts to control Malaria are still continuing.

As there is no vaccine available for protection against Malaria despite decades of research, there is a need for an alternative method that offers a fairly reliable protection against Malaria. And as Malaria can be severe in the non-immune, all visitors from non-malarious area to a malarious area should be protected. Antimalarial drugs offer protection against clinical attacks of Malaria.

The risk of contracting Malaria depends on the region visited, the length of stay, time of visit, type of activity, protection against mosquito bites, compliance with chemoprophylaxis etc.

Risk for Travelers

Risk can differ substantially even for persons who travel or reside temporarily in the same general areas within a country. For example, travelers staying in air-conditioned hotels may be at lower risk than backpackers or adventure travelers.

Basic Prevention

The ABCD of Malaria prevention are:

A. Awareness of risk;
B. Bite prevention – Travelers to Malarious areas are advised to wear long clothes that cover as much of the skin as possible. Exposed parts of the body should be treated with insect repellent. When sleeping, insecticide-impregnated bed nets should be used.
C. Chemoprophylaxis
D. Rapid Diagnosis and Treatment

Suppressive Prophylaxis

Chloroquine, Proguanil, Mefloquine and Doxycycline are suppressive prophylactics. This means that they are only effective at killing the Malaria parasite once it has entered the erythrocytic stage (blood stage) of its life cycle, and therefore have no effect until the liver stage is complete. That is why these prophylactics must be continued to be taken for four weeks after leaving the area of risk.

Causal Prophylaxis

Causal prophylactics target not only the blood stages of Malaria, but the initial liver stage as well. This means that the user can stop taking the drug seven days after leaving the area of risk. Malarone and Primaquine are the only causal prophylactics in current use.

Chemoprophylaxis

Chemoprophylaxis is the strategy that uses medications before, during, and after the exposure period to prevent the disease caused by Malaria parasites. The aims of Malaria treatment in broad terms are to alleviate symptoms, to prevent relapses and to prevent further transmission of the parasite. There are approximately 14 antimalarials that are advised for use in the prevention and treatment of uncomplicated Malaria.

Drug Regimens

The following regimens are recommended by the WHO, UK HPA and CDC:

1. Chloroquine 300 to 310 mg once weekly, and Proguanil 200 mg once daily (started one week before travel, and continued for four weeks after returning);
2. Doxycycline 100 mg once daily (started on day before travel, and continued for four weeks after returning);
3. Mefloquine 228 to 250 mg once a week (started two-and-a-half weeks before travel, and continued for four weeks after returning);
4. Malarone (Atavaquone + Proguanil) 1 tablet daily (started one day before travel, and continued for one week after returning).

Doses depend on what is available (eg in the US, Mefloquine tablets contain 228 mg base, but in the UK they contain 250 mg base). The data is constantly changing and no general advice is possible. Doses given above are appropriate for adults and children over 12 years of age.

Chloroquine, Mefloquine are safe in pregnancy, Doxycycline is not.

While chemoprophylaxis in pregnancy appears efficacious, a major question remains – which agents are safest for both the woman and the fetus? Some drugs routinely used in non-pregnant individuals should not be offered to pregnant women because of known direct effects on the fetus. Doxycycline is teratogenic, and Primaquine poses a significant of fatal intravascular hemolysis in G6PD deficient fetuses. Other drugs, such as Atovaquone / Proguanil and Artesunate, are not well studied in pregnancy, and therefore are not recommended for use unless other options are not available.

Given these reaction profiles, Chloroquine or Mefloquine are usually the best choice with their superior safety and efficacy.

*Chloroquine is widely used because it is inexpensive and well tolerated, with only pruritus, mouth ulcers and gastrointestinal upset as the most common adverse effects. Persons who experience uncomfortable side effects after taking Chloroquine may tolerate the drug better by taking it with meals.

*Mefloquine is usually well tolerated, but can cause dose-related neuropsychiatric effects; it is contraindicate in those with a history of epilepsy or psychiatric disease.

The World Health Organization (WHO) recommends Chloroquine as first-line prophylaxis in pregnancy (plus Proguanil if the region exhibits emerging Chloroquine resistance). In areas with proven Chloroquine resistance, Mefloquine is the drug of choice.

The Centers for Disease Control and Prevention (CDC) also advises use of Chloroquine (or Mefloquine in regions with Chloroquine resistance). The CDC discourages the use of Atovaquone/Proguanil, Doxycycline, and Primaquine, due to known adverse fetal effects or inadequate experience in pregnancy.

Chemoprophylaxis Regimen:
Malaria chemoprophylaxis with Mefloquine or Chloroquine should begin 1-2 weeks before travel to malarious areas. Beginning the drug before travel allows the antimalarial agent to be in the blood before the traveler is exposed to malaria parasites. In addition to assuring adequate blood levels of the drug, this regimen allows for evaluation of any potential side effects. Chemoprophylaxis should continue during the stay in Malarious area and for 1-4 weeks after departure from the area. Chemoprophylaxis can be started earlier if there are particular concerns about tolerating one of the medications. Starting the medication 3-4 weeks in advance allows potential adverse events to occur before travel. If unacceptable side effects develop, there would be time to change the medication before the traveler’s departure.

Antimalarials and Pregnancy: CDC Recommendations
Travel during Pregnancy to Areas without Chloroquine-Resistant P falciparum: Pregnant women traveling to areas where chloroquine-resistant P falciparum has not been reported may take chloroquine prophylaxis. Chloroquine has not been found to have any harmful effects on the fetus when used in the recommended doses for Malaria prophylaxis; therefore, pregnancy is not a contraindication for Malaria prophylaxis with chloroquine phosphate or hydroxychloroquine sulfate.
Travel during Pregnancy to Areas with Chloroquine-Resistant P falciparum: Mefloquine is currently the only medication recommended for malaria chemoprophylaxis during pregnancy. A review of Mefloquine use in pregnancy from clinical trials and reports of inadvertent use of Mefloquine during pregnancy suggest that its use at prophylactic doses during the second and third trimesters of pregnancy is not associated with adverse fetal or pregnancy outcomes. More limited data suggest it is also safe to use during the first trimester.

Because of insufficient data regarding the use during pregnancy, atovaquone/proguanil is not currently recommended for the prevention of Malaria in pregnant women. Doxycycline is contraindicated for Malaria prophylaxis during pregnancy because of the risk of adverse effects of tetracycline, a related drug, on the fetus, which include discoloration and dysplasia of the teeth and inhibition of bone growth. Primaquine should not be used during pregnancy because the drug may be passed transplacentally to a glucose-6-phosphate dehydrogenase (G6PD)-deficient fetus and cause hemolytic anemia in utero.
How to protect yourself

Know the Facts
Persons who are traveling to malaria risk areas can almost always prevent this potentially deadly disease if they correctly take an effective antimalarial drug and follow measures to prevent mosquito bites.

Know the Symptoms
Despite these protective measures, travelers may become infected with malaria. Malaria symptoms can include:
• fever
• chills
• headache
• flu-like symptoms
• muscle aches
• fatigue
• low blood cell counts (anemia)
• yellowing of the skin and whites of the eye (jaundice)

When Symptoms Appear, Seek Immediate Medical Attention
Malaria is always a serious disease and may be a deadly illness. Travelers who become ill with a fever or flu-like illness either while traveling in a malaria-risk area or after returning home (for up to 1 year) should seek immediate medical attention and should tell the physician their travel history.

Personal Protection Measures
It must be remembered that no chemoprophylaxis regime provides 100% protection. Therefore it is essential to prevent mosquito bites as well as to comply with chemoprophylaxis. Anopheles mosquitoes bite at nights, with peak biting between 10pm and 4am and Malaria transmission occurs at these hours. Travelers must take personal protective measures against mosquito bites at nights.

• Remaining in well-screened areas after dusk, using mosquito nets, and wearing clothes that cover most of the body are some simple but effective measures.
• In addition, mosquito repellents like N,N diethylmetatoluamide (DEET) can be used. It is better to have a pyrethrum-containing space spray to use in living and sleeping areas during evening and night hours. Travelers should take a flying insect spray on their trip to help clear rooms of mosquitoes. In the United States, permethrin (Permanone) is available as a liquid or spray. Overseas, either permethrin or another insecticide, deltamethrin, is available and may be sprayed on bed nets and clothing for additional protection against mosquitoes.
• Protect infants (especially infants under 2 months of age not wearing insect repellent) by using a carrier draped with mosquito netting with an elastic edge for a tight fit.
• Clothing, shoes, and camping gear, can also be treated with permethrin. Treated clothing can be repeatedly washed and still repel insects. Some commercial products (clothing) are now available in the United States that have been pretreated with permethrin.
• It is advisable to quickly report any febrile illness and disclose your travel histories to your healthcare providers.
Know the Signs and Symptoms of Malaria

You can still get malaria despite taking an antimalarial drug and using protection against mosquito bites. Taking an antimalarial drug greatly reduces your chances of getting malaria. Symptoms are very flu-like and can include fever, shaking chills, headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur.

Malaria symptoms will occur at least six to nine days after being bitten by an infected mosquito. Therefore, fever in the first week of travel in a malaria-risk area is unlikely to be malaria; however, ill travelers should still seek immediate medical care and any fever should be promptly evaluated.

Recommendations for travelers to malaria endemic areas
All travelers to malaria-endemic areas are at risk of contracting Malaria and being non-immune, P falciparum infection in these individuals can become severe. Therefore, all travelers to Malaria endemic areas are advised to use an appropriate chemoprophylaxis and personal protection measures to prevent Malaria. However, it should be remembered that, regardless of methods employed, Malaria can still be contracted. Symptoms can develop as early as 8 days after initial exposure in a Malarious area and as late as several months after departure from a Malarious area. Malaria is easily treatable early in the course of the disease but delay in treatment can lead to serious or even fatal consequences. Therefore, individuals who develop symptoms of malaria should seek prompt medical help, including blood smear (or QBC test) for malaria.

Dr Sulbha Arora MD DNB
Scientific Director
Deccan Fertility Clinic and Keyhole Surgery Center

Lavasa-Poseidon's Playground

















اَگر فِردؤس بر رُو-ائے زمین اَست،
ہمین اَست-او ہمین اَست-او ہمین اَست۔

Agar firdaus bar roo-e zameen ast,
Hameen ast-o hameen ast-o hameen ast.

If there is paradise on face of the earth,
It is this, it is this, it is this (Lavasa)

-Amir Khusro


The immortal verse of Amir Khusro was used to describe Kashmir. I am convinced that the same verse today can describe another paradise on earth - Lavasa. The Kingdom of Zeus is also Poseidon's playground. The township has come out of water - the Warasgaon lake - a 22km long stretch of clean, untouched water. Look at what the visionaries from India have done to this waterbody in the skies - an ethereal township has been laid out all around the lake (see pictures). If there was no water , there would be no Lavasa. The name Lavasa was coined after the village Lavarde in the Mose valley & Asopus - river God in Greek mythology, and father to river nymph Aegina! This was a brilliant branding success by the marketing team. India has taken to the name Lavasa, like a fish to water!

Water is considered a purifier in most religions. Major faiths that incorporate ritual washing (ablution) include Christianity, Hinduism, Rastafarianism, Islam, Shinto, Taoism, and Judaism. Immersion (or aspersion or affusion) of a person in water is a central sacrament of Christianity (where it is called baptism); it is also a part of the practice of other religions, including Judaism (mikvah) and Sikhism (Amrit Sanskar). In addition, a ritual bath in pure water is performed for the dead in many religions including Judaism and Islam. In Islam, the five daily prayers can be done in most cases after completing washing certain parts of the body using clean water (wudu). In Shinto, water is used in almost all rituals to cleanse a person or an area (e.g., in the ritual of misogi). Water is mentioned in the Bible 442 times in the New International Version and 363 times in the King James Version: 2 Peter 3:5(b) states, "The earth was formed out of water and by water" (NIV).

Some faiths use water especially prepared for religious purposes (holy water in some Christian denominations, Amrita in Sikhism and Hinduism). Many religions also consider particular sources or bodies of water to be sacred or at least auspicious; examples include Lourdes in Roman Catholicism, the Jordan River (at least symbolically) in some Christian churches, the Zamzam Well in Islam and the River Ganges (among many others) in Hinduism.

Water is often believed to have spiritual powers. In Celtic mythology, Sulis is the local goddess of thermal springs; in Hinduism, the Ganges is also personified as a goddess, while Saraswati have been referred to as goddess in Vedas. Also water is one of the "panch-tatva"s (basic 5 elements, others including fire, earth, space, air). Alternatively, gods can be patrons of particular springs, rivers, or lakes: for example in Greek and Roman mythology, Peneus was a river god, one of the three thousand Oceanids. In Islam, not only does water give life, but every life is itself made of water: "We made from water every living thing".

The Ancient Greek philosopher Empedocles held that water is one of the four classical elements along with fire, earth and air, and was regarded as the ylem, or basic substance of the universe. Water was considered cold and moist. In the theory of the four bodily humors, water was associated with phlegm. Water was also one of the five elements in traditional Chinese philosophy, along with earth, fire, wood, and metal. Water also plays an important role in literature as a symbol of purification.

The Greek word, glaukos, means the "gleaming" effect of silvery, greenish-grey, or greenish-blue colors. So, at least at the level of etymology, sea-god Glaucos reflects the sea in her elusive beauty of ever-changing hues. According to Robert Graves (The Greek Myths, 90.j,7), Glaucos was the son of Poseidon [Roman, Neptune] and an unnamed mortal woman. He grew up as a fisherman who loved the sea. By accident, he happened to find a grassy patch of herbs left over from the Golden Age -- this mysterious Herb of Immortality had originally been sown by Cronus [Roman, Saturn], an ancient sickle-carrying grain god who was later associated with time and death. Glaucos discovered that if he laid dead fish in this patch of herbs, they were restored to life. Curious, he tasted the herb for himself and became immortal (I assume it was this herb which also opened oracular realms to him since nothing else in the story accounts for this gift). Loving the sea as he did, he leaped into it, preferring to make his home within its depths instead of remaining on land. Like his father Poseidon, he had many love affairs, the most famous of which was with Scylla.

Poseidon's playground is getting ready (see pictures). the piers are getting cleaned, the boats are getting serviced. We are waiting for the rains to go away before the children come out to play on the lakes. This time, l walked around the circumference (2.4 Kms) of the main (developed) lake and was amazed by the differences in the color of water in different areas. The workers told me that certain areas of the lake have had silt-dredging done because the Sahyadri monsoons carry down a lot of silt from the mountains, and hence the variations in the color of water. I wonder if fishing will be allowed in designated areas of the lakes. Locals told me that they have caught fresh water heavies weighing almost 20 Kgs from the Lakes. At the end of the sun-break, the skies opened up again & i went rushing back to Ekaant on the top of the mountain ridge. What better way to end the evening - a bottle of Asti - Dezzani - Innocently light ... this glorious discovery comes from the hills of Piedmont. It has oceans of fruit flavour and a little bit of everything else that's delicious - sparkle sweetness crispness ... and the featherlight touch of just 5% alcohol. Moscato d'Asti is not to be confused with simple Asti - this has much greater depth of flavour and finesse. And family-made authentic gems like Dezzani Morelli seldom leave Italy - but look what happens when it does! Gold at the International Wine Challenge ... Plus a successful showing at the Vintage Festival and glowing recommendations in The Guardian and The Telegraph. This is a pride and joy speciality of the Dezzani family. And as one leading writer puts it: "The amount of work going into producing Moscato d'Asti makes a mockery of the price." This is a genuine bargain ... you simply must try it! "Straw yellow colour with emerald glints. Very aromatic - apples pears and floral notes - gently honeyed white fruit flavours and a crisp subtle sparkle. Perfect on its own or with fruit tarts." Sublime in the Kingdom of Zeus & the favored one in Poseidon's playground.

Friday, October 3, 2008

Ovarian stimulation before IVF 'does not influence birthweight'

German investigators claim they have produced "robust" evidence that ovarian stimulation for IVF does not influence the birthweight of resulting babies.

Singleton children conceived through IVF have lower birthweights, on average, than their naturally conceived counterparts, and it has been hypothesized that ovarian stimulation could be a cause.

To find out, Georg Griesinger (University Clinic of Schleswig-Holstein) and colleagues analyzed data from a national IVF registry with 65-70 percent coverage. They retrieved information for all IVF cycles in women aged 25-35 years who underwent ovarian stimulation and had a live, singleton birth (n = 32,416).

On multivariate regression, the baby's birthweight was significantly and independently predicted by each of maternal height, maternal weight, duration of infertility, and the number of embryos transferred.

However, none of the parameters of ovarian stimulation studied-including duration of stimulation, use of gonadotrophins, and the number of oocytes retrieved-significantly predicted birthweight.

"The present study provides robust evidence from a large sample of IVF singletons that ovarian stimulation and birthweight have no apparent quantitative (eg, dose-response) association," say the researchers.

However, they caution: "Although this is reassuring to the clinician, it does not invalidate the need for studying the effect of ovarian stimulation on outcomes other than birthweight, such as epigenetic alterations, and associated health disorders."

Source: Human Reproduction 2008; Advance online publication

Thursday, October 2, 2008

Prognosis 'encouraging' after total fertilization failure in IVF and ICSI

More than 40 percent of patients who experience total fertilization failure after an IVF cycle have a baby at a later attempt, researchers report.

Total fertilization failure after IVF or ICSI can be very frustrating for patients and clinicians alike.

Little information has been available about patients' chances of success in the future or how changes in treatment could improve the likelihood of fertilization in later cycles.

To investigate, Donna Kinzer (Boston IVF, Waltham, Massachusetts, USA) and colleagues conducted a retrospective analysis of data for 555 couples who experienced total fertilization failure during conventional IVF or ICSI.

They found that 44 percent of IVF patients who chose to continue treatment eventually gave birth. This equated to a delivery after 25 percent of embryo transfers and 22 percent of cycles.

After ICSI, 36 percent of couples had a child, after 23 percent of their embryo transfers, in 18 percent of their cycles.

Results also showed that fewer mature oocytes were used in the transfers that ended in complete fertilization failure, compared with earlier or later transfers, Kinzer et al report.

They say these results suggest that "total fertilization failure is not related to sperm parameters but rather is a result of suboptimal response to ovarian stimulation.

They add: "If subtle improvements in oocyte yield can be effected, this may increase the chance of fertilization in subsequent cycles for these patients."

Source: Fertility and Sterility 2008; 90: 284-8

Wednesday, October 1, 2008

Young, Childless & Snipped

Although he wasn't the neighborhood Lothario, and he didn't have a significant other, Jason Eskridge opted to have a vasectomy when he was 27.

"I did not want to raise children or be a parent due to some sort of mistaken encounter," explains the video engineer from San Jose, California, who is now 34 and lives with his girlfriend of three years.

It's not that Eskridge doesn't like kids; he has eight nieces and nephews whom he adores. He just likes his freedom more, especially the ability to travel throughout the U.S. and Europe, honing his photography chops.

"I've quit steady, solid jobs to work for next to nothing to live somewhere else in the country," Eskridge says. "Not having kids and not having to worry about finding a good city with a good school system certainly does free me to do that."

Eskridge isn't alone in downplaying the act of reproduction. In a 2007 Pew Research Center telephone survey of 2,000 U.S. men and women, only 41 percent said children are "very important to a successful marriage." In 1990, that figure was 65 percent.

Better sterile than sorry

According to the National Institutes of Health, by 2006 one in six U.S. men over age 35 has had a vasectomy, with about half a million getting snipped each year. And while men in their late 30s or 40s are often the ones who opt for the surgery, Dr. Dale McClure, director of Male Infertility at Virginia Mason Medical Center in Seattle, says he sees "a fair number of people under 35" who have undergone the procedure.

"I'm actually seeing more people than I have in the past that are younger that had a vasectomy at age 21 or 22," says McClure.

That doesn't mean doctors are doling out vasectomies like condoms at a free health clinic.

"I jokingly tell patients it's like buying a gun in Chicago," says Dr. Lawrence Ross, professor of urology at the University of Illinois at Chicago. "You can go look at the gun but you can't buy it right away."

That's because, Ross says, "there's no 100 percent guarantee in any case that we can reverse it." Within 10 years of having a vasectomy, there's a 90 to 95 percent success rate for reversal surgery. Beyond that, the success rate drops to 75 to 80 percent.

Given those stats, it's best to consider a vasectomy "a permanent form of sterilization," Ross says. "I will always tell young men that in my 38 years of practice, I've seen many men change their minds."

Second -- and third -- thoughts

McClure says he spends most of his time "putting vasectomies back together," performing more than 2,000 reversals since 1975.

"Over the last several years, it appears that more males under the age of 25 who've never had children and who had a vasectomy are coming in [for a reversal] because they've found a new partner and they want to have children," says McClure.

And sometimes there's more than one change of heart.

"Probably several times per year," the doctor says, "I have people come in who've done the reversal and had a couple kids and want the vasectomy again."

That can end up being an expensive form of birth control: Fees for a vasectomy range from several hundred dollars to $1,000, although it's often covered in part by insurance. Not so for reversals -- McClure charges $6,000, and the cost can run as high as $15,000.

Saving money was one incentive for Eskridge, whose insurance covered $800 of the cost of the procedure. The decision to have a vasectomy was drama-free. "It was something that I'd thought about for years," he says. "It wasn't like the idea came to me three months beforehand."

'So what does your girlfriend think?'

Eskridge's vasectomy wasn't a surprise to girlfriend Sonya Carr, 27, a sales accounts manager. The two were friends for several years before dating, so she knew all about his decision.

"I plan to spend the rest of my life with him, so before I moved in, I did have to consider that I was basically giving up the option of having children," Carr says. "I was already on the fence about having kids, and since realizing I either had to find a new guy or live without them, I've only become more convinced it was the right choice for me, too."

Gloria Mashayekhi, 29, from Houston, can relate. She and husband Dan Mitten, a security supervisor, weren't interested in raising children. But Mashayekhi's birth control pills were sending her blood pressure through the roof.

"I had to go off the birth control in January and he got the vasectomy in February," says Mashayekhi, an executive assistant. "I think the month of no sex was enough of an initiative to quickly find an alternative."

Mitten spent his 30th birthday getting a vasectomy.

Staying snipped

Chuck Rathmann, 42, had a vasectomy during his first marriage at age 33 and then warmed up to the idea of starting a family when he remarried at 38. But rather than undergo reversal surgery, he and his current wife adopted a daughter.

"Frankly, I don't think there is anything really special about my genetic material," says the marketing analyst from Delafield, Wisconsin.

Seven years after his decision, Eskridge admits to only one regret:

"My [best friend] from high school, she's going to get inseminated," he says. "She's a lesbian and she wants to have kids and she hasn't found a partner. I certainly would have liked to have donated [sperm] for her."

Tuesday, September 30, 2008

Now, Fertility Spas


Blame it on that ever-expanding Jolie-Pitt brood: I've been reading lots of reports about the increasing popularity of fertility spa treatments. This is not limited to big cities, where career women may be postponing having children. In Ohio, BecomingMom, a "Pregnancy Spa and Imaging Center" offers a 50-minute Preconception Massage for $69, and Peaceful Beginnings in North Carolina offers the same at $40 for 30 minutes.
Many spas list causes of infertility as stress and accumulation of toxins, none of which are causes listed on the evidence based medicine websites. In fact, really the only cause listed that a woman struggling with infertility may be able to change on her own is consumption of too much caffeine. Traditional infertility treatments can be dangerous and expensive so spas have picked up on the need for something more gentle and less invasive, which may be a good thing. But are they peddling false hope? While alternative treatments may be worth a try, it's worth considering why so few of these spas offer infertility treatment for wannabe fathers.

Monday, September 29, 2008

A Biological Clock for Dads Too

Turns out women aren't the only ones with an expiration date on their fertility. An emerging body of research is showing that men, too, have a "biological clock."

Not only do men become less fecund as they age, but their fertility begins to decline relatively early - around age 24, six years or so before women's. Historically, infertility has been seen as a female issue, as has the increased risk of Down syndrome and other birth defects, but studies now also link higher rates of autism, schizophrenia and Down syndrome in children born to older fathers. A recent paper by researchers at Sweden's Karolinska Institute found that the risk of bipolar disorder in children increased with paternal age, particularly in children born to men age 55 or older.

It used to be that "if you had hair on your chest, it was your wife's problem," says Barry Behr, an associate professor of obstetrics and gynecology at the Stanford Medical School and director of Stanford's in vitro fertilization laboratory. Even now, he said, though about half of infertility cases are caused by male factors, such as low sperm count or motility, there are many more tests to evaluate a woman's fertility than a man's.

To some degree, that bias is rooted in biology. Women are born with as many eggs as they'll ever have - about a million. That number steadily diminishes, and "the best eggs are ovulated first," Behr says. The ones that remain - after age 35 or so, on average - are vulnerable to toxins, radiation and other insults that may degrade their quality and viability.

By contrast, men make new sperm about every 90 days, Behr says, so the logic has been that there should not be that much difference between a young man's sperm and an old man's. Indeed, men as old as 94 have been known to father children.

Still, the research suggests it gets harder with age. A French study published in the current issue of Reproductive BioMedicine Online found that in couples undergoing infertility treatment, the father's age had as much effect as the mother's on rates of pregnancy and miscarriage - the older either parent was, the less likely they were to get pregnant, and the more likely to miscarry. Other studies have found similar trends: on average, it will take longer than a year to conceive for 8% of couples in which the man is younger than 25; that percentage nearly doubles, to 15%, in couples with men age 35 or older. Data have also suggested that couples whose partners are the same age, or in which the man is younger than the woman, are more likely to conceive within a year, compared with couples in which men are at least five years older than their partners.

There are many possible explanations for the decline in male fertility, from a decrease in the number of sperm and their motility to lower testosterone levels to the effects of other age-related diseases like diabetes, which is associated with erectile dysfunction and lower levels of testosterone. But researchers think that genetic factors may be behind the link between paternal age and a child's risk of bipolar disorder and psychiatric disorders like autism and schizophrenia, whose origins are increasingly being attributed to DNA. Although sperm may be no more than 90 days old, the cells that make sperm may be subject to increasing DNA mutations as men age, affecting the quality of the sperm they produce.

In the Swedish study, published Sept. 1 in the Archives of General Psychiatry, researchers found that the risk of developing bipolar disorder began to increase in children born to fathers around age 40. The highest risk, however, occurred in men age 55 and older; their offspring were 37% more likely to develop the disorder than children born to men in their 20s. Children of older men were also twice as likely to develop early-onset disease - before age 20 - which studies suggest has a strong genetic component.

What does all this mean for would-be older dads? While women are used to seeing grim statistics about their decreasing chances of achieving pregnancy and the increasing risks of Down syndrome as they age, men have typically believed that they have all the time in the world. Perhaps now, men in their mid-30s will start sharing the same "now or never" pressure to conceive that women have long endured.

When older men father children, Behr says, the traditional response has been to "pat them on the back and buy them a beer." He has seen patients that he felt were too old to become fathers, but "plenty of people make decisions about parenthood that I wouldn't," he says. "Our responsibility is to educate patients with the facts, and they decide."