Hyperinsulinemia in macrosomic infants of nondiabetic mothers

OBJECTIVE

We tested the hypothesis that macrosomic infants of nondiabetic mothers are more likely to have hyperinsulinemia and increased subcutaneous fat.

RESEARCH DESIGN AND METHODS

Plasma insulin concentrations were measured in cord blood from 50 macrosomic infants and 32 normal-sized (control), term infants. All mothers had had a normal 50-g 1-h GCT. Skin-fold measurements of the triceps and subscapular area were done on 44 macrosomic infants with a Halpern caliper.

RESULTS

No difference was observed in GCT between mothers of macrosomic (5.8 +/- 1.0 mM) and normal (5.7 mM) infants. The insulin level in macrosomic infants (18.75 +/- 19.08 microU/ml) was significantly higher than in control infants (8.67 +/- 6.64 microU/ml). Macrosomia was a predictor of hyperinsulinemia and vice versa (R2 = 0.26). Maternal height, prepregnancy weight, and weight gain were predictors for macrosomia (R2 = 0.26). No differences were noted in anthropometric measurements between hyperinsulinemic and normoinsulinemic infants.

CONCLUSIONS

A subset of macrosomic infants have hyperinsulinemia. Maternal anthropometric factors as well as hyperinsulinemia are correlated with macrosomia. The macrosomia may be causally related to the high insulin levels.

Elevated maternal serum alpha-fetoprotein and mild fetal uropathy

Sixty-one consecutive patients referred because of elevated maternal serum alpha-fetoprotein (MSAFP) levels and 80 referred for second-trimester ultrasound for other reasons were examined. Ultrasound examination of the genitourinary tract and assignment of phenotypic sex was done by ultrasonographers blinded to the MSAFP results. Among male fetuses with elevated MSAFP, 33% had pyelectasis compared with only 5% of controls. Among female fetuses, pyelectasis was seen in 16% of cases and no controls. Increased MSAFP not caused by an open neural tube defect may be seen in conjunction with mild benign uropathy in the second trimester.

Sexually transmitted diseases and human immunodeficiency virus infection among women with pelvic inflammatory disease

Both human immunodeficiency virus infections and pelvic inflammatory diseases are sexually acquired illnesses of great consequence to women. This study was undertaken to determine if women hospitalized with pelvic inflammatory disease, in a community endemic for human immunodeficiency virus, were at high risk to be infected with human immunodeficiency virus and if human immunodeficiency virus infections altered their hospital course. One hundred ten women hospitalized with pelvic inflammatory disease in Brooklyn (in a hospital in which 2% of parturients are human immunodeficiency virus seropositive) agreed to human immunodeficiency virus testing; 15 (13.6%) were found to be seropositive. Seropositive women were significantly more likely to have an admission white blood cell count less than 10,000/mm3 (p = 0.001). Human immunodeficiency virus seropositivity was not associated with a higher frequency of other sexually transmitted diseases although there was a trend toward more cases of syphilis among human immunodeficiency virus-infected women. Similarly, although there was no significant difference in rates of operative intervention (26.6% among seropositive and 8.4% among seronegative; p = 0.058), there was a trend toward more surgery among those who were human immunodeficiency virus infected. Women hospitalized with pelvic inflammatory disease, in a community endemic for human immunodeficiency virus, are at high risk for human immunodeficiency virus infection. More research is needed to verify a trend toward more refractory infections among human immunodeficiency virus-infected women.

Obstetrics and gynecology in the USSR

Knowledge of Soviet obstetrics and gynecology has been mostly inaccessible to Western physicians. We share our experience regarding medical education and practice in the USSR. Medical education lasts 6 years and is followed by 2 years of postdoctorate training. Residency is limited to clinical obstetrics and gynecology. No formal subspecialty training exists. Research projects are funded and guided by the Health Ministry and Academy of Medical Science. Most articles are published in Russian and are therefore unknown to physicians in the West. Modern medical technology is not available in the practice of obstetrics and gynecology. Abortion remains the leading method of contraception. Perinatal and infant mortality in the USSR is higher than that in comparable Western countries.

Lipid and glucose metabolism in human placental culture

Placental culture models have been used to increase the understanding of endocrinology and pathophysiology in pregnancy. This article describes glucose and lipid metabolism in several of these models. Of special interest is the availability of arachidonic acid for the production of prostanoids. Ten placentas were collected at the time of cesarean section in term pregnancies without labor. Minced villous tissue was incubated for 48 hours in media with a glucose concentration of 100, 200, or 500 mg/dl. Tissue was dispersed in the media or was left as a single clump during the incubation. Glucose levels in the culture media were measured at 8, 20, 32, and 48 hours. Tissue lipid levels were measured before and after incubation in seven placentas. At 8 hours, glucose utilization ranged from 2.38 +/- 0.40 to 9.44 +/- 1.22 mumol/gm tissue/hr (mean +/- SEM). By 48 hours the cumulative glucose utilization ranged from 1.56 +/- 0.09 to 6.87 +/- 0.38 mumol/gm tissue/hr. Tissue lipid analysis showed most of the fatty acids to be in the phospholipids initially (4477 +/- 179 micrograms/gm tissue). Subsequent to incubation for 48 hours, phospholipid levels fell to a range of 2686 +/- 90 to 3466 +/- 157 micrograms/gm tissue in various culture conditions (p less than 0.005 compared with initial values). Whereas phospholipid levels decreased during incubation, levels of triglycerides and nonesterified fatty acids increased significantly in placental tissue. Arachidonic acid, the precursor of prostaglandins, thromboxane, and prostacyclin, makes up about one quarter of the fatty acid in the initial placental phospholipid. Arachidonic acid follows the pattern of total fatty acids during incubation; it is released from phospholipid and is converted to nonesterified fatty acid and triglyceride. We may conclude from this study that each placenta has a unique glucose utilization rate and a unique capacity to produce triglyceride. In tissue culture, arachidonic acid is released to its nonesterified state much more quickly than it can be converted to prostanoids by cyclooxygenase. The choice of initial glucose concentration, tissue preparation (dispersed in media or left as single clump), and time of incubation all may determine the rate of glucose metabolism, the rate of phospholipid breakdown, the rate of triglyceride production, and the quantity of nonesterified arachidonic acid in placental tissue culture.

Prediction of VO2max during cycle exercise in pregnant women

We measured maximal O2 uptake (VO2max) during stationary cycling in 40 pregnant women [aged 29.2 +/- 3.9 (SD) yr, gestational age 25.9 +/- 3.3 wk]. Data from 30 of these women were used to develop an equation to predict the percent VO2max from submaximal heart rates. This equation and the submaximal VO2 were used to predict VO2max in the remaining 10 women. The accuracy of VO2max values estimated by this procedure was compared with values predicted by two popular methods: the Astrand nomogram and the VO2 vs. heart rate (VO2-HR) curve. VO2max values estimated by the derived equation method in the 10 validation subjects were only 3.7 +/- 12.2% higher than actual values (P greater than 0.05). The Astrand method overestimated VO2max by 9.0 +/- 19.4% (P greater than 0.05), whereas the VO2-HR curve method underestimated VO2max by only 1.6 +/- 10.3% in the same 10 subjects (P greater than 0.05). Both the Astrand and the VO2-HR curve methods correlated well with the actual values when all 40 subjects were considered (r = 0.77 and 0.85, respectively), but the VO2-HR curve method had a lower SE of prediction than the Astrand method (8.7 vs. 10.4%). In a comparison group of 10 nonpregnant sedentary women (29.9 +/- 4.5 yr), an equation relating %VO2max to HR nearly identical to that obtained in the pregnant women was found, suggesting that pregnancy does not alter this relationship. We conclude that extrapolating the VO2-HR curve to an estimated maximal HR is the most accurate method of predicting VO2max in pregnant women.

Fetal heart rate response to maternal exertion

Doppler monitoring of fetal heart rates during maternal exertion has suggested that fetal bradycardia occurs frequently during vigorous exercise, causing concern for fetal safety. Doppler determination of fetal heart rate during vigorous maternal effort is difficult. To avoid motion artifact, we observed fetal heart rate using two-dimensional ultrasound and determined the incidence of fetal bradycardia in 45 pregnant women (age, 29.0 +/- 3.7 years [mean +/- SD]; gestational age, 25.2 +/- 3.0 weeks) during 85 submaximal and 79 maximal cycle ergometer tests. Average fetal heart rate did not change during exercise. A single episode of fetal bradycardia (heart rate less than 110 beats per minute for greater than or equal to 10 s) occurred during submaximal exertion during a maternal vasovagal episode. Sixteen episodes of fetal bradycardia were noted within three minutes after cessation of exercise, 15 of which followed maximal maternal effort. We conclude that brief submaximal maternal exercise up to approximately 70% of maximal aerobic power (maternal heart rate less than or equal to 148 beats per minute) does not affect fetal heart rate. In contrast to submaximal maternal exertion, maximal exertion is commonly followed by fetal bradycardia. This may indicate inadequate fetal gas exchange.