Vicky O’Dwyer

Offspring birth weight and maternal fasting lipids in women screened for gestational diabetes mellitus (GDM).

OBJECTIVES Maternal lipid metabolism is altered during pregnancy but little is known about the influence of these alterations on either intrauterine fetal development or maternal wellbeing. The purpose of this study was to examine the relationship between both fasting cholesterol and triglycerides and offspring birth weight in women screened selectively for gestational diabetes mellitus (GDM). STUDY DESIGN In a prospective observational study in a University Maternity Hospital, women were recruited at their convenience when they were screened for GDM with a diagnostic 75 g oral glucose tolerance test (OGTT). An additional sample was taken for a lipid profile at the time the fasting glucose was obtained. Clinical and socio-demographic details were recorded. RESULTS Of the 189 women recruited, the mean age was 32 years, 35.4% (n=67) were primigravidas, 44.1% (n=82) were obese and 11.6% (n=22) had an abnormal OGTT. On univariate analysis, increasing birth weight was correlated positively with multiparity, first trimester body mass index (BMI), GDM and hypertriglyceridaemia but not with cholesterol levels. On multivariate analysis, increased birth weight correlated positively only with hypertriglyceridaemia. CONCLUSIONS This study provides further evidence that maternal hypertriglyceridaemia is important in programming intrauterine fetal growth and raises questions about whether women should be screened selectively for dyslipidaemia before, during and after pregnancy.

The risk of caesarean section in obese women analysed by parity.

OBJECTIVE This study looked at the association between caesarean section (CS) and Body Mass Index (BMI) in primigravidas compared with multigravidas. STUDY DESIGN We enrolled women at their convenience, in the first trimester after an ultrasound examination confirmed an ongoing pregnancy. Weight and height were measured digitally and BMI calculated. After delivery, clinical details were again collected from the Hospitals computerised database. RESULTS Of the 2000 women enrolled, there were 50.4% (n=1008) primigravidas and 49.6% (n=992) multigravidas. Of the 2000 8.5% were delivered by elective CS and 13.4% were delivered by emergency CS giving an overall rate of 21.9%. The overall CS rate was 30.1% in obese women compared with 19.2% in the normal BMI category (p<0.001). In primigravidas the increase in CS rate in obese women was due to an increase in emergency CS (p<0.005) and in multigravidas the increase was due to an increase in elective CS (p<0.01). In obese primigravidas 20.6% had an emergency section for fetal distress. In obese multigravidas 17.2% had a repeat elective CS. CONCLUSION The influence of maternal obesity on the increase in CS rates is different in primigravidas compared with multigravidas.

Maternal obesity and gestational weight gain

The aim of the study was to analyse gestational weight gain (GWG) according to body mass index (BMI) category and to explore the relationship between GWG and pregnancy complications. Women were recruited in the 1st trimester. Weight and height were measured and BMI calculated. Weight was measured at 38 weeks’ gestation and GWG calculated. Clinical details were obtained prospectively. Of the 604 women recruited, 45.5% were primigravidas and 25.2% were obese. The overall mean GWG was 11.6 kg (SD 6.0). In obese women, the mean GWG was 10.4 kg (SD 7.5) compared with 12.6 kg (SD 5.7) in the normal BMI category (p < 0.001). Maternal obesity but not increased GWG was associated with an increased risk of induction of labour, caesarean section and pre-eclampsia. It was concluded that obese women were more likely to exceed GWG recommendations, despite lower GWG than non-obese women. Maternal obesity and not GWG increased the risk of pregnancy complications.

Miscarriage after Sonographic Confirmation of an Ongoing Pregnancy in Women with Moderate and Severe Obesity

Objective: To compare the incidence of spontaneous miscarriage in women with moderate to severe obesity to that in women with a normal BMI after sonographic confirmation of the foetal heart rate in the first trimester. Methods: Women were enrolled in a prospective observational study at their convenience in the first trimester after an ultrasound confirmed an ongoing singleton pregnancy with foetal heart activity present. Maternal height and weight were measured digitally and BMI was calculated. Results: In the 3,000 women enrolled, the miscarriage rate overall was 3.9% (n = 117). The mean gestational age at enrolment was 11.1 weeks. In the class 2–3 (BMI > 34.9 kg/m2) obese primigravidas the miscarriage rate was 11.3% (n = 8) compared with 2.7% (n = 24) in the normal BMI category (p = 0.003), and 3.7% (n = 5) in the class 1 obese category (not significant). In multigravidas, there was no increased rate of miscarriage among class 2–3 obese women compared with multigravidas in the normal BMI category. The mean body composition values showed that primigravidas who miscarried had both increased fat and fat-free masses compared with those who did not, but multigravidas who miscarried had a similar fat mass and fat-free mass with those who did not. Conclusions: In women with sonographic evidence of foetal heart activity in the first trimester, the rate of spontaneous miscarriage is low. It was increased in moderate to severely obese primigravidas, but was not increased in other obese women compared to women in the normal BMI category.

National variations in operative vaginal deliveries in Ireland.

To compare the percentage of operative vaginal delivery (OVD) among all publicly funded maternity hospitals in Ireland and to develop quality control performance tables to facilitate national benchmarking.

International variation in caesarean section rates and maternal obesity

This study examined variations in caesarean section (CS) rates associated with a womans birthplace and differences in maternal adiposity. Women were enrolled in the 1st trimester. Maternal adiposity was assessed by body mass index (BMI) and bioelectrical impedance analysis (BIA). Irish women were compared with women born in the 14 countries who joined the European Union (EU) before 2004 (EU 14), and with those born in 12 countries who joined following enlargement (EU 12). Of the 2,811 women enrolled, 2,235 women were born in Ireland, 100 in EU 14 countries and 476 in EU 12 countries. Based on a BMI > 29.9 kg/m2, maternal obesity was higher in Irish (19.8%; n = 443) and EU 14 women (19.0%; n = 19) compared with EU 12 women (9.5%; n = 45), p < 0.001. BIA of maternal body composition confirmed increased adiposity in both the Irish and EU 14 women. Variations in emergency CS rates in primigravidas based on the womans birthplace were associated with maternal adiposity and induction of labour, both modifiable risk factors for CS. We recommend, therefore, that induction of labour in obese primigravidas should be undertaken only in carefully considered clinical circumstances. Our findings also suggest economic development in Europe may drive an increase in the CS rates mediated through increased levels of maternal obesity and, therefore, public health interventions should focus on optimising a womans prepregnancy weight.

Timing of screening for gestational diabetes mellitus in women with moderate and severe obesity.

Objective. We evaluated screening with a diagnostic oral glucose tolerance test earlier than 20 weeks gestation in women with moderate to severe obesity. Design. Prospective observational study. Setting. Large university teaching hospital. Population. We enrolled 100 women booking for antenatal care in the first trimester at their convenience. Methods. Height and weight were measured and body mass index calculated. Only women with a body mass index>34.9 kg/m2 were included. Women were booked for a 100 g oral glucose tolerance test before 20 weeks and, if normal, another test at 28 weeks gestation. Main outcome measures. Impaired glucose tolerance and gestational diabetes mellitus. Results. Of the 100 women given an appointment for an oral glucose tolerance test before 20 weeks gestation, 92 attended. Of these, 10 (10.8%) women had an abnormal result, with impaired glucose tolerance in five (5.4%) cases and gestational diabetes mellitus in five (5.4%) cases. Of those with a normal result at 20 weeks, 81 attended for a repeat test at 28 weeks gestation. A further four (4.9%) had impaired glucose tolerance and four (4.9%) had gestational diabetes mellitus. A total of 18 (20.5%) of the 88 women who complied with screening had an abnormal test. Conclusions. Women who have moderate/severe obesity have a one in five chance of having an abnormal diagnostic oral glucose tolerance test when screened for gestational diabetes mellitus. To optimize maternal glycemic control in pregnancy, we suggest that women with a body mass index>34.9 kg/m2 may need to be screened early in pregnancy and, if the test is normal, again at 28 weeks gestation.

Body mass index and hypertensive disorders of pregnancy

OBJECTIVES We compared the incidence of the hypertensive disorders of pregnancy in obese women with women of a normal body mass index (BMI). STUDY DESIGN Prospective observational study in which BMI was calculated accurately early in pregnancy. Women were enrolled after a sonographic confirmation of an ongoing pregnancy. To reduce confounding variables the study was confined to white European women with a singleton pregnancy. MAIN OUTCOME MEASURES Incidence of pre-eclampsia and gestational hypertension. RESULTS In 2230 women, 16.8% were obese. Pre-eclampsia was diagnosed in 3.3% (n=74) and gestational hypertension in 3.0% (n=67). Both pre-eclampsia (p=0.01) and gestational hypertension (p<0.01) were common in obese women compared with normal weight women. Overall 13.1% of obese women developed a hypertensive disorder during pregnancy. When analysed by parity pre-eclampsia occurred in 2.1% of primigravidas and 0.3% of multigravidas. Pre-eclampsia was increased in obese multigravidas (p=0.001), but not obese primigravidas, suggesting that parity is more influential than obesity in the development of pre-eclampsia. CONCLUSIONS Obese multigravidas are more likely to develop hypertensive disorders in pregnancy and obese primigravidas are more likely to develop gestational hypertension. This is important in clinical practice because maternal weight, unlike parity, is potentially modifiable before or during pregnancy.

Prediction of hypertensive disease in pregnancy using pulse pressure waveform analysis

Prediction of hypertensive disease in pregnancy remains a challenge in modern obstetrics. Risk factor based screening, ultrasound and serum markers have been used with varying success. As pre-eclampsia would appear to occur due to changes in the vasculature, the vessel wall has been investigated as a predictor of hypertension in pregnancy. This study looked at pulse pressure wave analysis, using the diastolic portion of the cardiac cycle, in the prediction of hypertensive disease of pregnancy. Women were recruited from the antenatal clinic. Women with known cardiac disease were excluded. All women had pulse pressure waveform analysis performed in the first half of pregnancy. The primary outcome studied was the development of hypertensive disease of pregnancy. Pulse wave analysis was performed on 600 patients. The elasticity of the arterial vessel wall differed in hypertensive pregnancies and in particular in pregnancies subsequently complicated by pre-eclampsia. In early pregnancy, the mean arterial pressure (p=0.02), large artery elasticity (p=0.01), small artery elasticity (p=0.02) and systemic vascular resistance (p=0.02) were all significantly different in women who later developed pre-eclampsia compared to normal pregnancy. In pregnancies complicated by pregnancy induced hypertension, mean arterial pressure measurements were significantly different in early pregnancy but arterial elasticity did not differ. Pulse pressure waveform analysis may be a useful screening tool in the prediction of hypertensive disease and in particular, pre-eclampsia. Use of this technology in combination with other screening tools may aid in the selection of high risk pregnancy for more intensive antenatal care.

Variation in caesarean section rates among european women and maternal adiposity

Introduction There has been a relentless rise in the caesarean section (CS) rate in Ireland. The reasons for this increase are multifactorial and complex. This prospective observational study examined whether the variation in CS rates in European women can be explained by differences in maternal adiposity. Study design Women were recruited after first trimester sonographic confirmation of an ongoing singleton pregnancy. Maternal adiposity was assessed indirectly by Body Mass Index (BMI) and directly by bioelectrical impedance analysis (BIA). Irish women were compared with other women born in the 14 countries who joined the EU before 2004, and with women born in the countries who joined following enlargement in 2004(EU 12). Results Of the 2811 women enrolled, 2235 women were born in Ireland, 100 in the EU 14 and 476 in the EU 12 countries. Based on a BMI >29.9 kg/m2, maternal obesity was higher in Irish (19.8%) and EU 14(19.0%) women compared with EU 12 women (9.5%), p< 0.001. BIA confirmed increased adiposity in Irish and EU 14 women compared with EU 12 women. After multivariate analysis was performed controlling for age, socioeconomic group, induction of labour and birth weight, the increased adiposity in Irish women was associated with an increase in emergency CS rate in primigravidas (p<0.001). Conclusion We found variation in CS rates in primigravidas based on the mothers country of birth, which was associated with maternal adiposity. Differences in maternal adiposity between nationalities may be hereditary in origin, but may be related to prepregnancy lifestyle.