Patterns of congenital anomalies and relationship to initial maternal fasting glucose levels in pregnancies complicated by type 2 and gestational diabetes

OBJECTIVES

We sought to determine the types of congenital anomalies affecting infants of women with gestational diabetes mellitus or type 2 diabetes and to examine the relationship between those malformation types and measures of initial glycemia of women at entry into prenatal care with type 2 diabetes or at time of diagnosis in women with gestational diabetes mellitus.

STUDY DESIGN

A total of 4,180 pregnancies complicated by gestational diabetes mellitus (n = 3764) or type 2 diabetes (n = 416) that were delivered after 20 weeks of gestation were reviewed for the presence of congenital malformations diagnosed before hospital discharge. Anomalies were categorized as being absent, minor, major, genetic syndromes, or aneuploidies. Major anomalies were further categorized by the number and type of affected organ systems. In addition to maternal clinical and historical parameters, the initial fasting serum glucose either from the diagnostic glucose tolerance test (gestational diabetes mellitus) or at entry to prenatal care (type 2 diabetes) and the initial glycosylated hemoglobin before insulin therapy were examined for a relationship to anomalies.

RESULTS

The initial fasting serum glucose and glycosylated hemoglobin levels were significantly higher in pregnancies with major (n = 143) and minor (n = 112) anomalies and genetic syndromes (n = 9) compared with pregnancies with no anomalies (n = 3895). Of those pregnancies with major anomalies, the most commonly affected organ systems were the cardiac (37.6%), musculoskeletal (14.7%), and central nervous systems (9.8%) and anomalies involving multiple organ systems (16%). There was no increased predominance of any specific organ system involvement seen with increasing fasting serum glucose levels in pregnancies with major congenital anomalies. Pregnancies with major anomalies affecting multiple organ systems had significantly higher initial fasting serum glucose levels (166 +/- 64 mg/dL) compared with pregnancies in which one organ system was affected (141 +/- 55 mg/dL, P <.04) or no organ systems were affected (115 +/- 38 mg/dL, P <.0001).

CONCLUSION

Congenital anomalies in offspring of women with gestational and type 2 diabetes affect the same organ systems that have been previously described in pregnancies complicated by type 1 diabetes. Increasing hyperglycemia at diagnosis or presentation for care was associated with an increasing risk of anomalies in general and with anomalies involving multiple organ systems without a preferential increase in involvement of specific organ system.

Congenital malformations in offspring of women with hyperglycemia first detected during pregnancy

OBJECTIVES

Our aim was to determine risk factors for congenital malformations in offspring of women with hyperglycemia first detected during pregnancy (i.e., women with gestational diabetes).

STUDY DESIGN

A total of 3743 pregnancies complicated by gestational diabetes mellitus delivered at > 20 weeks of gestation were reviewed for the presence of congenital malformations diagnosed before hospital discharge. Anomalies were categorized as major, minor, or absent. Pregnancies with genetic syndromes and aneuploidies were excluded. In addition to maternal clinical and historic parameters, diagnostic glycemic parameters (fasting and post-glucose-challenge levels from the diagnostic glucose tolerance test, highest fasting serum glucose level, and hemoglobin A1c level before insulin therapy) were examined by logistic regression for predictive risk of major anomalies.

RESULTS

One or more major congenital anomalies were present in 108 (2.9%) of the newborns; an additional 91 (2.4%) had only minor anomalies. None of the maternal variables were associated with the risk of minor anomalies. By contrast, parity, a history of gestational diabetes mellitus, and several glycemic parameters were associated with the risk of major anomalies. The highest fasting serum glucose level was the best independent predictor (odds ratio 1.13/10 mg/dl, 95% confidence interval 1.09 to 1.34). The fasting serum glucose level at diagnosis, a parameter that is almost uniformly available to clinicians, gave similar predictive information about the risk of major anomalies (odds ratio 1.13, 95% confidence interval 1.08 to 1.14). Stratification of women into subgroups of fasting serum glucose level at diagnosis revealed the incidence of major anomalies to be as follows: 2.1% with a fasting serum glucose level < 120 mg/dl (2973 pregnancies), 5.2% with a fasting serum glucose level of 121 to 260 mg/dl (747 pregnancies), and 30.4% with a fasting serum glucose level > 260 mg/dl (23 pregnancies).

CONCLUSION

In a large population of women without a diagnosis of diabetes before pregnancy, the maternal fasting serum glucose concentration at diagnosis was a useful predictor of the risk of major but not minor anomalies. The rate of major anomalies doubled with a fasting glucose level > 120 mg/dl. Thus a fasting glucose level below that of overt diabetes outside of pregnancy carries an important risk of major anomalies that must be considered in the counseling and management of these patients.

Satellited 4q identified in amniotic fluid cells

Extra material was identified on the distal long arm of a chromosome 4 in an amniotic fluid specimen sampled at 16.6 weeks of gestational age. There was no visible loss of material from chromosome 4, and no evidence for a balanced rearrangement. The primary counseling issue in this case was advanced maternal age. Ultrasound findings were normal, and family history was unremarkable. The identical 4qs chromosome was observed in cells from a paternal peripheral blood specimen and appeared to be an unbalanced rearrangement. This extra material was NOR positive in lymphocytes from the father, but was negative in the fetal amniocytes. Father's relatives were studied to verify the familial origin of this anomaly. In situ hybridization with both exon and intron sequences of ribosomal DNA demonstrated that ribosomal DNA is present at the terminus of the 4qs chromosome in the fetus, father, and paternal grandmother. This satellited 4q might have been derived from a translocation event that resulted in very little or no loss from the 4q and no specific phenotype. This derivative chromosome 4 has been inherited through at least 3 generations of phenotypically normal individuals.

Performing cytogenetic studies on ascitic, amniotic and hygroma fluid

The importance of obtaining cytogenetic studies on antenatally diagnosed structural malformations is well recognized. In two cases, three fetal compartments were sampled, each resulting in successful cytogenetic studies. Fluid was obtained under ultrasound guidance from amniotic fluid, fetal ascites and cystic hygroma fluid. Fluid from the hygroma itself may be the easiest compartment to analyze.

Preterm breech delivery: another retrospective study

To evaluate the significance of the route of delivery for preterm breech deliveries, a retrospective study was performed on 136 infants in breech presentation, weighing less than 1500 g. Thirty-seven (27%) were delivered vaginally, and the remaining 99 (73%) by cesarean section. Although perinatal mortality was higher in the vaginally delivered infants than in those born by cesarean section (54 versus 37%), statistical significance was not shown. One-fourth of the deaths in the vaginal delivery group occurred intrapartum. Although most previous studies have suggested improved outcome with delivery by cesarean section, the present study fails to demonstrate any statistically significant difference. Whether there is, in fact, no difference in outcome attributable to the route of delivery or a difference exists that is not demonstrable by a retrospective study is an open question. It is concluded that the design of the present retrospective study, as in all published studies on this subject, confounds the results and thereby makes conclusions precarious. The limited value of nonrandomized retrospective studies for the evaluation of a certain obstetric procedure is discussed.

Preinduction cervical priming with PGE2 intracervical gel

A prospective, randomized, controlled clinical trial was conducted to evaluate the safety and efficacy of a single, 0.5-mg dose of prostaglandin E2 gel in a shelf-stable triacetin base administered intracervically in patients with an unfavorable cervix (Bishop score less than or equal to 4) 12 hours prior to oxytocin-induction of labor. forty-eight evaluable patients were enrolled, 25 in the PGE2 group and 23 in the control group. PGE2 gel treatment resulted in a significant improvement in the mean Bishop score compared to control (3.14 versus 0.70, P less than .00005). Sixty-four percent of the patients treated with PGE2 had regular uterine contractions during the 12-hour preinduction period beginning 2.18 +/- 2.0 hours after gel insertion, compared to 9% in the control group, P = .0001. Moreover, 12% (3/25) of the patients receiving PGE2 progressed into active labor and delivered during the preinduction period. The duration of oxytocin infusion required for the induction or augmentation of labor was significantly shorter for patients who received intracervical PGE2 gel compared to the control group (13.1 +/- 8.1 versus 19.0 +/- 8.7, P less than .05). However, there was no significant difference in the incidence of cesarean section between the two study groups (40 and 22% in the PGE2 and control groups, respectively). No episodes of uterine hypertonus or hyperstimulation or gastrointestinal side effects occurred as a result of PGE2 gel treatment.(ABSTRACT TRUNCATED AT 250 WORDS)