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.     

Size at birth, maternal nutritional status in pregnancy, and blood pressure at age 17: population based analysis

OBJECTIVE: To assess the effect of size at birth, maternal nutrition, and body mass index on blood pressure in late adolescence. DESIGN: Population based analysis of birth weight corrected for gestational age, mother's weight before pregnancy and weight gain in pregnancy, obtained from the Jerusalem perinatal study, and blood pressure and body mass index at age 17, available from military draft records. SETTING: Jerusalem, Israel. SUBJECTS: 10,883 subjects (6684 men and 4199 women) born in Jerusalem during 1974-6 and subsequently drafted to the army. MAIN OUTCOME MEASURES: Systolic and diastolic blood pressures measured at age 17 and their correlation with birth weight, size at birth, mother's body mass index and weight gain during pregnancy, and height and weight at age 17. RESULTS: Systolic and diastolic blood pressures were significantly and positively correlated with body weight, height, body mass index at age 17, and with mother's body weight and body mass index before pregnancy, but not with birth weight or mother's weight gain in pregnancy. CONCLUSION: Variables reflecting poor intrauterine nutrition, including low maternal body mass index before pregnancy, poor maternal weight gain in pregnancy, and being born small for gestational age, were not associated with a higher blood pressure in late adolescence.     

Is maternal malnutrition associated with a low sex ratio at birth?

The low male/female ratio at birth in African populations has been attributed to a variety of genetic, behavioral, and environmental factors. A low sex ratio at birth has been associated with maternal malnutrition in mammals, but this issue has not been studied in humans. In this study we analyzed the relation between maternal nutritional status and sex ratio at birth in 3282 children born to 684 women from a rural African society. Short maternal stature and obesity were independently related to a low sex ratio at birth. These results are consistent with animal experiments that indicate an adverse effect of maternal malnutrition on male fetuses. The results warrant further research in this area.     

mtDNA recombination in a natural population

Variation in mtDNA has been used extensively to draw inferences in phylogenetics and population biology. In the majority of eukaryotes investigated, transmission of mtDNA is uniparental and clonal, with genotypic diversity arising from mutation alone. In other eukaryotes, the transmission of mtDNA is biparental or primarily uniparental with the possibility of "leakage" from the minority parent. In these cases, heteroplasmy carries the potential for recombination between mtDNAs of different descent. In fungi, such mtDNA recombination has long been documented but only in laboratory experiments and only under conditions in which heteroplasmy is ensured. Despite this experimental evidence, mtDNA recombination has not been to our knowledge documented in a natural population. Because evidence from natural populations is prerequisite to understanding the evolutionary impact of mtDNA recombination, we investigated the possibility of mtDNA recombination in an organism with the demonstrated potential for heteroplasmy in laboratory matings. Using nucleotide sequence data, we report here that the genotypic structure of mtDNA in a natural population of the basidiomycete fungus Armillaria gallica is inconsistent with purely clonal mtDNA evolution and is fully consistent with mtDNA recombination.     

Quality of care given to first time birth control patients at a free clinic

In an empirical study of the quality of care at a free clinic, criteria for optimal care for female first visits for birth control were established and 100 charts were reviewed, 50 in April 1974 and 50 in April 1975 with an interval in between of in-service training accompanied by new medical forms and procedures. An encouraging improvement in record keeping was observed. The authors feel it is important that free clinics concentrate on quality as well as quantity and accessibility of care.     

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.     

Gastrin concentration in plasma of the neonate at birth and after the first feeding

Plasma gastrin was determined simultaneously in 19 newborn infants and their respective mothers shortly after birth and in ten neonates before and after the first feeding. The gastrin concentrations in the umbilical vein plasma of the newborn infants were significantly higher than in the peripheral vein plasma of their mothers. The values were statistically not different from those obtained in the neonates before the first feeding. There was an increase in gastrin concentrations after the first feeding. From these results it is suggested that gastrin is produced in the neonate independently from the mother. It is already secreted after the first feeding. Experiments in rats showed that 125I-gastrin is not transported through the placenta. From these findings we assume that most likely the gastrin measured in plasma of newborn infants is of neonatal origin.     

Home birth or short-stay hospital birth in a low risk population in The Netherlands

In The Netherlands women with low risk pregnancies can choose whether they want to give birth at home or in hospital, under the care of their own primary caregiver. The majority of these women prefer to give birth at home, but over the last few decades an increasing number of low risk women have chosen a hospital birth, leaving hospital with their baby shortly after delivery. As both this trend and its effects have not been extensively investigated, a study was designed to examine the determinants of the choice for home or hospital birth. It was hypothesized that the choice would be determined by a combination of personal and social factors. Structural equation modelling indicated that social factors, especially the confidence of significant others in home birth and the expectations of hospital care during childbirth, were by far the strongest predictors of choice. Personal factors, measured as perceived health status before and during pregnancy, the existence of minor symptoms and fear of pain or complications during birth, were found to play an indirect role. Demographic variables such as age, education and urbanization showed no effect. These findings indicate that emphasizing the good results and excellent quality of Dutch maternity care at home is likely to support and strengthen the general acceptance of home birth.     

Maternal weight gain patterns and birth weight outcome in twin gestation

OBJECTIVE: To evaluate the association between maternal weight gain patterns, based on pregravid body mass index (BMI) and birth weight outcome in twins, and to make specific recommendations for maternal weight gain during twin gestation. METHODS: One hundred eighty-nine twin pregnancies were reviewed retrospectively. Weekly rates of maternal weight gain before 20 weeks, from 20 weeks to delivery, and for total gestation were calculated. Thresholds of weekly maternal weight gain were determined for underweight and normal-weight women. RESULTS: In underweight women, a higher weekly rate of gain before 20 weeks was associated with the birth of both twins weighing at least 2500 g (1.13 versus 0.70 lb/week, P = .017), when compared with mothers of at least one twin weighing less than 2500 g. A higher rate of weight gain from 20 weeks to delivery was associated with the delivery of twins weighing at least 2500 g in both underweight (1.92 versus 1.29 lb/week, P = .031) and normal weight (1.63 versus 1.29 lb/week, P = .046) women. No significant differences in weight gain patterns were found between overweight women delivering twins weighing less than 2500 g or at least 2500 g. A weekly rate of gain from 20 weeks' gestation to delivery of at least 1.75 lb/week in underweight women and at least 1.50 lb/week in normal-weight women was associated with the birth of both twins weighing at least 2500 g. After controlling for other potential determinants of birth weight, the threshold of 1.75 lb/week in underweight women showed a trend toward significance as an independent predictor of both twins weighing at least 2500 g (P = .06). CONCLUSION: Certain maternal weight gain patterns during twin pregnancy are associated with the birth of each twin weighing at least 2500 g. As with singletons, recommendations for maternal weight gain during twin pregnancy can be based on pregravid BMI.     

Early prenatal direct gene diagnosis of cystic fibrosis in a twin pregnancy and subsequent selective termination

This study was designed to demonstrate a role of serotonin in the anticonvulsant effect of fluoxetine, a serotonin reuptake inhibitor, in genetically epilepsy-prone rats. When varied doses of 5-hydroxytryptophan (12.5, 25, 50 mg/kg) were administered i.p. along with a fixed dose of fluoxetine (15 mg/kg) to severe seizure genetically epilepsy-prone rats, the severity of audiogenic seizures was decreased dose-dependently, and the combination treatment also produced a marked potentiation of the anticonvulsant effect when compared with administration of either drug alone. Pretreatment of severe seizure genetically epilepsy-prone rats with p-chlorophenylalanine depleted brain serotonin and reduced the anticonvulsant effectiveness of fluoxetine. By using intracerebral microdialysis, the depletion of serotonin after p-chlorophenylalanine treatment was confirmed by measuring thalamic extracellular serotonin and 5-hydroxyindoleacetic acid concentrations during basal release and in response to a challenge dose of fluoxetine. We concluded that serotonergic transmission may be involved in the anticonvulsant effect of fluoxetine in severe seizure genetically epilepsy-prone rats.     

Urine marking and maternal aggression of wild female mice in relation to anogenital distance at birth

A series of experiments were conducted with wild house mice to verify the effect of intrauterine position on females' anogenital distance at birth (AGD) and to examine the relationships between a female's AGD, used as a bioassay of androgen exposure during fetal life, and her social behavior and reproductive success in adulthood. Experiment 1 showed that cesarean-delivered females that developed in utero between two males (2 M females) have significantly longer AGD's than females positioned between two females (0 M females). We then categorized naturally delivered females shortly after birth as having a long, medium or short AGD. In adulthood, these females were tested for their behavior towards unfamiliar pups, their rate of urine-marking in response to a variety of social stimuli, postpartum aggression and success in protecting their litters in response to male and female intruders. Adult females with different AGD's at birth did not differ either in their behavior toward pups or in their rate of urine marking. Conversely, males housed across a wire mesh partition from a long-AGD female deposited a higher number of urine marks than those exposed to a short-AGD female. When tested after delivering a litter, long-AGD females displayed more tail-rattling (a component of agonistic behavior) towards intruders of both sexes in comparison to short-AGD females. These results are consistent with the hypothesis that females with a long AGD are exposed to higher levels of Testosterone during fetal life than females with a short AGD. Although not related to AGD, other measures of maternal aggression were affected by postpartum day, sex of intruders and a female's infanticidal potential while a virgin.     

Social groups and prevention of preterm births in a population of twin mothers

Prenatal care was equally distributed to all twin pregnant women of the district of Haut de Seine in France in 1989-91, without differences by socio-economic level. No difference in rates of preterm births and very early preterm births (26-31 weeks) was measured by socioeconomic level among twin pregnancies.     

Norgestomet implants synchronize estrus and enhance fertility in beef heifers subsequent to a timed artificial insemination

Three trials involving 128 heifers were conducted to determine whether norgestomet implants administered during the mid- and late luteal phases after breeding could be used to synchronize a second estrus in nonpregnant, inseminated heifers without adversely affecting pregnancy in pregnant heifers. All heifers were initially synchronized with Syncro-Mate B and artificially inseminated 47 h after implant removal. On d 9 (Trial 1) or d 12 (Trial 2) after the timed AI, the heifers were randomly assigned to treated or control groups. Treated heifers received two silicone implants containing 10.0 mg of norgestomet each (Trial 1) or one silicone implant containing 3.6 mg of norgestomet (Trial 2). Silicone implants were removed on d 21 after the initial AI. In Trial 1, the calving rate to the initial AI of the control heifers was 35 vs 55% for the norgestomet-implanted heifers (P > .05). In Trial 2 the calving rate to the initial AI of the control heifers was 9 vs 45% in the treated heifers (P < .01). At the return estrus 52% of the control heifers returned to estrus within a 3-d period, whereas 93% of the norgestomet-treated heifers returned to estrus within a 3-d period (P < .01). Norgestomet treatment had no effect on serum progesterone concentrations of the pregnant heifers on d 21 after the initial AI. In Trial 3, both control and treated heifers were administered silicone implants containing 3.6 mg of norgestomet on d 12; additionally, the treated heifers received an injection containing 3.0 mg of norgestomet and 5.0 mg of estradiol valerate. Norgestomet implants were removed on d 21.(ABSTRACT TRUNCATED AT 250 WORDS)     

Declining fecundity and ovarian ageing in natural fertility populations

Lower leg length measurements in 19 healthy preterm infants were obtained by knemometry to assess short term growth. Eight infants received fortified human milk and 11 infants commercially available preterm formulas. Two independent observers measured lower leg length in each infant daily during the study period, weight was measured daily with a neonatal scale. While weight gain showed linearity in all infants, lower leg length growth showed mini growth spurts of 5 +/- 1.7 days, growth periods of 20 +/- 11 days or both types of short term growth. The overall weight gain was 35 +/- 5.6 g/day in infants fed human milk and 33 +/- 7 g/day in infants fed preterm formula. The overall lower leg length growth velocity was 0.51 +/- 0.04 mm/day versus 0.54 +/- 0.09 mm/day, respectively. Both groups had comparable weight and length increments. No correlation existed between the type of nonlinear lower leg length growth (mini growth spurts versus growth periods) and the feedings received by the infants.     

Low birth weight: some considerations in a Zambian population

A retrospective analysis of 2401 consecutive births revealed a lowbirth weight rate of 11.4 percent of all births and 14.2 percent all live borns. Sixty-five percent of late fetal and first week neonatal deaths were low birthweight babies. The cause of low birthweight labour was unknown in 48.2 percent of cases. The major known associations with low birthweight labour and delivery were twin birth, antepartum haemorrhage, premature rupture of the membranes and toxaemia of pregnancy. Nutritional factors were considered to be of significance in the incidence of low birthweight. The earlier attendance of mothers at ante-natal clinics and the availability of experienced medical and nursing personnel with adequate facilities are necessary for perinatal mortality to be significantly reduced in the low birthweight group.     

Thinness at birth in a northern industrial town

OBJECTIVE: To determine whether babies in an area of Britain with unusually high perinatal mortality have different patterns of fetal growth to those born elsewhere in the country. DESIGN: Measurement of body size in newborn babies. SETTING: Burnley (perinatal mortality in 1988 15.9/1000 total births) and Salisbury (perinatal mortality 10.8/1000 total births), England. SUBJECTS: Subjects comprised 1544 babies born in Burnley, Pendle, and Rossendale Health District, and 1025 babies born in Salisbury Health District. MAIN OUTCOME MEASURES: Birthweight, length, head, arm and abdominal circumferences, and placental weight were determined. RESULTS: Compared with babies born in Salisbury, Burnley babies had lower mean birthweight (difference 116 g, 95% confidence interval (CI) 77,154), smaller head circumferences (difference 0.3 cm, 95% CI 0.2, 0.4), and were thinner as measured by arm circumference (difference 0.3 cm, 95% CI 0.3, 0.4), abdominal circumference (difference 0.5 cm, 95% CI 0.4, 0.6) and ponderal index (difference 0.8 kg/m3, 95% CI 0.6, 1.0). The ratio of placental weight to birthweight was higher in Burnley (difference 0.6%, 95% CI 0.4, 0.9). These differences were found in boys and girls and did not depend on differences in duration of gestation or on the different ethnic mix of the two districts. Mothers in Burnley were younger, shorter in stature, had had more children, were of lower social class, and more of them smoked during pregnancy than mothers in Salisbury. These differences did not explain the greater thinness of their babies. CONCLUSIONS: Babies born in Burnley, an area with high perinatal mortality, are thin. The reason is unknown. Poor maternal nutrition is suspected because Burnley babies have a higher ratio of placental weight to birthweight. The greater thinness at birth of Burnley babies could have long term consequences, including higher rates of cardiovascular disease.     

Paternal height and weight as determinants of birth weight in a Chinese population

To evaluate the relationship between paternal weight and height and birth weight, 355 middle class patients with uncomplicated singleton pregnancies who booked within the first trimester were recruited from a homogenous obstetric population from a teaching hospital unit. Maternal height and prepregnant maternal weight were recorded at the booking visit. Paternal height and weight were recorded when the fathers entered the labor ward or visited the postnatal ward at or shortly after the time of delivery. These data were then correlated with the birth weight of the babies. There was a significant correlation between paternal height and weight and the corresponding maternal parameters (correlation coefficients 0.21, p<0.001 and 0.21, p < 0 > 0.01). When the crude birth weight was adjusted for the gestation at delivery, and then controlled for maternal height and weight with the use of a regression model, analysis of variance tests showed that paternal height was significantly correlated to the adjusted birth weight (p<0.01), while paternal weight only showed a marginal correlation (p = 0.05). There was a significant correlation between maternal and paternal height and weight, indicating that couples tend to be of similar sizes. When controlling for maternal size, paternal height was significantly correlated to birth weight, while paternal weight showed only marginal significance. The data suggested that paternal genetic influence could be a significant determinant of in utero fetal growth and thus birth weight.     

Randomized trial of conservative laparoscopic treatment and methotrexate administration in ectopic pregnancy and subsequent fertility

Methotrexate treatment was compared to laparoscopic salpingotomy for conservative management of ectopic pregnancy in a prospective randomized study. One hundred patients were randomized into two groups using random numbers. Inclusion criteria were an ectopic pregnancy visualized by ultrasound with a pre-therapeutic score <13 as assessed by the following six criteria, graded from 1 to 3: gestational age, human chorionic gonadotrophin (HCG) concentration, progesterone concentration, abdominal pain, haemoperitoneal volume and diameter of the haematosalpinx. The treatments were either 1 mg/kg of methotrexate injected transvaginally into the ectopic pregnancy without anaesthesia or administered i.m. when the pregnancy could not safely or easily be punctured (group 1), or laparoscopic salpingotomy (group 2). Success was defined as the return to normal (<10 mIU/ml) of HCG concentrations. Treatment was successful for 45 of 51 patients in group 1 (88.2%) and 47 of 49 in group 2 (95.9%). Medical treatment was significantly (P < 0.05) associated with shorter postoperative stay (24 compared with 46 h), but HCG returned to normal more quickly after laparoscopic treatment (13 compared with 29 days). Spontaneous reproductive performance was similar in both groups, but overall intrauterine pregnancy was higher, and repeat ectopic pregnancy lower, after methotrexate treatment. In selected cases of ectopic pregnancy, with a pre-therapeutic score <13, methotrexate treatment appeared as safe and efficient as conservative treatment by laparoscopy and was associated with improved subsequent fertility.