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Biomedical subjects

L S Wilcox

Publications and source records attributed to L S Wilcox.

At least 19 recordsLinked to original sources
PubMed2001

Risk of multiple birth associated with in vitro fertilization using donor eggs.

Multiple birth, which is associated with adverse fetal, infant, and maternal outcomes, is increasingly related to the use of in vitro fertilization (IVF). Among women undergoing IVF who use their own eggs, greater maternal age is associated with decreased risk of multiple birth; using donor eggs from younger women may negate this age effect. Data from 6,936 IVF procedures performed in the United States in 1996-1997 on women aged 35-54 years who used donor eggs were analyzed to assess the effect of maternal age, number of embryos transferred, and cryopreservation of extra, nontransferred embryos (an indicator of higher embryo quality) on risk of multiple birth. Greater maternal age did not decrease multiple-birth risk. Rates of multiple birth were related to number of embryos transferred and whether extra embryos had been cryopreserved, and they were high compared with those of IVF patients the same age who had used their own eggs. Among women who had extra embryos cryopreserved, transferring more than two embryos increased multiple-birth risk, with no corresponding increase in the chance for a livebirth. These results highlight the need to consider the age of the donor and embryo quality when making embryo transfer decisions involving use of donor eggs.

Adult↗
PubMed2001

Pregnancy after tubal sterilization with silicone rubber band and spring clip application.

OBJECTIVE: To determine risk factors for pregnancy after tubal sterilization with silicone rubber bands or spring clips. METHODS: A total of 3329 women sterilized using silicone rubber bands and 1595 women sterilized using spring clips were followed for up to 14 years as part of a prospective cohort study conducted in medical centers in nine US cities. We assessed the risk of pregnancy by cumulative life-table probabilities and proportional hazards analysis. RESULTS: The risk of pregnancy for women who had silicone rubber band application differed by location of band application and study site. The 10-year cumulative probabilities of pregnancy varied from a low of 0.0 per 1000 procedures at one study site to a high of 42.5 per 1000 procedures in the four combined sites in which fewer than 100 procedures per site were performed. The risk of pregnancy for women who had spring clip application varied by location of clip application, study site, race or ethnicity, tubal disease, and history of abdominal or pelvic surgery. The probabilities across study sites ranged from 7.1 per 1000 procedures at 10 years to 78.0 per 1000 procedures at 5 years (follow-up was limited to 5 years at that site). CONCLUSION: The 10-year cumulative probability of pregnancy after silicone rubber band and spring clip application is low but varies substantially by both clinical and demographic characteristics.

Adult↗
PubMed2001

The prevalence of socioeconomic and behavioral characteristics and their impact on very low birth weight in black and white infants in Georgia.

OBJECTIVES: We examined possible reasons for the disparity in the rate of very low birth weight (VLBW) delivery (<1500 g) in the United States between black women and white women. METHODS: Using data from a population-based, case-control study of very low birth weight infants, we compared the prevalence of sociodemographic and behavioral characteristics between black and white mothers of normal birth weight infants; the difference in these characteristics between case and control mothers; and, using logistic regression, calculated odds ratios for VLBW for black versus white infants, adjusting for these characteristics. RESULTS: Although black women were disadvantaged on every variable examined, they did not report more behavioral risk factors. Among white women, several traditional risk factors were associated with VLBW, while among black women, only marital status, cigarette smoking, and vitamin nonuse were associated with VLBW delivery. Controlling for the socioeconomic and behavioral factors reduced the odds ratio for VLBW delivery among black mothers from 3.7 to 3.3. CONCLUSIONS: Racial disparity in socioeconomic status may be greater than our current ability to adjust for it in epidemiologic studies. The fact that traditional risk factors were not associated with VLBW delivery in black women may be due to the very high prevalence of these risk factors among black women or to different or additional risks or stresses experienced by black women.

Black or African American↗
PubMed2000

The risk of menstrual abnormalities after tubal sterilization. U.S. Collaborative Review of Sterilization Working Group.

BACKGROUND: The existence of a post-tubal-ligation syndrome of menstrual abnormalities has been debated for decades. We used data from the U.S. Collaborative Review of Sterilization to determine whether the likelihood of persistent menstrual abnormalities was greater among women who had undergone tubal sterilization than among women who had not. METHODS: A total of 9514 women who underwent tubal sterilization and 573 women whose partners underwent vasectomy were followed in a multicenter, prospective cohort study for up to five years by means of annual telephone interviews. All women were asked the same questions about six characteristics of their menstrual cycles in the presterilization and follow-up interviews. Multiple logistic-regression analysis was used to assess the risk of persistent menstrual changes. RESULTS: The women who had undergone sterilization were no more likely than those who had not undergone the procedure to report persistent changes in intermenstrual bleeding or the length of the menstrual cycle. They were more likely to have decreases in the number of days of bleeding (odds ratio, 2.4; 95 percent confidence interval, 1.1 to 5.2), the amount of bleeding (odds ratio, 1.5; 95 percent confidence interval, 1.1 to 2.0), and menstrual pain (odds ratio, 1.3; 95 percent confidence interval, 1.0 to 1.8) and to have an increase in cycle irregularity (odds ratio, 1.6; 95 percent confidence interval, 1.1 to 2.3). Among women who had had very heavy bleeding at base line, women who had undergone sterilization were more likely than women who had not undergone the procedure to report decreased bleeding (45 percent vs. 33 percent, P=0.03). CONCLUSIONS: Women who have undergone tubal sterilization are no more likely than other women to have menstrual abnormalities.

Adult↗
PubMed2000

Does assisted hatching pose a risk for monozygotic twinning in pregnancies conceived through in vitro fertilization?

OBJECTIVE: To examine the association between assisted hatching and monozygotic (MZ) twinning. DESIGN: Case-control. SETTING: Population-based sample of IVF-ET cycles initiated in U.S. clinics, 1996. PATIENT(S): The IVF-ET (n = 35,503) cycles and 11,247 resultant pregnancies. INTERVENTION(S): Use of an assisted hatching procedure on embryos transferred. MAIN OUTCOME MEASURE(S): Cases were pregnancies for which number of fetal hearts observed on ultrasound exceeded number of embryos transferred. These pregnancies were considered to contain at least one MZ set of twins. Cases were compared with two control groups: other multiple-gestation pregnancies (>/=2 fetal hearts but number of fetal hearts </= number of embryos transferred); and singleton pregnancies (1 fetal heart). RESULT(S): Women with a case pregnancy were more likely to have received embryos treated with assisted hatching procedures than were women in either control group. After adjustment for patient age, number of embryos transferred, prior cycles, infertility diagnosis, intracytoplasmic sperm injection, and whether embryos from the current cycle were cryopreserved for later use, odds ratios and 95% CIs for use of assisted hatching were 3.2 (1.2-8.0), compared with other multiple-gestation pregnancies, and 3.8 (1.8-9.8), compared with singleton pregnancies. CONCLUSION(S): Assisted hatching may pose a risk for MZ twinning.

Adult↗
PubMed2000

Overview of women's decision making regarding elective hysterectomy, oophorectomy, and hormone replacement therapy.

Over 600,000 hysterectomies are performed each year in the United States, the majority of which are to improve quality of life for perimenopausal women. Hysterectomy rates for common conditions differ between African American and white women, and African American women undergo surgery at a younger age for most diagnoses. Many hysterectomies are accompanied by elective oophorectomy, and hormone replacement therapy (HRT) is commonly used, especially among women experiencing surgical menopause, despite questions about its long-term benefits and risks. Despite the high rates of hysterectomy in the United States, little is known about how women make decisions regarding this surgery and, in particular, how ethnic and cultural factors may influence these decisions. This article provides a review of what is currently known about the epidemiology of hysterectomy, oophorectomy, and HRT use and identifies gaps in knowledge about women's decision making, with a special focus on ethnic variations and cultural influences, issues addressed by the Ethnicity, Needs, and Decisions of Women (ENDOW) project.

Cultural Characteristics↗
PubMed1999

Live-birth rates and multiple-birth risk using in vitro fertilization.

CONTEXT: To maximize birth rates, physicians who perform in vitro fertilization (IVF) often transfer multiple embryos, but this increases the multiple-birth risk. Live-birth and multiple-birth rates may vary by patient age and embryo quality. One marker for embryo quality is cryopreservation of extra embryos (if embryos are set aside for cryopreservation, higher quality embryos may have been available for transfer). OBJECTIVE: To examine associations between the number of embryos transferred during IVF and live-birth and multiple-birth rates stratified by maternal age and whether extra embryos were available (ie, extra embryos cryopreserved). DESIGN AND SETTING: Retrospective cohort of 300 US clinics reporting IVF transfer procedures to the Centers for Disease Control and Prevention in 1996. SUBJECTS: A total of 35554 IVF transfer procedures. MAIN OUTCOME MEASURES: Live-birth and multiple-birth rates (percentage of live births that were multiple). RESULTS: A total number of 9873 live births were reported (multiple births from 1 pregnancy were counted as 1 live birth). The number of embryos needed to achieve maximum live- birth rates varied by age and whether extra embryos were cryopreserved. Among women 20 to 29 years and 30 to 34 years of age, maximum live-birth rates (43 % and 36%, respectively) were achieved when 2 embryos were transferred and extra embryos were cryopreserved. Among women 35 years of age and older, live-birth rates were lower overall and regardless of whether embryos were cryopreserved, live-birth rates increased if more than 2 embryos were transferred. Multiple-birth rates varied by age and the number of embryos transferred, but not by whether embryos were cryopreserved. With 2 embryos transferred, multiple-birth rates were 22.7%, 19.7%, 11.6%, and 10.8% for women aged 20 to 29, 30 to 34, 35 to 39, and 40 to 44 years, respectively. Multiple-birth rates increased as high as 45.7% for women aged 20 to 29 years and 39.8% for women aged 30 to 34 years if 3 embryos were transferred. Among women aged 35 to 39 years, the multiple-birth rate was 29.4% if 3 embryos were transferred. Among women 40 to 44 years of age, the multiple-birth rate was less than 25% even if 5 embryos were transferred. CONCLUSIONS: Based on these data, the risk of multiple births from IVF varies by maternal age and number of embryos transferred. Embryo quality was not related to multiple birth risk but was associated with increased live-birth rates when fewer embryos were transferred.

Adult↗
PubMed1999

Pregnancy after tubal sterilization with bipolar electrocoagulation. U.S. Collaborative Review of Sterilization Working Group.

OBJECTIVE: To determine risk factors for pregnancy after tubal sterilization with bipolar electrocoagulation. METHODS: A total of 2267 women who had bipolar electrocoagulation were followed for up to 8 to 14 years as part of a multicenter, prospective, cohort study conducted in medical centers in nine United States cities. We used proportional hazards analysis and cumulative life-table probabilities to assess pregnancy risk in these women. RESULTS: The 5-year cumulative probability of pregnancy for women sterilized in 1978-1982 was 19.5 per 1000 procedures (95% confidence interval [CI], 12.2, 26.9); the comparable probability for women sterilized in 1985-1987 was significantly lower, 6.3 per 1000 procedures (95% CI, 0.0, 13.5) (one-tailed P = .01). Women enrolled in 1985-1987 who had fewer than three sites of coagulation had a probability of failure of 12.9 per 1000 procedures (95% CI, 0.0, 38.0); by contrast, women who had three or more sites coagulated had a probability of failure of 3.2 per 1000 procedures (95% CI, 0.0, 9.6) (one-tailed P = .01). CONCLUSION: The long-term probability of pregnancy after tubal sterilization with bipolar coagulation was very low when three or more sites of the fallopian tube were coagulated. Bipolar coagulating systems can be highly effective for sterilization when the fallopian tube is coagulated adequately.

Adolescent↗
PubMed1999

Surveillance of assisted reproductive technology in the United States. An update.

The Centers for Disease Control and Prevention published the first Assisted Reproductive Technology (ART) Pregnancy Success Rate Report in 1997. This article presents a description of the law that initiated the public report, a description of the surveillance system used to accumulate data for the report, and some of the results from ART cycles initiated in 1995.

Female↗
PubMed1998

Are we underestimating rates of vaginal birth after previous cesarean birth? The validity of delivery methods from birth certificates.

Previous studies of birth certificates have not fully evaluated how accurately they identify delivery methods that have a historical component, such as repeat cesarean and vaginal birth after previous cesarean (VBAC). The authors used linked Georgia birth certificates for first and second deliveries to examine the accuracy of four reported delivery methods in the second pregnancy: vaginal (without previous cesarean), VBAC, primary cesarean, and repeat cesarean, as well as an indicator of a previous cesarean. From the immediate birth certificates, the delivery method for each of the two births was classified as vaginal (V) or cesarean section (CS), which produced possible sequences of V-V, CS-V, V-CS, and CS-CS. The delivery method for the second births to 106,049 women from 1989 through 1992 was reviewed, taking into account the historical information from the linked certificates regarding the first births. Only 42.0% of women with a CS-V sequence were correctly designated on the second birth certificate as a VBAC; 79.3% of women with a V- CS sequence were correctly designated as primary cesarean. From 1980 through 1988, birth certificates contained a check box indicating a previous cesarean (but no VBAC box). During this period, only 75.5% of 25,491 women with a previous cesarean were so designated on the birth certificate. These findings suggest that cross-sectional vital records data substantially underestimate VBAC and primary cesarean rates.

Birth Certificates↗
PubMed1997

Hysterectomy surveillance--United States, 1980-1993.

PROBLEM/CONDITION: In the United States, approximately 600,000 hysterectomies are performed each year, and the procedure is the second most frequently performed major surgical procedure among reproductive-aged women. REPORTING PERIOD COVERED: 1980-1993. DESCRIPTION OF SYSTEM: This surveillance system uses data obtained from CDC's National Hospital Discharge Survey (NHDS) to describe the epidemiology of hysterectomy. The NHDS is an annual probability sample of discharges from non-Federal, short-stay hospitals in the United States. RESULTS: In the United States during 1980-1993, an estimated 8.6 million women aged > or =15 years had a hysterectomy. The overall rate of hysterectomy declined slightly from 1980 (7.1 hysterectomies per 1,000 women) to 1987 (6.6 per 1,000 women). The redesign of the NHDS in 1988 resulted in a decrease in estimated rates (i.e., the average annual rate for 1988-1993 was 5.5 per 1,000 women). Rates differed by age, with women aged 40-44 years most likely to have this procedure. Overall annual rates of hysterectomy did not differ significantly by race. The diagnosis most often associated with hysterectomy was uterine leiomyoma; during 1988-1993, this diagnosis accounted for 62% of hysterectomies among black women, 29% among white women, and 45% among women of other races. During 1988-1993, the percentage of hysterectomies performed by the vaginal route increased significantly; furthermore, an increasingly higher percentage of vaginal hysterectomies were accompanied by bilateral oophorectomy. From 1991 through 1993, laparoscopy was associated more frequently with vaginal hysterectomy than in previous years. INTERPRETATION: The rate of hysterectomy decreased slightly during the first half of the 14-year surveillance period, then leveled off during the second half. The increase in simultaneous coding of laparoscopy and vaginal hysterectomy on hospital discharge forms probably reflected the growing use of laparoscopically assisted vaginal hysterectomy. ACTIONS TAKEN: Continued surveillance for hysterectomy will enable changes in clinical practice (e.g., the use of LAVH) to be identified, and information derived from the surveillance system may assist in directing biomedical assessment priorities (e.g., to determine the reasons for race-specific differences in the prevalence of uterine leiomyoma).

Adolescent↗
PubMed1997

The risk of ectopic pregnancy after tubal sterilization. U.S. Collaborative Review of Sterilization Working Group.

BACKGROUND: Tubal sterilization is an increasingly common method of contraception in the United States. Although pregnancy after sterilization is uncommon, it can occur and may be ectopic. We used data from the U.S. Collaborative Review of Sterilization to estimate the risk of ectopic pregnancy in women who had undergone the common types of tubal sterilization. METHODS: A total of 10,685 women undergoing tubal sterilization were followed in a multicenter, prospective cohort study. We intended to follow all the women for 5 years by means of annual telephone interviews; for women enrolled early in the study, we attempted an additional follow-up telephone interview 8 to 14 years after sterilization. To assess the risk of ectopic pregnancy in these women, we used cumulative life-table probabilities and proportional-hazards analysis. RESULTS: There were 47 ectopic pregnancies in the 10,685 women; the 10-year cumulative probability of ectopic pregnancy for all methods of tubal sterilization combined was 7.3 per 1000 procedures. The cumulative probability varied substantially according to the method of sterilization and the woman's age at the time of sterilization. Women sterilized by bipolar tubal coagulation before the age of 30 years had a probability of ectopic pregnancy that was 27 times as high as that among women of similar age who underwent postpartum partial salpingectomy (31.9 vs. 1.2 ectopic pregnancies per 1000 procedures). The annual rate of ectopic pregnancy for all methods combined in the 4th through 10th years after sterilization was no lower than that in the first 3 years. CONCLUSIONS: A history of tubal sterilization does not rule out the possibility of ectopic pregnancy, even many years after the procedure.

Adolescent↗
PubMed1996

The risk of pregnancy after tubal sterilization: findings from the U.S. Collaborative Review of Sterilization.

OBJECTIVE: Our purpose was to determine the risk of pregnancy after tubal sterilization for common methods of tubal occlusion. STUDY DESIGN: A multicenter, prospective cohort study was conducted in U.S. medical centers. A total of 10,685 women who underwent tubal sterilization was followed up for 8 to 14 years. The risk of pregnancy was assessed by cumulative life-table probabilities and proportional hazards models. RESULTS: A total of 143 sterilization failures was identified. Cumulative 10-year probabilities of pregnancy were highest after clip sterilization (36.5/1000 procedures) and lowest after unipolar coagulation (7.5/1000) and postpartum partial salpingectomy (7.5/1000). The cumulative risk of pregnancy was highest among women sterilized at a young age with bipolar coagulation (54.3/1000) and clip application (52.1/1000). CONCLUSIONS: Although tubal sterilization is highly effective, the risk of sterilization failure is higher than generally reported. The risk persists for years after the procedure and varies by method of tubal occlusion and age.

Age Factors↗
PubMed1996

Assisted reproductive technologies: estimates of their contribution to multiple births and newborn hospital days in the United States.

OBJECTIVE: Estimate the contribution of assisted reproductive technology (ART) in the United States to multiple gestation births and newborn hospital days. DESIGN: Analysis of successful ART conceptions occurring during 1990 to 1991 compared with vital statistics. Newborn hospital days are estimated from the 1990 National Hospital Discharge Survey. SETTING: The American Fertility Society and the Society for Assisted Reproductive Technology registry. PATIENTS: Infants delivered from ART. INTERVENTIONS: Assisted reproductive technology. MAIN OUTCOME MEASURES: Number of multiple gestation infants and newborn hospital days. RESULTS: Approximately 12,327 live-born infants were delivered from ART conceptions during 1990 to 1991, representing 22.2% of all live-born triplet, 17.3% of quadruplet, and 11.4% of quintuplet infants born in the United States. The number of newborn hospital days attributed to ART infants was 87,135 days. Between the periods 1972 through 1974 and 1990 through 1991, the rate of triplet and higher order multiple gestation infants per 100,000 white live births increased by 191%, with 38% due to ART conceptions and 30% to increased childbearing among older women. CONCLUSIONS: Assisted reproductive technology contributed 22% of U.S. triplet and higher order multiple births during 1990 to 1991.

Female↗
PubMed1995

Rate of hospitalization for gynecologic disorders among reproductive-age women in the United States.

OBJECTIVE: To analyze reproductive-tract disorders that resulted in hospitalization of reproductive-age women in the United States. METHODS: Data from the National Hospital Discharge Survey for 1988, 1989, and 1990 were used to study women 15-44 years old who had any gynecologic diagnoses noted in their discharge summaries. RESULTS: Based on average annual discharge rates per 10,000 women, the five most frequent diagnostic groups were pelvic inflammatory disease (PID) (average annual rate 49.3, 95% confidence interval [CI] 43.6-55.0), benign cysts of the ovary (average annual rate 32.7, 95% CI 28.8-36.6), endometriosis (average annual rate 32.4, 95% CI 28.5-36.3), menstrual disorders (average annual rate 31.4, 95% CI 27.6-35.2), and uterine leiomyomas (average annual rate 30.4, 95% CI 26.7-34.1). The highest rates for PID were among women 25-39 years old and for women of races other than white. Highest rates for uterine leiomyomas were among women 40-44 years old and for women of races other than white. Highest rates for endometriosis were among women 40-44 years old and white women. Racial difference existed among all ages in the uterine leiomyoma and endometriosis groups. Average annual rates of benign cysts and menstrual disorders increased with age, but there were no statistically significant differences according to race in these two diagnostic groups. CONCLUSIONS: Our findings confirmed the importance of PID as a common cause of hospitalization among reproductive-age women and identified additional gynecologic conditions as causes for hospitalization as well. We found significant age and racial differences not only among women with discharge diagnoses of PID but also among those with discharge diagnoses of uterine leiomyomas and endometriosis.

Adolescent↗
PubMed1994

Hysterectomy in the United States, 1988-1990.

OBJECTIVE: To describe patient characteristics and diagnoses associated with hysterectomy in the United States from 1988-1990 using data from the National Hospital Discharge Survey. METHODS: We analyzed data from the National Hospital Discharge Survey, an annual probability sample of discharges from nonfederal, short-stay hospitals in the United States. A population-based sample of all women aged 15 years or older in the United States civilian population who had a hysterectomy during 1988-1990 was examined to characterize factors associated with hysterectomy: patients' age and race, diagnoses, surgical approach, and oophorectomy. RESULTS: Approximately 1.7 million women had a hysterectomy during 1988-1990. The highest rates--100.5 hysterectomies per 10,000 women--were for women aged 30-54 years. Total rates of hysterectomy for black women were similar to those for white women (61.7 and 56.5 per 10,000 women, respectively); uterine leiomyoma ("fibroid tumor") was reported as the primary diagnosis for 61% of black women and 29% of white women. Abdominal surgery was used for 75% of all hysterectomies. Concomitant bilateral oophorectomy was done for 37% of the women under 45 years old and 68% of the women 45 years or older. CONCLUSIONS: Two-thirds of all hysterectomies for noncancerous conditions were performed for uterine leiomyoma or endometriosis--conditions that are most common before the age of menopause. Future assessments of the appropriateness of hysterectomy will require better understanding of these disorders. Continued monitoring of hysterectomy rates is critical to understanding the appropriate use of hysterectomy, alternative therapies for uterine disorders, and future trends in women's health care.

Adolescent↗