Baby Boy or Baby Girl?

A slightly greater number of males than females are born worldwide every year. In recent decades, although there are still more baby boys born than girls, there has been an apparent decline in the ratio of male to female newborns in several industrialized countries, including Canada, Denmark, England, Germany, Japan and the United States. That has led researchers to ask: Are there any factors that can influence the probability of giving birth to a baby boy or girl? A new study from the Harvard School of Public Health (HSPH) and Karolinska Institutet in Stockholm, Sweden, found that mothers who experienced an increase in weight from the beginning of the first pregnancy to the beginning of the second pregnancy may be slightly more likely to give birth to a baby boy during their second pregnancy. The study appears online September 24, 2007 in the journal Fertility & Sterility.

"The results are provocative because few biological factors are known in humans to influence the chances of either conceiving or carrying to term a baby boy or girl. Our study suggests that maternal nutritional factors might play a role," said Eduardo Villamor, assistant professor of international nutrition at HSPH and lead author of the study. Some prior studies had looked at what factors might influence the sex ratio, but evidence of causality has been weak. Parental smoking, for example, has been associated with both lower and higher sex ratios. Maternal nutritional status had been studied, but there was little evidence to support a causal relationship with the sex ratio. One of the hypotheses that the authors of this study wanted to test was whether the increase in maternal obesity in several industrialized countries could play a role in the declining sex ratio. Their study found the opposite--maternal weight gain seemed to favor the birth of boys.

The study population, drawn from the Swedish Birth Registry, included 220,889 women who had successive pregnancies between 1992 and 2004 (live births and stillbirths were included). The researchers analyzed the change in women's body mass index (BMI) between the first and second pregnancies. (BMI is weight in kilograms divided by the square of height in meters.) The male to female sex ratio of the second pregnancy increased linearly with the amount of weight change from the first to second pregnancy, from 1.024 in women who lost more than 1 unit BMI to 1.080 in women who gained 3 or more units (a male to female sex ratio of 1.000 would indicate an equal number of boys and girls being born). The trend was independent of obstetric complications, maternal smoking, parental age, length of the interpregnancy interval and the sex or survival status of the first-born child. The data suggest that interpregnancy weight gain appears related to a slight increase in the probability of giving birth to a baby boy during a second pregnancy. The obesity epidemic does not appear to explain the observed decline in the sex ratio in some industrialized countries, which indicates that there are factors still unknown influencing the probability of giving birth to boys or girls.

The authors are careful to note that women should not gain weight to try to influence the sex of their baby. "Weight gain before pregnancy carries significant risks to the mother and the baby, and should not be practiced to influence the odds of having a boy," said Villamor. "Other factors of which weight gain is only an indicator could be at play here."

You cannot beat age

A report published by the US Centers for Disease Control and Prevention (CDC) shows that the younger a woman is when she uses assisted reproductive technology (ART), the more likely she is to become pregnant and have a live birth using her own eggs. The report defines ART as procedures in which both egg and sperm are handled in a laboratory, and says the majority of ART treatments its data include refers to IVF. The CDC's annual report,used data for the year 2002 collected from 391 of the 428 fertility clinics in the US. The report, called '2002 Assisted Reproductive Technology Success Rates', showed that, in 2002, 45,751 live births were achieved from 115,392 ART procedures performed in the US. This was an increase from the previous year's figures, when there were 40,687 live births from 107,758 treatments. Overall, the per-cycle ART success rate in 2002 was 35 per cent, compared to 28 per cent in 1996.The 2002 data show that 37 per cent of women who undergo ART using their own, fresh eggs when they are below the age of 35, had a live birth. This is compared with 31 per cent of women aged between 35 and 37; 21 per cent of women aged between 38 and 40; 11 per cent of women aged between 41 and 42 and just four per cent for women older than 42. However, the report also showed that the age of the woman undergoing ART had 'little effect' on success rates if donated eggs were used. In 2002, the live birth rate for all ART procedures where donated eggs were used was 50 per cent, with the success rate varying only slightly between age groups.
Victoria Wright, one of the authors of the CDC report, said that the data show that 'women in their 20s and early 30s who used ART had the most success with pregnancies, and single live births'. But, she added, 'success rates declined steadily once a woman reached her mid-30s'. She said the figures should act as 'a reminder that age remains a primary factor with respect to pregnancy success, and younger women have greater success than older women, even with technology'

Online Gene Mapping

Two rival companies have launched novel genetic services which, for a price tag of $1000 (Rs. 40,000), will allow people to have their genomes scanned, delivering them personal information about their ancestry, some personal disease risks and other inherited traits.
The first - called deCODEme - was launched by Icelandic company deCODE Genetics on 16 November. Customers send a cheek swab in the post from which DNA can be extracted and analysed for 'over one million variants in your genome', says the website. This is achieved by comparing the customer's genome with a database of thousand's of people's genomes in search for single letter changes - known as SNPs - which can act as signposts for disease risk or other inherited traits. Within 2-3 weeks customers can expect to have access to their personal genome profile via a password-protected online account.
The second - called 23andMe, a reference to the number of pairs of chromosomes in the human genome - was launched on 19 November by a start-up company based in California's Silicon Valley. Similarly, customers send a saliva sample in the post from which DNA can be extracted and analysed for 'nearly 60,000 datapoints on your genome', says the website. 23andMe
co-founder Anne Wojcicki is married to Google co-founder Sergey Brin, who is also a major funder of the venture.
Both websites emphasise that they are not medical-diagnostic services, instead marketing themselves as providers of genetic information. 23andMe even promotes the novelty of being able to 'connect with other 23andMe customers through sharing features', raising the prospect that a kind of gene-based social networking service might evolve, like MySpace or FaceBook.
Some critics have raised concerns over the potential value of a growing body of genetic information to a biotech or insurance company, particularly in light of the fact that 23andMe intends to share anonymised information with outside groups for the purpose of research. While both companies have stressed that they take confidentiality very seriously, promising to accept customers anonymously if specified, there are further concerns that insurance companies might mount legal pressure on such
companies in order to force information disclosure. 'Will they stoutly defend privacy if sued by insurers?' asks The Economist, also worried that any personal genetic information shared with doctors in the US could inadvertently make its way into the hands of insurers via medical records.
Although there are obvious benefits to be gained from the availability of personal genome services, there are also legitimate concerns that such services could cause unnecessary anxiety for some. 'I would think twice before spitting into that vial', says author Nicholas Carr, writing in the Guardian (UK).

Bolo Ta Ra Ra Ra

A sardar went hunting one day in Ontario and bagged three ducks. He put them in the bed of his pickup truck and was about to drive home when he was confronted by an honorary game warden who didn't like sardars.

The game warden ordered the sardar to show his hunting license, and the sardar pulled out a valid Ontario hunting license. The game warden looked at the license, then reached over and picked up one of the ducks, sniffed its butt, and said, "This duck ain't from Ontario. This is a Quebec duck. You got a Quebec huntin' license, boy?" The sardar reached into his wallet and produced a Quebec hunting license.

The game warden looked at it, then reached over and grabbed the second duck, sniffed its butt, and said "This ain't no Quebec duck. This duck's from Manitoba. You got a Manitoba license?" The sardar reached into his wallet and produced a Manitoba hunting license.

The warden then reached over and picked up the third duck, sniffed its butt, and said, "This ain't no Manitoba duck. This here duck's from Nova Scotia. You got a Nova Scotia huntin' license?" Again the sardar reached into his wallet and brought out a Nova Scotia hunting license.

The game warden was extremely frustrated at this point, and he yelled at the sardar "Just where the hell are you from?" The sardar smiled turned around, bent over, dropped his pants, and said, "You tell me, you're the expert."

Child Support Agency Forms - Dallas, USA 2007

The following are all replies that Dallas women have written on Child Support Agency forms in the section for listing fathers name details.  
1.Regarding the identity of the father of my twins, child A was fathered by Jim Munson. I am unsure as to the identity of the father of child B, but I believe that he was conceived on the same night.  
2.I am unsure as to the identity of the father of my child as I was being sick out of a window when taken unexpectedly from behind. I can provide you with a list of names of men that I think were at the party if this helps.  
3.I do not know the name of the father of my little girl. She was conceived at a party at 3600 Grand Avenue where I had unprotected sex with a man I met that night. I do remember that the sex was so good that I fainted. If you do manage to track down the father, can you send me his phone number? Thanks.  
4.I don't know the identity of the father of my daughter. He drives a BMW that now has a hole made by my stiletto in one of the door panels. Perhaps you can contact BMW service stations in this area and see if he's had it replaced.  
5.I have never had sex with a man. I am awaiting a letter from the Pope confirming that my son's conception was immaculate and that he is Christ risen again.  
6.I cannot tell you the name of child A's dad as he informs me that to do so would blow his cover and that would have cataclysmic implications for the economy. I am torn between doing right by you and right by the country. Please advise.  
7.I do not know who the father of my child was as all blacks look the same to me.
8.Peter Smith is the father of child A. If you do catch up with him, can you ask him what he did with my AC/DC CDs?  
9.From the dates it seems that my daughter was conceived at Disney World; maybe it really is the Magic Kingdom.  
10.So much about that night is a blur. The only thing that I remember for sure is Delia Smith did a program about eggs earlier in the evening. If I'd have stayed in and watched more TV rather than going to the party at 146 Miller Drive, mine might have remained unfertilized.  
11.I am unsure as to the identity of the father of my baby, after All when you eat a can of beans you can't be sure which one made you fart.
Amen!

Anti-Epileptic Drugs

The use of antiepileptic drugs (AEDs) can lead to decreased fertility and increased incidence of reproductive endocrine disorders in both men and women. A new study published in Epilepsia investigates the effects of withdrawal from two common AEDs, carbamazepine (CBZ) and valproate (VPA), on the sex-hormones of male and female AED users. The study finds that reproductive endocrine dysfunction resulting from AED use is reversible, even after years of treatment. After withdrawal from CBZ and VPA, sexual hormone levels returned to pre-treatment levels, and treatment-associated reproductive endocrine changes reversed.
Increases in serum testosterone concentration and decreases in estradiol, another sexual hormone, lead to improved sexual function for both men and women. Women who stopped using CBZ and VPA also saw a return to normal estrogen levels and decreases in body mass index (BMI). “These findings provide further evidence of the potentially negative effects of epilepsy treatment on reproductive endocrine functions in men and women, but they also show that some of these changes may be reversible,” says Morten I. Lossius, author of the study.
A history of maternal epilepsy and its associated treatment may be linked to impaired intelligence later in life, says a new study published in Epilepsia. Dr. Nina Oyen, M.D., of the University of Bergen and Norwegian Institute of Public Health, Bergen, Norway, investigated the I.Q. levels of sons born to mothers with and without epilepsy, and found a correlation between intelligence and the illness. Drawing on extensive data on maternal epilepsy reported to the Medical Birth Registry of Norway and adult I.Q. scores and anthropometric measures taken later in life, the study monitored male children until the age of nineteen, providing a long-term look at the possible effects of maternal epilepsy on fetal brain development. The study finds that almost twenty years after birth, the sons of mothers who suffered from epilepsy before or during pregnancy exhibited reduced I.Q. scores when compared to men whose mothers did not have epilepsy. A history of maternal epilepsy was also found to be associated with shorter height. “Our results underline the need for population-based registries with complete long-term follow-up of infants with prenatal exposure to phenobarbital and phenytoin, drugs that are still widely used in many countries,” says Oyen, noting that studying the effects of exposure to newer medications is also important. Information on the specific antiepileptic drugs used by the epileptic mothers of children in the study was not available. “It remains to be seen whether the newer antiepileptic drugs are safer to offspring exposed during fetal life.”

Pesticides, Contaminants & Fertility

Methoxychlor (MXC), a common insect pesticide used on food crops, may interfere with proper development and function of the reproductive tract, leading to reduced fertility in women, researchers at Yale School of Medicine write in the journal Endocrinology. The researchers found that MXC, which was manufactured as a safer replacement for the now-banned DDT, alters the estrogen-regulated gene Hoxa10 in the reproductive tract and reduces the ability of the uterus to support embryo implantation. The researchers used mice and then human cell lines to confirm their findings. MXC is a man-made pesticide used to kill flies, mosquitoes, cockroaches and other insects, and is applied directly to food crops, livestock, home gardens and pets. It is one of a large number of chemicals that can mimic the action of hormones and in some instances interfere with endocrine function. Some of these endocrine disruptors bind estrogen receptors and adversely affect reproductive tract development, which is heavily influenced by estrogen. MXC and other chemicals like DDT have been shown in other studies to induce abnormalities in tissue development and function in the female reproductive tract. "MXC has an adverse effect on these mice similar to that of DES, a synthetic estrogen," said senior author Hugh S. Taylor, M.D., associate professor in the Division of Reproductive Endocrinology and Infertility in the Department of Obstetrics, Gynecology & Reproductive Sciences at Yale School of Medicine. "Female offspring of women exposed to DES were more likely to have an abnormally shaped cervix, were more prone to cancer of the vagina, miscarriages, early labor and other complications."
The contaminant bisphenol-A (BPA)--widely used to make many plastics found in food storage containers and dental products--can have long-term effects in female development, according to a recent study by Yale School of Medicine researchers. Lead investigator Hugh S. Taylor, said the study shows that BPA changes the expression of key developmental genes that form the uterus. Taylor explained that if pregnant women are exposed to the estrogen-like properties found in BPA, it may impact female reproductive tract development and the future fertility of female fetuses the mother is carrying. The study was conducted on pregnant female mice by administering a range of doses of BPA on days 9-16 of their pregnancies. The aim was to see what interaction BPA would have with the HOXA10 gene, which is necessary for uterine development.
Taylor and co-author Caroline C. Smith of the Department of Epidemiology and Public Health at Yale School of Medicine, found that BPA does, in fact, alter the expression of the HOXA 10 gene, implying that exposure to the popular plastics component may lead to infertility in humans. "The net effect is concerning," said Taylor. "We are all exposed to multiple estrogen-like chemicals in industrial products, food and pollutants." BPA is found in plastics, including baby bottles, epoxy resins used in canned goods and dental sealants. In addition to this new link to fertility and reproductive health, previous findings by Csaba Leranth, M.D., also in Yale Ob/Gyn, found that low doses of BPA in female rats inhibited estrogen induction in the brain. This can lead to learning impairment and, in old age, the onset of neurodegenerative disorders such as Alzheimer's disease.