Diabetes, preeclampsia and infant death: The associations with placental weight

Fetal growth is dependent on oxygen and nutrients that are transferred from the mother by the placenta. Placental weight is an indicator of placental function. Johanne Dypvik has explored how placental weight may be associated with diabetes, preeclampsia and infant death. Data from the Medical Birth Registry of Norway were used in all three studies. We found that placental weight was higher in preeclamptic pregnancies with diabetes and lower in preeclamptic pregnancies without diabetes than in non-preeclamptic pregnancies. Hence, it is possible that the biological mechanisms that cause preeclampsia may differ between women with diabetes and women without diabetes. Prediction of the women who will develop preeclampsia in a second pregnancy may be difficult. We found that low placental weight in the first pregnancy increased the risk of preeclampsia in the second pregnancy. Additionally, high placental weight in the first pregnancy increased the risk of developing term preeclampsia in the second pregnancy in women without previous preeclampsia. Information about placental weight in the first pregnancy may therefore contribute to identify women at increased risk of developing preeclampsia in the second pregnancy. Low placental weight seemed to increase the risk of infant death independent of gestational age at birth. However, the results differed for infants born in gestational weeks 29-32. In these infants, high placental weight doubled the risk of infant death. Information about placental weight could help in the identification of infants at increased risk of infant death

Maternal human chorionic gonadotrophin concentrations in very early pregnancy and risk of hyperemesis gravidarum: A retrospective cohort study of 4372 pregnancies after in vitro fertilization

Objective We investigated the association of human chorionic gonadotrophin (hCG) concentrations on a fixed day in very early pregnancy with development of hyperemesis gravidarum. Study design This retrospective cohort study included 3107 singleton and 1265 twin pregnancies after in vitro fertilization treated at Department of Reproductive Medicine, Rikshospitalet, Oslo University Hospital, Norway in the period 1996–2013. Maternal serum hCG concentrations was measured on day 12 after embryo transfer. Information about development of hyperemesis gravidarum was obtained by individual linkage to the Medical Birth Registry of Norway. We studied hCG concentrations in very early pregnancy according to development of hyperemesis gravidarum, in singleton and twin pregnancies separately. We estimated the odds ratios for hyperemesis gravidarum with 95% confidence intervals according to quartiles of hCG concentrations. Results In twin pregnancies as compared to singleton pregnancies, we found higher mean maternal hCG concentrations (219 IU/L versus 130 IU/L, p < 0.001 Student’s t-test) and higher prevalence of hyperemesis gravidarum (2.7% versus 1.4%, p = 0.002 chi-squared test). However, both in singleton and in twin pregnancies, we found no significant difference in mean hCG concentrations between women who developed hyperemesis gravidarum and women who did not (Singletons: 122 IU/L versus 130 IU/L, p = 0.504. Twins: 234 IU/L versus 219 IU/L, p = 0.417 Student’s t-test). We found no significant differences in odds ratios for developing hyperemesis gravidarum according to quartiles of hCG concentrations. Conclusions We found no association of maternal hCG concentrations on a fixed day in early pregnancy with development of hyperemesis gravidarum

Placental weight and birthweight : the relations with number of daily cigarettes and smoking cessation in pregnancy. A population study

Background: We studied associations of number of daily cigarettes in the first trimester with placental weight and birthweight in women who smoked throughout pregnancy, and in women who stopped smoking after the first trimester. Methods: We included all women with delivery of a singleton in Norway (n = 698 891) during 1999-2014, by using data from the Medical Birth Registry of Norway. We assessed dose-response associations by applying linear regression with restricted cubic splines. Results: In total, 12.6% smoked daily in the first trimester, and 3.7% stopped daily smoking. In women who smoked throughout pregnancy, placental weight and birthweight decreased by number of cigarettes; however, above 11-12 cigarettes we estimated no further decrease (Pnon-linearity &lt; 0.001). Maximum decrease in placental weight in smokers compared with non-smokers was 18.2 g [ 95% confidence interval (CI): 16.6 to 19.7], and for birthweight the maximum decrease was 261.9 g (95% CI: 256.1 to 267.7). In women who stopped smoking, placental weight was higher than in non-smokers and increased by number of cigarettes to a maximum of 16.2 g (95% CI: 9.9 to 22.6). Birthweight was similar in women who stopped smoking and non-smokers, and we found no change by number of cigarettes (Pnon-linearity &lt; 0.001). Conclusions: In women who smoked throughout pregnancy, placental weight and birthweight decreased non-linearly by number of cigarettes in the first trimester. In women who stopped smoking, placental weight was higher than in non-smokers and increased linearly by number of cigarettes; birthweight was almost similar to that of non-smokers

Placental weight in the first pregnancy and risk for preeclampsia in the second pregnancy: A population-based study of 186 859 women

Objective To study whether placental weight in the first pregnancy is associated with preeclampsia in the second pregnancy. Study design In this population-based study, we included all women with two consecutive singleton pregnancies reported to the Medical Birth Registry of Norway during 1999–2012 (n = 186 859). Placental weight in the first pregnancy was calculated as z-scores, and the distribution was divided into five groups of equal size (quintiles). We estimated crude and adjusted odds ratios with 95% confidence intervals for preeclampsia in the second pregnancy according to quintiles of placental weight z-scores in the first pregnancy. The 3rd quintile was used as the reference group. Results Among women without preeclampsia in the first pregnancy, 1.4% (2507/177 149) developed preeclampsia in the second pregnancy. In these women, the risk for preeclampsia in the second pregnancy was associated with placental weight in the first pregnancy in both lowest (crude odds ratio (cOR) 1.30, 95% confidence interval (CI); 1.14–1.47) and highest quintile (cOR 1.20, 95% CI; 1.06–1.36). The risk associated with the highest quintile of placental weight was confined to term preeclampsia. Among women with preeclampsia in the first pregnancy, 15.7% (1522/9710) developed recurrent preeclampsia, and the risk for recurrent preeclampsia was associated with placental weight in lowest quintile in the first pregnancy (cOR 1.30, 95% CI; 1.10–1.55). Adjustment for interval between pregnancies, maternal diabetes, age, and smoking in the first pregnancy did not alter these estimates notably. Conclusion Placental weight in the first pregnancy might help to identify women who could be at risk for developing preeclampsia in a second pregnancy