Percentage Of Live Births Research Articles

Single‐centre vs. population‐based outcome data of extremely preterm infants at the limits of viability

In response to the disappointing outcome data of the population-based EPICure study published in 2000, we compared the outcome of infants 22 0/7 to 25 6/7 weeks of gestational age (GA) in a single tertiary care centre 2000-2004 with that of EPICure. EPICure tools and definitions, including 30 months' Bayley Scales. Of 83 infants <26 weeks born alive, more were admitted to intensive care--82% vs. 68% (p < 0.0001)--and more infants survived to discharge (57% vs. 26%, p < 0.0001; 69% vs. 39%, p < 0.01, of those admitted to intensive care). More infants, as a percentage of live births, survived without severe (41%, 34/83 vs. 20%, 233/1185, p < 0.0001) or overall disability (22%, 18/83 vs. 13%, 155/1185, p = 0.03). However, at the border of viability--GA 23 and 24 weeks--the rate of infants surviving without overall disability was not significantly higher (13%, 6/45 vs. 9%, 56/623). In infants <26 weeks of GA, increased rates of survival and survival without disability were observed in a single-centre inborn cohort born 5-8 years later than the EPICure cohort. This did not translate into increased survival without overall disability in infants of 23-24 weeks of GA.

Reconstruction of Congenital Differences of the Hand

Congenital differences of the upper limb occur in approximately 0.16 to 0.18 percent of live births. These patients provide a unique challenge for the reconstructive hand surgeon. The correct and timely diagnosis of hand and upper limb congenital differences will lead to appropriate care and rehabilitation. The International Federation of Societies for Surgery of the Hand has classified congenital upper limb differences based on abnormalities of embryogenesis: failure of formation of parts, failure of differentiation of parts, duplication, overgrowth, undergrowth, constriction ring syndrome, and general skeletal abnormalities. This classification scheme is used as a basis for discussion of the most common upper limb anomalies. Both surgical and nonsurgical treatments are discussed, as is appropriate timing of intervention.

Survival and major neurodevelopmental impairment in extremely low gestational age newborns born 1990–2000: a retrospective cohort study

BackgroundIt is important to determine if rates of survival and major neurodevelopmental impairment in extremely low gestational age newborns (ELGANs; infants born at 23–27 weeks gestation) are changing over time.MethodsStudy infants were born at 23 to 27 weeks of gestation without congenital anomalies at a tertiary medical center between July 1, 1990 and June 30, 2000, to mothers residing in a thirteen-county region in North Carolina. Outcomes at one year adjusted age were compared for two epochs of birth: epoch 1, July 1, 1990 to June 30, 1995; epoch 2, July 1, 1995 to June 30, 2000. Major neurodevelopmental impairment was defined as cerebral palsy, Bayley Scales of Infant Development Mental Developmental Index more than two standard deviations below the mean, or blindness.ResultsSurvival of ELGANs, as a percentage of live births, was 67% [95% confidence interval: (61, 72)] in epoch 1 and 71% (65, 75) in epoch 2. Major neurodevelopmental impairment was present in 20% (15, 27) of survivors in epoch 1 and 14% (10, 20) in epoch 2. When adjusted for gestational age, survival increased [odds ratio 1.5 (1.0, 2.2), p = .03] and major neurodevelopmental impairment decreased [odds ratio 0.54 (0.31, 0.93), p = .02] from epoch 1 to epoch 2.ConclusionThe probability of survival increased while that of major neurodevelopmental impairment decreased during the 1990's in this regionally based sample of ELGANs.

Effects of Carbon-Ion Radiation on the Postnatal Development of Mice and on the Yield of White Spots in the Mid-ventrum and Tail Tips

Pregnant female C57BL/10JHir mice were irradiated whole-body at 9 days of gestation with a single acute dose of carbon-ion radiation. The average linear energy transfer (LET) of the carbon ions was 50 keV/microm within a spread-out Bragg peak (SOBP). The effects were studied by scoring changes in the postnatal development of the mice as well as in the pigmentation of the cutaneous coats and tail tips of their offspring 22 days after birth. The percentage of live births was reduced in mice exposed to carbon ions at doses greater than 0.5 Gy. The survival to day 22 was also reduced in mice exposed to carbon ions at doses greater than 0.75 Gy. Moreover, the body weight at day 22 was reduced in mice exposed to carbon ions at doses greater than 0.1 Gy. A comparison of the survival to day 22 after exposure to carbon ions with our previous results for 60Co gamma rays indicated that carbon ions were twice as effective as gamma rays. White spots were found in the mid-ventrum as well as in the tail tips of offspring exposed to carbon ions in utero. The frequency and the size of the white spots in the mid-ventrum and in the tail tips increased as the dose increased. Carbon ions appear to be slightly more effective than the gamma rays used in our previous study. In the ventral white spots, no melanocytes were observed in the epidermis, dermis and hair follicles. These results indicate that prenatal exposure to carbon ions has a greater effect on the postnatal development and survival of mice than does exposure to gamma rays, and that the relative biological effectiveness is greater than that for effects on melanocyte development.

Trends in embryo-transfer practice and in outcomes of the use of assisted reproductive technology in the United States.

During the past decade in the United States, increasing attention has been paid to lowering the incidence of multiple gestations resulting from the use of assisted reproductive technology. To determine whether such efforts have been successful, we assessed national trends in embryo-transfer practice patterns and in outcomes after the use of assisted reproductive technology. We analyzed data on outcomes of assisted reproductive technology procedures as reported to the Centers for Disease Control and Prevention from 1995 to 2001 by fertility clinics in the United States. We also analyzed data from the National Center for Health Statistics on the rates of twin births and triplet or higher-order multiple births. From 1995 to 2001 in the United States, the number of infertility clinics, the number of fresh-embryo cycles initiated, and the number of fresh-embryo transfers increased steadily. The average number of embryos transferred per cycle began decreasing in 1997, with the steepest decline (an 11.1 percent decrease) between 1998 and 1999. In contrast, the number of pregnancies and live births per cycle during the period from 1995 to 2001 steadily increased. Even though the percentage of pregnancies with twins did not change significantly between 1997 and 2001, the percentage of pregnancies with three or more fetuses significantly decreased every year, with the steepest decline (a 20.8 percent decrease) between 1998 and 1999, after the publication in 1998 of the American Society for Reproductive Medicine guidelines for embryo transfer. Since 1997 in the United States, there have been consistent decreases in both the number of embryos transferred per cycle and the percentage of pregnancies with three or more fetuses, as well as a consistent increase in the percentage of live births per cycle.

Ductus venosus blood flow assessment at 11 to 14 weeks of gestation and fetal outcome.

To evaluate the association between abnormal ductus venosus (DV) at 11-14 weeks' gestation and chromosomal abnormalities, structural defects and fetal outcome. DV flow-velocity waveform (DV-FVW) and nuchal translucency thickness (NT) were prospectively evaluated in 1217 singleton pregnancies. The DV-FVW was abnormal in 84 fetuses, NT was above the 95th centile in 160 fetuses and both markers were observed in 41 fetuses. Chromosomal defects were diagnosed in 22 fetuses. The sensitivity, specificity and positive and negative predictive values for an abnormal karyotype were 86.4%, 86.9%, 11.9% and 99.7%, respectively, for an increased NT. These values were 68.2%, 96.9%, 31.3% and 99.3%, respectively, for DV-FVW abnormalities and 68.2%, 97.6%, 36.6% and 99.3%, respectively, when both markers were found simultaneously. Regarding structural defects, these values were 43.8%, 92.9%, 8.3% and 99.1% for an abnormal NT, 25.0%, 92.6%, 4.8% and 98.8% for DV-FVW abnormalities and 25.0%, 97.9%, 15.4% and 98.9% for both together. Considering those cases of unexplained fetal demise, the values were 44.4%, 85.9%, 5.0% and 98.9% for NT abnormalities, 22.2%, 92.6%, 4.8% and 98.6% for an abnormal DV-FVW and 22.2%, 98%, 15.4% and 98.7% for both. In cases with increased NT, the percentage of live births with normal karyotype and no major fetal structural defects decreased from 93.8% in normal DV-FVW fetuses to 77.3% in abnormal ones. DV assessment at 11-14 weeks' gestation is useful in screening for fetal chromosomal abnormalities and may help to reduce the false-positive rate when combined with NT measurement. Abnormal DV-FVW is also associated with an increase in adverse perinatal outcome in fetuses with enlarged NT. However, the value of DV-FVW assessment in cases with normal NT is unclear.

Percentage of Live Births Attended by CNMS in the United States, 1989‐2001

Percentage of Live Births Attended by CNMS in the United States, 1989‐2001

Percentage of live births attended by CNMS in the United States, 1989?2001

Percentage of live births attended by CNMS in the United States, 1989?2001

The effect of antenatal corticosteroids on fetal growth, survival, and neurodevelopmental outcome in triplet pregnancies.

Triplet pregnancies have increased as a result of infertility therapy. The objectives of this study are to review the outcome of triplet pregnancies and to determine the effect of different antenatal corticosteroid treatments on fetal growth, survival, and neurodevelopmental outcome. A retrospective case note review of infant and maternal records from a single tertiary neonatal unit was performed from January 1, 1986, through December 31, 1999; 173 live births from 60 triplet pregnancies were divided into groups according to maternal antenatal corticosteroid exposure. Logistic regression model showed only gestation had a significant effect on survival. There was no adverse effect of steroid exposure on weight or head circumference at birth. Ninety percent of live births survived to discharge. Of 143 survivors, only five infants had documented neurodevelopmental problems. Survival rate in triplet pregnancy is high. In this analysis of cohort data repetitive antenatal steroids were not associated with adverse outcome.

Reproductive Epidemiology of Aluminium Foundry Workers

non-smoking male workers engaged in the production of aluminium alloys were studied for their reproductive performance. The reproductive pa- rameters studied included number of pregnancies, still- births, abortions in their wives and number of neonatal deaths, premature births, congenital abnormalities in their offspring. For comparison, 150 controls belonging to the same age group and socio-economic status and with no occupational exposure to any known physical or chemical agent were also studied. A significant in- crease in the percentage of abortions, congenital defects and a significant decrease in the percentage of livebirths were observed in the exposed group when compared with the control group. This could be due to occupational ex- posure to fumes of aluminium at the workplace.

Reproductive Epidemiology of Aluminium Foundry Workers

non-smoking male workers engaged in the production of aluminium alloys were studied for their reproductive performance. The reproductive pa- rameters studied included number of pregnancies, still- births, abortions in their wives and number of neonatal deaths, premature births, congenital abnormalities in their offspring. For comparison, 150 controls belonging to the same age group and socio-economic status and with no occupational exposure to any known physical or chemical agent were also studied. A significant in- crease in the percentage of abortions, congenital defects and a significant decrease in the percentage of livebirths were observed in the exposed group when compared with the control group. This could be due to occupational ex- posure to fumes of aluminium at the workplace.

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

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). 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). Retrospective cohort of 300 US clinics reporting IVF transfer procedures to the Centers for Disease Control and Prevention in 1996. A total of 35554 IVF transfer procedures. Live-birth and multiple-birth rates (percentage of live births that were multiple). 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. 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.

Determinants of Preterm Birth Rates in Canada from 1981 through 1983 and from 1992 through 1994

The rates of preterm birth have increased in many countries, including Canada, over the past 20 years. However, the factors underlying the increase are poorly understood. We used data from the Statistics Canada live-birth and stillbirth data bases to determine the effects of changes in the frequency of multiple births, registration of births occurring very early in gestation, patterns of obstetrical intervention, and use of ultrasonographic dating of gestational age on the rates of preterm birth in Canada from 1981 through 1983 and from 1992 through 1994. All births in 9 of the 12 provinces and territories of Canada were included. Logistic-regression analysis and Poisson regression analysis were used to estimate changes between the two three-year periods, after adjustment for the above-mentioned determinants of the likelihood of preterm births. Preterm births increased from 6.3 percent of live births in 1981 through 1983 to 6.8 percent in 1992 through 1994, a relative increase of 9 percent (95 percent confidence interval, 7 to 10 percent). Among singleton births, preterm births increased by 5 percent (95 percent confidence interval, 3 to 6 percent). Multiple births increased from 1.9 percent to 2.1 percent of all live births; the rates of preterm birth among live births resulting from multiple gestations increased by 25 percent (95 percent confidence interval, 21 to 28 percent). Adjustment for the determinants of the likelihood of preterm birth reduced the increase in the rate of preterm birth to 3 percent among all live births and 1 percent among singleton births. The recent increase in preterm births in Canada is largely attributable to changes in the frequency of multiple births, obstetrical intervention, and the use of ultrasound-based estimates of gestational age.

Live births resulting from unintended pregnancies: an evaluation of synthetic state-based estimates.

Most states lack information on the proportion of live births resulting from unintended pregnancies. We evaluated a potential solution to the lack of data, a synthetic state-based estimate of the percentage of live births resulting from unintended pregnancies for the state of Georgia. We constructed the synthetic estimate by standardizing the 1995 National Survey of Family Growth data by the race, marital status, and age distribution of Georgia residents ages 15-44 years who delivered a live birth during 1990-1994. Two surveys conducted in Georgia during the same period that collected information on unintended pregnancies were used for comparison: the Georgia Women's Health Survey (GWHS) and the Georgia Pregnancy Risk Assessment Monitoring System (PRAMS). The synthetic estimate (35.2%, 95% CI = 33.5%-36.7%) was not statistically different from the GWHS estimate (39.6%, 95% CI = 35.7%-43.5%), but was significantly lower than the Georgia PRAMS estimate (49.0%, 95% CI = 45.5%-52.5%). When we stratified by race, marital status, and age, the synthetic and GWHS estimates were statistically similar except for married females and females ages 25-34 years, for whom the synthetic estimates were lower. For all groups of females, the synthetic estimates were statistically lower than the Georgia PRAMS estimates. The synthetic estimate can be a useful method for states that need to know the overall magnitude of the percentage of live births resulting from unintended pregnancy for purposes such as program planning.

Nuclear fallout, low birthweight, and immune deficiency.

An investigation of the mortality rates of young adults born in the postwar period of large-scale atmospheric nuclear testing (1945-1965) in the United States and other western industrial nations reveals an increasingly anomalous rise in mortality from its previous secular decline. Beginning in the late 1970s and particularly since 1983, the deterioration in the health of the 25-44 age group is related to in utero exposure to fission products in the milk and diet, associated with an unprecedented rise in underweight births and neonatal mortality known to be accompanied by loss of immune resistance. The 1945-1965 rise in the percentage of live births below 2500 grams is highly correlated with the amount of strontium-90 in human bone, both peaking in the mid-1960s. In the 1980s, for the baby boom generation (those born between 1945 and 1965), cancer incidence and mortality due to infectious diseases associated with a rising degree of immune deficiency, such as pneumonia, septicemia, and AIDS, increased sharply. This process of increasing immune deficiency appears to have been exacerbated by continuing secondary exposures to accidental reactor releases and by an acceleration of radiation-induced mutation of pathogenic microorganisms increasingly resistant to drugs.

MECONIUM AND FETAL OUTCOME.

Meconium staining of amniotic fluid occurs in as many as 20 percent of live births, but its significance as a risk factor for adverse perinatal

Effects of estrogen and prostaglandin on progesterone-delayed farrowing

Effects of estradiol benzoate and prostaglandin F 2α (PGF 2α) on concentrations of progesterone and estrogen in serum and the percentage of live births were determined in 21 gilts treated with exogenous progesterone in late gestation. All gilts received progesterone (25mg s.c. four times daily) from Days 108 through 113 of gestation. Gilts receiving no other treatments (controls) had elevated levels of progesterone through 1800 h on Day 114 (29.2 ± 11.4 ng/ml) and farrowed at 115.6 ± 0.3 d of gestation with a relatively low percentage of live births (66.8 ± 17.3). Gilts treated with PGF 2α administered at 0600 h on Day 114 had less (P<0.01) progesterone by 1800 h (7.0 ± 1.3 ng/ml) relative to that of the controls, but they had similar gestation lengths (115.5 ± 0.3) and percentages of live births (50.0 ± 16.2). Administration of estradiol benzoate (10 mg) to gilts at 0600 h on Day 114 did not reduce progesterone on Day 114 or the gestation length relative to that of the control gilts, but it did increase (P<0.05) the percentage of live births (100%)

CRISIS IN NICUS

Since 1985, the rate of admissions to our neonatal intensive care unit has risen from 14 percent of live births to 22 percent—more than three times the national average. A lot of this is due to crack. . . .The system is so overloaded that we can't handle the babies we are getting anymore.

Effects of Spinal Blockade with Bupivacaine on Parturition in Rats

On the day of expected delivery, primigravid rats received 0.5% bupivacaine continuously through a chronically implanted intrathecal cannula to produce intense sensory and motor blockade below the T10 level. The mean duration of delivery was prolonged to 3.1 h compared with 1.4 h in a control group without intrathecal blockade and a group which received an intrathecal infusion of Hartmann's solution. The mean percentages of live births per litter surviving the first 6 h was 94% in the control groups and 42% in those receiving bupivacaine by intrathecal infusion. No increased perinatal mortality was observed in another control group receiving an i.p. infusion of 0.5% bupivacaine in the same dose as that given intrathecally. Two mother rats died during delivery under spinal blockade because of prolonged labour. It is concluded that, without obstetric intervention, intense sensory and motor blockade delayed parturition and increased fetal mortality in the pregnant rats.

PERINATAL OUTCOME IN WESTERN AUSTRALIA, 1968 TO 1975.; 2. SOCIAL AND BIOLOGICAL DETERMINANTS

Trends in perinatal mortality and low birthweight (percentage of livebirths under 2500 g) were analysed in relation to certain social and biological variables. Mothers at high risk of adverse perinatal outcome in terms of perinatal mortality and low birthweight were found to be very young and grand multiparous mothers, old primiparas, unmarried mothers, those with multiple pregnancies and mothers born in Asia.