Inaccuracy of Dubowitz gestational age in low birth weight infants

The Dubowitz gestational age was compared to the obstetric clinical age of 119 predominantly black mother-infant pairs for whom certain clinical criteria were met. Forty-five hypertensive and 74 nonhypertensive gestations with infant birth weight less than 2500 g were evaluated. Overall the clinical age was 33.6 +/- 4.5 weeks versus 34.7 +/- 4.3 weeks by Dubowitz age (P = NS). The Dubowitz age differed from clinical age by more than 2 weeks in 33.6% (40/119). Of gestations under 33 weeks (clinical age) (N = 45) the clinical age was 30.1 +/- 2.4 weeks as compared to the Dubowitz age of 32.2 +/- 2.7 weeks (P less than .01). Fifty-one percent (23/45) of Dubowitz ages were more than two weeks discordant with the clinical age. The Dubowitz assessment of gestational age may be unacceptably inaccurate in the determination of gestational age in low birth weight infants, particularly in those whose gestational age is less than 33 weeks. The findings suggest that studies in which conclusions were based on the Dubowitz age assessment may need reevaluation.     

Ultrasonic prediction of birth weight in preterm fetuses: which formula is best?

Data from previous studies have suggested that birth weight prediction was enhanced by using formulas specifically derived from preterm fetuses. However, no prospective comparison of different formulas was performed. We obtained ultrasonic data on 61 pregnancies at risk for preterm delivery with a gestational age of 29.0 +/- 3.0 weeks (mean +/- SD). In all women birth weight was predicted within 7 days of delivery. Of the 61 pregnancies, 49 (80%), 41 (67%), 30 (49%), and 17 (28%) weighed less than 1750, 1500, 1250, and 1000 gm, respectively; 14 published formulas were compared for accuracy in predicting birth weight in these four categories. The formulas with the smallest absolute mean percent errors incorporated head and abdominal circumferences and femur length. The formula of Weiner et al., derived from low birth weight infants, produced the smallest absolute mean percent error and SD, 10.9% +/- 7.9%; this error was further reduced to 7.7% +/- 6.5% in infants weighing less than 750 gm. These findings suggest that birth weight in the preterm fetus is best predicted by a formula targeted to such a population.     

Maternal and cord serum glycosylated protein in neonatal macrosomia and correlation with birth weight

Maternal glycosylated hemoglobin and glycosylated protein and cord glycosylated protein were measured at delivery in 20 normal mothers of 20 macrosomic neonates over 4000 g (group I) and compared with values in two groups of mother/infant pairs: 20 normal/20 appropriate for gestational age (group II) and nine diabetic mothers/ten neonates (group III). Infants in group I, by design, weighed more (mean +/- SD 4403 +/- 337 g) than those in group II (2902 +/- 278 g) or group III (3365 +/- 898 g) (P less than .001). There was no significant difference in weight between group II and group III infants. Birth weight ratio was greater (P less than .001) in group I than in group II or group III (1.39 +/- 0.1, 0.9 +/- 0.08, and 1.08 +/- 0.25, respectively); group III infants had a higher birth weight ratio (P less than .05) than those in group II. Hematocrit (%) was higher (P less than .05) in group III (62 +/- 3) than in group I (59 +/- 5) or group II (57 +/- 6) infants. Glycosylated hemoglobin values were similar in all three groups. Mean serum glycosylated protein was higher (P less than .001) in group III (13.8 +/- 2%) than in group I (10 +/- 2%) or group II (9.8 +/- 2.5%) mothers. Cord glycosylated protein was also higher (P less than .001) in group III (12.3 +/- 1.9%) than in group I (9 +/- 1.3%) or group II (8.6 +/- 1.7%) neonates.(ABSTRACT TRUNCATED AT 250 WORDS)     

Obstetric outcomes of human immunodeficiency virus-1-serodiscordant couples following in vitro fertilization with intracytoplasmic sperm injection

The objective of this article is to report obstetric outcomes of human immunodeficiency virus-1 (HIV-1)-serodiscordant couples who underwent in vitro fertilization and embryo transfer (IVF-ET) with intracytoplasmic sperm injection (ICSI) at a tertiary care center. We reviewed the outcomes of seronegative women after IVF-ET with ICSI from January 1, 1997 to June 1, 2002. Serodiscordant couples (n = 25) successfully conceived 27 pregnancies delivering 40 neonates (16 singletons, 9 twins, and 2 triplets). The mean gestational age at delivery was 37 0/7 weeks +/- 3 6/7 weeks (range 26 0/7 to 41 2/7 weeks). The mean birth weight was 2646 g +/- 952 g (range 678 to 4396 g). The cesarean section rate was 70%. Preterm delivery (<37 weeks) occurred in 7 pregnancies, and low birth weight (<2500 g) was observed in 8 pregnancies. There were no HIV-1 seroconversions detected at delivery. One hundred percent of the mothers and offspring were beyond 3 months postpartum and remained seronegative. IVF-ET with ICSI seems safe and effective for serodiscordant couples. Obstetric outcomes are favorable, and HIV-1 infection risk is limited.     

Short-term outcome in infants with birth weights less than 1750 g born to mothers with HELLP syndrome.

Premature infants born to mothers with HELLP syndrome were reported to have a less favourable outcome compared to infants with uncomplicated maternal history. We investigated the short term outcome in 21 premature infants with birth weights less than 1750 g born to mothers with HELLP syndrome. Median birth weight was 1050 g (range 420 g-1750 g), corresponding gestational age 29 weeks (range 26-35 weeks). Mechanical ventilation for RDS was necessary in 15 infants. Intracranial hemorrhage was diagnosed in 2 infants, 1 of the surviving infants developed bronchopulmonary dysplasia. Acute renal failure was observed in 3 infants immediately after birth. Mortality was attributed to progressive respiratory failure in 2 patients (b.w. 420 g and 490 g) and persisting acute renal failure in 1 patient (b.w. 520 g) Leucocytopenia (less than 9000/mm3) was observed in 13 infants and thrombocytopenia (less than 115000/mm3) was noted in 4 infants during the first day. Eighteen infants survived. We conclude, that the short term outcome in infants born to mothers with HELLP syndrome is not as poor, as previously reported.     

Maternal factors associated with high birth weight

Maternal characteristics associated with high birth weight were studied in 473 mothers delivered of singleton infants at term with a birth weight of 4500 g or more. The controls were mothers who gave birth to singleton infants at term, with a normal birth weight +/- 1 SD for Swedish newborns. In the multivariate analysis the maximum symphysis-fundus height measurement and gestational duration were strongly significant (p less than 0.001), after correction for other variables, for the probability of being delivered of an infant of high birth weight. Maternal height, weight at beginning of pregnancy, total gestational weight increase and previous live birth of an infant weighing greater than or equal to 4500 g were also important (p less than 0.05) for high birth weight. The maternal characteristics included were evaluated in a prognostic model. With symphysis-fundus height measurement included, the sensitivity increased from 80.3 to 83.3% and specificity from 78.8 to 85.6%, compared with a model where symphysis-fundus measurement was not available.     

Placental weight in diabetic pregnancies

The placenta from 30 women with diabetes mellitus were examined and weighed at delivery. Nineteen of these were from women with overt and eleven from women with gestational diabetes. Eleven placentae from normal pregnancies served as controls. There was no difference between the mean +/- s.d. placental weight for the diabetic group and the control group (609 +/- 148 versus 591 +/- 93 g, NS). The mean placental weight ratios for the diabetic group and the control group were also similar (0.98 +/- 0.23 versus 0.89 +/- 0.15, NS). Moreover, there was no difference between the weights and weight ratios of placentae from women with overt (622 +/- 173 g, 1.02 +/- 0.27) and those with gestational diabetes (586 +/- 90 g, versus 0.90 +/- 0.13). Placental weights correlated with birthweights (r = 0.70, P less than 0.01) and with skinfold thickness measurements fo the infants (r = 0.40, P less than 0.05), but neither with gestational ages (r = 0.15, NS) nor with maternal glycosylated haemoglobin levels in the third trimester (r = 0.24, NS). Among the women with overt diabetes, placental weights were greater in those in White's class B and C than those in class D and R (689 +/- 143 versus 530 +/- 177 g; P less than 0.05). In general, placentae from well controlled diabetic patients were not heavier than those from normal pregnant women, although there was an increase in placental weight in White's class B and C, as compared with those in class D and R.     

Synchronized ventilation of very-low-birth-weight infants; report of 6 years' experience.

OBJECTIVES: To evaluate the effects of long-term patient triggered ventilation (PTV) using assist/control or synchronized intermittent mandatory ventilation (SIMV) in very-low-birth-weight infants with respiratory distress. METHODS: Ninety-seven very-low-birth-weight infants who had undergone synchronized ventilation for respiratory distress or insufficiency were assessed from January 1995 to December 2000. Death, oxygen support, pneumothorax development while ventilated, intracranial hemorrhage, necrotizing enterocolitis, periventricular leukomalacia, retinopathy of prematurity and duration of ventilation were noted as the mean outcome measures. RESULTS: The mean birth weight was 1139 +/- 268 g (range 450-1500 g) and the mean gestational age was 29.0 +/- 2.8 weeks (range 23-36 weeks). Eighty-four per cent of 97 infants survived. Antenatal steroids were administered to only 20% of mothers. Surfactant was administered to all of the 67% of infants with respiratory distress syndrome. The mean duration of ventilator support was 4.7 +/- 7.3 days (1-43 days) for survivors and 8.9 +/- 11 days (1-45 days) for infants who died. No respiratory paralysis was necessary in any case during ventilation and pneumothorax was diagnosed in only eight infants. Severe intracranial hemorrhage (grade > or = III) and periventricular leukomalacia developed in 15% and 12% of infants, respectively. Necrotizing enterocolitis (Bell's classification stage > or = 2) and retinopathy of prematurity were noted in two infants. Four infants had evidence of chronic lung disease. The rate of survival without major morbidity was 83.5%. CONCLUSION: Patient-triggered ventilation, initially PTV with Asist/Control and subsequently with SIMV in very-low-birth-weight infants with respiratory distress is feasible, but optimization of trigger and ventilator performance with respect to respiratory diagnosis is essential.     

Human fetal-placental weight ratio in normal singleton near-term pregnancies.

OBJECTIVE: To determine the fetal-placental weight ratio in normal near-term singleton pregnancies. PATIENTS AND METHODS: 431 consecutive singleton near-term live deliveries following uncomplicated pregnancies were included in a prospective study. Mean maternal age was 28.6 years (range 17-50), mean parity was 2.9 (range 1-16). Mean gestation age at delivery was 39.7 weeks (range 33-42). RESULTS: Mean newborn weight was 3,382.1 +/- 486.7 g (range 2,180-4,810). Mean placental weight was 613.0 +/- 123.8 g (range 319-1,266). Mean fetal-placental weight ratio was 5.6 +/- 0.96 (range 2.9-10.6) with kurtosis of 3.6 and skewness of 1.05. The ratio did not differ significantly between male (n = 253) and female (n = 176) infants, 5.7 +/- 0.89 and 5.6 +/- 1.04, respectively. There was a progressive increase in the fetal-placental weight ratio with gestational age (r = 0.87): from 5.3 +/- 0.90 at 33-36 weeks to 5.9 +/- 1.06 at the 41st week and 5.7 +/- 0.71 at the 42nd week (p < 0.05) and with birth weight distribution (r = 0.85) from 5.0 +/- 1. 06 in newborns weighing 2,000-2,499 g to 5.9 +/- 0.94 in newborns weighing >4,000 g (p < 0.05). There was a positive relationship between the fetal-placental weight ratio in teenage and elder parturients (r = 0.98): 5.2 +/- 0.98 (age 17-19), 5.7 +/- 0.88 (age 20-29), 5.6 +/- 1.08 (age 30-39), and 5.7 +/- 0.96 (age 41-50) (p < 0.05). The most contributing variable was birth weight. CONCLUSIONS: The fetal-placental weight ratio tends to be low in teenage women, early near-term gestational age, and low fetal weight. There was a progressive increase in the fetal-placental weight ratio with gestational age and with birth weight distribution.     

Does Maternal Age Predict Multiple Birth,Preterm Delivery or Low Birth Weight in Successful In Vitro Fertilization Pregnancies?

Objective: to describe the influence of maternal age on births associated with in vitro fertilization (IVF), including lower birth weights, delivery prior to 37 weeks gestational age, and multiple birth.Methods: data on IVF pregnancies from 1994 to 1997 was reviewed. This data included infant birth weight, gestational age, occurrence of multiple births, and maternal age.The age of mothers was categorized as less than 30 years, 30 to 34 years, and 35 years or greater.Results: maternal age information was available for 76 percent of the clients. Four hundred and forty-six births were reviewed, of which 306 (49.8%) infants were multiples, 236 (38.4%) infants were less than 2,500 g and 329 (53.8%) were less than 37 weeks gestation. In successful IVF pregnancies, mothers age 35 and over, compared to those under age 30, were slightly less likely to have a multiple birth (26.1 % versus 37.3%, p&lt;0.08 ), less likely to deliver a low birth weight infant (LBW, &lt;2,500 g) (32.4% versus 48.3%, p&lt;0.005), and less likely to deliver at less than 37 weeks (49.6% versus 57.1%, p&lt;0.005). Among singleton deliveries, advanced maternal age was not associated with higher rates of LBW (9.6% versus 13.5%, p = 0.54) or preterm delivery (21.3% versus 13.5%, p = 0.24).Conclusions: these findings indicate that IVF can be performed in older women without concern that infant morbidity is greater than among younger IVF clients.     

Pregnancy outcome after age 50

OBJECTIVE: To evaluate pregnancy complications occurring after age 50. METHODS: We compared the pregnancy outcomes of women aged 50-64 years with those aged 45-49 years and with the general population. RESULTS: During 5 years from January 1, 1999, to June 30, 2004, 123 women aged 45 years and older gave birth. Fifty-five percent were nulliparous, 24 of 123 were aged 50-64 years, and 99 of 123 women were aged 45-49 years. All women older than age 50 conceived via in vitro fertilization with oocyte donation. For these 123 women, the overall mean gestational age at delivery was 37.6+/-2.6 weeks. The mean birth weight was 2,684+/-754 g, significantly lower than the general population, and the incidences of multifetal pregnancies, diabetes, and hypertension were high. Women aged 50 years and older were more likely to be hospitalized during pregnancy than women younger than 50 years (63% versus 22%, P<.001). Neonatal outcome was generally good. Women aged 50 years and older gave birth to significantly more low birth weight babies than those younger than age 50 years (61% versus 32%, P=.002). Gestational age and birth weight were both significantly lower for singletons and multiples in women older than age 50 years compared with those younger than age 50 years (gestational age of singletons 36.9 versus 38.4 weeks, P=.005; birth weight of singletons 2,694 versus 3,027 g, P=.019; gestational age of multiples 35.1 versus 36.4 weeks, P=.01; birth weight of multiples 1,976 versus 2,310 g, P=.038, respectively). CONCLUSION: Pregnant women aged 50-64 years have increased risks of preterm birth, low birth weight babies, diabetes mellitus, hypertension, and hospitalization. LEVEL OF EVIDENCE: II-2.     

Psychosocial support for maternal stress during pregnancy: effect on birth weight

In a previous study we showed that moderate to severe stress during pregnancy was inversely related to infant birth weight. Using the same criteria for stress (according to the Social Readjustment Rating Scale of Holmes and Rahe), we studied 86 white mothers with singleton pregnancies and with no known medical or obstetric risk factors for reduced birth weight. After strict randomization, data were analyzed for 43 mothers who received psychosocial support between enrollment at +/- 20 weeks and delivery at +/- 38 weeks and for 43 control mothers who received standard care at the antenatal clinic. In the supported group seven infants weighed less than 3000 gm at birth versus 18 control infants (p = 0.008), and analysis revealed that this effect was more the result of improved intrauterine growth than of prolongation of pregnancy. These findings are of little clinical relevance as far as the neonate is concerned, but they do indicate that psychosocial support has a significant effect on birth weight. It is possible that previous studies that have looked only for an effect on low- or very-low-birth-weight rates might have missed this clinically measurable benefit of counseling.     

The effect of blood transfusion on the hemoglobin oxygen dissociation curve of very early preterm infants during the first week of life

A study was conducted during the first week of life to determine the changes in P50 (PO2 required to achieve a saturation of 50% at pH 7.4 and 37 degrees C) and the proportions of fetal hemoglobin (HbF) and adult hemoglobin (HbA) prior to and after transfusion in very early preterm infants. Eleven infants with a gestational age < or = 27 weeks have been included in study. The hemoglobin dissociation curve and the P50 was determined by Hemox-analyser. Liquid chromatography was also performed to determine the proportions of HbF and HbA. The mean gestational age of the 11 infants was 25.1 weeks (+/- 1 weeks) and their mean birth weight was 736 g (+/- 125 g). They received 26.9 mL/kg of packed red cells. The mean P50 prior and after transfusion was 18.5 +/- 0.8 and 21.0 +/- 1 mm Hg (P = .0003) while the mean percentage of HbF was 92.9 +/- 1.1 and 42.6 +/- 5.7%, respectively. The data of this study show a decrease of hemoglobin oxygen affinity as a result of blood transfusion in very early preterm infants prone to O2 toxicity. The shift in HbO2 curve after transfusion should be taken into consideration when oxygen therapy is being regulated for these infants.     

Complications of pregnancy in infertile couples: routine treatment versus assisted reproduction

Ninety pregnancies conceived by infertile couples using assisted reproductive technologies and 86 pregnancies conceived by infertile couples with routine infertility treatment were analyzed to determine the outcome of and the complications experienced during the pregnancies. Pregnancies ending after 24 weeks' gestation were evaluated for the following complications: pregnancy-induced hypertension, diabetes mellitus, preterm labor, premature rupture of membranes, placenta previa, and fetal growth retardation. A matched control group of normal fertile patients admitted to the obstetric service at Vanderbilt University Medical Center was used to compare the incidence of pregnancy complications among the groups. In the group treated by assisted reproduction, 81 pregnancies were singleton and nine were multiple gestations, whereas in the routine group, 84 were singleton and two were multiple gestations. In the group treated by assisted reproduction, 29 of 90 gestations (32%) ended before 24 weeks, compared with 18 of 86 (21%) in the routine group, a nonsignificant difference. Mean birth weight and gestational age were similar among the three groups for singleton gestations. Among multiple gestations, the mean (+/- standard error of the mean [SEM]) birth weights were 2513 +/- 115, 724 +/- 57, and 2282 +/- 132 g in the group treated by assisted reproduction, the group receiving routine methods, and the control group, respectively (P less than .001 when those treated by routine methods were compared with the other two groups). The mean (+/- SEM) gestational ages were 36 +/- 1.2, 26.5 +/- 2.0, and 35.5 +/- 1.2 weeks, respectively (P less than .01 comparing those treated by routine methods and the other two groups).(ABSTRACT TRUNCATED AT 250 WORDS)     

Foetal and placental weights in relation to maternal characteristics in gestational diabetes

An increased placental weight has been reported in pregnancies complicated with gestational diabetes (GDM). We have analysed foetal (F) and placental weight (P) and foetal length in 143 consecutive normal (N) and 132 GDM pregnancies in relation to type of treatment and to a number of maternal variables. All N pregnancies had a negative oral glucose challenge test at 24-28 weeks. GDM was diagnosed at 28-32 weeks by a 100-gm, 3-h oral glucose tolerance test (OGTT). Treatment was diet (D: n=82) or diet plus insulin (D+I: n=50) according to self-monitoring of blood glucose. A significant difference was observed between N and GDM pregnancies for maternal age (N=30.6+/-5.38 years; GDM=33.2+/-4.53 years; P< 0.001), pre-pregnancy weight (N=58.2+/-8.0 kg; GDM=63.0+/-12.9 kg; P< 0.001) and BMI (N= 21.9+/-2.63; GDM=24.4+/-4.71;P< 0.001). Foetal weight became significantly higher in the GDM group (N=3274.2+/-296.0 g; GDM=3287.1+/-474.1g; P< 0.05) once correction was made for the significant difference in gestational age between the two groups (N=39.4+/-1.17 weeks; GDM=38.8+/-1.39 weeks; P< 0.001). Significantly higher placental weights (N=561.87+/-91.0 g; GDM=592.2+/-115.8 g;P< 0.01) and significantly lower F/P weight ratios were found in GDM pregnancies (N=5.96+/-1.02; GDM=5.69+/-1.13; P< 0.05).In GDM pregnancies a significantly negative correlation was found between the OGTT response and weights of foetus and placentae at delivery, suggesting that both foetal and placental growth are affected by maternal insulin resistance.     

Prospective comparative study of the safety and effectiveness of ginger for the treatment of nausea and vomiting in pregnancy

OBJECTIVES: The primary objective of our study was to examine the safety and the secondary objective was to examine the effectiveness of ginger for nausea and vomiting of pregnancy (NVP). STUDY DESIGN: Pregnant women who called the Motherisk Program who were taking ginger during the first trimester of pregnancy were enrolled in the study. The women were compared with a group of women who were exposed to nonteratogenic drugs that were not antiemetic medications. The women were followed up to ascertain the outcome of the pregnancy and the health of their infants. They were also asked on a scale of 0 to 10 how effective the ginger was for their symptoms of NVP. RESULTS: We were able to ascertain the outcome of 187 pregnancies. There were 181 live births, 2 stillbirths, 3 spontaneous abortions, and 1 therapeutic abortion. The mean birth weight was 3542+/-543 g, the mean gestational age was 39+/-2 weeks, and there were three major malformations. There were no statistical differences in the outcomes between the ginger group and the comparison group with the exception of more infants weighing less than 2500 g in the comparison group (12 vs 3, P < or =.001). There were a total of 66 completed effectiveness scores with the mean score of 3.3+/-2.9 SD. CONCLUSION: These results suggest that ginger does not appear to increase the rates of major malformations above the baseline rate of 1% to 3% and that it has a mild effect in the treatment of NVP.     

Neonatal outcome of infants delivered at 26-28 weeks of gestation

The delivery results of 42 infants born to 40 mothers at the gestational age of 26-28 weeks during a period of 5 years were analyzed. The study was evaluated in two periods of time: in the first period out of 15 infants born only 5 (33.3%) survived, while in the second period 21 (77.7%) out of 27 infants survived (p less than 0.01). 38 infants were transferred to a neonatal intensive care unit for premature infants. Only 41% of the infants transferred in the first period survived, as compared to 80.7% of those transferred during the second period (p less than 0.01). There was no significant difference in the mean birth weight at each gestational age between the survivors and those who subsequently died in both periods of the study. In the study groups, cesarean section rate rose from 13.3% in the first period to 44% in the second. Mode of delivery, regardless of the presenting part, did not seem to influence neonatal survival. Obstetrical management, including the performance of operative delivery for fetal indications and active neonatal resuscitation, seems to be reasonable for infants at the gestational age of 26 weeks or more.     

The wider perinatal significance of the Australian in vitro fertilization data collection program

The most recent report (1986) from the Australian Register of In Vitro Fertilization pregnancies comprises 2242 in vitro fertilization (IVF) pregnancies and 261 gamete intrafallopian transfer (GIFT) pregnancies. A review of this data base indicated that this population had a relatively high incidence of both obstetric and perinatal morbidity and perinatal mortality. About 58% of the IVF pregnancies resulted in live births and 36.4% of the infants weighted less than 2500 gm at birth. These high rates could be partially accounted for by maternal prepregnancy risk factors, such as age, and by risk factors associated with the infertility management, such as multiple pregnancy (22% of all pregnancies more than 20 weeks), which accounted for approximately 50% of the preterm births (less than 37 weeks). Singleton pregnancies also had a higher incidence of preterm birth (17.8% at gestational age 24 to 36 weeks), low-birthweight babies (15.9% less than 2500 g) and perinatal mortality rates (35.4% per 1000 live births) than the Australian population at large. This warrants these patients being regarded as high risk. It is reassuring that the incidence of major malformations in IVF births (2.2%) is similar to that in the general population (1.4%).     

The effect of gender and gestational diabetes mellitus on cord leptin concentration

OBJECTIVE: The purpose of this study was to determine the relationship of neonatal sex and gestational diabetes mellitus on cord leptin concentration and to determine whether cord leptin has a stronger correlation with fat mass compared with birth weight or lean body mass. We hypothesized that there are no significant differences in fetal leptin concentration between male and female or between neonates of mothers with gestational diabetes mellitus and control neonates, when adjusted for body composition. STUDY DESIGN: Cord blood leptin concentrations were measured in newborn infants of 78 women (44 control neonates and 34 gestational diabetes mellitus). Of the 78 neonates, 32 babies were female, and 46 babies were male. Birth weights were measured with a calibrated scale, and body compositions were measured by total body electrical conductivity. RESULTS: Estimated mean gestational age at delivery was 39.1 +/- 1.1 weeks for control neonates versus 38.6 +/- 1.3 weeks for neonates of mothers with gestational diabetes mellitus (P =.01). The fat mass for the control neonates and neonates of mothers with gestational diabetes mellitus was 0.36 +/- 0.15 kg versus 0.48 +/- 0.21 kg (P =.01); the percent body fat for the control neonates and neonates of mothers with gestational diabetes mellitus was 10.5% +/- 3.8% versus 13.2% +/- 4.3% (P =.006), respectively. There was no significant difference in cord leptin concentration between male and female neonates (16.0 +/- 13.8 ng/dL vs 12.7 +/- 12.8 ng/dL, P =.24). Cord leptin concentrations (18.1 +/- 16.2 ng/dL vs 10.9 +/- 9.5 ng/dL, P =.02) were significantly greater in neonates of mothers with gestational diabetes mellitus than in control neonates. In all subjects, cord leptin was significantly correlated with percent body fat (r = 0.51, P <.0001), fat mass (r = 0.49,P <.0001), and birth weight (r = 0.25, P =.03). After the adjustment for fat mass, there was no significant difference in cord leptin concentration between control neonates and neonates of mothers with gestational diabetes mellitus (P =.20), but there was a significant difference between male and female neonates (P =.04). However, when an adjustment was made for both fat mass and lean body mass, there was no longer a significant difference between male and female neonates (P =.12) CONCLUSION: The differences in cord leptin concentration between male and female neonates and between infants of women with gestational diabetes mellitus and control neonates are related to differences in body composition.