Women who develop a mild case of gestational diabetes during pregnancy tend to have fewer complications and healthier babies if the diabetes is treated according to the first large-scale randomized trial in the U.S. to address whether such treatment leads to health benefits for mother and child.

As many as 14% of pregnant women in the U.S., or about 200,000 women annually, develop gestational diabetes. This pregnancy-related diabetes can cause the fetus to grow too rapidly, and the excess weight can make delivery difficult and lead to complications. What’s more, gestational diabetes increases the risk of preeclampsia, a potentially life-threatening rise in blood pressure in the mother.

However, the benefits of treating gestational diabetes are somewhat controversial; although most obstetricians screen and treat pregnant women for blood-sugar abnormalities, the 2008 guidelines of the U.S. Preventive Services Task Force has said there is not enough strong evidence for or against screening and treating gestational diabetes.

“Almost all obstetricians do screen for gestational diabetes, but some of them have not been particularly aggressive about treating milder cases, reserving aggressive treatment for people with higher blood-glucose results,” says lead study author Mark Landon, MD, of Ohio State University Medical Center, in Columbus. “For them, this study serves as notice that aggressive treatment with diet alone is useful for even mild gestational diabetes cases.”

Gestational diabetes can be treated with dietary restrictions, the oral drug metformin, or insulin injections. Dr. Landon says that, unfortunately, some women diagnosed with the condition are not even given a real meal plan to follow; instead they are simply advised to watch their sugar intake.

In the study, published in the New England Journal of Medicine, 958 women diagnosed with mild gestational diabetes between 24 and 31 weeks of pregnancy were divided into two groups; half were treated for diabetes, half were not. Women were considered to have mild gestational diabetes if they had an abnormal result after taking an oral glucose-tolerance test (a test in which women drink a sugary liquid and blood sugar is measured at regular intervals), but their fasting glucose level (a test in which blood sugar is measured after fasting) was below 95 milligrams per deciliter. Many doctors treat gestational diabetes only if it is more severe, generally considered to be 95 milligrams per deciliter or higher.

The new research, a partnership of 14 different institutions, showed that women were half as likely to have larger-than-normal babies if they were treated. For example, 14% of women who weren’t treated had a baby that weighed more than 8 pounds, 13 ounces, compared with only 6% who were treated.

The newborns also had fewer cases of shoulder dystocia (1.5% with treatment vs. 4% without treatment), a potential emergency in which the birthing process stalls due to entrapment of the infant’s shoulders—a problem that’s more likely if a newborn is larger-than-normal. Women who were treated had fewer cases of high blood pressure or preeclampsia (8.6% vs. 13.6%) and were less likely to need a cesarean section (about 27% vs. 33.8%) than women who were not.

Most women in the U.S. are screened for gestational diabetes between 24 to 28 weeks of pregnancy but may be tested even earlier if they are very obese, have a strong family history of the condition, or if they had gestational diabetes or gave birth to a large baby during previous pregnancies. If a one-hour oral glucose test is positive for elevated blood sugar, then women generally undergo a similar three-hour test in order to be diagnosed.

Although gestational diabetes usually goes away after a woman gives birth, women who have the condition are 50% more likely to develop type 2 diabetes within the next 20 years. For that reason, the American Diabetes Association recommends occasional blood-sugar testing, a healthy diet, and regular exercise even after childbirth.

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PregnancyWeekly.com

Pregnancy is a time of wonder and amazement -- and for women with pre-existing diabetes, it is also a time for extremely careful (and sometimes baffling) disease management. How do you plan for this? What risks are involved? What can you expect? The August issue of Diabetes Forecast, the consumer magazine of the American Diabetes Association, features articles about pregnancy with pre-existing diabetes to help. With good care and planning women with either type 1 or type 2 diabetes can have safe pregnancies -- and healthy babies.

If you have diabetes and want to become pregnant, the first step should be visiting your doctor -- or several doctors. Depending on your diabetes management, you may want to see an endocrinologist in addition to your ob-gyn for a pre-conception visit. When choosing your doctors, keep in mind that you may have appointments as often as twice a week, so try to find a physician that you are comfortable with and whose office you are comfortable getting to.

While pre-existing diabetes automatically puts your pregnancy in the high-risk category, healthy habits can lower the chance of problems for both mother and child. First and foremost, keep your blood glucose in check -- in general, your A1C should be below 7 percent before you conceive. Your health care team may also want to discuss your weight, use of prenatal vitamins and other supplements, the status of any diabetes-related complications, and your current medications (such as ACE inhibitors or statins, which are not considered safe for use in pregnancy). Polycystic ovary syndrome is associated with type 2 diabetes, so for some women with diabetes, asking about fertility treatments may also be in order.

Once you become pregnant, your body's changes can make blood glucose levels go from one extreme to the other. "I spent the entire first trimester with my face buried in the fridge," says Kerri Sparling, 31, who has type 1 diabetes and whose daughter was born in April. "I was low all the time. It wasn't until probably the second trimester that the insulin resistance kicked in. Everything I ate, the insulin didn't cover it." As your body changes through your pregnancy, so will its reactions to the elements you normally use to manage your blood glucose, so be prepared to communicate with your health care team often and make any necessary adjustments.

From pre-conception planning to integrating diabetes management into your birth plan and facing post-partum depression, having a baby can seem like an overwhelming task for women with diabetes, and yet, many women with diabetes find they have the best glucose control of their life during pregnancy. "This was so, so important to me that I was willing to do whatever to make sure she came out right," says Sparling. "It's so worth it."

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PregnancyWeekly.com

Commuters at some railway stations in Switzerland are finding a new convenience via a vending machine: pregnancy tests.

The Austrian Times reports that pregnancy testing kits are being stocked in the machine at stations during a month-long trial.

Makers Maybe Baby said the idea is that women will not have to be embarrassed by buying a test from a pharmacist.

"We've had a few demands for refunds where people thought they were getting chocolate but they seem to be very popular," a rail worker told the Austrian Times.

The Daily Mail said a sex clinic in London is trying something similar by offering teens pregnancy tests and infection checks from a vending machine originally meant for soda drinks.

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PregnancyWeekly.com

Children of mothers whose blood glucose (sugar) was high during pregnancy are more likely to have low insulin sensitivity-a risk factor for type 2 diabetes-even after taking into consideration the children's body weight, a new study shows. The results will be presented Tuesday at The Endocrine Society's 92nd Annual Meeting in San Diego.

"We know that children born to women with type 2 diabetes or gestational diabetes, or who have high blood sugar during pregnancy are at risk of becoming diabetic themselves. This study suggests that the children's increased risk appears to be due, at least in part, to their prenatal exposure to relatively high maternal blood glucose," said study co-author Paula Chandler-Laney, PhD, a postdoctoral fellow at the University of Alabama at Birmingham.

Chandler-Laney and her colleagues studied 21 children ages 5 to 10 years and measured the children’s sensitivity to insulin, the hormone that regulates sugar in the blood. They also evaluated the pregnancy medical records of the children’s mothers to determine maternal blood sugar concentration during the oral glucose tolerance test.

The researchers found an inverse association between maternal blood sugar during pregnancy and the child’s insulin sensitivity, meaning that the higher the mother’s blood sugar levels during pregnancy, the lower her child’s insulin sensitivity. Low insulin sensitivity is a major risk factor for type 2 diabetes.

Obesity lowers insulin sensitivity, but the children’s reduced insulin sensitivity was independent of their amount of body fat, the authors reported.

In addition, children exposed to high blood sugar levels in the womb also were more likely to have exaggerated insulin secretion after a meal, independent of their reduced insulin sensitivity. Relatively high insulin secretion is also associated with increased risk for later development of type 2 diabetes, Chandler-Laney explained.

None of the children had high blood sugar, but puberty would further lower their insulin sensitivity, she noted.

“High maternal blood glucose during pregnancy may have lasting effects on children’s insulin sensitivity and secretion, potentially raising the risk for type 2 diabetes,” Chandler-Laney said. “Obstetricians, pediatricians, and pregnant women should all be aware of the potential far-reaching consequences that elevated blood sugar during pregnancy can have on children’s health.”

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PregnancyWeekly.com

Researchers found that among nearly 140,000 women in one large California health plan, Asian women had the highest rate of gestational diabetes, at nearly 7 percent. They were followed by Native American women, at 5.6 percent, and Latina women, at 5 percent.

Rates of gestational diabetes among white and black women, meanwhile, stood between 3 and 4 percent.

But it wasn't only women's race and ethnicity that mattered, the study found. Expectant fathers' backgrounds also showed an independent association with the risk of gestational diabetes.

When the father was Asian or Hispanic, the researchers found, a woman's risk of gestational diabetes was 41 percent and 29 percent higher, respectively, compared with when the father was white. That was with other factors -- including the mother's race and ethnicity, age, body weight and education -- taken into account.

Native American ethnicity was also linked to relatively higher risks, though the association was weakened when other factors were considered.

Estimated to affect between 3 percent and 8 percent of pregnant women in the U.S., gestational diabetes arises during pregnancy and goes away soon after childbirth, though women who develop it have a higher-than-average risk of eventually developing type 2 diabetes.

Gestational diabetes can raise the risk of certain pregnancy complications, like high blood pressure in the mother and having a larger-than-normal baby, which may require a C-section.

Studies have shown that in the U.S., minorities generally have a higher risk of gestational diabetes than white women do.

These latest findings, published in the American Journal of Obstetrics & Gynecology, confirm a role for women's race and ethnicity in gestational diabetes risk.

But they also suggest that "in addition to women who are Asian, Latina, or Native American, women whose partners are of these racial/ethnic groups also appear to be at higher risk for (gestational diabetes)," write Dr. Aaron B. Caughey and his colleagues at the University of California, San Francisco.

The findings may help guide gestational diabetes screening, the researchers note.

For women at average risk of gestational diabetes, doctors typically perform a blood sugar test at some point in the second trimester. Those considered to be at high risk may be screened at their first prenatal visit and then retested later in pregnancy.

It is not clear why certain racial and ethnic groups are at increased risk of gestational diabetes, but genetic predisposition likely plays a role, according to Caughey's team.

They point out that a number of studies have found increased risks among Asian women, despite the fact that they have relatively low levels of obesity, a risk factor for both gestational and type 2 diabetes.

As for why the father's race and ethnicity matters, the researchers explain that fathers' genes, as well as mothers', influence hormones in the placenta. Placental hormones, in turn, affect a pregnant woman's sensitivity to the hormone insulin, which regulates blood sugar. Impaired insulin sensitivity can then lead to gestational diabetes.

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PregnancyWeekly.com

A mother's nurture may provide powerful protection against risks her baby faces in the womb, according to a new article published online today in the journal Biological Psychiatry. The research shows that fetuses exposed to high levels of stress hormone - shown to be a harbinger for babies' poor cognitive development - can escape this fate if their mothers provide them sensitive care during infancy and toddler-hood.

The new study represents the first, direct human evidence that fetuses exposed to elevated levels of the stress hormone cortisol may have trouble paying attention or solving problems later on. But what may be more intriguing is the study's second finding – that this negative link disappears almost entirely if the mother forges a secure connection with her baby.

"Our results shape the argument that fetal exposure to cortisol – which may in part be controlled by the mother's stress level – and early caregiving experience combine to influence a child's neurodevelopment," said study author Thomas O'Connor, Ph.D., professor of Psychiatry and of Psychology at the University of Rochester Medical Center, and director of the Wynne Center for Family Research. "If future studies confirm these findings, we'll need to not only engineer ways to reduce stress in pregnancy, but we'll need to also promote sensitive caregiving by moms and dads."

For the study, researchers recruited 125 women at an amniocentesis clinic in an urban maternity hospital, taking a sample of their amniotic fluid so that stress hormones in it could be measured. The mothers were at 17 weeks gestation on average; only mothers with normal, healthy pregnancies and subsequent deliveries were followed.

When their children reached 17 months of age, researchers administered a Bayley infant developmental scale test, which relies on puzzles, pretend play, and baby "memory" challenges to gauge youngsters' cognitive development. They also observed the baby and mother using the Ainsworth "Strange Situation" test, which judges child-rearing quality, categorizing mom-baby pairs as either showing secure or insecure attachment to each other.

With cortisol levels, relationship quality results, and cognition scores in hand, researchers analyzed how the first two measures might influence the third. Indeed, for children showing "insecure attachment" to their mothers, a high prenatal cortisol level was linked with shorter attention spans and weaker language and problem-solving skills. But interestingly, for kids who enjoyed secure relationships with their moms, any negative link between high prenatal cortisol exposure and kids' cognitive development was eliminated.

"This is such refreshing news for mothers," O'Connor said. "Pregnancy is an emotional experience for many women, and there is already so much for mothers to be careful of and concerned about. It's a relief to learn that, by being good parents, they might 'buffer' their babies against potential setbacks."

O'Connor goes on to note a couple important nuances of the study. The first is that the amniotic (in-utero) cortisol studied could result from two sources, and it's hard to pinpoint which. It might, for instance, be passed along the placenta from an anxious mother to her unborn baby – or it could be created and excreted directly by a stressed fetus itself.

This study plays into the much larger theory of "fetal programming," which suggests that events in the womb may prime the developing child for long-term health and developmental outcomes. Past studies, for instance, have found a pregnant mother's diet can sway a child's long-term risk for heart disease, diabetes and obesity. Along with diet, prenatal stress has emerged as another large-looming factor in such programming.

"Our results support this emerging theory," said London-based study co-author, Vivette Glover, Ph.D. "In neurology, the idea emerging is that unborn children sense their mothers' stress hormone levels, programming them for greater watchfulness. We're trying to determine whether or not that sensitivity comes with greater anxiety during childhood, and if so, what we can do about it."

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PregnancyWeekly.com

Some of mankind's most devastating inherited diseases appear to be declining, and a few have nearly disappeared, because more people are using genetic testing to decide whether to have children.

Births of babies with cystic fibrosis, Tay-Sachs and other less familiar disorders seem to have dropped since testing came into wider use, The Associated Press found from interviews with numerous geneticists and other experts and a review of the limited research available.

Now, more women are being tested as part of routine prenatal care, and many end pregnancies when diseases are found. One study in California found that prenatal screening reduced by half the number of babies born with the severest form of cystic fibrosis because many parents chose abortion.

More couples with no family history of inherited diseases are getting tested before starting families to see if they carry mutations that put a baby at risk. And a growing number are screening embryos and using only those without problem genes.

The cost of testing is falling, and the number of companies offering it is rising. A 2008 federal law banning gene-based discrimination by insurers and employers has eased fears.

Genetic testing pushes hot-button issues: abortion, embryo destruction and worries about eugenics - selective breeding to rid a population of unwanted traits.

Some diseases - sickle cell, cystic fibrosis, Tay-Sachs, thalassemia, spinal muscle atrophy - occur when people inherit two bad genes, one from each parent. The genes can pass quietly for generations until two carriers mate; then children have a one-in-four chance of getting the disease.

Comparisons to couples not given prenatal screening suggested that screening had cut births of babies with severe disease in half, researchers reported at a genetics conference in 2008. Studies in Canada, Italy, Australia and in Europe also found that cases dropped after screening began.

Gene testing hasn't led to declines in all diseases. Sickle cell, a blood disorder that causes anemia and pain and raises the risk of stroke, has not dropped. It mostly afflicts blacks; gene carriers are said to have sickle cell "trait," which sounds harmless.

"Now we're actually learning that it's not as benign as we thought it was," and that carriers have higher risks for certain medical problems, said Dr. Lanetta Jordan, a Florida physician and chief medical officer of the Sickle Cell Disease Association of America.

Newborn screening is finding more sickle cell carriers and cases, but this doesn't seem to affect parents' future family plans, Jordan said.

The number of fertility treatments that include embryo screening has been on the rise in recent years, with nearly 5,200 screenings in 2006, according to the Society for Assisted Reproductive Technology. Carrier testing also is rising. A California company, Counsyl, sells a $349 saliva test for genes for more than 100 inherited disorders. Several thousand people used it over the last year, the company reports.

Eliminating disease is a noble goal but also "should give us pause," Lerner, the Columbia historian, wrote recently in the New England Journal of Medicine.

"If a society is so willing to screen aggressively to find these genes and then to potentially to have to abort the fetuses, what does that say about the value of the lives of those people living with the diseases?" he asked.

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PregnancyWeekly.com

Three out of five women who have given birth to a child with a congenital heart defect (CHD) -- the number-one birth defect and leading killer of infants and newborns -- were never tested for the defect during pregnancy. This is according to a survey just released by Little Hearts, Inc.

These findings come just as CHD Awareness Week begins (Feb. 7 - 14). The Little Hearts survey found that 60 percent of parents did not know their child had a CHD until after giving birth -- because the mothers were not tested for heart defects during pregnancy.

Of these parents, nearly three out of four (71.6 percent) wished they had known their child had a CHD during pregnancy -- mostly because they would have given birth at a hospital more equipped to handle the care of newborns with a CHD (41.6 percent).

"Congenital heart defects kill more children than childhood cancer, and yet, pregnant women are not routinely tested -- and newborns are not routinely screened -- for this defect," says Lenore Cameron, President and Executive Director, Little Hearts, Inc. "Early detection is absolutely critical to the successful treatment of congenital heart defects and, in countless cases, it saves lives."

Those families that did know their child had a CHD before giving birth (40.0 percent) reaped tremendous benefits from knowing in advance:

• Three out of five (59.5 percent) said they gave birth at a hospital more equipped to handle the care of newborns with a CHD
• One in five (19.8 percent) prepared themselves mentally and emotionally for the arrival of a seriously ill child
• Others did their homework: 14.9 percent of respondents said they arranged for a pediatric cardiologist in advance of their baby's arrival, and 5.8 percent said that knowing in advance was most beneficial because it gave them time to do research on CHDs during the pregnancy

More Survey Results

• Four out of five respondents (81.7 percent) said neither parent of the heart child had any family history of CHDs
• Giving birth to a child with a CHD was more common for women in their 30s (65.2 percent) than in any other age group
• Three out of four respondents (76.1 percent) said the mother did not take prescription drugs (which is considered a CHD risk factor) while pregnant with the heart child
• Almost all respondents (96.4 percent) have only one child with a congenital heart defect; 3.6 percent have two or more children with a CHD
Nearly three out of five respondents (58.0 percent) said their heart child has two or more CHDs; 42.0 percent said their heart child has one CHD
• The most common CHD among children of respondents was Hypoplastic Left Heart Syndrome (30.3 percent), a very serious heart defect that occurs when the left side of the heart does not develop completely

There are approximately 35 different types of CHDs. Some may be treated with surgery, medicine and/or devices, such as artificial valves and pacemakers. In the last 25 years, advances in the treatment of heart defects have enabled half a million U.S. children with serious CHDs to survive into adulthood. However, many cases of sudden cardiac death in young athletes are caused by undiagnosed CHDs and childhood-onset heart disease.

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PregnancyWeekly.com

My story starts back in 2006.

I have a history of miscarriage. I had two early losses before giving birth to Noah, but for some reason had thought it would not happen again.

We decided to start trying for another baby in December 2005, and got pregnant right away. However, this pregnancy sadly ended in a miscarriage at the end of January, a very traumatic loss.

Since this was my third loss, despite not being consecutive, I talked my GP into referring me to the hospital for further testing. I had a ton of blood taken for various different tests, however by the time my appointment came along to see the consultant to discuss my results I was already pregnant again, after suffering a chemical pregnancy the cycle before, it turned out this time the baby was going to stick. I had about 8 scans as they monitored my pregnancy very closely this time.

However, things were not to go completely smoothly, as at 16 weeks I consented to having the triple test done for Downs/Edwards syndrome/Spina Bifida, something I regret doing as I feel very strongly against abortion apart from in extreme medical circumstances. This test came back with an elevated risk for Downs Syndrome, at 1 in 200. (The risk for my age, 29, should have been 1 in 1000.) Due to my loss history I refused an amniocentesis. The risk for losing my baby was double the actual risk of it having Downs and I could not accept those odds. So I opted for a detailed scan instead. The scan showed no soft markers for Downs and confirmed what we already suspected was true, that I was carrying another little boy.

At 34 weeks, I had another scan which also showed no markers for Downs. The consultant tried to talk me into an amnio at that stage, which I refused, as I could see little point. She said,

Do you know what risk you are taking?

I felt that was completely ridiculous, as whatever abnormalities my child might have had, we would just deal with whatever came up. I would love my child no matter what and strongly believe that we got given what we can handle and no greater than that. My gut told me though that my child was healthy and I clung onto this.

We started to plan the delivery, our local hospital had recently upgraded their birthing pool so that mothers could actually give birth in it rather than just laboring in it and then getting out before the birth itself. I fully intended on using this pool, especially after researching it and finding out that a warm bath is the second most effective form of pain relief after an epidural!

I had an epidural with Noah’s birth which had not taken properly (just down one side) and I had some horrible side effects (nausea and shaking). I was determined not to have one this time.

A good family friend of ours, Joana, is a midwife and had delivered Noah, we had her on call whenever I went into labor, although she would need some assistance as this would be her first waterbirth.

At 39 weeks, 4 days, I woke up to mild contractions, timed them as coming every 10 minutes.

As the day wore on though, they did not intensify, or get any closer together. By the time Gary got home from work I was getting very frustrated and at that point not even bothered if they stopped, I just wanted SOMETHING to happen or let me get some rest. At 9 p.m., I decided to try and get some sleep so went to bed. It was difficult as I was woken with every contraction, but I was determined I would need some sleep if I was going to have any energy to deal with labor.

Somehow I managed to get to sleep and the next thing I knew, it was 1 a.m. and I awoke having a very intense contraction. I lay there timing them again, and noticed they were coming about 3 minutes apart and lasting about 50 seconds each. I woke DH and we both got up, rang the in-laws. I got dressed and headed over to the hospital. I rang Joana on the way over.

At this point my contrax were 3 min apart, but every now and again I would have an extra one in between; they were painful but manageable. When we got there they had the pool all ready for me and they checked me before I hopped in. Joana was shocked to find I was already 9cm dilated – so I had already gone through most of labour at home!

I got into the tub and as soon as I hit the water I hit transition and started to lose it. Seconds after, I felt a huge pop and my waters broke. (Great timing!) I managed to focus on the contractions, which were getting really intense.

About 10 mins after I started to feel the urge to push, my body just took over – this part always freaks me out, how the body just does things with no input.

With my last labor, the pushing had been very, very difficult, as I was on my back wired up to machines after having an epidural, and it took over 2 hours to get him out.

This time though, I was able to get right into a good position and let gravity help me. Still, I was nervous. I also tore badly last time and was worried about it happening again.

In the end though I just realized the faster I get him out the sooner the pain is over and just pushed along with my body. I knew he was coming soon. I could feel the infamous “ring of fire”.

Joana called the other midwife in. They got me to squat right in the center of the pool as low as I could and as he came out, they told me not to touch his head, as it might stimulate him to breathe. His head popped out and very soon after the rest of his body.

When they told me the time was right I brought him up to the surface and laid him on my chest. I remember thinking how soft his skin was and what a big boy! He didn’t even cry and soon pinked right up nicely.

Seamus weighed on at 8lbs, 4oz, born at 4.50am (45 minutes after reaching the hospital) on the 24th February 2007. Perfectly healthy.

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PregnancyWeekly.com

Normally, parents who want to know the sex of their baby before it's born find out through ultrasound done in the second trimester. A blood test that can be done early in pregnancy is highly accurate at determining the sex of the fetus, however, a new study finds.

The test is important, write the authors of the study, because in some cases, there are medical reasons to determine fetal sex earlier. That has traditionally meant invasive tests, like amniocentesis, which carry a small risk of miscarriage.

Consequently, maternal blood tests that pick up certain markers of fetal sex have been developed and put into use in recent years. So far, research has shown the accuracy of these tests to vary widely, depending on the methods used.

In this latest study, published in the journal Obstetrics & Gynecology, researchers in the Netherlands found that the testing method used at their center was 100 percent accurate in determining fetal sex among nearly 200 pregnant women.

Part of what's new about the findings is that they show the effectiveness of blood testing as it is done in routine practice -- and not just in the research setting, Dr. Ellen van der Schoot, of Sanquin Research Amsterdam, told Reuters Health in an email. The study does not discuss costs, nor when the test might be available to the general public.

Still, the findings, according to van der Schoot and her colleagues, support using the tests in cases where fetal sex is important in detecting or managing certain inherited medical conditions.

For example, congenital adrenal hyperplasia (CAH) is a genetic disorder that causes girls to develop abnormal external genitalia and male-like characteristics like a deep voice and excessive body hair.

It is possible, however, to treat the disorder with the steroid dexamethasone as soon as pregnancy is established, so knowing the fetal sex sooner is better than later.

Similarly, fetal sex is key in genetic disorders linked to abnormalities in the X chromosome. These disorders -- such as hemophilia and Duchenne/Becker muscular dystrophy -- are almost always seen in boys rather than girls, because boys inherit only one X chromosome, from the mother. (Girls inherit an X chromosome from each parent.)

In cases where a mother is known to carry an X-linked genetic defect, blood testing for fetal sex tells doctors whether further, invasive testing for the particular genetic disorder should be done. If the fetus is female, invasive tests can be avoided.

In the current study, van der Schoot and her colleagues looked at 201 pregnant women who had blood testing at their lab between 2003 and 2009. The test, done as early as the seventh week of pregnancy, determines fetal sex by looking for two genes found on the Y sex chromosome.

Only men carry the Y chromosome, so when these genes were found in a pregnant woman's blood sample, the fetus was assumed to be male. When the test did not detect the genes, the mother's blood was analyzed further to confirm that certain other fetal DNA was present; with that confirmation, the researchers concluded that the fetus was female.

Of the 201 women in this study, blood tests gave conclusive results to 189. In each case, that result turned out to be correct.

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PregnancyWeekly.com