Pregnancy

Updated 12-6-12: In the video above, Shawn Chavez, PhD, first author of the study, describes the work and its significance.

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12-4-12: Couples who turn to in vitro fertilization, or IVF, are desperate to have a family. But, despite many advances, the odds of a successful pregnancy from each round of costly, emotionally demanding embryo transfer are only about 30 percent. The problem stems from the fact that many human embryos are faulty from the earliest stages and will never develop successfully.

Stanford researchers Renee Reijo Pera, PhD, and Barry Behr, PhD, have been working to find out why – and to develop ways to increase the odds of a successful pregnancy through IVF. They report findings from some of their work in today’s Nature Communications, which I describe in a release:

The research suggests that fragmentation — a common but not well-understood occurrence in the early stages of human development in which some of the cells in an embryo appear to break down into smaller particles — is often associated with a lethal loss or gain of genetic material in an embryo’s cells. Coupling a dynamic analysis of fragmentation with an analysis of the timing of the major steps of embryonic development can significantly increase the chances of selecting an embryo with the correct number of chromosomes, the researchers found.

…

“It is amazing to me that 70 to 80 percent of all human embryos have the wrong number of chromosomes,” said [Reijo Pera], professor of obstetrics and gynecology. “But less than 1 percent of all mouse embryos are similarly affected. We’re trying to figure out what causes all these abnormalities.”

Reijo Pera and Behr started a company called Auxogyn to investigate ways to bring these findings into the clinic. The company, which is now privately held, is currently conducting clinical trials of an earlier version of the technique. Reijo Pera and Behr hold stock in the company.

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There’s a nice article  in the current issue of Harvard Magazine on C-sections and their rising rates. One online commenter calls it “quite likely the most comprehensive and accurately written overview of the obstetrical situation in the U.S.” that she’s ever read, and I also appreciated writer Nell Lake’s balanced approach on an issue that Lake accurately describes as “much contested.”

Previously: Unneeded cesareans are risky and expensive, NIH panel weighs in on vaginal birth after cesarean and NIH panel weighs in on vaginal birth after cesarean
Via Longreads

Stanford researchers and several collaborating institutions have helped nearly a dozen hospitals in California significantly improve breast milk feeding rates for premature infants, a strategy that carries larger implications for assisting hospitals in adopting underused evidence-based practices.

A paper (subscription required) describing the researchers’ findings was published this week in Pediatrics. Hospitals participating in the study received an information package detailing ten best practices for promoting breast milk feeding in premature infants in the NICU. Health-care providers were encouraged to implement the methods in any order they wished and were supported in making modifications to hospital practices. My colleague explains more in a release:

Over the 12-month study and subsequent six-month follow-up period, the 11 participating hospitals increased their rates of breast milk feeding for NICU babies at discharge from 55 percent to 64 percent, bringing these hospitals up to the average rates for the state. (Some participating hospitals had above-average rates before the study began, and enrolled to both learn and share their expertise with other institutions, [Paul Sharek, MD, the senior author of the new research] noted.) Participating hospitals also reduced the rate of a serious complication of prematurity — the bowel disease known as necrotizing enterocolitis — by two-thirds, from 7 percent to about 2 percent of all infants in their NICUs.

The fact that the hospitals continued to sustain, and even improve on, their gains after the 12-month intervention ended is “a really important quality statement,” said Sharek, who is also the medical director of the Center for Quality and Clinical Effectiveness at Packard Children’s. “In many quality-improvement projects, improvements decrease after the hospitals’ attention is transitioned to another project. Something about our approach, and the changes made at the participating hospitals, resulted in a lasting improvement.”

During the study, hospitals made two important changes: increasing babies’ skin-to-skin time with their mothers and improving the education of NICU staff about breast milk feeding. Before the study began, four of 11 hospitals reported that their staff had a comprehensive knowledge base and skill set in breast milk nutrition. After the study, the number rose to 10 of 11 hospitals. The number of hospitals providing daily skin-to-skin time for moms and babies increased from six to 11 during the study.

Previously: More-nutritious breast milk for preemies
Photo by bradleyolin

Our immune systems are designed to respond to dangerous intruders. While the obvious laundry list of bad guys consists of pathogenic viruses and bacteria, there are several other inhabitants that exist within an immunological gray area. Cancerous cells, for example, are not foreign. They’re just badly-behaved versions of our own cells. While it is known that the immune system frequently disciplines cells with cancer pipe dreams by killing them, the existence of malignant disease shows that sometimes the selfish cells get their way.

On the other side of the coin, consider the developing fetus, which contains DNA from both mother and father, and is therefore partially foreign to the mother’s immune system. Unlike cancer – a mischievous self – the fetus is a precious foreign inhabitant that must be nurtured rather than eliminated. In a study recently published in Nature, researchers led by Jared H. Rowe, PhD, at the University of Minnesota, illuminate the mechanisms that the immune system employs to shelter the fetus from attack.

Although T cells are best known for their seminal role in sniffing out foreign invaders and killing them, some T cells are immunological wet blankets instead. T regulatory cells (Tregs) dampen immune responses to harmless inhabitants, and are known to play a key role in protecting the developing fetus from attacks waged by their killer T cell cousins. Rowe’s study moves this story a step further by showing that, in a pregnant mouse model, this protective population of Tregs specifically recognizes paternal proteins expressed by the fetus. Following birth, these fetus-shielding Tregs stick around, lying in wait for the next pregnancy, when they perform their wet-blanketing duties with even more gusto than the first time around. If the father is different for the second pregnancy, then new Tregs need to be called to the job instead.

The study, which is the first to reveal fetal-specific “memory Tregs” that endure after the first pregnancy, could offer clues about the causes of preeclampsia, a syndrome which can lead to miscarriage. Preeclampsia is characterized by insufficient tolerance to the fetus, and it occurs with much higher frequency during first pregnancies or when the father is different in a subsequent pregnancy. Increased protection afforded by memory Tregs could therefore explain why second pregnancies with the same father are at lower risk for pre-eclampsia. The new data may also shed light on autoimmune disorders and point to novel therapies that promote the expansion of these party-poopers with a good memory.

Previously: Why some autoimmune diseases go into remission during pregnancy
Photo by Thomas van Ardenne

Jessica Shugart, a science writing intern with a PhD in immunology, is a graduate student in the Science Communication Program at UC Santa Cruz.

Earlier this week, a bill designed to better protect pregnant women in the workplace was introduced in the U.S. Senate. Under the Pregnant Workers Fairness Act, employers would be required to provide mothers-to-be with “reasonable accommodations” – akin to protections provided by the Americans with Disabilities Act. As described by Health Watch, “a boss might have to reassign heavy-lifting tasks, for example, or provide a pregnant employee with a stool if she experiences pain while standing for long periods during work.”

More from that blog:

The National Women’s Law Center (NWLC), a group that supports the bill, says it would toughen a 1978 law that banned discrimination toward pregnant women.

The Pregnancy Discrimination Act is not enough on its own, the NWLC argues, because some pregnant women have not been sufficiently protected under that law.

In one case cited by the group, Wal-Mart fired a pregnant employee for insubordination after she refused to stop carrying a water bottle at work as recommended by her doctor.

In another case, a pregnant Old Navy employee was dismissed after she asked to be exempt from climbing ladders and lifting heavy objects for the final month and a half before her maternity leave.

Via Our Bodies Our Blog

About 15 million premature babies are born worldwide each year. Infants born before 37 full weeks are at an increased risk for health complications, including cerebral palsy, developmental delays, and impaired vision and hearing. Researchers from Sweden have developed a new method that may predict preterm delivery and hope the test can offer new possibilities to delay delivery or better prepare parents in caring for their premature baby.

In a study (subscription only) published in Obstetrics & Gynecology, researchers studied 142 pregnant women who came to Sahlgrenska University Hospital in Gothenburg, Sweden during the years 1995-2005 with early contractions without rupture of the membranes. They were able to predict with 75 to 80 percent accuracy if a pregnant woman with contractions will give birth within seven days. Researchers discussed the significant of the findings in a University of Gothenburg release:

“To have time to give the woman cortisone, which speeds up the development of the fetal lungs, it is common practice to delay the delivery by a couple of days with the help of tocolytic treatment. Being able to predict if a woman who comes to the hospital with preterm contractions will actually give birth early and thereby requires follow-up and possible treatment is therefore very important,” according to Panagiotis Tsiartas, researcher at the Sahlgrenska Academy, University of Gothenburg and specialist at the Obstetrical and Gynecological Clinic at Sahlgrenska University Hospital.

The method is based on a newly developed blood test that looks at two specific proteins in the woman’s blood combined with an already established examination that uses ultrasound to measure the length of the cervix.

The authors noted that further research is needed before this method can be used in a clinical setting.

Previously: How Stanford researchers are working to understand the complexities of preterm birth, Hormone could prevent 10,000 preterm births per year, New research center aims to understand premature birth, Device designed to better detect preterm labor and Moms who were born prematurely more likely to have premature babies themselves
Via Medical News Today
Photo by  MammaLoves

My husband has often told me I deserve a medal after giving birth to two girls in two years. There’s a lot of blood, sweat and tears involved with having kids, and I couldn’t help but feel amused when I saw the headline – “After a Baby, a Gold?” – of a New York Times blog entry that a colleague (also a mom with two daughters) brought to my attention today. In the piece, writer David Gendelman looks at something a handful of the women competing in this year’s Olympic high jump have in common (well, besides trying to win gold): They’re all new mothers.

Is it a coincidence that these women are performing so well after childbirth, or does having children actually make you stronger? (One mom-competitor reports that she can squat “a lot more” than the 225 pounds she could before having her second daughter.) Sports medicine specialist Elizabeth Joy, MD, isn’t sure about the purported performance-enhancing effects of pregnancy, but she offers one explanation for why athletes may feel so good and strong after delivery:

When a woman delivers, she still has this incredibly expanded blood volume, which declines over the next six weeks. But in that first six-week postpartum period, and particularly among elite athletes who are very fit, I bet they’re getting back to exercise pretty quickly. After their delivery, they just lost 15 pounds. They probably do feel like they have this huge engine with a much lighter load.

Benjamin Levine, MD, who teaches exercise sciences at the University of Texas Southwestern Medical Center, also can’t attribute a single factor to postpartum strength, but he thinks perhaps parenting has a positive change on the mental perspective of these Olympic-competing moms. “It’s a major life change, and the ones that deal with it and thrive, perhaps it focuses their concentration. Maybe they have more to win for. Maybe they’re more highly motivated.”

So even though there may be no scientific evidence indicating a link between strength and childbirth, I thought high jumper Amy Acuff said it best when she described why working out seemed easier after having a baby. “I thought about how I do almost the same thing with a 20-plus pound baby all day that I did with the medicine ball,” she said.

Oh – and Hubby, if you’re reading this, a medal is nice but getting more sleep would be even sweeter.

Previously: How safe is rigorous exercise during pregnancy?, Pregnant curler competing in Olympics and Pregnant and on the move: The importance of exercise for moms-to-be
Photo by Steve Fair

More news from the International AIDS Conference: Stanford researchers have presented findings showing that family planning counseling could be a cost-effective way to help minimize the number of children born HIV-positive in sub-Saharan Africa. The study involved 98 HIV-positive women – two-thirds of whom attended three 90-minute group courses on family planning, sexual negotiation, and self-esteem building. My colleague Ruthann Richter, who has been reporting from the conference, writes:

According to [Clea Sarnquist, DrPH, MPH, a senior research scholar in pediatrics] and her colleagues, about 40 percent of pregnancies in sub-Saharan Africa are unplanned. Such unwanted pregnancies could be prevented if women relied on long-acting forms of contraception — such as the intra-uterine device, or IUD, or hormonal implants — rather than birth control pills or diaphragms. Indeed, the researchers found that [three months] after receiving group counseling almost 90 percent of the HIV-positive women in the study chose a long-acting form of contraception.

The women in the study, which was conducted in a suburban region of Zimbabwe, also said they felt a greater sense of power in negotiating sexual activity, including condom use, and were more open with their partners about their HIV status, the researchers reported.

Sarnquist, who is hoping to expand the study to a larger population of women who could be followed over a longer period of time, said of the significance of this work, “If you can help prevent HIV-positive women from having unplanned children, obviously you’re going to prevent unnecessary HIV transmission.”

Previously: International AIDS Conference Day Four: Focusing on a vaccine, International AIDS Conference Day Three: Daring to talk about a cure, International AIDS Conference Day Two: Hillary Clinton envisions AIDS-free generation, International AIDS Conference: Day One, WHO’s new recommendations on contraceptive use and HIV and New book shows the pain and hope of AIDS orphans

Recently published research from Tufts University suggests that babies born to obese mothers have lower iron levels at birth than those born to moms at a healthy weight.

The reason? Obesity causes chronic low-grade inflammation that boosts production of hepcidin, a protein that lowers circulating iron levels. Hepcidin production is a helpful part of the immune response if an infection is present: since many bugs need iron to reproduce, keeping blood iron levels low is a good infection-fighting mechanism. But if too much hepcidin is inappropriately produced in pregnancy, it may interfere with iron transfer to the fetus, the new research found.

The impact on the babies’ health isn’t entirely clear, but could be significant. ScienceDaily reports:

Because iron plays a crucial role in the formation of the central nervous system, children born with iron deficiency are at a greater risk for delays in motor and cognitive development.

“The data on the impact of low maternal iron levels on the fetus comes from undernourished populations,” said first author Sarbattama Sen, MD, a neonatologist at Tufts Medical Center and an assistant professor of pediatrics at Tufts University School of Medicine (TUSM). “To the best of our knowledge, ours is the first study to demonstrate that obesity might hamper iron transfer from mother to child and offers some insight into the mechanism of how it occurs. Future studies, however, are needed to confirm the role of obesity associated with inflammation during pregnancy on hepcidin and iron status of the newborn.”

For now, the story concludes, pregnant mothers at any weight should eat a balanced diet, take their prenatal vitamins (which include extra iron) and follow their doctors’ advice about how much weight to gain in pregnancy. Study authors say further work is needed to assess whether nutrition recommendations for pregnant women should be modified to take obesity into account.

Earlier this month, researchers presented findings at the annual Pediatric Academic Societies meeting showing women who consume high doses of vitamin D during pregnancy have a significantly reduced risk of complications.

Now new research from the University of Southampton in the U.K. offers additional insights into how mothers’ vitamin D levels may influence their offspring’s health. In the study (.pdf), researchers followed 977 pregnant women and compared their vitamin D levels with the body composition of their children three weeks after birth and at age 4 and age 6.

Results showed children born to mothers who had low vitamin D status in pregnancy had more body fat when they were 6 years old. Healthland reports:

How vitamin D in mothers affects their children’s weight gain remains unknown, but the authors speculate that there are “programmed effects on the fetus that arise from maternal vitamin D insufficiency that remain with the [baby] and that may predispose him or her to gain excess body fat in later childhood.”

The researchers add that childhood weight gain can also be attributed to other issues associated with insufficient maternal nutrition like too much or too little weight gain by pregnant mothers.

Previously: Better diet in pregnancy shown to protect against birth defects
Photo by Aristocrats-hat