Mary Jo O'Sullivan

Maternal Morbidity Associated With Multiple Repeat Cesarean Deliveries

OBJECTIVE: Although repeat cesarean deliveries often are associated with serious morbidity, they account for only a portion of abdominal deliveries and are overlooked when evaluating morbidity. Our objective was to estimate the magnitude of increased maternal morbidity associated with increasing number of cesarean deliveries. METHODS: Prospective observational cohort of 30,132 women who had cesarean delivery without labor in 19 academic centers over 4 years (1999–2002). RESULTS: There were 6,201 first (primary), 15,808 second, 6,324 third, 1,452 fourth, 258 fifth, and 89 sixth or more cesarean deliveries. The risks of placenta accreta, cystotomy, bowel injury, ureteral injury, and ileus, the need for postoperative ventilation, intensive care unit admission, hysterectomy, and blood transfusion requiring 4 or more units, and the duration of operative time and hospital stay significantly increased with increasing number of cesarean deliveries. Placenta accreta was present in 15 (0.24%), 49 (0.31%), 36 (0.57%), 31 (2.13%), 6 (2.33%), and 6 (6.74%) women undergoing their first, second, third, fourth, fifth, and sixth or more cesarean deliveries, respectively. Hysterectomy was required in 40 (0.65%) first, 67 (0.42%) second, 57 (0.90%) third, 35 (2.41%) fourth, 9 (3.49%) fifth, and 8 (8.99%) sixth or more cesarean deliveries. In the 723 women with previa, the risk for placenta accreta was 3%, 11%, 40%, 61%, and 67% for first, second, third, fourth, and fifth or more repeat cesarean deliveries, respectively. CONCLUSION: Because serious maternal morbidity increases progressively with increasing number of cesarean deliveries, the number of intended pregnancies should be considered during counseling regarding elective repeat cesarean operation versus a trial of labor and when debating the merits of elective primary cesarean delivery. LEVEL OF EVIDENCE: II-2

Maternal Viral Load, Zidovudine Treatment, and the Risk of Transmission of Human Immunodeficiency Virus Type 1 from Mother to Infant

BACKGROUND AND METHODS A placebo-controlled trial has shown that treatment with zidovudine reduces the rate at which human immunodeficiency virus type 1 (HIV-1) is transmitted from mother to infant. We present data from that trial showing the number of infected infants at 18 months of age and the relation between the maternal viral load, the risk of HIV-1 transmission, and the efficacy of zidovudine treatment. Viral cultures were obtained, and HIV-1 RNA was measured by two assays in samples of maternal blood obtained at study entry and at delivery. RESULTS In 402 mother-infant pairs, the rate of transmission of HIV-1 was 7.6 percent (95 percent confidence interval, 4.3 to 12.3 percent) with zidovudine treatment and 22.6 percent (95 percent confidence interval, 17.0 to 29.0 percent) with placebo (P<0.001). In the placebo group, a large viral burden at entry or delivery or a positive culture was associated with an increased risk of transmission (the transmission rate was greater than 40 percent in the highest quartile of the RNA level). In both groups, transmission occurred at a wide range of maternal plasma HIV-1 RNA levels. Zidovudine reduced plasma RNA levels somewhat (median reduction, 0.24 log). Zidovudine was effective regardless of the HIV-1 RNA level or the CD4+ count at entry. In the zidovudine group, however, after we adjusted for the base-line HIV-1 RNA level and CD4+ count, the reduction in viral RNA from base line to delivery was not significantly associated with the risk of transmission of HIV-1. CONCLUSIONS A high maternal plasma concentration of virus is a risk factor for the transmission of HIV-1 from an untreated mother to her infant. The reduction in such transmission after zidovudine treatment is only partly explained by the reduction in plasma levels of viral RNA. To prevent HIV-1 transmission, initiating maternal treatment with zidovudine is recommended regardless of the plasma level of HIV-1 RNA or the CD4+ count.

Maternal viral load, zidovudine treatment, and the risk of transmission of human immunodeficiency virus type 1 from mother to infant

BACKGROUND AND METHODS A placebo-controlled trial has shown that treatment with zidovudine reduces the rate at which human immunodeficiency virus type 1 (HIV-1) is transmitted from mother to infant. We present data from that trial showing the number of infected infants at 18 months of age and the relation between the maternal viral load, the risk of HIV-1 transmission, and the efficacy of zidovudine treatment. Viral cultures were obtained, and HIV-1 RNA was measured by two assays in samples of maternal blood obtained at study entry and at delivery. RESULTS In 402 mother-infant pairs, the rate of transmission of HIV-1 was 7.6 percent (95 percent confidence interval, 4.3 to 12.3 percent) with zidovudine treatment and 22.6 percent (95 percent confidence interval, 17.0 to 29.0 percent) with placebo (P<0.001). In the placebo group, a large viral burden at entry or delivery or a positive culture was associated with an increased risk of transmission (the transmission rate was greater than 40 percent in the highest quartile of the RNA level). In both groups, transmission occurred at a wide range of maternal plasma HIV-1 RNA levels. Zidovudine reduced plasma RNA levels somewhat (median reduction, 0.24 log). Zidovudine was effective regardless of the HIV-1 RNA level or the CD4+ count at entry. In the zidovudine group, however, after we adjusted for the base-line HIV-1 RNA level and CD4+ count, the reduction in viral RNA from base line to delivery was not significantly associated with the risk of transmission of HIV-1. CONCLUSIONS A high maternal plasma concentration of virus is a risk factor for the transmission of HIV-1 from an untreated mother to her infant. The reduction in such transmission after zidovudine treatment is only partly explained by the reduction in plasma levels of viral RNA. To prevent HIV-1 transmission, initiating maternal treatment with zidovudine is recommended regardless of the plasma level of HIV-1 RNA or the CD4+ count.

Timing of elective repeat cesarean delivery at term and neonatal outcomes

BACKGROUND Because of increased rates of respiratory complications, elective cesarean delivery is discouraged before 39 weeks of gestation unless there is evidence of fetal lung maturity. We assessed associations between elective cesarean delivery at term (37 weeks of gestation or longer) but before 39 weeks of gestation and neonatal outcomes. METHODS We studied a cohort of consecutive patients undergoing repeat cesarean sections performed at 19 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network from 1999 through 2002. Women with viable singleton pregnancies delivered electively (i.e., before the onset of labor and without any recognized indications for delivery before 39 weeks of gestation) were included. The primary outcome was the composite of neonatal death and any of several adverse events, including respiratory complications, treated hypoglycemia, newborn sepsis, and admission to the neonatal intensive care unit (ICU). RESULTS Of 24,077 repeat cesarean deliveries at term, 13,258 were performed electively; of these, 35.8% were performed before 39 completed weeks of gestation (6.3% at 37 weeks and 29.5% at 38 weeks) and 49.1% at 39 weeks of gestation. One neonatal death occurred. As compared with births at 39 weeks, births at 37 weeks and at 38 weeks were associated with an increased risk of the primary outcome (adjusted odds ratio for births at 37 weeks, 2.1; 95% confidence interval [CI], 1.7 to 2.5; adjusted odds ratio for births at 38 weeks, 1.5; 95% CI, 1.3 to 1.7; P for trend <0.001). The rates of adverse respiratory outcomes, mechanical ventilation, newborn sepsis, hypoglycemia, admission to the neonatal ICU, and hospitalization for 5 days or more were increased by a factor of 1.8 to 4.2 for births at 37 weeks and 1.3 to 2.1 for births at 38 weeks. CONCLUSIONS Elective repeat cesarean delivery before 39 weeks of gestation is common and is associated with respiratory and other adverse neonatal outcomes.

A Randomized, Controlled Trial of Magnesium Sulfate for the Prevention of Cerebral Palsy

BACKGROUND Research suggests that fetal exposure to magnesium sulfate before preterm birth might reduce the risk of cerebral palsy. METHODS In this multicenter, placebo-controlled, double-blind trial, we randomly assigned women at imminent risk for delivery between 24 and 31 weeks of gestation to receive magnesium sulfate, administered intravenously as a 6-g bolus followed by a constant infusion of 2 g per hour, or matching placebo. The primary outcome was the composite of stillbirth or infant death by 1 year of corrected age or moderate or severe cerebral palsy at or beyond 2 years of corrected age. RESULTS A total of 2241 women underwent randomization. The baseline characteristics were similar in the two groups. Follow-up was achieved for 95.6% of the children. The rate of the primary outcome was not significantly different in the magnesium sulfate group and the placebo group (11.3% and 11.7%, respectively; relative risk, 0.97; 95% confidence interval [CI], 0.77 to 1.23). However, in a prespecified secondary analysis, moderate or severe cerebral palsy occurred significantly less frequently in the magnesium sulfate group (1.9% vs. 3.5%; relative risk, 0.55; 95% CI, 0.32 to 0.95). The risk of death did not differ significantly between the groups (9.5% vs. 8.5%; relative risk, 1.12; 95% CI, 0.85 to 1.47). No woman had a life-threatening event. CONCLUSIONS Fetal exposure to magnesium sulfate before anticipated early preterm delivery did not reduce the combined risk of moderate or severe cerebral palsy or death, although the rate of cerebral palsy was reduced among survivors. (ClinicalTrials.gov number, NCT00014989.)

Risk Factors and Opportunities for Prevention of Early-onset Neonatal Sepsis: A Multicenter Case-Control Study

Background. Early-onset group B streptococcal (GBS) prevention efforts are based on targeted use of intrapartum antibiotic prophylaxis (IAP); applicability of these prevention efforts to infections caused by other organisms is not clear. Methods. Multicenter surveillance during 1995 to 1996 for culture-confirmed, early-onset sepsis in an aggregate of 52 406 births; matched case-control study of risk factors for GBS and other sepsis. Results. Early-onset disease occurred in 188 infants (3.5 cases per 1000 live births). GBS (1.4 cases per 1000 births) andEscherichia coli (0.6 cases per 1000 births) caused most infections. GBS sepsis less often occurred in preterm deliveries compared with other sepsis. Compared with gestation-matched controls without documented sepsis, GBS disease was associated with intrapartum fever (matched OR, 4.1; CI, 1.2–13.4) and frequent vaginal exams (matched OR, 2.9; CI, 1.1–8.0). An obstetric risk factor—preterm delivery, intrapartum fever, or membrane rupture ≥18 hours—was found in 49% of GBS cases and 79% of other sepsis. IAP had an adjusted efficacy of 68.2% against any early-onset sepsis. Ampicillin resistance was evident in 69% of E coliinfections. No deaths occurred among susceptible E coliinfections, whereas 41% of ampicillin-resistant E coliinfections were fatal. Ninety-one percent of infants who developed ampicillin-resistant E coli infections were preterm, and 59% of these infants were born to mothers who had received IAP. Conclusions. Either prenatal GBS screening or a risk-based strategy could potentially prevent a substantial portion of GBS cases. Sepsis caused by other organisms is more often a disease of prematurity. IAP seemed efficacious against early-onset sepsis. However, the severity of ampicillin-resistant E colisepsis and its occurrence after maternal antibiotics suggest caution regarding use of ampicillin instead of penicillin for GBS prophylaxis.

Insulin action during pregnancy. Studies with the euglycemic clamp technique

To assess the mechanisms responsible for the insulin resistance associated with both normal human pregnancy and gestational-onset diabetes, we have measured exogenous glucose disposal using sequential insulin infusions with the euglycemic glucose clamp technique and erythrocyte insulin binding. Three groups of women were studied: nonpregnant women with normal glucose tolerance (N = 7, mean age 32.9 ± 2.1 yr), pregnant women with normal glucose tolerance (N = 5, mean age 24.8 ± 3.5 yr), and pregnant women with gestational-onset diabetes (N = 5, mean age 34.6 ± 2.6 yr). Despite normal plasma glucose levels obtained during a 100-g oral glucose tolerance test, plasma insulin levels were significantly elevated in the pregnant women compared with the nonpregnant control subjects, suggesting a state of insulin resistance. Insulin binding to erythrocytes was similar in all three groups (maximum specific binding being 5.0 ± 0.6%, 5.5 ± 1.1%, and 6.0 ± 0.7% in nonpregnant, nondiabetic pregnant, and gestational-onset diabetic women, respectively). In vivo peripheral insulin action was measured using the euglycemic glucose clamp technique during an insulin infusion of 40 mil/ m2 · min, with blood glucose clamped at a concentration of 75 mg/dl using a variable glucose infusion. Glucose infusion rates were 213 ± 11 mg/m2 min, 143 ± 23 mg/m2 · min, and 57 ± 18 mg/m2 · min in nonpregnant, nondiabetic pregnant, and gestationalonset diabetic women, respectively. This demonstrates that pregnant subjects display a state of insulin resistance, and that this appears to be more marked in gestational-onset diabetic subjects. To further define the possible mechanism of insulin resistance during pregnancy, the insulin infusion rate was increased to 240 mU/m2 · min and further euglycemic clamp measurements performed. Glucose infusion rates were 372 ± 11 mg/m2 · min, 270 ± 31 mg/m2 · min, and 157 ± 26 mg/m2 · min, in nonpregnant, nondiabetic pregnant, and gestational-onset diabetic women, respectively. This demonstrates a shift to the right of the dose-response curve of insulin action and suggests that the insulin resistance of pregnancy may include a decrease in presumed “maximum” insulin responsivity. In four subjects, studies were repeated in the postpartum period, and these demonstrated that the insulin resistance of pregnancy is ameliorated shortly after delivery. These studies suggest that the insulin resistance of pregnancy results from a target cell defect in insulin action beyond the initial step of insulin binding to cellular receptors, a postreceptor (or postbinding) defect in insulin action.

Menopausal symptoms and treatment-related effects of estrogen and progestin in the women's health initiative

OBJECTIVE: To estimate the effects of estrogen plus progestin (E+P) therapy on menopausal symptoms, vaginal bleeding, gynecologic surgery rates, and treatment-related adverse effects in postmenopausal women. METHODS: Randomized, double-blind, placebo-controlled trial of 16,608 postmenopausal women, ages 50–79 (mean ± standard deviation 63.3 ± 7.1) years, with intact uterus, randomized to one tablet per day containing 0.625 mg conjugated equine estrogens plus 2.5 mg medroxyprogesterone acetate (n = 8,506) or placebo (n = 8,102), and followed for a mean of 5.6 years. Change in symptoms and treatment-related effects were analyzed at year 1 in all participants. Bleeding and gynecologic surgery rates were analyzed through study close-out. RESULTS: Baseline symptoms did not differ between the treatment groups. More women assigned to E+P than placebo reported relief of hot flushes (85.7% versus 57.7%, respectively; odds ratio 4.40; 95% confidence interval 3.40–5.71), night sweats (77.6% versus 57.4%; 2.58; 2.04–3.26), vaginal or genital dryness (74.1% versus 54.6%; 2.40; 1.90–3.02), joint pain or stiffness (47.1% versus 38.4%; 1.43; 1.24–1.64), and general aches or pains (49.3% versus 43.7%; 1.25; 1.08–1.44). Women asymptomatic at baseline who were assigned to E+P more often developed breast tenderness (9.3% versus 2.4%, respectively; 4.26; 3.59–5.04), vaginal or genital discharge (4.1% versus 1.0%; 4.47; 3.44–5.81), vaginal or genital irritation (4.2% versus 2.8%; 1.52; 1.27–1.81), and headaches (5.8% versus 4.7%; 1.26; 1.08–1.46) than women on placebo. Estrogen plus progestin treatment prevented the onset of new musculoskeletal symptoms. Vaginal bleeding was reported by 51% of women on E+P and 5% of women on placebo at 6 months; most bleeding was reported as spotting. Gynecologic surgeries (hysterectomy and dilation and curettage) were performed more frequently in women assigned to E+P (3.1% versus 2.5% for hysterectomy, hazard ratio = 1.23, P = .026; 5.4% versus 2.4% for dilation and curettage, hazard ratio = 2.23, P < .001). CONCLUSION: Estrogen plus progestin relieved some menopausal symptoms, such as vasomotor symptoms and vaginal or genital dryness, but contributed to treatment-related effects, such as bleeding, breast tenderness, and an increased likelihood of gynecologic surgery. LEVEL OF EVIDENCE: I

Oestrogen plus progestin and lung cancer in postmenopausal women (Women's Health Initiative trial): a post-hoc analysis of a randomised controlled trial.

BACKGROUND In the post-intervention period of the Womens Health Initiative (WHI) trial, women assigned to treatment with oestrogen plus progestin had a higher risk of cancer than did those assigned to placebo. Results also suggested that the combined hormone therapy might increase mortality from lung cancer. To assess whether such an association exists, we undertook a post-hoc analysis of lung cancers diagnosed in the trial over the entire follow-up period. METHODS The WHI study was a randomised, double-blind, placebo-controlled trial undertaken in 40 centres in the USA. 16 608 postmenopausal women aged 50-79 years with an intact uterus were randomly assigned by a computerised, stratified, permuted block algorithm to receive a once-daily tablet of 0.625 mg conjugated equine oestrogen plus 2.5 mg medroxyprogesterone acetate (n=8506) or matching placebo (n=8102). We assessed incidence and mortality rates for all lung cancer, small-cell lung cancer, and non-small-cell lung cancer by use of data from treatment and post-intervention follow-up periods. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00000611. FINDINGS After a mean of 5.6 years (SD 1.3) of treatment and 2.4 years (0.4) of additional follow-up, 109 women in the combined hormone therapy group had been diagnosed with lung cancer compared with 85 in the placebo group (incidence per year 0.16%vs 0.13%; hazard ratio [HR] 1.23, 95% CI 0.92-1.63, p=0.16). 96 women assigned to combined therapy had non-small-cell lung cancer compared with 72 assigned to placebo (0.14%vs 0.11%; HR 1.28, 0.94-1.73, p=0.12). More women died from lung cancer in the combined hormone therapy group than in the placebo group (73 vs 40 deaths; 0.11%vs 0.06%; HR 1.71, 1.16-2.52, p=0.01), mainly as a result of a higher number of deaths from non-small-cell lung cancer in the combined therapy group (62 vs 31 deaths; 0.09%vs 0.05%; HR 1.87, 1.22-2.88, p=0.004). Incidence and mortality rates of small-cell lung cancer were similar between groups. INTERPRETATION Although treatment with oestrogen plus progestin in postmenopausal women did not increase incidence of lung cancer, it increased the number of deaths from lung cancer, in particular deaths from non-small-cell lung cancer. These findings should be incorporated into risk-benefit discussions with women considering combined hormone therapy, especially those with a high risk of lung cancer. FUNDING National Heart, Lung and Blood Institute, National Institutes of Health.

Algorithms for adjustment of insulin dosage by patients who monitor blood glucose.

Patient self-monitoring of blood glucose is a useful adjuvant to diabetes therapy that facilitates improved glycemic control when used as part of an intensive diabetes management program that includes careful balancing of food intake, energy expenditure, and insulin dosage. This paper describes an approach by which patient-determined blood glucose measurements may be used to attain and maintain glycemic control. The patient is provided with a set of algorithms by which minor adjustments in a therapeutic routine may be made to achieve the desired control.