Author Insights: Daily Vitamin C for Women Who Smoke During Pregnancy May Help Improve Lung Function of Their Children

Cindy McEvoy, MD, MCR of Oregon Health & Science University discusses the beneficial effects in women who smoke of taking vitamin C during pregnancy. Image from author.

Cindy McEvoy, MD, MCR of Oregon Health & Science University discusses the benefits of vitamin C supplementation for women who smoke during pregnancy. Image from author.

Though it’s well established that smoking during pregnancy is not good for fetal health, some women who smoke have difficulty quitting the habit during pregnancy. Now, according to new research, there may be a way to help protect the lung function of infants born to such women: a simple daily vitamin C pill.

The findings were described in a study released in JAMA in concert with its presentation at the American Thoracic Society meeting in San Diego on Sunday.

Researchers from Oregon Health & Science University in Portland randomly assigned a group of 179 pregnant women who smoked to receive either a daily 500 mg vitamin C pill or a placebo pill during the early stages of pregnancy. When the investigators assessed the newborns’ with standardized pulmonary function tests within 3 days of birth, they found that 2 important measures of lung function (the ratio of time to peak tidal expiratory flow to expiratory time and the passive respiratory compliance) were significantly better in newborns of mothers who took vitamin C compared with those who did not. At 1 year of age, however, these differences on pulmonary function tests were no longer significant.

However, at 1 year of age, the percentage of infants who had wheezing, as reported by their primary caregivers, was significantly different between the two groups: 15% in the vitamin C group vs 30% in the placebo group.

Lead author Cindy McEvoy, MD, MCR, discussed these findings with news@JAMA.

news@JAMA: Why did you conduct this study?

Dr McEvoy: Unfortunately, 50% of pregnant smokers are unable to quit smoking during pregnancy, and this has significant negative effects on the fetus, particularly on their future lung function and asthma risk. We had compelling preliminary data from studies in monkeys to support our hypothesis that daily vitamin C may help improve the babies’ lung function, and did this study to investigate this possibility.

news@JAMA: The primary measures of lung function that you found to be better in infants of the vitamin C group were the ratio of time to peak tidal expiratory flow to expiratory time, and the passive respiratory compliance. What do these measures actually mean in terms of how well the infants’ lungs are working?

Dr McEvoy: Basically, it means that the lungs are less stiff—in other words, more compliant. The small airways of the lungs are healthier, so it is easier to move air in and out when breathing. When moving air in and out of the small airways becomes difficult, wheezing occurs.

news@JAMA: Why did you no longer see a difference in lung function testing at 1 year of age? How do you explain the differences in wheezing observed at 1 year when there was no difference in lung function measures?

Dr McEvoy: One possibility for why we didn’t see differences in the 1-year pulmonary function tests is because we were only able to get this testing on about two-thirds of all the infants studied at delivery. Also, the pulmonary function tests at 1 year were done with the infants sedated, while the newborn tests were done with nonsedated infants. The use of passive respiratory mechanics at 1 year may have been less sensitive to detect lung function abnormalities. In terms of wheezing, we were able get this history from more than 90% of the patients studied at delivery, so that may have accounted for the differing results.

news@JAMA: Are you going to follow up these infants longer? What are the next steps for this research?

Dr McEvoy: Yes, we are currently getting follow-up respiratory histories on these infants. We are also doing additional studies looking at more sensitive pulmonary function tests, as well as some potential epigenetic changes caused by smoking during pregnancy that can be potentially prevented by vitamin C.

news@JAMA: Even though taking vitamin C during pregnancy seems to help with infant lung function at birth, you mention in your article that, importantly, it does not negate the other negative effects of smoking during pregnancy on newborn health. So what is the take-home message for pregnant smokers, based on this study?

Dr McEvoy: The ideal solution is still for pregnant smokers to quit smoking. But if they are unable to quit, vitamin C may be helpful for their infants’ lung function.

Opening Day Isn’t an Indication for Cesarean Delivery

Image: ©iStock/ryan_christensen

A sportscaster was sharply criticized for suggesting that a baseball player’s pregnant wife should have opted for  “elective” cesarean delivery before the start of baseball season so that her husband would not miss playing on opening day. Image: ©iStock/ryan_christensen

Although one doesn’t expect hear the phrases “C-section” and baseball season “opening day” in the same breath, that’s what happened last week when sportscaster Boomer Esiason criticized New York Mets second baseman Daniel Murphy on Esiason’s morning radio show for Murphy’s decision to miss the first 2 games of the regular season to be with his wife and newborn son. And when Esiason suggested that the couple should have opted for “elective” cesarean delivery of their son before the season started, it triggered an avalanche of criticism for his remark and sparked discussions about paternity leave and the potential risks of elective cesarean delivery.

According to the Centers for Disease Control and Prevention, 1 of 3 births in the United States is a cesarean delivery. However, elective cesarean delivery, which is performed before the onset of natural labor based on the mother’s request, is a small fraction of overall births. Because there are no medical reasons for performing this surgery, there also are no clear-cut health benefits for either mother or newborn.

In contrast, medically indicated cesarean deliveries are performed to benefit the health of the mother or baby, primarily because of placental abnormalities (such as placenta previa, in which the placenta covers all or part of the opening of the cervix) or the position of the fetus (such as a breech presentation, in which the infant’s feet or buttocks enter the birth canal first rather than the head). Pregnant women with genital herpes simplex infection who have active lesions or women with HIV infection who have high levels of the virus in their bodies also are advised to undergo the procedure to prevent transmitting the infection to the infant during childbirth. In addition, women who have had a previous cesarean delivery are often advised to undergo the procedure with subsequent births.

“We do [cesarean delivery] all the time for breech babies,” explains Caren Stalburg, MD, clinical assistant professor of obstetrics and gynecology at the University of Michigan. But obstetricians also see patients who feel they have compelling reasons for requesting the procedure on an elective basis. Stalburg says that when a woman requests a cesarean delivery, she begins a discussion early and tries to understand the patient’s reasons, such as worries about tears in the perineum, the area between the vagina and anus. “I explore the topic and massage all of the reasons. Is she afraid of the birth process? Is she worried about her perineum?”

Stalburg has coined what she calls the “6 Cs of elective cesarean delivery: clarification of request, comorbidities (other health conditions) in the mother, number of children planned, consent, correct gestational age, and confirmation of insurance coverage. These 6 Cs provide a useful framework for decision making about elective cesarean sections. “The discussion is very different in a 21-year-old having her first child vs a 40-year-old having her only child,” explains Stalburg, who notes that the risk of surgical complications and subsequent placental abnormalities increase with each additional cesarean delivery.

As with any medical procedure, the risks and benefits of planned cesarean delivery should be considered. In addition to convenience, a concern about pelvic floor dysfunction (which occurs when the muscles in the pelvic area are weakened or injured, resulting in problems such as urinary incontinence) is frequently cited as a reason for opting for the procedure on an elective basis. But “risk of pelvic floor dysfunction shouldn’t be the only reason to have an elective section,” says Stalburg, who notes that although the incidence is lower with cesarean delivery, some risk remains. On the risk side of the equation, the procedure involves an increased likelihood of breastfeeding difficulties, postoperative pain, longer recovery time, and wound infection.

Risks of elective cesarean delivery also extend to the newborn. For example, uncertainty surrounding gestational age can result in prematurely delivering an infant thought to be full term. Stalburg explains that infants have an increased risk of respiratory difficulties if they are delivered before 39 weeks of gestation, so it’s important to confirm gestational age.

Regarding insurance coverage, some carriers may not provide full coverage for elective cesarean delivery. Stalburg advises all of her patients to discuss potential restrictions with their insurance company.

Finally, social issues frequently play a role in the birth process. For example, Stalburg has cared for patients whose husbands were going to be deployed on a particular date. “Although elective C-section is an option, scheduled induction of birth may be another option,” says Stalburg, who adds that a woman’s recovery after an uncomplicated vaginal birth is generally faster than after cesarean delivery.

Stalburg says it is essential that women who feel they have compelling reasons for requesting an elective cesarean delivery understand the ramifications.

“If she has made an informed choice and has a good understanding of the risks and benefits, and if after multiple discussions and visits, she decides this is the best option for her and her baby, I feel ethically comfortable with the option,” says Stalburg.


For additional information:

Ecker, J. Elective cesarean delivery on maternal request. JAMA. 2013:309[18]:1930-1936.


Malnutrition May Interfere With HIV Treatment in Pregnant and Breastfeeding Women

   To protect child health, public health authorities in Uganda must combat both malnutrition and mother-to-child transmission of HIV.  Image: JAMA, ©AMA

To protect child health, public health authorities in Uganda must combat both malnutrition and mother-to-child transmission of HIV. Image: JAMA, ©AMA

Malnutrition may reduce levels of human immunodeficiency virus (HIV) medications in pregnant or breastfeeding women, which may hamper efforts to prevent mother-to-child transmission, according to a study published today in the The Journal of Clinical Pharmacology.

Maternal infections with HIV in sub-Saharan Africa present a pressing public health concern, with as many as 40% of pregnant women infected, according to the study authors. Antiretroviral treatment during pregnancy and breastfeeding can substantially reduce the risk that these mothers will pass the virus to their newborns, so many governments and aid organizations have emphasized maternal treatment as a way to curb transmission. The new findings bolster previous evidence demonstrating the importance of addressing malnutrition simultaneously with drug treatment.

Imke H. Bartelink, PharmD, of the University of California, San Francisco, and colleagues from the United States and Uganda found that malnutrition may complicate efforts to reduce mother-to-child transmission through antiretroviral treatment. The study involved 225 Ugandan women who were being treated for HIV infection. Many were malnourished; 80% reported lacking adequate food for their families, 50% reported moderate to severe hunger, and 26% lost weight during pregnancy.

The researchers analyzed blood spots and hair samples from the women for lopinavir, ritonavir, and efavirenz levels. They found that drug levels were substantially reduced in malnourished study participants compared with well-nourished participants, with a decrease in exposure of 33% for lopinavir, 15% for efavirenz, and 17% for ritonavir. As expected, they also found that during pregnancy the body clears lopinavir and ritonavir more quickly, something that clinicians account for when dosing pregnant women.

Previous studies also have suggested that malnutrition may reduce the likelihood that patients taking antiretroviral medication will take them as prescribed, without skipping doses. Bartelink and colleagues used the samples as a means to verify whether the adherence rates that patients reported were accurate, and confirmed that such testing can be a useful tool in helping to verify adherence.

Task Force Backs Screening Women for Gestational Diabetes Late in Pregnancy

A US task force recommends routinely screening women for gestational diabetes after 24 weeks of pregnancy. Image: MayaMoody/

A US task force recommends routinely screening women for gestational diabetes after 24 weeks of pregnancy. Image: MayaMoody/

All pregnant women should be screened for gestational diabetes but not until the pregnancy has passed the 24th week, according to a new recommendation from the US Preventive Services Task Force (USPSTF) published today in the Annals of Internal Medicine. In 2008, the task force had found insufficient evidence to support routine screening for gestational diabetes in women.

About 6% of pregnant women in the United States develop symptoms of diabetes during pregnancy. In certain populations, particularly minority populations, the rate can be as high as 25%. If left untreated, gestational diabetes increases the risk of poor outcomes for mother and child. Women with gestational diabetes may develop life-threatening preeclampsia, and the fetus may grow unusually large, leading to a complicated delivery and possible injury to the newborn. To avert these problems, nearly all (96%) US pregnant women are currently screened for this condition so that their blood sugar levels may be managed, if needed.

Women who are identified as having gestational diabetes may be advised to increase physical activity, make dietary changes, and monitor their glucose levels. If those steps don’t improve the condition, medications may be prescribed. The USPSTF in 2008 found inadequate evidence to support screening for gestational diabetes before or after 24 weeks, despite the widespread adoption of screening. Other prominent groups such as the American Academy of Family Physicians, the American Diabetes Association, and the Endocrine Society recommend screening after 24 weeks.

But the USPSTF’s new review of the evidence found enough evidence to support the benefits of screening for gestational diabetes after 24 weeks, and the task force has updated its recommendation accordingly. The review did not find sufficient evidence to support screening before 24 weeks, but the report notes that there may be specific circumstances in which a physician may choose to do so. For example, if a woman has risk factors that place her at greater risk, such as obesity or a family history of gestational diabetes, her physician may want to consider earlier screening.

Raw Milk Risky, Especially for Children, Pregnant Women

Raw milk may cause more illnesses that previously recognized, a new study finds. Image: Maria Volchetskaya/

Raw milk may cause more illnesses that previously recognized, a new study finds. Image: Maria Volchetskaya/

As many as 1 in 5 individuals who consume raw milk develop related infections, including some that are life threatening, particularly to young children, suggest new data from the Minnesota Department of Health published in the journal Emerging Infectious Diseases. In light of these risks, the American Academy of Pediatrics (AAP) is reaffirming its position that children and pregnant women should avoid consuming raw milk products.

Prior to widespread pasteurization of milk in the 1920s, raw milk was a major driver of foodborne illnesses in the United States, according to a policy statement published in Pediatrics. Among the pathogens that were routinely passed through raw milk were Mycobacterium tuberculosis, Brucella abortus, Streptococcus, and enteric pathogens such as Salmonella. These microbes found their way into milk via various routes, including contamination of milk by cows’ feces or through contact with a cow’s skin or other potentially contaminated surfaces or animals. Ill cows could also transmit infections. But pasteurization, which involves briefly heating milk above 161°F and then rapidly cooling it, kills such pathogens.

Today only 1% to 3% of all milk consumed is unpasteurized, but serious outbreaks continue to occur among those ingesting raw milk. Between 1998 and 2011, there were 148 outbreaks associated with raw milk consumption, resulting in 2384 illnesses, 284 hospitalizations, and 2 deaths, according to the US Centers for Disease Control and Prevention (CDC).

But the analysis by the Minnesota Department of Health suggests that the CDC’s figures may underestimate the risks associated with raw milk consumption because many illnesses are sporadic and are not part of a larger outbreak. The department found 530 sporadic raw milk–associated cases compared with 21 raw milk–associated outbreaks. Based on this analysis and the number of Minnesotans drinking raw milk, the department estimates that between 2001 and 2010, 20 502 raw milk drinkers—nearly 1 in 5—had become ill as a result of drinking raw milk. One-quarter of the cases occurred in children younger than 5 years and 1 child death was documented.

Children and pregnant women are particularly at risk of serious raw milk–related illness. Pregnant women face an increased risk of stillbirth; preterm delivery; and delivering a child with a serious infection, such as sepsis or meningitis. Young children have an elevated risk of diarrhea caused by Escherichia coli 0157, which can lead to life-threatening hemolytic-uremic syndrome.

Some advocates of raw milk say this food is more nutritious than pasteurized milk and offers other health benefits. But the AAP found no evidence supporting these claims and emphasizes that the risks far outweigh any potential benefits.

“Given the progress we have made in prevention, there is no reason to risk consuming raw milk in this day and age,” said AAP statement coauthor Jatinder Bhatia, MD, in a statement. “Consumption of raw milk products is especially risky for pregnant women, infants, immunocompromised individuals, and the elderly, and the evidence overwhelmingly establishes the benefits of pasteurization on food safety.”

Fat Cell Hormone May Help Predict Gestational Diabetes

The fat cell hormone adiponectin may help predict which women are at increased risk of developing gestational diabetes. (Image: nyul/

The fat cell hormone adiponectin may help predict which women are at increased risk of developing gestational diabetes. (Image: nyul/

Researchers have found that low levels of the hormone adiponectin detected as early as 6 years before pregnancy may help predict which women have an increased risk of developing gestational diabetes.

Adiponectin is secreted from fat cells and plays a key role in regulating glucose and lipid metabolism. Because pregnancy decreases insulin sensitivity, which causes adiponectin levels to plummet, researchers wanted to know the extent to which prepregnancy levels of the hormone might affect the risk for gestational diabetes.

Investigators at Kaiser Permanente Northern California in Oakland analyzed records of 4098 women who had a routine checkup between 1985 and 1996 and subsequently delivered an infant by 2010. Of the group, 256 developed gestational diabetes, which is a common complication of pregnancy. The condition can increase a woman’s risk of developing types 2 diabetes after delivery by 7-fold. Children of women with gestational diabetes are at increased risk for becoming obese and developing diabetes.

As part of their routine care, women in the study had provided an extra blood sample that was stored for future use. On average, 7 years passed between the time they gave blood and became pregnant. For each woman with gestational diabetes, 2 matched control participants were selected.

Adiponectin levels in the blood samples were measured and divided into quartiles, from highest to lowest levels. After adjusting for variables including family history of diabetes, body mass index, and glucose and insulin concentrations in blood, analyses showed that women with the lowest adiponectin levels about 6 years before pregnancy had a 5-fold increased risk of developing gestational diabetes compared with women having the highest levels. The risk increased by 7-fold among overweight women with low adiponectin levels.

Among normal-weight women, those with low adiponectin levels had a 3.5-fold increased risk of gestational diabetes compared with women having the highest levels. Among women with high adiponectin levels, those who were overweight or obese had a 2-fold increased risk of developing gestational diabetes compared with normal-weight women.

“Our findings indicate important pregnancy interventions may be possible before a woman even conceives,” principal investigator Monique M. Hedderson, PhD, a research scientist with Kaiser Permanente in Oakland, said in a statement.

“Adiponectin levels are easy and inexpensive to measure and could potentially be used to identify women who are at risk for gestational diabetes,” she added. “Future research is needed to determine whether lifestyle interventions targeting diet and physical activity can increase adiponectin levels.”

Most Women Treated for Cancer as Children Are Able to Conceive

Most survivors of childhood cancers will eventually conceive, although it may take them longer to do so than women without a history of childhood cancer treatment, a study has found. Image: BrianAJackson/

Most survivors of childhood cancers will eventually conceive, although it may take them longer to do so than women without a history of childhood cancer treatment, a study has found. Image: BrianAJackson/

Two-thirds of women who are treated for cancer as children will eventually conceive, although it may take them longer than other women to do so, according to a study published today in Lancet Oncology.

The possibility of future infertility is a concern for parents seeking treatment for girls with childhood cancers, but physicians have had limited data on which to base treatment recommendations. Some studies have suggested birth rates were lower for survivors of childhood cancer. To provide better data, a multi-institution team of researchers collected and compared fertility data from women enrolled in the Childhood Cancer Survivor Study, including 3531 female childhood cancer survivors and 1366 female siblings, who served as controls.

The data indicate that compared with women in the sibling group, women who had been treated for childhood cancers did have a higher risk of infertility, defined as not conceiving after more than 12 months of attempts. But the good news was that even after experiencing such difficulties, most of the women with a history of childhood cancer treatment (64%) became pregnant. On average, childhood cancer survivors took longer than members of the control group to become pregnant.

The authors were concerned, however, to find that although the cancer survivors were as likely as the sibling control group to seek care for infertility, they were less likely to receive infertility treatment. The authors said it was not clear whether physicians were less likely to offer treatment to survivors, whether survivors were disinclined to pursue such treatment, or if other factors were at play. Survivors who had received pelvic radiation, alkylating agents, or total body irradiation were at higher risk of infertility than those who had not.

“What we found delivers a really nice message to clinicians,” said Lisa Diller, MD, medical director of the David B. Perini, Jr. Quality of Life Clinic at Dana-Farber Cancer Institute in a statement. “If you have a patient who is a childhood cancer survivor and is self-reporting clinical infertility, the chances are good that she will become pregnant. Women who have a history of childhood cancer treatment should consider themselves likely to be fertile. However, it might be important to see an expert sooner rather than later if a desired pregnancy doesn’t happen within the first 6 months.”