October 26th, 2009 
Women who are obese during pregnancy are at increased risk for preterm birth, preeclampsia, gestational diabetes, cesarean delivery and postpartum weight retention, according to data presented today.
Kimberly K. Vesco, MD, MPH, obstetrician-gynecologist at Mount Talbert Medical Office and Kaiser Sunnyside Medical Center, presented data on pregnancy outcomes and postpartum weight retention for 5,551 normal-weight women and 3,110 obese women included in an HMO database.
Weight gain at one year defined the difference between baseline weight during pregnancy and weight at 300 to 420 days postpartum.
Mean baseline weight was 131 lb for normal-weight women vs. 214 lb for obese women. Mean gestational weight gain was lower among obese women compared with normal-weight women (22 lb vs. 32 lb; P<.001). However, 33% of obese women gained more than 10 lb at one year postpartum compared with 22% of normal-weight women (P=.0001).
Obese women had an increased risk for preterm birth (10% vs. 8%), preeclampsia (15% vs. 6%), gestational diabetes (8% vs. 3%) and cesarean delivery (36% vs. 20%; P<.001).
Further, infants born to obese women had a higher mean birth weight when compared with infants born to normal-weight women (P<.001).
Study results also revealed that obese women were more likely to smoke (7% vs. 10%), have a diagnosis of depression (7% vs. 11%) and hypertension during pregnancy (9% vs. 22%), and have diabetes (1% vs. 5%; P=.0001) compared with leaner women.
“There should be inquiries to prevent weight loss among obese reproductive-age women, particularly those planning a pregnancy,” Vesco said during the oral presentation. “In addition, programs should be developed to limit gestational weight gain during pregnancy and to assist with weight loss after delivery.”
Related
- Excess weight raises pregnancy risks: study
Being overweight or obese increases a woman’s chances of having an extra-big baby, even after the effects of pregnancy-related, or “gestational,” diabetes are taken into account, new research shows.
Excess weight in and of itself also sharply increased a woman’s risk of pre-eclampsia, a potentially deadly pregnancy complication, Dr. Boyd E. Metzger of Northwestern University Feinberg School of Medicine in Chicago and his colleagues found.
Women have more difficulty delivering very large babies, while these newborns are also at risk of suffering injury during birth, including shoulder dislocation. While women who are overweight or obese are known to run a greater risk of having very large babies and experiencing other pregnancy complications, it has been difficult to separate out the effects of a mother’s weight from those of gestational diabetes, Metzger and his colleagues note in the British Journal of Obstetrics and Gynecology.
This led them to investigate whether body mass index (BMI) — a standard measure of weight in relation to height used to gauge how fat or thin a person is — might influence pregnancy risks and fetal and newborn health, independently of a woman’s blood sugar levels.
The study involved 23,316 women from 15 different medical centers in nine different countries. All had undergone an oral glucose tolerance test, which is used to identify women with, or at risk for, pregnancy-related diabetes; at that time, their height and weight were measured, too.
The researchers then used statistical techniques to control for women’s oral glucose tolerance test results. Even after this adjustment, they found that the women with BMIs of 42 or greater, denoting severe obesity (for example, a 5-foot-5-inch tall woman weighing at least 250 pounds), were at more than triple the risk of having an excessively large baby, compared to the thinnest women in the study, who had BMIs of 22.6 or less (a 5′5″ woman weighing less than 138 pounds).
The heaviest women’s risks of having a C-section were more than doubled, while their likelihood of pre-eclampsia was 14-fold greater than for the leanest women. However, the heaviest women’s risk for delivering a preterm baby was actually cut in half.
These findings help sort out the role BMI and gestational diabetes each play in the risk of complications of pregnancy and delivery, Metzger told Reuters Health in an interview.
He noted that recent studies have shown that dietary changes can effectively treat gestational diabetes for more than 90 percent of women with the condition.
“We’re pretty confident that treating gestational diabetes going forward is going to continue to be beneficial,” the researcher said. “We have much less evidence at this point as to how to neutralize or reduce the impact of overweight on pregnancy outcome.”
What is becoming clear, he added, is that it’s probably a woman’s weight before she gets pregnant, rather than how much she gains during pregnancy, that’s important in determining risk.
- Excessive Weight Gain During Pregnancy Raises Gestational Diabetes Risk
Excessive weight gain during pregnancy, especially the first trimester, may increase a woman’s risk of gestational diabetes, say U.S. researchers.
Their three-year study included 345 pregnant women with gestational diabetes and 800 pregnant women without gestational diabetes, which is defined as glucose intolerance that typically occurs during the second or third trimester of pregnancy.
After the researchers adjusted for a number of factors — age at delivery, previous births, pre-pregnancy body-mass index and race/ethnicity — they found that women who gained more weight during pregnancy than recommended by the U.S. Institute of Medicine were 50 percent more likely to develop gestational diabetes, compared to those whose weight gain was within or below the IOM recommendations.
The link between pregnancy weight gain and gestational diabetes was strongest among overweight and non-white women.
The study was published online Feb. 22 in the journal Obstetrics & Gynecology.
Gestational diabetes — which causes complications in as many as 7 percent of pregnancies in the United States — can lead to early delivery, cesarean section and type 2 diabetes in the mother. It also increases the child’s risk of developing diabetes and obesity later in life.
- Chinese and Korean-American Women Have Increased Risk for Diabetes During Pregnancy
Chinese and Korean-American women are at a higher risk than Caucasian and African-American women of developing diabetes during pregnancy, according to a new study. The study, by researchers at Kaiser Permanente, also found that Pacific Islanders, Filipinos, Puerto Ricans and Samoans were also at a higher-than-average risk of developing diabetes during pregnancy, while Caucasian, native-American and African-American women have a lower than average risk.
Untreated diabetes during pregnancy can lead to complications to the women and fetus. It can also lead to the child becoming obese later in life, the researchers said in a statement.
According to the study, as many as 10 percent of women of Chinese and Korean descent could be at risk of developing the disease during pregnancy.
The study is published in the journal Ethnicity and Disease.
- Prompt treatment beneficial for pregnant and postpartum women with H1N1
Delayed treatment of suspected influenza A (H1N1) illness among pregnant women may result in a four-fold risk of intensive care admission or death, according to results of a recent study.
Regardless of rapid antigen test results, prompt evaluation and antiviral treatment should be considered for pregnant or postpartum women displaying influenza A (H1N1)-like symptoms, according to researchers from the California Department of Public Health.
The study was a review of records for women of reproductive age who had been hospitalized or died from influenza A (H1N1) between April 23 and August 11, 2009.
The study involved 94 pregnant women, 137 non-pregnant women and 8 postpartum women who had delivered <2 weeks prior. False negative results for rapid antigen tests were observed in 38% of patients.
Among 94 pregnant women, 95% were in the second or third trimester. Risk factors for complications from influenza other than pregnancy were observed in 32 of 93 (34%) of those pregnant women.
Early antiviral treatment was defined as treatment <2 days after the onset of symptoms. Pregnant women treated later than this had an RR of 4.3 for admission to an ICU or death.
Intensive care was required for 18 pregnant women and four postpartum women (total, 22 of 102 [22%]). There were eight deaths (8%).
Of six deliveries which took place in the ICU, four were emergency cesarean deliveries.
The specific mortality ratio associated with influenza A (H1N1), which the researchers defined as the number of maternal deaths per 100,000, was 4.3.
- Too little weight gain risky in twin pregnancy
Women pregnant with twins should be sure to gain the recommended amount of weight, according to a new study, which shows that gaining less weight than recommended during a twin pregnancy ups the risk of early birth and low weight babies.
“A woman should gain about a pound a week; less than that, and we had smaller babies and more pre-term births,” Dr. Nathan Fox of Maternal-Fetal Medicine Associates of New York City told Reuters Health.
Fox and his partners wanted to know if the twin pregnancy weight gain guidelines updated by the Institute of Medicine in 2009 made a difference in pregnancy outcomes.
These recommendations suggest a range of weight gain depending on a woman’s weight at the start of her twin pregnancy. A normal weight woman should gain 37 to 54 pounds; an overweight woman, 31 to 50 pounds; and an obese woman, 25 to 42 pounds.
In looking at 281 mostly normal weight women pregnant with twins, Fox and colleagues found that women who gained the recommended amount of weight did much better in regards to the pregnancy outcomes.
Women who gained less than the recommended amount of weight were more likely to give birth early (before 32 weeks of pregnancy) than women who gained the correct amount of weight (14 percent versus 5 percent). They were also more likely to give birth to smaller babies.
Unlike in singleton pregnancies, gaining enough weight in twin pregnancies can be Herculean task. “It’s often not easy,” Fox said. “We send our patients to nutritionists and have them on high calorie diets a lot to have them gain the right amount of weight. It’s not easy for many (women).”
About 3 in every 100 pregnancies is a twin pregnancy, the investigators note, and preterm births occur about 60 percent of the time, making the issue of correct weight gain even more important.
The strong link between inadequate weight gain in twin pregnancies and increased rates of pre-term birth “has not been conclusively demonstrated previously,” the investigators point out in the journal Obstetrics & Gynecology.
Their findings, they say, shed light on the importance on what “could be a correctable cause of prematurity in twins,” they conclude.
