Target position variability throughout prostate radiotherapy

OBJECTIVE: It was our objective to evaluate the association between early maternal weight gain (before 20 weeks), midpregnancy weight gain (20-28 weeks), and late pregnancy weight gain (28 weeks to birth) with fetal growth and birth weight in twins. STUDY DESIGN: This historic cohort study was based on 1564 births of live twins >/=28 weeks' gestation from Baltimore, Maryland, Miami, Florida, Charleston, South Carolina, and Ann Arbor, Michigan. RESULTS: Early fetal growth was affected only by smoking and chorionicity. Factors in models of both mid and late fetal growth included maternal age, pregravid weight, parity, rates of early pregnancy and midpregnancy maternal weight gain, smoking, and pre-eclampsia. Increased midpregnancy fetal growth was associated with early maternal weight gain (10.91 g/wk per pound per week) and midpregnancy maternal weight gain (15.89 g/wk per pound per week). Increased late fetal growth was associated with early maternal weight gain (16.86 g/wk per pound per week) and midpregnancy maternal weight gain (23.88 g/wk per pound per week). Increased birth weight was associated with early (283.02 g per pound per week), mid (163.58 g per pound per week), and late (69.76 g per pound per week) maternal weight gains. CONCLUSIONS: These findings confirm the importance of early maternal weight gain in twin fetal growth and birth weight.     

Causes of perinatal mortality in twins

The author analyses perinatal mortality in 244 twin pregnancies. In 80% the twins' Apgare score at birth was 10 to 8 and neonatal mortality in this group 1.26%. The slightly asphyxial group (Apgar 7 to 4) comprised 62 (38.75%) twins and the neonatal mortality in this group was 14.51%. There were 20 (12.5%) severely asphyxial (Apgar 3 or less) twins, their neonatal mortality amounting to 80.0%. Out of 193 twins weighing at birth less than 2500 g, 45 (23.31%) died, while in the twins weighing more than 2500 g there was not a single death. The perinatal mortality of twins up to the 37th week of pregnancy amounted to 17.37% and from the 38th week of pregnancy to 1.22%. The mean duration of pregnancy in twins was 38.1 +/- 2 SD 6.3 weeks. The most frequent cause of death in twins has proved to be immaturity and asphyxia at birth, leading to the development of hyaline membranes (80.0%). Other causes were far less frequent. The author concludes that in the perinatal mortality of twins their vitality at birth (assessed by the Apgar score), birth weight, and the duration of pregnancy play an important role.     

Accuracy of ultrasound estimation of fetal weight in multiple pregnancies

Our objective was to assess the accuracy of ultrasonographic estimation of fetal weight in twins and triplets as compared to singleton pregnancies. Retrospective analysis was undertaken of ultrasound data of all fetuses who underwent an examination within 1 week of delivery (singletons 1832, twins 518, triplets 51). At birth weights below 2500 g, there was a significant overestimation of fetal weight in twins as compared to singletons, but the accuracy of the estimate was the same, except in twins between 1500 and 2499 g, when the weight was based on abdominal circumference and femur length alone. At birth weights of more than 2500 g, no difference was detected between twins and singletons. At all birth weights below 2500 g, the accuracy of weight estimation in triplets was equal to that in singletons and there were no triplets above this weight. We conclude that ultrasonographic estimation of fetal weight is as accurate in twins and triplets as it is in singletons.     

Maternal risk factors in infants with very low birth weight

To determine whether maternal risk factors associated with the delivery of very low birth weight infants under 1501 g are different from those associated with low birth weight infants of 1501 to 2500 g, prenatal data on 12,247 deliveries were evaluated. The sample contained 302 very low birth weight infants. Maternal race, age, height, weight, gravidity, parity, past pregnancy performance, and pregnancy complications were analyzed. Factors related to very low birth weight but not to low birth weight infants were previous abortions, previous fetal deaths, and hypertensive vascular disease. Race, maternal height, and prepregnancy weight were not related to very low birth weight but were associated with an increase in low birth weight. There was no significant difference in the rate of very low birth weight or low birth weight by maternal age from 14 to 40 years. These results contradict the concept of a uniform set of predisposing factors for birth of all infants weighing 2500 g or less.     

Lower risks of adverse outcome in twins conceived by artificial reproductive techniques compared with spontaneously conceived twins

The outcomes of twins conceived by 136 women after medical assistance (MA) such as ovulation induction with or without assisted reproductive techniques, and twins conceived spontaneously (SP) by 72 women were compared. All 208 women were monitored from < 20 weeks gestation; they all delivered at > or = 24 weeks gestation. The chorionicity of the placenta was diagnosed antenatally and confirmed after delivery. There were 10 perinatal deaths; the physical and neurological status of the remaining 406 infants was assessed at 1 year of corrected age. There were no differences in gestational age at birth, the birth weights of the larger and smaller twins, the birth weight discordance, or the incidence of life-threatening major malformations between groups. Adverse infant outcomes, such as death, cerebral palsy and mental retardation occurred in nine (3.3%) of 272 MA twins compared with 12 (8.3%) of 144 SP twins (P < 0.05). The placenta was monochorionic in only three (2.2%) of 136 MA twin pregnancies compared with 41 (57%) of 72 SP twin pregnancies (P < 0.001). Of the 21 infants with adverse outcomes, nine had monochorionic placentas. Thus, the risk of an adverse outcome was 2.8-fold higher (95% confidence interval (CI) 1.2-6.4) in monochorionic twins than in dichorionic twins (10 versus 3.7%; P < 0.05). There was no difference in the incidence of adverse infant outcomes between SP (4.8%) and MA (3.4%) twins with dichorionic placentas. These findings suggest that ovulation induction in itself was not associated with an adverse outcome of twin pregnancies. The lower frequency of monochorionic placentas in MA twins may have been responsible for the lower risk of an adverse outcome in MA twins.     

The effect of maternal smoking on birth weight in twin pregnancies

Information on 869 076 singletons and 17 566 twins, born during the period 1983-1991, was obtained from the Swedish Medical Birth Registry. Data on birth weight, gestational duration, vital status, and maternal smoking habits during pregnancy were analyzed in order to investigate whether twinning potentiates the effect of maternal smoking on birth weight and perinatal mortality. The individual birth weights were expressed as percentages of mean birth weight, where mean birth weights of singletons and twins were calculated separately. The birth weight reducing effect of maternal smoking was found to be of the same magnitude among twins and singletons weighing > 90% of mean birth weight. For infants weighing < 90% of mean birth weight, maternal smoking had a significantly stronger effect on birth weight among singletons than among twins. When gestational duration was taken into consideration, this difference was less pronounced. The effect of maternal smoking on gestational duration was stronger among singletons than twins. The smoking-related risk increase of perinatal death was of about the same magnitude among twins and singletons.     

First-trimester growth and the risk of low birth weight

BACKGROUND: Previous studies have demonstrated a correlation between first-trimester size and birth weight. It is not known, however, whether low birth weight is related to first-trimester growth. We sought to determine whether the risk of low birth weight and birth weight that was low for gestational age is related to the size of the embryo or the fetus in the first trimester. METHODS: From a data base of ultrasound records of more than 30,000 pregnancies, we identified women who had no important medical problems, a normal menstrual history, and a first-trimester ultrasound scan in which the crown-rump length of the embryo or fetus had been measured. We examined the relation between the outcome of 4229 pregnancies and the difference between the measured and the expected crown-rump length in the first trimester, expressed as equivalent days of growth. RESULTS: A first-trimester crown-rump length that was two to six days smaller than expected was associated with an increased risk (as compared with a normal or slightly larger than expected crown-rump length) of a birth weight below 2500 g (relative risk, 1.8; 95 percent confidence interval, 1.3 to 2.4), a birth weight below 2500 g at term (relative risk, 2.3; 95 percent confidence interval, 1.4 to 3.8), a birth weight below the fifth percentile for gestational age (relative risk, 3.0; 95 percent confidence interval, 2.0 to 4.4), and delivery between 24 and 32 weeks of gestation (relative risk, 2.1; 95 percent confidence interval, 1.1 to 4.0), but not with delivery between 33 and 36 weeks (relative risk, 1.0; 95 percent confidence interval, 0.7 to 1.5). CONCLUSIONS: Suboptimal first-trimester growth may be associated with low birth weight, low birth-weight percentile, and premature delivery.     

Mothers' birth weight and survival of their offspring: population based study

OBJECTIVE: To test the hypothesis that a baby's survival is related to the mother's birth weight. DESIGN: Population based dataset for two generations. SETTING: Population registry in Norway. SUBJECTS: All birth records for women born in Norway since 1967 were linked to births during 1981-94, thereby forming 105104 mother-offspring units. MAIN OUTCOME MEASURES: Perinatal mortality specific for weight for offspring in groups of maternal birth weight (with 500 g categories in both). RESULTS: A mother's birth weight was strongly associated with the weight of her baby. Maternal birth weight was associated with perinatal survival of her baby only for mothers with birth weights under 2000 g. These mothers were more likely to lose a baby in the perinatal period (odds ratio 2.3, 95% confidence interval 1.4 to 3.7). Among mothers with a birth weight over 2000 g there was no overall association between mother's weight and infant survival. There was, however, a strong interaction between mother's birth weight, infant birth weight, and infant survival. Mortality among small babies was much higher for those whose mothers had been large at birth. For example, babies weighing 2500-2999 g had a threefold higher mortality if their mother's birth weight had been high (> or = 4000 g) than if the mother had been small (2500-2999 g). CONCLUSION: Mothers who weighed less than 2000 g at birth have a higher risk of losing their own babies. For mothers who weighed > or = 2000 g their birth weight provides a benchmark for judging the growth of their offspring. Babies who are small relative to their mother's birth weight are at increased risk of mortality.     

Identifying twin gestations at low risk for preterm birth with a transvaginal ultrasonographic cervical measurement at 24 to 26 weeks' gestation

OBJECTIVE: Because twins are a high-risk group for preterm birth, many clinicians routinely use prophylactic interventions such as home bed rest, hospital bed rest, oral tocolytics, or home uterine activity monitoring to prevent preterm delivery. We sought to identify twin gestations at low risk for spontaneous preterm birth with transvaginal ultrasonography of the cervix to avoid the unnecessary use of prophylactic interventions in these pregnancies. STUDY DESIGN: We measured cervical length at 24 to 26 weeks' gestation by transvaginal ultrasonography in women with twin gestations referred to our prematurity prevention clinic. Each delivery was classified as (1) spontaneous preterm birth < 34 weeks' gestation, (2) delivery at > or = 34 weeks' gestation with intervention, or (3) delivery at > or = 34 weeks' gestation without intervention. Intervention included strict bed rest at home or in the hospital, either parenteral or oral tocolysis, or both, or home uterine activity monitoring. Indicated preterm deliveries and patients with cerclage were excluded from this analysis. The ability of transvaginal cervical length to predict women who would deliver at > or = 34 weeks without intervention was evaluated. A cervical length of 35 mm was chosen by scatter diagram as the best cutoff to discriminate between the group delivered at term without intervention and the other two groups. RESULTS: Of 85 women with twin gestations who underwent ultrasonographic cervical length measurements at 24 to 26 weeks' gestation, 17 had spontaneous preterm birth at < 34 weeks, 23 were delivered at > or = 34 weeks but required intervention, and 45 were delivered at > or = 34 weeks without intervention. The mean cervical length for those delivered at > or = 34 weeks' gestation without intervention (36.4 +/- 5.8 mm) was significantly greater (p < 0.0001) than the mean for those delivered preterm (27.4 +/- 8.5) and those delivered at > or = 34 weeks' gestation who required intervention (27.7 +/- 10.5 mm). The sensitivity, specificity, and positive and negative predictive values of a cervical length > 35 mm for predicting delivery at > or = 34 weeks' gestation are 49%, 94%, 97%, and 31%, respectively. CONCLUSION: A transvaginal ultrasonographic measurement of the cervix of > 35 mm at 24 to 26 weeks in twin gestations can identify patients who are at low risk for delivery before 34 weeks' gestation.     

Plasma leptin influences gestational weight gain and postpartum weight retention

BACKGROUND: Leptin, a product of the obese (ob) gene, is released from adipocytes. At the same body mass index, women have higher concentrations than men. Thus, during pregnancy, leptin may influence gestational weight gain and retention of a portion of that gain postpartum. OBJECTIVE: We examined the relation between plasma leptin at entry to prenatal care and subsequent changes in weight from entry to prenatal care (at 17 wk gestation, baseline) until 6 mo postpartum. DESIGN: This was an observational study of leptin, gestational weight gain, and postpartum weight retention (at 6 wk and 6 mo postpartum) in 103 low-income pregnant women from Camden, NJ, with a pregravid body mass index (in kg/m2) in the normal range (19.8-26). RESULTS: After potential confounding variables were controlled for, leptin at entry significantly (P < 0.05) predicted weight gain in pregnancy, including measured rate of weight gain (x +/- SEE: 0.25 +/- 0.13 kg x unit log leptin(-1) x wk(-1)), measured rate of third-trimester weight gain (0.37 +/- 0.15 kg x unit log leptin(-1) x wk(-1)), rate of weight gain from recalled pregravid weight (0.23 +/- 0.09 kg x unit log leptin(-1) x wk(-1)), and net rate of gestational weight gain (0.22 +/- 0.09 kg x unit log leptin(-1) x wk(-1)). The leptin concentration at entry also significantly predicted retained weight in the postpartum period (at 6 mo: 7.29 +/- 3.33 kg/unit log leptin at entry) and marginally predicted changes in the sum of skinfold thicknesses (at 6 mo: 14.7 +/- 7.5 mm/unit log leptin at entry). CONCLUSION: These results suggest that a high leptin concentration at entry to prenatal care may predict an increased risk of overweight and obesity in vulnerable women.     

The effect of maternal obesity on the accuracy of fetal weight estimation

OBJECTIVE: To determine if maternal obesity affects the accuracy of either clinical or sonographic fetal weight estimations. METHODS: In a year-long study, 998 singleton pregnancies of 26-43 weeks' gestation underwent both clinical (Leopold) and sonographic (Shepard and Hadlock) fetal weight estimation within 5 days of delivery (mean 1.1, 95% confidence interval 1.0-1.3). Patients were stratified into four different groups based on increasing maternal body mass index (BMI): underweight (less than 19.8), normal weight (19.8-26.0), overweight (26.1-29.0), and obese (more than 29.0). The various estimations of fetal weight were compared with actual birth weight, and the mean absolute percent error was calculated for each specific method and analyzed among the four BMI groups. RESULTS: For each method of weight estimation, there was no difference (specifically, no increase) in the magnitude of the absolute percent error with increasing maternal obesity. Regardless of maternal size, almost half of the weight predictions were within 5% of the actual birth weight. CONCLUSION: Increasing maternal obesity does not alter or decrease the accuracy of either clinical or sonographic fetal weight estimations. Therefore, fetal weight predictions provide equally accurate and valid guidelines for determining management decisions in women, regardless of body size.     

Oocyte donation to women of advanced reproductive age: pregnancy results and obstetrical outcomes in patients 45 years and older

We analysed the results of oocyte donation to women of advanced reproductive age (> or = 45 years old) and followed their pregnancies through to delivery in order to assess obstetrical outcomes. Patients (n = 162) aged 45-59 years (mean +/- SD; 47.3 +/- 3.4 years) underwent 218 consecutive attempts to achieve pregnancy. Oocytes (16.2 +/- 7.2 per retrieval) were provided by donors < or = 35 years old. Cleaving embryos (8.2 +/- 4.8 zygotes/couple) were transferred transcervically (4.5 +/- 1.1 per embryo transfer) to recipients prescribed oral micronized oestradiol and intramuscular progesterone. Following oocyte aspiration there were six instances of non-fertilization (2.8%) and 212 embryo transfers. A total of 103 pregnancies was established for an overall pregnancy rate (PR) of 48.6%, which included 17 preclinical pregnancies, 12 spontaneous abortions, and 74 delivered pregnancies (clinical PR 40.6%; delivered PR 34.9%). Multiple gestations were frequent (n = 29; 39.2% of pregnancies) and included 20 twins, seven triplets, and two quadruplets. Two of the triplet and both of the quadruplet pregnancies underwent selective reduction to twins. Antenatal complications occurred in 28 women (37.8% of deliveries) and included preterm labour (n = 9), gestational hypertension (n = 8), gestational diabetes (n = 6), carpel tunnel syndrome (n = 2), pre-eclampsia (n = 2), HELLP syndrome (n = 2), and fetal growth retardation (n = 2). 48 (64.8%) deliveries were by Caesarean section. The gestational age at delivery for singletons was 38.3 +/- 1.3 weeks (range 35-41 weeks), with birth weight 3218 +/- 513 g (range 1870-4775 g); twins 35.9 +/- 2.0 weeks (range 32-39 weeks), birth weight 2558 +/- 497 g (range 1700-3450 g); and triplets 33.5 +/- 0.7 weeks (range 32-34 weeks), birth weight 1775 +/- 190 g (range 1550-2100 g). Neonatal complications (4.6% of babies born) included growth retardation (n = 2), trisomy 21 (n = 1), ventricular septal defect (n = 1), and small bowel obstruction (n = 1). There were no maternal or neonatal deaths. We conclude that oocyte donation to women of advanced reproductive age is highly successful in establishing pregnancy. However, despite careful antenatal screening, obstetrical complications are common, often secondary to multiple gestation.     

The anti-craving drug acamprosate inhibits the conditioned place aversion induced by naloxone-precipitated morphine withdrawal in rats

OBJECTIVE: To assess the influence of maternal race, age, marital status, and education on risk for earlier and later preterm births in twin pregnancies. METHODS: We analyzed 8109 white and 1906 black liveborn twin pregnancies in the Missouri Linked Sibship files for the years 1978-1990, using contingency tables and multiple logistic regression. RESULTS: Black twin gestations had 1.61-fold (95% confidence interval [CI] 1.46, 1.76) greater risk than whites for preterm birth before 34 weeks' gestation. However, there was no race difference after 33 weeks. Among whites, teen age, unmarried status, and education fewer than 12 years were independently associated with risk for delivery before 34 weeks in multivariate analysis (odds ratios [OR] 1.28-1.51, each P < or=.001). These associations were diminished or absent for preterm births after 33 weeks' gestation. White unmarried teen mothers with fewer than 12 years of education had 1.83-fold (95% CI 1.39, 2.40) greater risk for preterm birth before 34 weeks' gestation compared with white married women more than 19 years of age with at least 12 years of education. In blacks, this difference was 1.47-fold (95% CI 1.13, 1.92). In both races, these differences were absent after 33 weeks' gestation. CONCLUSION: Traditional sociodemographic risk factors were present for twin preterm birth, but mainly before 34 weeks' gestation. This, together with previous data from Missouri Linked Sibship files, indicates that dominant pathogenic mechanisms of early preterm birth in twin gestations are likely to be different from those causing later preterm twin birth. Therefore, gestational age should be accounted for in future studies seeking to identify predictive factors or biomechanisms for twin preterm birth.     

Placental pathology in discordant twins

OBJECTIVE: The aim of this study was to evaluate placental abnormalities in relation to birth weight discordance in dichorionic and monochorionic twins. STUDY DESIGN: The maternal charts and placental abnormalities of 147 structurally normal twin pairs with cords labeled at delivery were reviewed. The placental weight belonging to each twin was determined by measuring the length, width, and thickness in each of the two placental disks. Placental weight, chorionicity, infarction, abruptio placentae, decidual vascular abnormality, villous fibrosis and hypovascularity, chronic villitis, and intraplacental thrombi were also assessed. Birth weight was discordant if > or = 20%. The data were analyzed with chi 2 and analysis of variance after log transformation of skewed discordancy values. RESULTS: Of the 147 twin pairs, 99 were dichorionic and 48 monochorionic. Placental weights were known for 91 dichorionic and 40 monochorionic twins. Of the lighter cotwins in dichorionic twin pairs 36.3% (33/91) belonged to the heavier placenta, 49.5% (45/91) belonged to the lighter placenta, and 14.3% (13/91) had an equal share of the placental weight with the heavier sibling (p < 0.05). In 42.4% (42/99) the lighter dichorionic twin had more placental lesions than the heavier twin, in 38.4% (38/99) the same number of lesions were present in both placentas, and in 19.2% (19/99) the heavier twin had more placental lesions. There was linear correlation between percent discordance and number of placental lesions in the lighter twin. In dichorionic twins 18 of the 99 (18.1%) were discordant. In 77.8% (14/18) the lighter twin had more placental lesions than the heavier twin, in 16.7% (3/18) the number of lesions was the same in both, and in 5.6% (1/18) the heavier twin had one more lesion than the lighter twin (p < 0.05). In monochorionic twins, regardless of birth weight discordance, no differences in placental abnormalities were observed. CONCLUSIONS: In dichorionic twins significant birth weight discordance was attributable not to differences in placental weight but to a greater number of placental lesions in the lighter twin than in the heavier twin (p < 0.05). This did not hold true for monochorionic twins.     

Triplet pregnancy and delivery after intracytoplasmic injection of round-headed spermatozoa

Intracytoplasmic sperm injection (ICSI) of round-headed spermatozoa into mature oocyte resulted in normal fertilization, embryo development and pregnancy in a 28 year old female. The husband had a long history of primary infertility. Three ICSI attempts were carried out and fertilization and embryo development occurred in all trials. However, only the third trial led to a pregnancy, which proved to be quadruplet after the transfer of four embryos. One embryo vanished and the remaining triplets were delivered at 35 weeks of gestation by Caesarean section. Two of the babies, a boy weighing 2000 g and a girl weighing 2250 g at birth were discharged in a good condition 1 week after delivery and the third baby, a boy weighing 1550 g, was discharged 3 weeks after delivery.     

Multifetal pregnancy reduction: modification of the technique and analysis of the outcome

OBJECTIVE: To modify the technique of multifetal pregnancy reduction and to study the outcome of reduced twins in comparison with nonreduced twins and high-order multiple gestations. DESIGN: Prospective controlled study. SETTING: The Egyptian IVF-ET Center, Cairo. PATIENT(S): Seventy-five patients with high-order multiple pregnancies resulting from assisted reproduction. Controls were 40 nonreduced twin pregnancies and 22 high-order multiple gestations. INTERVENTION(S): Transvaginal ultrasonically guided multifetal pregnancy reduction was performed. The first 30 cases were done using KCl as a cardiotoxic agent. The modified technique was used for the last 45 cases at an earlier gestational age (approximately 7 weeks) by eliminating the use of KCI and by aspirating the embryonic parts. MAIN OUTCOME MEASURE(S): Miscarriage rate, gestational age at delivery, birth weight, and pregnancy complications. RESULT(S): Using the modified technique, the miscarriage rate was 8.8% and 41 patients delivered between 32 and 39 weeks of gestation (mean+/-SD, 36.9+/-2.45 weeks). The mean (+/-SD) birth weight was 2,450.51+/-235.44 g. The miscarriage rate, fetal wastage rate, mean gestational age, and mean birth weight were similar in reduced and nonreduced twins and were significantly better than in nonreduced triplets and quadruplets. CONCLUSION(S): The modified technique of multifetal pregnancy reduction significantly improved outcomes, which were similar to those of nonreduced twins resulting from assisted reproduction and significantly better than those of nonreduced triplets and quadruplets.     

The use of maternal weight measurements during antenatal care. A national survey of midwifery practice throughout the United Kingdom

The aim of the present study was to examine the use of maternal weight measurements during antenatal care throughout the United Kingdom. A postal questionnaire and follow-up letter were sent to 1500 midwives throughout the United Kingdom, selected at random from the UKCC register. The postal survey achieved a response rate of 44.8% (672/1500 questionnaires), and obtained responses from at least 10 midwives in all but the lowest grade. Respondents were representative of midwives practising throughout the country, in terms of their gender, working hours and grade, although there were fewer midwives in community settings than those in a contemporary representative English sample. The questionnaire obtained information on the background, training and experience of each midwife, together with their attitudes towards antenatal weighing. For those midwives currently involved in antenatal care, additional information was collected on the schedule of antenatal weight measurements, the criteria used to identify 'abnormal' weight gain, and the action taken in response to 'abnormal' weight gain. 61.8% of the midwives thought that the pattern of maternal weight gain was 'not important' in antenatal care, and only 51.5% of those who currently provided antenatal care weighted women at every antenatal visit. However, most midwives (86.1%) cited at least one clinical condition to explain why women are routinely weighed during pregnancy, and over a third of midwives thought that maternal weight gain could detect seven clinical conditions, including obesity, oedema, pre-eclampsia and polyhydramnios. Midwives with more advanced qualifications (degrees and teaching qualifications) and those working in educational or community settings were least likely to believe that weight gain was good at detecting clinical outcomes. Differences in the perceived utility of antenatal weighing influenced whether midwives would act in response to 'abnormal' maternal weight gain, and whether they advised women to gain or lose weight during pregnancy. However, the criteria that midwives used for identifying 'abnormal' weight gain were variable, and often inappropriate, so that different midwives are unlikely to intervene consistently or to give consistent advice on the basis of maternal weight gain. These differences in practice may lead to extensive and inappropriate variation in antenatal care. Clear guidelines are urgently required to ensure that, if maternal weight measurements are collected during antenatal care, they are collected and used consistently.     

Examination of wear in Duraloc acetabular components: two- to five-year evaluation of Hylamer and Enduron liners

BACKGROUND: The purpose was to determine the prognostic value of interleukin (IL) 1-alpha, IL-6 and IL-8 in cervico/vaginal secretion for preterm birth (<37 weeks of gestation) in twin pregnancies. METHODS: The study included screening of 121 women with twin pregnancies with sampling at 24, 26, 28, 30, 32 and 34 weeks of gestation. IL-1alpha, IL-6 and IL-8 was analyzed with ELISA immunoassays. The detection limit was 30 pg/mL for IL-1 and IL-8 and 40 pg/mL for IL-6. Vaginal fluid was smeared and dried for later evaluation of bacterial vaginosis (presence of clue cells). RESULTS: Spontaneous preterm birth occurred in 36 women and 65 women were delivered at term. IL-8 was significantly higher (p=0.03) in samples from women delivered preterm (median 3.72 ng/g mucus, range <0.07-220.00) compared with samples from women delivered at term (median 3.03 ng/g mucus, range <0.08-378.60). At 28 weeks of gestation, IL-8 (cut off 1.75 ng/g mucus) was associated with preterm delivery (relative risk 2.2, CI 95% 1.1-4.5) with a sensitivity, specificity, positive and negative predictive value of 78.8, 45.8, 44.8 and 79.4%, respectively. The levels of IL-1alpha and IL-6 were not significantly associated with preterm birth. Bacterial vaginosis was found in 47/541 (8.7%) samples analyzed. The levels of IL-1alpha and IL-8 were significantly higher in samples positive for bacterial vaginosis than in negative samples (p<0.0001 and p<0.01, respectively). There was no significant association between the level of IL-6 and bacterial vaginosis. CONCLUSIONS: IL-8, but not IL-1alpha and IL-6, was associated with preterm delivery but the relationship was too weak to be of predictive value for preterm birth in twin pregnancies. IL-1alpha and IL-8, but not IL-6, were associated with bacterial vaginosis.     

Estimated gains in birth weight associated with reductions in smoking during pregnancy

OBJECTIVE: To compare the estimated effect on birth weight of reductions in maternal cigarette consumption and urinary cotinine during pregnancy. STUDY DESIGN: An observational study of 641 women with complete data on cigarette consumption, urinary cotinine and infant birth weight. Correlation and regression analyses were used to examine relationships between birth weight, cigarette consumption and urinary cotinine at first and last prenatal visits. RESULTS: Correlations of cigarette consumption and urinary cotinine with infant birth weight were -.23 and -.30 (first visit) and -.26 and -.31 (last visit); all P values were < .001. The regression equation relating urinary cotinine concentrations at first and last visits to infant birth weight explained a significantly larger proportion of the variability in birth weight than the equation relating cigarette consumption at these visits to infant birth weight, 11% vs. 7%, P = .04. Among continuing smokers, both equations predicted gains in birth weight in association with reductions in cigarette consumption, but quitting smoking before the first visit was associated with the most weight gain. As compared to the average infant birth weight of a woman who smoked 20 cigarettes per day throughout pregnancy, the estimated gain in birth weight would be 105 g if she cut down by 10 cigarettes per day after the first visit, 210 g if she quit after this visit and 310 g if she quit before the first visit. CONCLUSION: For women still smoking at their first prenatal visit, infant birth weight is already compromised, but subsequent reductions in cigarette consumption are associated with gains in birth weight. For women who cannot quit smoking, these reductions need to be substantial if increases in birth weight of > 100 g are to be achieved.     

Inadequate weight gain among pregnant adolescents: risk factors and relationship to infant birth weight

OBJECTIVE: Our purpose was to identify behavioral markers for inadequate weight gain (< 20 pounds) during pregnancy among adolescents < 18 years old. STUDY DESIGN: A total of 337 adolescents who were delivered of a term infant at our institution between March 10, 1992, and November 28, 1994 participated in this study. A comprehensive structured interview conducted at the first prenatal visit elicited demographic information and behavioral risk factors. Maternal weights, reproductive history, evidence of sexually transmitted disease, and infant birth weight were extracted from medical records. Logistic regression and chi 2 analyses compared characteristics and infant birth weights between those who gained < 20 pounds with those who gained > or = 20 pounds. RESULTS: A total of 11.6% (39/337) of the total sample gained < 20 pounds during the pregnancy. Adolescents who gained < 20 pounds compared with > or = 20 pounds were delivered of significantly lighter (2942 gm vs 3392 gm) infants and were more likely to be delivered of infants weighing < 2500 gm (13% vs < 1%). Stepwise logistic regression revealed that adolescents who were battered (odds ratio 5.3) or had a sexually transmitted disease (odds ratio 2.3) or an unplanned pregnancy (odds ratio 8.1) were at increased risk for insufficient weight gain during pregnancy. CONCLUSION: Our data suggest that behavioral risk factors are important in the identification of adolescents at greatest risk for inadequate weight gain. Early identification during pregnancy is essential to modify nutritional practices and thus minimize poor obstetric outcomes.