Postnatal Assessment Research Articles

Ethnic variation in postnatal assessments of gestational age: a reappraisal.

While the possibility of an ethnic bias in postnatal assessments of gestational age has been suggested by several investigators, others have reported that postnatal assessments do not provide biased estimates in non-White ethnic groups. In the light of this ongoing controversy, this study examines the validity of the Ballard postnatal assessment of gestational age by ethnicity, using a relatively large hospital data base that allows for the inspection of ethnic variations in the agreement between the Ballard assessment and last menstrual period (LMP). The results indicate that there is a greater over-estimation of the LMP interval by the Ballard method in Blacks compared with Whites and suggest that systematic differences exist by ethnicity of mother in the agreement between the Ballard postnatal assessment and the LMP interval. After taking maternal characteristics and pregnancy complications into account, for a given gestational age interval, Blacks have on average a greater level of maturity as measured by Ballard. One interpretation of these findings is that postnatal assessments may provide biased over-estimates of the LMP gestational age interval in certain ethnic groups. An alternative interpretation of these data is that the gestational age interval based on LMP is not a valid indicator of fetal maturity, readiness for birth and infant risk status across all ethnic groups.

Gestational Age Assessment in Preterm Neonates Weighing Less Than 1500 Grams

Postnatal assessment of gestational age in preterm neonates traditionally has been performed using the methods of Dubowitz and Ballard. This study was designed to determine the accuracy of these methods in a sample of very low birth weight preterm neonates. Dubowitz and Ballard examinations were done on 110 preterm neonates within the first 72 hours of life by a neonatologist masked to the gestational age assessed antenatally. Mean birth weight was 1066 ± 256 g (SD). These data were compared with gestational age assessments using last menstrual period and best obstetric estimate calculated by an obstetrician unaware of the neonatal examination. Mean gestational age using last menstrual period was 28.3±2.9 weeks. Mean differences between last menstrual period and Dubowitz/Ballard were -2.8±2.1 weeks and -2.6±2.2 weeks, respectively. Results using best obstetric estimate were similar. An ophthalmologist examined lens vessels of 89 neonates. A similar pattern toward overestimation of gestational age interval by Dubowitz/Ballard was seen at each lens vessel grade. The Dubowitz and Ballard examinations are inaccurate methods of assessing gestational age in preterm neonates with birth weights less than 1500 g.

Validity of postnatal assessments of gestational age: A comparison of the method of Ballard et al. and early ultrasonography

This study investigates the accuracy of the postnatal gestational age assessment method of Ballard et al. to predict very preterm, preterm, term, postterm, and small-for-gestational-age infants, with gestational age by early ultrasonography used as the gold standard. Sensitivity, specificity, and predictive value were examined for each gestational age category, with 4193 single live births occurring during the period from 1982 through 1989 with an ultrasonographic examination done by 20 weeks' gestation and a postnatal assessment at 28 to 44 weeks. These data indicate that the postnatal assessment overestimated the gestational age of preterm births, resulting in an underestimation of very preterm and preterm percentages. Nearly three fourths of the postterm births by ultrasonography were misclassified by the method of Ballard et al. because of underestimation of postterm gestational ages. These data indicate that, for research purposes, appreciable misclassification of preterm, postterm, and small-for-gestational-age infants will occur if gestational age is determined by the technique of Ballard et al.

Peripartum changes in gastric emptying.

Applied potential tomography was used to measure changes in gastric emptying during the peripartum period. Gastric emptying was measured sequentially in each of 10 healthy patients at 37-40 weeks gestation, 2-3 days postpartum and after the 6-week postnatal assessment (control). Mean (SD) times to 50% emptying were 15 (6.05), 11 (5.9) and 15 (5.5) min, respectively. There was no statistically significant change in gastric emptying as a result of pregnancy in this group of women. Retrospective power analysis (assuming alpha = 0.05 and beta = 0.20) shows the study design was adequate to detect a difference of 8 min.

Teratological, neurochemical, and postnatal neurobehavioral assessment of METASYSTOX-R, an organophosphate pesticide in the rat

The purpose of this study was to assess the embryotoxic, fetotoxic, and teratogenic potential of METASYSTOX-R (MSR) in the rat. Furthermore, the study was designed to determine if maternally toxic doses of MSR altered fetal brain acetylcholinesterase (AChE), compromised neonatal survival, growth, and development, or affected neurobehavioral development. Inseminated female rats (45/dose group) received single daily oral doses of 0, 0.5, 1.5, or 4.5 mg/kg of MSR from Days 6 to 15. Dose groups were subdivided into three termination phases: Phase I, 5 females terminated on Day 16 of gestation; Phase II, 28 females terminated on Day 20 of gestation; Phase III, 12 females terminated on Day 21 postpartum. MSR produced a dose-related reduction in maternal plasma (30–72%), red blood cell (18–56%), and brain (21–68%) cholinesterase (ChE) activity, when measured on Day 16 of gestation. The high dose of MSR significantly ( p ≦ 0.05) reduced food consumption, suppressed body weight gain, and produced tremors in 98% of the dams. MSR administered at maternally toxic doses as high as 4.5 mg/kg was devoid of embryotoxic, fetotoxic, and teratogenic effects. Fetal brain AChE was not substantially different from control for any dose level in Day 20 fetuses. Furthermore, neonatal survival, growth, and development were unaffected and an extensive neurobehavioral testing scheme demonstrated no alteration of sensory or reflex functions, maze learning ability, or open field activity for neonates.

Prenatal and postnatal assessment of Maneb-exposed CD-1 mice

Skeletons of CD-1 mice exposed in utero during days 6 to 15 of gestation by gavage of their dams with 1200 mg/kg/day of Maneb in 1.0% carboxymethylcellulose (CMC), were examined between 60 and 65 days postnatal (DPN) for the 88 variants of the skeletal variant assay system (SVAS). Of the 58 variants that appeared, 13 differed ( P < 0.01) from untreated (UNTD), and 15 from vehicle-treated (VEH), despite absence of malformations at birth, weaning, or time of sacrifice. Major changes in frequencies of Parted Frontals, Abnormal Metoptic Roots, Reduced Articular Processes of the Thoracic (Th) Vertebrae, and Carpal Fusions occurred. Several variants affecting the Spinous Process of Th2 occurred in significant proportions as an unusual effect of this compound. In a series of 20 Maneb-treated litters dissected at 18 days post coitus (DPC), of 168 live fetuses, 9 had minor abnormalities, one was exencephalic, and 14 showed growth retardation. Prenatal mortality (20%) was higher than in UNTD (7.5%); litter size and litter weight were not significantly reduced. Ossification of cervical vertebral centra, and caudal vertebrae were significantly reduced, sternebra and limb ossification were not. Occurrence of 14-Ribs was increased. Although maternal mortality complicates interpretation, both traditional prenatal and postnatal examination focusing primarily on the skeleton revealed effects of exposure in the absence of frank malformations.

Views of cesarean birth among primiparous women of Mexican origin in Los Angeles.

ABSTRACT: This study examined data from a larger project on the cultural context of first birth among low‐income women of Mexican origin giving birth in Los Angeles. Data on knowledge of cesarean birth and perceptions of the cesarean birth experience were collected. In addition, differences in perceptions of the experience between women giving birth vaginally and those giving birth by cesarean as reported in the literature were assessed. Five hundred eighteen women were surveyed, of whom 58 had a cesarean birth. Statistical analyses revealed few significant differences between the two groups with regard to childbirth knowledge and attitudes, which may indicate that Latinas are different from the Anglo women discussed in the literature. In their postnatal assessment, 28 percent of the women giving birth by cesarean reported dissatisfaction with the experience, the majority regarded cesareans as “normal,” and 11 percent thought they were at an advantage to have had cesarean births. These results suggest that cultural beliefs and attitudes may affect a woman's perceptions of the childbirth experience. The findings discussed here have implications for cross‐cultural research on childbirth for childbirth educators and for health care providers working in multicultural settings.

Postnatal overestimation of gestational age in preterm infants.

In a study involving 25 preterm infants, obstetric clinical age (standard gestational age) was determined by history, physical examination, and ultrasonographic evaluation. Postnatally, these infants were then evaluated using the Dubowitz Scoring System (DSS) for gestational age assessment. The DSS, as administered by us, significantly overestimated gestational age compared with the standard gestational age (mean +/- 1 SD: 34.2 +/- 2.9 vs 32.5 +/- 3.9 weeks, respectively) in preterm infants. To illustrate, the gestational ages of 13 newborns (52%) in the total study group were each overestimated by more than two weeks. This percentage increased to 75% among the 16 infants whose gestational ages were less than 34 weeks (by standard gestational age). When the standard gestational age was underestimated by the DSS, this difference never exceeded two weeks. These findings suggest that the present system of postnatal assessment of gestational age in preterm infants needs further investigation.

Longitudinal studies of femur growth in normal fetuses.

As an indicator of fetal limb growth, change in the femur diaphysis length (FDL) between 15 and 38 weeks, menstrual age, has been evaluated in a longitudinal study of 20 normal fetuses, as determined by prenatal biparietal diameter, head circumference, and abdominal circumference growth patterns as well as postnatal pediatric assessment. Individual FDL growth curves were uniformly parabolic and followed very similar trajectories. The projected start points [mean: 9.7 (+/- 1.5 SD) weeks] for these curves were in complete agreement with embryologic data, and the curves themselves were well characterized by the Rossavik model [R2 99.5 (+/- 0.5 SD)%]. No differences between males and females were detected, and good agreement was obtained between the average longitudinal growth curve and the cross-sectional growth curve derived from a previously studied data set. Individual growth curve standards, determined from Rossavik models based on data obtained before 26.1 weeks, menstrual age, were within 7% of actual measurements in 94% of the 97 time points studied after 26 weeks. These results indicate that the Rossavik model and its associated individual growth curve standards can be used to evaluate the growth of the femur and thus provide an improved means for detecting skeletal dysplasias and fetal growth retardation.

Management of Fetal Urinary Tract Anomalies Detected by Prenatal Ultrasonography

Over a three and a half year period 32 babies were referred with a urinary tract anomaly diagnosed by prenatal ultrasound. This diagnosis was subsequently confirmed in 19 infants by postnatal assessment. Three of 13 infants in whom the original diagnosis was incorrect were subsequently found to have intra-abdominal pathology but no urological anomaly, while the other 10 had lesions in the urinary tract but not those suggested prenatally. Nineteen of the 29 babies with urological abnormalities were clinically normal at birth; 20 underwent surgery. There were three deaths; two from a combination of renal and pulmonary failure secondary to posterior urethral valves, and a third (in an infant who had normal renal function) from diaphragmatic hernia and cardiac anomalies. Prenatal diagnosis was thought to have been of benefit in six patients, of probable benefit in 16, and of no benefit in seven.

1365 SURFACTANT APOPROTEINS IN INFANTS WITH RESPIRATORY DISTRESS SYNDROME (RDS)

We have measured levels of pulmonary apoprotein (Apo) in tracheal aspirates (TA) of infants with RDS during the course of their treatment. This was done with an ELISA capable of detecting concentrations as low as 10 ng/ml in samples as small as 50 ul. The assay employs an affinity-purified rabbit IgG raised against human apoproteins. A similar assay was established to measure albumin (Alb) in the same samples. Determinations were also made on amniotic fluid (AF) of full-term infants and infants subsequently developing RDS. TA samples from infants with RDS were obtained within six hours of birth and then daily while intubated. Values shown below are from TA's soon after birth, and 3-4 days of age when the infants were recovering from RDS. We conclude that this measure will be useful not only for prediction of RDS, but also for postnatal diagnosis and assessment of clinical course.

Management of fetal urinary tract anomalies detected by prenatal ultrasonography.

Over a three and a half year period 32 babies were referred with a urinary tract anomaly diagnosed by prenatal ultrasound. This diagnosis was subsequently confirmed in 19 infants by postnatal assessment. Three of 13 infants in whom the original diagnosis was incorrect were subsequently found to have intra-abdominal pathology but no urological anomaly, while the other 10 had lesions in the urinary tract but not those suggested prenatally. Nineteen of the 29 babies with urological abnormalities were clinically normal at birth; 20 underwent surgery. There were three deaths; two from a combination of renal and pulmonary failure secondary to posterior urethral valves, and a third (in an infant who had normal renal function) from diaphragmatic hernia and cardiac anomalies. Prenatal diagnosis was thought to have been of benefit in six patients, of probable benefit in 16, and of no benefit in seven.

Ovarian torsion cyst presenting as a wandering tumor in a newborn: antenatal diagnosis and post natal assessment.

A case of an in-utero torsion ovarian cyst is reported. The diagnosis was made antenatally and the 4-cm cystic mass was followed by US from birth until the age of 3 months. Surgery was delayed until the baby reached a satisfactory weight. In the meanwhile, the follow-up studies showed the mass to wander in the abdomen. Surgery revealed an ovarian cyst. Ovarian torsion cysts should be considered in the differential diagnosis of wandering tumors.

In utero allogeneic bone transplantation in primates: roentgenographic and histological observations.

Intrauterine allogeneic bone transplantation was performed on 25 monkey fetuses at 120 to 135 days of gestation. Two surgical techniques for orthotopic transplantation of the humeral midshaft were utilized: (1) A segment (5 to 7 mm) of fetal humerus was transplanted from fetus (donor) to fetus (recipient). An intramedullary pin (Kirschner orthopedic wire) was used for fixation of the severed humerus. (2) Without severing the humerus, a midshaft area (5 to 7 mm X 5 to 6 mm) was surgically ablated. A bone paste composed of crushed bone particles mixed with an agar-enriched culture medium was sculpted to fill this lesion. We used fresh frozen or fresh allograft tissue with equal success. Postsurgical observations included serial roentgenographic and histological evaluation of humeral osteogenesis, as well as postnatal assessment of limb use. The contralateral arm served as a control. Our findings indicate that the immune surveillance system of fetal monkeys may be tolerant of these bone allografts; alternatively, healing by substitution may also occur. The roentgenographic and histological results demonstrate that both of the transplantation procedures used here achieved restoration of the long bone. The use of bone paste allowed us to sculpt the allograft to the desired conformation. These results from laboratory primate models encourage continued investigation of fetal allogeneic bone transplantation, because of its ultimate potential for intrauterine repair of skeletal anomalies in man.

Accuracy of Pre-and Postnatal Assessment of Gestational Age

The gestational age at delivery in a group of 20 neonates was estimated prenatally from measurements of the biparietal diameter made by ultrasound during pregnancy, and postnatally from the newborn infant's neurological and external physical criteria or maturity using the method of Dubowitz et al. (1970). These two assessments were compared with the gestational age at delivery calculated from the date of the last menstrual period (LMP) in mothers certain of their dates. Gestational age derived from the ultrasound data correlated well with that derived from the mother's LMP, and much better than did gestational age derived from the postnatal scoring system.

Accuracy of pre- and postnatal assessment of gestational age.

The gestational age at delivery in a group of 20 neonates was estimated prenatally from measurements of the biparietal diameter made by ultrasound during pregnancy, and postnatally from the newborn infant's neurological and external physical criteria or maturity using the method of Dubowitz et al. (1970). These two assessments were compared with the gestational age at delivery calculated from the date of the last menstrual period (LMP) in mothers certain of their dates. Gestational age derived from the ultrasound data correlated well with that derived from the mother's LMP, and much better than did gestational age derived from the postnatal scoring system.