Biomedical subjects

Anjel Vahratian

Publications and source records attributed to Anjel Vahratian.

14 recordsLinked to original sources

PubMed2006

State-specific trends in preterm delivery: are rates really declining among non-Hispanic African Americans across the United States?

OBJECTIVES: This study sought to examine state-specific trends in preterm delivery rates among non-Hispanic African Americans and to assess whether these rates are influenced by misclassification of gestational age. METHODS: The sample population consisted of singleton non-Hispanic White and non-Hispanic African-American infants born in 1991 and 2001 to U.S. resident mothers. For both time periods, state-specific and national preterm delivery rates were calculated for all infants, stratified by infant race/ethnicity. Next, birth-weight distributions within strata of gestational age were studied to explore possible misclassifications of gestational age. Lastly, state-specific and national preterm delivery rates among infants who weighed less than 2,500 g were separately computed. RESULTS: National analyses showed that the frequency of preterm delivery increased by 15.8% among non-Hispanic Whites but declined by 10.3% among non-Hispanic African Americans over the same period. For both subgroups, a bimodal distribution of birth weights was apparent among preterm births at 28-31 weeks of gestation. The second peak with its cluster of normal-weight infants was more prominent among non-Hispanic African Americans in 1991 than in 2001. After excluding preterm infants who weighed 2,500 g or more, the national trends persisted. State-specific analyses showed that preterm delivery rates increased for both subgroups in 13 states during this period. Of these 13, 6 states had a number of non-Hispanic African-American births classified as preterm that were apparently term births mistakenly assigned short gestational ages. Such misclassification was more frequent in 1991 than in 2001 and inflated 1991 rates. CONCLUSION: There is heterogeneity in state-specific preterm delivery rates. Such differences are often overlooked when aggregate results are presented.

Adolescent↗

PubMed2006

Comparison of labor progression between induced and noninduced multiparous women.

OBJECTIVE: The incidence of labor induction is rising rapidly in the United States. Among multiparas, labor is often followed with traditional labor curves derived from noninduced pregnancies. We sought to determine how labor progression of multiparous women who presented in spontaneous labor differed from those who were electively induced with and from those induced without preinduction cervical ripening. METHODS: We analyzed data on all low-risk multiparous women with an elective induction or spontaneous onset of labor between 37(+0) and 40(+6) weeks of gestation from January 2002 to March 2004 at a single institution. The median duration of labor by each centimeter of cervical dilatation and the risk of cesarean delivery were computed for 61 women with preinduction cervical ripening and oxytocin induction, 735 women with oxytocin induction, and 1,885 women with a spontaneous onset of labor. An intracervical Foley catheter was used to ripen the cervix. RESULTS: Those women who experienced electively induced labor without cervical ripening had a shorter active phase of labor than did those admitted in spontaneous labor (99 minutes in induced labor versus 161 minutes in spontaneous labor, P < .001). However, the cesarean delivery rate was elevated in the induction group (3.9% versus 2.3%, P < .05). Women who underwent preinduction cervical ripening also had a shorter active phase than those admitted in spontaneous labor (109 minutes versus 161 minutes, P = .01). CONCLUSION: The pattern of labor progression differs for women with an electively induced labor without cervical ripening compared with those who present with spontaneous onset of labor.

Adult↗

PubMed2006

The impact of parity on course of labor in a contemporary population.

BACKGROUND: Few studies have examined in depth the labor progression of multiparas to determine if there is any additional impact of being parous beyond the first birth. The objective of this study was to determine the effect of parity on labor progression in contemporary obstetric practice. METHODS: Our sample consisted of all low-risk women who delivered a term, live-born infant from January 2002 to March 2004 at a single institution in Delaware, United States (n = 5,589). The median duration of labor by each centimeter of cervical dilation was computed for parity = 0 (n = 2,645); parity = 1 (n = 1,839); parity = 2 (n = 750); and parity = 3 + (n = 355). RESULTS: Multiparas had a significantly faster labor progression from 4 to 10 cm (293, 300, and 313 min, respectively, for parity = 1, parity = 2, and parity = 3 +), compared with nulliparas (383 min for parity = 0), as well as a shorter second stage of labor. However, no significant differences were found in duration of the active phase or the second stage of labor among multiparas. CONCLUSIONS: Additional childbearing appears to have no effect of on the progression of labor among multiparous subgroups. The difference in duration of the active phase between nulliparas and multiparas is substantially smaller in a contemporary population.

Adult↗

PubMed2006

Methodological challenges in studying labour progression in contemporary practice.

In the 1950s, Emanuel Friedman described the first comprehensive method of evaluating labour in clinical practice. In this landmark work, Friedman described the relationship between the duration of labour and cervical dilation as a sigmoid curve and outlined a tool for following labour progression and for identifying abnormal labour. His definitions of labour protraction and arrest continue to be applied in contemporary obstetric practice, although there have been considerable changes since in the clinical management of labour and delivery. This paper provides an overview of Friedman's work, addresses various methodological challenges in studying labour progression, and describes the utility of more advanced statistical methods for studying labour progression, such as survival analysis, compared with other approaches. Additional research that utilises and refines such methods will provide greater insight into labour progression and may assist in updating the diagnostic criteria for labour protraction and arrest disorders in contemporary obstetric practice. Moreover, such detailed information could have important clinical implications towards reducing the rate of primary caesarean delivery in the United States.

Cesarean Section↗

PubMed2005

Maternal pre-pregnancy overweight and obesity and the risk of cesarean delivery in nulliparous women.

PURPOSE: To examine the effect of maternal pre-pregnancy overweight and obesity on the risk of term cesarean delivery in nulliparous women. METHODS: The authors examined data from 641 nulliparous women with a term pregnancy that participated in the Pregnancy, Infection, and Nutrition Study from 1995 to 2002. Unadjusted and adjusted risk ratios and 95% confidence intervals (CI) were computed for normal weight (BMI 19.8-26.0 kg/m(2)), overweight (BMI 26.1-29.0 kg/m(2)), and obese (BMI>29.0 kg/m(2)) women. Normal weight women served as the referent population. RESULTS: The unadjusted risk ratio for cesarean delivery for overweight women compared with normal weight women was 1.4 (95% CI, 0.97, 2.1) and for obese women compared with normal weight women was 1.4 (95% CI, 1.03, 2.0). After controlling for maternal height, education, weight gain during pregnancy, and labor induction, the adjusted risk ratio for cesarean delivery among overweight women was 1.2 (95% CI, 0.8, 1.8). The adjusted risk ratio for obese women was 1.5 (95% CI, 1.05, 2.0). CONCLUSION: Our analysis confirms that there is a moderate association between maternal pre-pregnancy obesity and an unplanned term cesarean delivery. However, the risk is not as large as previously reported.

Adolescent↗

PubMed2005

Labor progression and risk of cesarean delivery in electively induced nulliparas.

OBJECTIVE: To describe the pattern of labor progression and risk of cesarean delivery in women whose labor was electively induced. METHODS: We analyzed data on all low-risk, nulliparous women with an elective induction or spontaneous onset of labor between 37 + 0 and 40 + 6 weeks from January 2002 to March 2004 at a single institution. The median duration of labor by each centimeter of cervical dilation and the risk of cesarean delivery were computed for 143 women with preinduction cervical ripening and oxytocin induction, 286 women with oxytocin induction, and 1,771 women with a spontaneous onset of labor. An intracervical Foley catheter was used to ripen the cervix. RESULTS: Electively induced labor with cervical ripening had substantially slower latent and early active phases. After controlling for potential confounders, women who had an elective induction with cervical ripening had 3.5 times the risk of cesarean delivery during the first stage of labor (95% confidence interval 2.7-4.5), compared with those admitted in spontaneous labor. Elective induction without cervical ripening, on the other hand, was associated with a faster labor progression from 4 to 10 cm (266 compared with 358 minutes, P < .01) and did not increase the risk of cesarean delivery, compared with those in spontaneous labor. CONCLUSION: The pattern of labor progression differs substantially for women with an electively induced labor compared with those with spontaneous onset of labor. Furthermore, elective induction in nulliparous women with an unfavorable cervix has a high rate of labor arrest and a substantially increased risk of cesarean delivery. LEVEL OF EVIDENCE: II-2.

Adult↗

PubMed2004

Multivitamin use and the risk of preterm birth.

Previous research suggests that multivitamin use before and during pregnancy can diminish diet-related deficiencies of certain micronutrients and potentially prevent preterm birth. To assess this association, the authors performed an analysis by using data from the Pregnancy, Infection, and Nutrition Study (n = 2,010). Women were recruited at 24-29 weeks of pregnancy from four prenatal care clinics in North Carolina from August 1995 to June 2000. For women who took multivitamins prior to pregnancy, compared with nonusers, the adjusted risk ratio was 0.50 (95% confidence interval: 0.20, 1.25) for delivering preterm (<37 weeks). In contrast, prenatal and periconceptional use, compared with nonuse, were not related to preterm birth, with adjusted risk ratios of 1.1. Preconceptional multivitamin use was inversely associated with both early (<35 weeks; adjusted odds ratio = 0.59, 95% confidence interval: 0.12, 2.76) and late (35-36 weeks; adjusted odds ratio = 0.40, 95% confidence interval: 0.12, 1.40) preterm birth; findings were based on only two and three exposed cases, respectively. These results suggest that, compared with nonusers, women who take multivitamin supplements prior to conception may have a reduced risk of preterm birth, but further studies are needed with a larger sample of preconceptional users.

Adult↗

PubMed2004

Monozygotic twinning associated with day 5 embryo transfer in pregnancies conceived after IVF.

BACKGROUND: This study examines the association between day of embryo transfer and monozygotic (MZ) twinning. METHODS: We used a population-based sample of 108,36 IVF/embryo transfer procedures in which the patients oocytes' were freshly fertilized (non-frozen; non-donor) and 39,98 resultant pregnancies from US clinics in 1999 and 2000. Cases were pregnancies for which the number of fetal hearts observed on ultrasound exceeded the number of embryos transferred. These pregnancies were considered to contain at least one set of MZ twins. A total of 226 MZ pregnancies were compared with two control groups: 23,880 singleton pregnancies (one fetal heart) and 15,092 other multiple-gestation pregnancies (> or = 2 fetal hearts but the number of fetal hearts on ultrasound was less than or equal to the number of embryos transferred). RESULTS: Cases of presumed MZ multiple-gestation pregnancies were more likely to have had a day 5 embryo transfer compared with day 3 embryo transfers than singleton pregnancies [adjusted odds ratio (AOR) = 3.92, 95% confidence interval (CI) = 2.97-5.17] or other multiple-gestation pregnancies (AOR = 3.91, 95% CI = 2.96-5.17) conceived with IVF/embryo transfer. CONCLUSIONS: Day 5 embryo transfer may be associated with increased MZ twinning.

Adult↗

PubMed2004

Preterm delivery rates in North Carolina: are they really declining among non-Hispanic African Americans?

The preterm delivery rate in North Carolina is consistently higher than the national average. However, recent reports suggest that singleton preterm delivery rates for non-Hispanic Whites are increasing while those for non-Hispanic African Americans are decreasing. To study this pattern further, the authors examined data on singleton non-Hispanic White and non-Hispanic African-American births in 1989 and 1999 by using North Carolina vital statistics data. They found that the frequency of preterm delivery rose 1.1% (8.5% to 9.6%) among non-Hispanic Whites but declined 1.4% (17.9% to 16.5%) among non-Hispanic African Americans over the same time period. For both subgroups, a bimodal distribution of birth weights was apparent among preterm births at 28-31 weeks of gestation. The second peak with its cluster of normal-weight infants was more prominent among non-Hispanic African Americans in 1989 than in 1999. To reduce the potential for bias due to misclassification of infant gestational age, frequencies of preterm delivery of infants who weighed less than 2,500 g were calculated. Unlike the original analysis, this calculation showed that preterm delivery increased for both subgroups. A number of non-Hispanic African-American births classified as preterm were apparently term births mistakenly assigned short gestational ages. Such misclassification was more frequent in 1989 than in 1999, inflating 1989 preterm delivery rates.

Adult↗

PubMed2004

The effect of early epidural versus early intravenous analgesia use on labor progression: a natural experiment.

OBJECTIVE: The purpose of this study was to compare the effect of early epidural with the use of early intravenous analgesia on labor progression. STUDY DESIGN: We systematically selected singleton, nulliparous term pregnancies with a spontaneous labor and analgesia placement <or=4 cm who were delivered at a hospital where the rate of epidural analgesia in labor increased from 1% (before) to 84% (after) in 1 year (a natural experiment). In the before period (n=223 pregnancies), 98% of women used intravenous analgesia, and 2% of women used epidural analgesia. In the after period (n=278 pregnancies), 92% of women used epidural analgesia, and 8% of women used intravenous analgesia. The median duration of labor by each centimeter of cervical dilation was computed and used as a measurement of labor progression. RESULTS: After adjustment had been made for confounders, women in the after period had a slower labor progression only from 4 to 5 cm, compared with those women in the before period. Interestingly, the process of labor admission and epidural analgesia placement, rather than analgesia use per se, appeared to explain most of the slowdown. No significant difference in the rest of the active phase was observed between the 2 groups. CONCLUSION: Our data support recent American College of Obstetricians and Gynecologists guidelines that the restraining use of epidural analgesia at <4 cm of cervical dilation is unnecessary.

Adult↗

PubMed2004

Birthweight differences among infants of North African immigrants and Belgians in Belgium.

BACKGROUND: Infants of North African immigrants are reported to have higher birthweights than their Belgian counterparts. It is unclear what mechanism contributes to this difference. METHODS: Analyses were based on a hospital-based cohort of 1,162 women. RESULTS: Infants of North African immigrants were less likely to be born preterm, compared to infants of Belgian women. After adjusting for sociodemographic and maternal factors, the estimated difference in mean birthweight was 74 g (p=0.05). When limited to term births, this difference was 28 g (p=0.42). CONCLUSION: The difference in mean birthweight between North African and Belgian infants was explained by differences in preterm birth and other risk factors.

Adult↗

PubMed2004

Maternal prepregnancy overweight and obesity and the pattern of labor progression in term nulliparous women.

OBJECTIVE: To examine the effect of maternal overweight and obesity on labor progression. METHODS: We analyzed data from 612 nulliparous women with a term pregnancy that participated in the Pregnancy, Infection, and Nutrition Study from 1995 to 2002. The median duration of labor by each centimeter of cervical dilation was computed for normal-weight (body mass index [BMI] 19.8-26.0 kg/m2), overweight (BMI 26.1-29.0 kg/m2), and obese (BMI > 29.0 kg/m2) women and used as a measurement of labor progression. RESULTS: After adjusting for maternal height, labor induction, membrane rupture, oxytocin use, epidural analgesia, net maternal weight gain, and fetal size, the median duration of labor from 4 to 10 cm was significantly longer for both overweight and obese women, compared with normal-weight women (7.5, 7.9, and 6.2 hours, respectively). For overweight women, the prolongation was concentrated around 4-6 cm, whereas for obese women, their labor was significantly slower before 7 cm. CONCLUSION: Labor progression in overweight and obese women was significantly slower than that of normal-weight women before 6 cm of cervical dilation. Given that nearly one half of women of childbearing age are either overweight or obese, it is critical to consider differences in labor progression by maternal prepregnancy BMI before additional interventions are performed.

Body Mass Index↗

PubMed2003

Live-birth rates and multiple-birth risk of assisted reproductive technology pregnancies conceived using thawed embryos, USA 1999-2000.

BACKGROUND: Increasing use of assisted reproductive technology treatments has been associated with the current rise in multiple births in the USA. Embryo cryopreservation and subsequent thawed embryo transfer may favourably impact the multiple-birth risk by relieving some pressure that patients and providers may feel to transfer several embryos in a single cycle. The study objective was to examine both live-birth rates and multiple-birth risk in thawed cycles. METHODS: The authors used a population-based sample of 21 555 assisted reproductive technology procedures performed in US clinics in 1999 and 2000 that used thawed embryos derived from the patient's oocytes. RESULTS: Both patient age and the number of embryos transferred were independent predictors of live birth. Even among women aged 20-29 years, the transfer of three embryos resulted in an increase in the live-birth rate compared with cycles in which one or two embryos were transferred. This increase in success was accompanied by an increased multiple-birth risk. In all age groups up to 40 years, the transfer of just two embryos resulted in a multiple-birth risk of 16-17%. The multiple-birth risk increased with the number of embryos transferred. CONCLUSIONS: Patient age and the number of embryos transferred significantly affect live-birth and multiple-birth rates among women who use thawed embryos.

Adult↗

PubMedDate not supplied

Insurance coverage and health care use among near-elderly women.

OBJECTIVES: Data on near-elderly (ages 55-64) women's access to and use of health care have been limited. In this study, we sought to examine the status of near-elderly women's health insurance coverage in the United States and how it may influence their use of health care services. METHODS: A nationwide random sample of women aged 55-64 was drawn from the 2002 wave of the Health and Retirement Study. Descriptive statistics were calculated and multivariable regression analyses were performed to quantify the impact of insurance coverage on near-elderly women's use of outpatient services, inpatient services, and prescription medication over a 2-year period. RESULTS: In 2002, 9.4% of near-elderly women in the United States were uninsured and 15.4% had public coverage. Those who had coverage for a particular service were significantly more likely to use that service compared to women without coverage, with odds ratios ranging from 2.0-6.7 for services such as a physician visit, hospital stay, dental visit, and use of prescription medication. Among those who had at least one physician visit, near-elderly women who had some of the cost covered by insurance reported significantly more visits than women without coverage. Likewise, for near-elderly women regularly taking prescription medications, having more extensive coverage significantly increased their likelihood of medication adherence. The frequency of hospitalization was also higher for women who had complete coverage for the cost. CONCLUSIONS: The nature of a near-elderly woman's insurance coverage significantly affects her use of health care services. More attention is needed to improve the health care of near-elderly women with inadequate insurance coverage.

Attitude to Health↗