Increase in fetal breech presentation in female carriers of Duchenne muscular dystrophy.

Female carriers of Duchenne muscular dystrophy (DMD) may demonstrate elevated serum creatine kinase (CK) and reduction of muscle dystrophin in all muscle types. We hypothesized that decreased dystrophin in uterine or pelvic girdle musculature might affect the obstetrical performance of females heterozygous for a dystrophin mutation. We reviewed the outcome of 34 deliveries resulting in 35 children from 13 women who were mothers of males attending a muscular dystrophy clinic. Obstetrical performance was examined retrospectively by chart review and patient contact. Of 35 children, 6 (17%) were delivered in the breech position, which is a fivefold increase above the national standards for term pregnancies. Of the six infants with breech presentation, two were males affected with DMD, one was a female heterozygote, one was a male who died perinatally, and the carrier status of the other two females is unknown. Most DMD affected males (12/14) were delivered in the vertex position. Thus, it is likely that maternal, rather than fetal, muscle weakness was the significant factor in determination of fetal position at term. We speculate that subtle changes in uterine or pelvic girdle muscle tone may contribute to a higher rate of fetal breech position in carriers of the DMD gene.

Ultrasonographic estimation of fetal body composition for children of diabetic mothers.

The authors hypothesized that ultrasound-generated measurements of the fetus could be used to predict body composition for children of diabetic mothers. Seven ultrasonically identifiable fetal morphometric parameters were measured on 21 fetuses of diabetic mothers within 7 days of delivery. These seven individual measurements were then matched to neonatal morphometric estimations of body composition by means of stepwise regression analysis. Ultrasound variables which were found to show significant correlation to the newborn estimates of body composition were combined to generate an equation that could predict neonatal lean body mass and fat mass. Neonatal lean body mass could be predicted with R = .93 (P less than .001, 95% confidence limits .80-.98). Neonatal fat mass could be predicted with R = .81 (P less than .001, 95% confidence limits .55-.92). Prospective evaluation of the regression equations in an additional 18 patients showed no significant difference between ultrasound-predicted body composition and newborn morphometric estimation of body composition. The authors conclude that estimations of fetal body composition are possible, and may provide a valuable tool in the identification of fetal growth abnormalities.

Elevated maternal serum alpha-fetoprotein and hydrops fetalis in association with fetal parvovirus B-19 infection.

A woman was referred at 19 weeks' gestation for genetic counseling regarding elevated maternal serum alpha-fetoprotein levels. Sonography identified fetal hydrops and fetal death. Fetal tissue specimens showed evidence of human parvovirus infection by DNA probe analysis.

Influence of fetal fat on the ultrasound estimation of fetal weight in diabetic mothers.

Currently available formulas for the estimation of fetal weight assume uniform density of tissue. Because fat tissue is less dense than lean body mass, we hypothesized that the sonographic overestimation of fetal weight in infants of diabetic mothers is the consequence of an elevated proportion of body fat, resulting in a lower body density. We prospectively examined 52 children of diabetic mothers. Each had ultrasound estimation of fetal weight within 7 days of delivery and estimates of neonatal body composition made from anthropometric evaluation within 48 hours of birth. Ultrasound estimates of fetal weight were considered acceptable if they were within 10% of actual birth weight. There was no difference in mean birth weight between those overestimated (N = 22) and those underestimated (N = 8). The sum of skinfolds from two sites, the ponderal index, and percent body fat were all significantly greater in the neonates with sonographic overestimation of fetal weight. Lean body mass was significantly greater (P less than .05) in infants whose sonograms underestimated birth weight. When all subjects were included, a significant correlation was found between the degree of error in the ultrasound estimation of fetal weight and the ponderal index (r = 0.40, P less than .01), the sum of the skinfold measurements (r = 0.29, P less than .05), and the present body fat (r = 0.28, P less than .05). These data suggest that increased body fat in infants of diabetic mothers is associated with sonographic overestimation of fetal weight.

Examination of factors contributing to the risk of cesarean delivery in women with gestational diabetes.

OBJECTIVE: To determine whether increased neonatal fat is associated with an elevated risk of cesarean delivery in infants born to mothers with gestational diabetes mellitus. METHODS: Of 166 infants born to mothers with gestational diabetes, 110 were born vaginally (91 spontaneous, 19 instrumental) and 56 by cesarean. Data were collected on maternal demographics, maternal anthropometrics, delivery variables, and neonatal anthropometrics. We compared all characteristics between women who delivered vaginally and the 29 delivered by cesarean in labor. RESULTS: The difference in birth weight between infants delivered by cesarean and vaginally was not statistically significant (3520 +/- 456 and 3374 +/- 559 g, respectively [mean +/- standard deviation]). There were significant differences between the cesarean and vaginal delivery groups in the rate of nulliparity (80 versus 48%, respectively), maternal pregravid body mass index (28.6 +/- 7.7 versus 25.2 +/- 5.8 kg/m2), fetal position at delivery (23.8 versus 96.2% occiput anterior), and all estimates of neonatal body fat (ponderal index: 2.77 +/- 0.20 versus 2.67 +/- 0.26 kg/m3; sum of two-site skinfold measurements: 11.7 +/- 2.8 versus 10.5 +/- 1.8 mm; and percent body fat: 15.1 +/- 4.9 versus 13.0 +/- 3.3). Stepwise logistic regression analysis demonstrated that fetal position, maternal nulliparity, and fetal fat contributed independently to the cesarean risk. CONCLUSION: Increased newborn fat is associated independently with an increased risk for cesarean in labor.

Plasma volume expansion in early pregnancy.

OBJECTIVE: To determine the time course of plasma volume expansion in early pregnancy. METHODS: We prospectively measured plasma volume by Evans blue dye dilution during the menstrual (cycle day 2--3), follicular (cycle day 9--10), and luteal phases (cycle day urinary leutinizing hormone [LH] surge plus 9--10) of the menstrual cycle and at three additional time points (LH surge + 16 days, LH surge + 28 days, and LH surge + 70 days) in women achieving pregnancy. Twenty-one subjects were examined during 38 menstrual cycles to establish baseline menstrual cycle data. Ten subjects conceived within 1 year of menstrual cycle studies. All ten pregnancies were viable and reached the third trimester. Analyses used repeated-measures analysis of variance with P <.05 accepted for significance. RESULTS: Mean plasma volume was found to change significantly across the period of observation (P <.008) in those who conceived. Plasma volume at LH surge + 70 days (12 menstrual weeks, 2320 +/- 280 mL) was greater than either menstrual cycle estimates or early pregnancy estimates of plasma volume. There was no difference in plasma volume at LH surge + 16 days (2077 +/- 288 mL) or LH surge + 28 days (2010 +/- 271 mL) compared with menstrual cycle measurements during the menstrual phase (2156 +/- 292 mL), follicular phase (2036 +/- 280 mL), and luteal phase (2120 +/- 425 mL). There was no significant difference between those who conceived and those who did not in their mean menstrual cycle plasma volume. CONCLUSION: Plasma volume expansion in early human pregnancy cannot be identified until after the sixth menstrual week. By 12 menstrual weeks, plasma volume has expanded by approximately 14% +/- 12% (mean +/- SD) over follicular phase measurements.

Amniotic fluid glycine-valine ratio and neonatal morbidity in fetal growth restriction.

OBJECTIVE: To test the hypothesis that an elevated amniotic fluid glycine-valine ratio predicts neonatal morbidity in growth-restricted newborns. METHODS: Amniotic fluid (AF) was collected from 122 third-trimester pregnancies (range 31-39 weeks), 49 of which were complicated by fetal growth restriction. Amino acid analysis was performed by high-pressure liquid chromatography. Glycine-valine ratios were compared between normal and growth-restricted fetuses. Neonatal morbidity within the group of growth-restricted fetuses was characterized by evaluation of neonatal hypoglycemia, arterial cord blood gas analysis, and birth weight percentile. We also examined the correlation of AF glycine-valine ratio to the umbilical artery resistance index. The median interval between AF sampling and delivery was 1 day (range 0-8 days). Analyses were performed by Student t test, chi 2 with Yates correction, or simple correlation when appropriate. P < .05 was considered significant. RESULTS: Growth-restricted fetuses have a significantly elevated AF glycine-valine ratio compared with control subjects (3.31 +/- 1.06 versus 2.61 +/- 0.77, respectively, P < .001). There was no association of the glycine-valine ratio with gestational age for either group. An elevated glycine-valine ratio was not associated with neonatal hypoglycemia within the growth-restricted group (hypoglycemia: [n = 16] 3.19 +/- 1.07; no hypoglycemia: (n = 30) 3.44 +/- 1.09). There were no significant correlations of glycine-valine ratio with arterial cord blood pH (r = -0.10), oxygen pressure (r = 0.04), or base deficit (r = 0.12). There were no significant correlations of glycine-valine ratio and birth weight percentile (r = -.24) or umbilical artery resistance index (r = -.14). CONCLUSION: Amniotic fluid glycine-valine ratio is elevated in growth-restricted fetuses compared with control fetuses. However, the level of glycine-valine elevation is not associated with neonatal morbidity related to hypoglycemia, arterial cord blood gas abnormalities, or birth weight percentile.

Maternal insulin sensitivity and cord blood peptides: relationships to neonatal size at birth.

OBJECTIVE: To examine the relationship of multiple maternal and cord blood correlates of newborn size to determine the relative strength of the insulin-like growth factor-I association. METHODS: Thirty-seven venous cord blood specimens were obtained at the time of delivery. Ponderal index and birth weight percentile were calculated at birth. Neonatal length estimates were performed with a measuring board. All mothers were nonsmokers and had normal glucose tolerance. There was a wide range of maternal prepregnancy body mass indexes (BMI) (19.6-43.4). Neonates had a wide range of ponderal indexes (2.12-2.75) and birth weight percentiles (7-99th percentile). Univariate correlation coefficients were calculated to determine simple relationships. Stepwise linear regression analyses were performed to determine the relative contribution of potential explanatory variables to both ponderal index and birth weight percentile. Potentially explanatory independent variables included maternal prepregnancy BMI, weight gain in pregnancy, and maternal insulin sensitivity at 32 weeks' gestation. Maternal insulin sensitivity was estimated using the minimal model technique. Neonatal variables included sex, cord blood albumin, insulin, insulin-like growth factor-I, insulin-like growth factor-binding protein-1, and insulin-like growth factor-binding protein-3. RESULTS: Significant positive univariate correlations were identified between cord blood insulin-like growth factor-I and insulin-like growth factor-binding protein-3 with neonatal ponderal index and birth weight percentile. Maternal insulin sensitivity demonstrated a negative correlation with birth weight percentile (r = -.35, P < .05). Cord blood insulin correlated positively with birth weight percentile (r = .32, P < .05). There were no significant associations of cord blood insulin-like growth factor-binding protein-1 or albumin with either index of newborn size. Stepwise logistic regression analysis demonstrated an independent association of insulin-like growth factor-I with ponderal index (r2 = .41, P < .001). Both insulin-like growth factor-I and male sex were associated independently with birth weight percentile (r2 = .38, P < .001). No additional independent variables contributed to the prediction of ponderal index or birth weight percentile. CONCLUSION: These data support a unique relationship between cord blood insulin-like growth factor-I and newborn size under normal growth conditions. This is manifest by the strength and independence of the association between insulin-like growth factor-I and neonatal birth weight percentile ponderal index.

Intolerance to volume expansion: a theorized mechanism for the development of preeclampsia.

We present a theorized mechanism for the development of preeclampsia, suggesting that one important underlying pathophysiologic mechanism is intolerance to volume expansion. The stage is set for this intolerance by chronic volume constriction, which leads to a requirement for increased basal peripheral vasoconstrictor tone to maintain blood pressure and allow for continued perfusion of the upright hominid head. In pregnancy, volume expansion signaled by the placenta cannot be accommodated by the constricted vascular system. The inability of the normally adaptive endothelial vasodilatory mechanisms to overcome the chronic vasoconstrictor tone leads to endothelial damage, exacerbation of vasoconstriction, and clinical hypertension. Disease resolution, characterized by diuresis, occurs with the elimination of the placenta-derived drive to retain volume. The reason preeclampsia does not recur uniformly with subsequent pregnancy is permanent restructuring of the maternal cardiovascular system with pregnancy that allows for greater plasma volume expansion in future gestations.

Elevated maternal serum alpha-fetoprotein: association with placental sonolucencies, fetomaternal hemorrhage, vaginal bleeding, and pregnancy outcome in the absence of fetal anomalies.

Elevated maternal serum alpha-fetoprotein (MSAFP) levels have been associated with an increased incidence of both placental sonolucencies and pregnancy complications. We designed a prospective study to test the hypothesis that the presence of these sonolucencies or a positive maternal Kleihauer-Betke stain would be associated with an elevated risk of obstetric complications. We enrolled 95 women with singleton pregnancies, elevated MSAFP, and no evidence of fetal anomalies on second-trimester ultrasound evaluation. Placental sonolucencies were documented at the time of ultrasound examination, and a maternal Kleihauer-Betke stain for fetal cells was obtained on the same day. Complications of pregnancy included fetal growth retardation, preterm delivery, late vaginal bleeding (at or after the 20th week of gestation), and fetal death. Women with elevated MSAFP had an increased incidence of placental sonolucencies, positive maternal Kleihauer-Betke stains, first-trimester vaginal bleeding, late vaginal bleeding, preterm delivery, fetal growth retardation, and fetal death compared with controls. Thirty-nine of 95 women with elevated MSAFP (41.1%) had at least one complication. In women with elevated levels, neither the presence of placental sonolucencies nor a positive Kleihauer-Betke stain correlated with first-trimester vaginal bleeding, the MSAFP level, or an increased risk of pregnancy complications. First-trimester vaginal bleeding was associated with an increased risk of preterm delivery in subjects with elevated MSAFP.

Placenta previa percreta with bladder invasion.

BACKGROUND: Although the clinical presentation and imaging techniques can raise suspicion for placenta previa percreta, this potentially catastrophic condition may remain undiagnosed or its extent underappreciated until delivery. The decision to proceed with definitive surgery in cases of placenta previa percreta should be carefully considered. CASE: A case of placenta previa percreta with bladder invasion was diagnosed prenatally. This case illustrates the magnitude of complications that can arise despite aggressive multidisciplinary perioperative management. CONCLUSION: When possible, hysterectomy performed for placenta previa percreta is best avoided under anything other than ideal conditions. A multidisciplinary approach for preoperative, intraoperative, and postoperative management of placenta previa percreta optimizes maternal outcome.

Angiotensinogen genotype and plasma volume in nulligravid women.

OBJECTIVE: To determine if nonpregnant plasma volume is altered in women who are homozygous for the T 235 coding angiotensinogen allele, which predisposes women to an increased risk of preeclampsia. METHODS: We measured plasma volume by Evans blue dilution and analyzed it as a function of angiotensinogen genotype in 15 nulligravid women during midfollicular phase of 26 menstrual cycles. Eleven women were evaluated during two cycles, and four women were evaluated in one cycle. Fourteen women were white, and one was Asian. No subjects had illnesses or were taking medication. The range of body mass index (BMI [kg/m2]) was 20.2-31.0. Plasma volume (mL) was reported as plasma volume divided by BMI to control for variations in body sizes. Statistical analysis was performed by analysis of variance with post hoc testing using Fisher least significant difference test for multiple comparisons (P < .05 accepted for significance). RESULTS: Angiotensinogen genotype analysis showed five women homozygous for M 235, three women homozygous for T 235, and seven women who were heterozygous (MT 235). T 235 homozygotes had significantly lower plasma volume divided by BMI compared with women who were homozygous for M 235 and women who were heterozygous for MT 235 (mean + standard deviation [SD] [71.2 + 8.8, 86.6 + 5.2, 95.8 + 15.6, respectively, P < .05]). There was a tendency toward higher plasma volume in heterozygote MT 235 compared with homozygote M 235 carriers, but it was not statistically significant. CONCLUSION: We conclude that the homozygous T 235 coding angiotensinogen genotype is associated with reduced plasma volume in nulligravid women during the follicular phase of the menstrual cycle compared with M 235 homozygotes and heterozygotes. This association of the T 235 coding genotype might contribute to fetal growth restriction in preeclampsia.

Maternal brain death and prolonged fetal survival.

A 30-year-old woman suffered massive brain injuries after a motor vehicle accident at 15 weeks' gestation. The patient was diagnosed as brain-dead on her tenth hospital day. She was supported with intensive care for 107 days after this diagnosis, and a normal 1555-g male infant was delivered at approximately 32 weeks' gestation by repeat cesarean section. The child is developing normally at 11 months of age. This represents the longest reported case of prolongation of pregnancy after brain death.

Comparison of fetal growth estimates based on birth weight and ultrasound references.

OBJECTIVE: To compare three different methods for modeling fetal weight gain during the third trimester of pregnancy. METHODS: Ultrasound and live birth weight data were used to construct three models for defining fetal growth during the third trimester: longitudinal ultrasound estimates of fetal weight obtained serially at 3-4 week intervals in 50 uncomplicated, well-dated pregnancies between 19 and 40 weeks' gestation; cross-sectional ultrasound estimates of fetal weight obtained from 2018 ultrasound examinations of singleton, non-anomalous fetuses between 24 and 39 weeks' gestation; and cross-sectional birth weight data obtained from 9553 live singleton, non-anomalous neonates between 24 and 43 completed weeks. Analysis was performed by pairwise partial f test to compare regression curves and zeta test for comparison of mean weekly weight gain. A value of p < 0.05 was accepted for significance. RESULTS: Derived regression lines depicting fetal size across gestation were significantly different from each other (f tests, p < 0.05). Estimates of mean fetal weight were significantly different between the three different models at specific gestational ages. Significant weekly variations in fetal weight gain were observed within the raw cross-sectional data sets, both for ultrasound-estimated fetal weight (range 91-278 g/week) and birth weight (65-309 g/week). CONCLUSIONS: Each of the methods used to model normal fetal weight gain in the third trimester defined a distinct pattern of fetal growth. Normal fetal growth, defined longitudinally, was most closely matched by a combination of cross-sectional ultrasound-derived estimated fetal weight in preterm gestation below 34 weeks' gestation and live birth weight at or beyond 34 weeks.

Ketoacidosis in pregnancy associated with the parenteral administration of terbutaline and betamethasone. A case report.

Diabetic ketoacidosis occurred in a woman without a prior history of glucose intolerance. The condition was associated with the combined administration of terbutaline and betamethasone. The patient required insulin therapy for the remainder of her pregnancy but had no further insulin requirements postpartum.