Alistair B. Roberts

Perinatal mortality in Type 2 diabetes mellitus

Aims In many parts of the world the number of pregnancies in women with Type 2 diabetes mellitus (DM) now exceeds that in women with Type 1 DM, but there are few data published on perinatal mortality in Type 2 DM. This study reports observational data on perinatal mortality in Type 2 DM from a population with a high background rate of this disorder.

Fetal blood sampling immediately before and within 24 hours of death in monochorionic twin pregnancies complicated by single intrauterine death

OBJECTIVE Our goal was to investigate the mechanisms that play a role in intrauterine death in monochorionic twins and that contribute to the high perinatal mortality and morbidity in the survivors. STUDY DESIGN In 8 monochorionic twin pregnancies complicated by the intrauterine death of a single twin, we took samples from 5 twin fetuses immediately before death and from 4 of their cotwins and also from 4 surviving fetuses within 24 hours after death of the cotwin. RESULTS Four of the 5 fetuses sampled who subsequently died were acidemic and 3 were hypoxemic. None of these fetuses or their cotwins were anemic at that time. All 4 survivors sampled within 24 hours of the death of each cotwin had low hematocrits. CONCLUSION Fetal anemia, probably the consequence of acute blood loss just before the time of death of the cotwin, may play a role in the high mortality and morbidity found in the surviving twin. It is unlikely that immediate delivery of the surviving twin after death could affect the outcome.

Fetal liver length in normal and isoimmunized pregnancies.

The length of the right lobe of the fetal liver was measured by means of ultrasound examined on 53 occasions in 21 isoimmunized pregnancies. Fetal blood samples were taken in all patients within 24 hours. Comparisons were made with 350 measurements of liver length in normal pregnancies. A good correlation was found between liver length and fetal hemoglobin level (r = 0.794, p less than 0.001) and between liver length and reticulocyte count (r = 0.721, p less than 0.001). At the time of first sample, all fetuses with a hemoglobin of less than 100 gm/L had a liver length that was greater than the ninetieth percentile. Liver length measurement seems to be a useful indicator of the degree of fetal anemia in isoimmunized pregnancies.

Preterm delivery: A risk factor for retained placenta

The purpose of this study was to determine whether preterm delivery, with and without intraamniotic infection, is a risk factor for retained placenta. This complication occurred more frequently in women with preterm vaginal delivery than in women with term vaginal delivery (9.1% [21/231] vs 1.1% [6/561]; p less than 0.00001; odds ratio = 9.25). There was no significant difference in the prevalence of retained placenta between women with preterm labor and intact membranes and those with preterm premature rupture of membranes (8% [10/125] vs 10.4% [11/106]; p greater than or equal to 0.05). A positive amniotic fluid culture or clinical chorioamnionitis was not associated with a higher incidence of retained placenta. This study indicates that preterm delivery is associated with an increased risk of complications of the third stage of labor.

Serum fructosamine: A screening test for diabetes in pregnancy

Serum fructosamine levels were measured in 1200 pregnant women at different stages of gestation, 167 of them having a glucose tolerance test. There was a significant fall in fructosamine levels throughout pregnancy and details of normal values at different gestational stages are presented. A good correlation was found between fructosamine and glucose tolerance test (r = 0.813). Nine women had gestational diabetes diagnosed by glucose tolerance test and eight of those had a serum fructosamine level greater than the ninety-fifth percentile. This study confirms our previous findings that serum fructosamine may be a useful screening test for gestational diabetes.

Fetal Doppler and behavioral responses during hypoglycemia induced with the insulin clamp technique in pregnant diabetic women.

OBJECTIVE This study was undertaken to assess human fetal behavior and fetal blood flow after insulin-induced symptomatic maternal hypoglycemia of sufficient magnitude to elicit counterregulatory hormones and a symptomatic response. STUDY DESIGN Plasma glucose was lowered from approximately 95 mg/dl to 45 mg/dl in decrements of 10 mg/dl every 40 minutes with the insulin clamp technique. In 10 insulin-dependent diabetic women in the third trimester, the fetus was studied by monitoring fetal heart rate and recording fetal body and breathing movements and by performing Doppler waveform analysis with real-time ultrasonography. Maternal levels of glucagon, cortisol, epinephrine, and growth hormone were measured at each plasma glucose level. RESULTS The mean number of fetal limb and body movements at the start of the study was 25 +/- 16 per 15 minutes, which increased to a mean of 38 +/- 28 at a glucose level of 60 mg/dl and then declined to a mean of 23 +/- 10 at a glucose level of approximately 45 mg/dl. These changes, however, did not achieve statistical significance. In addition, no significant reductions in fetal breathing movements or heart rate were observed, although maternal epinephrine and growth hormone levels were significantly (p < 0.001) increased. No consistent changes in Doppler velocity waveforms were observed. CONCLUSION These data suggest that fetal well-being remains unaltered in spite of moderate maternal hypoglycemia in diabetic women.

Determinants of Birth‐weight in Women with Established and Gestational Diabetes

Summary: Increased birth‐weight (macrosomia) can complicate the diabetic pregnancy, but many factors other than hyperglycaemia can influence birth‐weight, in particular maternal obesity. In a mixed population (European, Maori and Pacific Islander) with a high prevalence of glucose intolerance and obesity we have examined the relative impact of various maternal factors on birth‐weight in women with both established and gestational diabetes. Mean birth‐weight was significantly greater in women with established or gestational diabetes than in controls (p < 0.0001), but was similar in women with gestational and established diabetes, despite glycaemic control being significantly poorer (p < 0.0001) in the latter. Birth‐weight closely paralleled prepregnancy body mass index rather than glycaemic control, but in Maori women it was lower than expected, probably because of their high prevalence of smoking. Daily cigarette consumption was negatively correlated with birth‐weight (p<0.01) despite the smokers having significantly poorer glycaemic control (p<0.001). The most significant variables influencing birth‐weight in the diabetic pregnancy were gestational age at delivery, prepregnancy body mass index, maternal height, estimated weight gain during pregnancy, the presence of hypertension and cigarette smoking (the latter 2 having negative effects on birth‐weight). Glycaemic control in the last half of pregnancy was not significant in this analysis. We conclude that within the limits of glycaemic control which we obtained, birth‐weight was largely determined by maternal factors other than hyperglycaemia. Birth‐weight thus has severe limitations as an outcome measure of the diabetic pregnancy.

Administration of low-dose aspirin to mothers with small for gestational age fetuses and abnormal umbilical Doppler studies to increase birthweight: a randomised double-blind controlled trial

Objective To determine whether antenatal treatment (for ≥= 14 days) with 100 mg aspirin daily, given to mothers with small for gestational age fetuses and abnormal umbilical Doppler, will increase birthweight.

Ultrasonographic measurement of liver length in the small-for-gestational-age fetus

OBJECTIVE Our purpose was to measure fetal liver size in small-for-gestational-age fetuses diagnosed by ultrasonography and to determine whether the small abdominal circumference used to diagnose small for gestational age is the result of a small liver. STUDY DESIGN Ninety-eight pregnant women who were diagnosed as having a fetus that was small for gestational age were included. All had a fetal ultrasonographic measurement of abdominal circumference <10th percentile for gestational age. Measurements were made of the length of the right lobe of the fetal liver within 2 weeks of delivery. The liver length measurements were compared with data collected from a normal population that had been previously published by the authors. The group of fetuses with liver length measurements <10th percentile for gestational age were compared with those with liver length measurements within normal limits. RESULTS Liver length measurements were >10th percentile in 80 fetuses (82%). Eighteen fetuses (18%) had small liver lengths, and this group had significantly smaller antenatal ultrasonographic measurements of head, abdomen, and femur. They were smaller at birth with smaller placentas and they had a higher perinatal mortality rate. CONCLUSION The small abdominal circumference measurement that is the mainstay of ultrasonographic diagnosis of small for gestational age is thought to be a reflection of fetal liver size. This study questions that assumption. The majority of small-for-gestational-age fetuses in this small study did not have small liver lengths. The small abdominal circumference measurement may reflect a reduction in size of other intra-abdominal organs, reduced amounts of fat, or possibly an elevated diaphragm because of poor lung growth.

Pulmonary hypoplasia and fetal breathing in preterm premature rupture of membranes

Forty-eight patients with premature rupture of membranes prior to 24 weeks gestation (PPROM) were studied to investigate whether there was any difference in fetal breathing movements in those fetuses that did or did not develop pulmonary hypoplasia. The diagnosis of pulmonary hypoplasia was made on the basis of ultrasound measurement of fetal lung length. A control group of fetuses with intact membranes and normal pregnancies at the same gestation was also studied. The group that developed pulmonary hypoplasia had significantly less breathing movements than those that did not develop pulmonary hypoplasia and controls. This reduction in breathing movements may contribute to the development of pulmonary hypoplasia.