Offspring birthweight and placental weight-does the type of maternal diabetes matter? A population-based study of 319 076 pregnancies.

INTRODUCTION: Our aim was to estimate the difference in birthweight and in placental weight in pregnancies with type 1 diabetes, type 2 diabetes, and gestational diabetes compared with pregnancies without diabetes. MATERIAL AND METHODS: By using data from the Medical Birth Registry of Norway during the years 2009-2017, we included 319 076 singleton pregnancies with delivery after the 21st week of pregnancy. We used linear regression analyses to estimate the difference in birthweight and in placental weight in grams (g) in pregnancies with type 1 diabetes, type 2 diabetes, and gestational diabetes, using pregnancies without diabetes as the reference. Adjustments were made for pregnancy duration and pre-pregnancy body mass index. RESULTS: In pregnancies without diabetes, mean crude birthweight was 3527 g (SD 552 g). The adjusted mean birthweight was 525 g (95% CI 502-548 g) higher in pregnancies with type 1 diabetes compared with pregnancies without diabetes. In pregnancies with type 2 diabetes, and pregnancies with gestational diabetes, birthweights were 192 g (95% CI 160-223 g) and 102 g (95% CI 93-110 g) higher, respectively. Mean crude placental weight was 664 g (SD 147 g) in pregnancies without diabetes. Compared with pregnancies without diabetes, the adjusted mean placental weight was 109 g (95% CI 101-116 g) higher in pregnancies with type 1 diabetes, 50 g (95% CI 39-60 g) higher in pregnancies with type 2 diabetes, and 31 g (95% CI 28-34 g) higher in pregnancies with gestational diabetes. CONCLUSIONS: The increase in birthweight and in placental weight associated with maternal diabetes was most pronounced for type 1 diabetes, followed by type 2 diabetes, and gestational diabetes.

The associations of maternal body mass index with birthweight and placental weight. Does maternal diabetes matter? A population study of 106 191 pregnancies.

INTRODUCTION: The aim of this study was to study whether the associations of maternal body mass index with offspring birthweight and placental weight differ by maternal diabetes status. MATERIAL AND METHODS: We performed a population study of 106 191 singleton pregnancies by using data from the years 2009-2012 in the Medical Birth Registry of Norway. We estimated changes in birthweight and in placental weight (in grams) by maternal body mass index by linear regression analysis. RESULTS: In pregnancies of women without diabetes, birthweight increased by 14.7 g (95% confidence interval 14.1-15.2) per unit increase in maternal body mass index, and the increase in placental weight was 4.2 g (95% confidence interval 4.0-4.4). In pregnancies of women with gestational diabetes, the corresponding figures were 11.8 g (95% confidence interval 8.3-15.4) and 2.9 g (95% confidence interval 1.7-4.0). In pregnancies of women with type 1 diabetes we found no significant changes in birthweight or in placental weight by maternal body mass index. Overall, mean birthweight was 513.9 g (95% confidence interval 475.6-552.1) higher in pregnancies involving type 1 diabetes than in pregnancies of women without diabetes. Mean placental weight was 102.1 g (95% confidence interval 89.3-114.9) higher. Also, in pregnancies of women with gestational diabetes, both birthweight and placental weight were higher than in women without diabetes (168.2 g and 46.5 g, respectively). Adjustments were made for maternal body mass index and gestational age at birth. CONCLUSIONS: Birthweight and placental weight increased with increasing maternal body mass index in pregnancies of women without diabetes and in pregnancies of women with gestational diabetes, but not in pregnancies of women with type 1 diabetes. Independent of body mass index, mean birthweight and mean placental weight were highest in pregnancies of women with type 1 diabetes.

Childbirth or termination of pregnancy: does paid employment matter? A population study of women in reproductive age in Norway.

INTRODUCTION: We studied whether female paid employment is associated with pregnancy outcome; childbirth or pregnancy termination. MATERIAL AND METHODS: All women in Norway, 16-54 years of age, during the years 2007-10 were included. Data sources were; the Norwegian Central Person Registry, the Medical Birth Registry of Norway, and the Registry of Pregnancy Termination. We compared the proportion without paid employment among all women, women who gave birth, and among women who requested termination of pregnancy. Thereafter, and among pregnant women, we estimated the odds ratio for pregnancy termination request for women without paid employment by applying logistic regression analyses, using women with paid employment as reference. RESULTS: Among all women 16-54 years of age, 23.5% were without paid employment. Among women who gave birth, 15.8% were without paid employment, whereas this proportion was 46.4% among women who requested pregnancy termination (p < 0.05). Among the 307 512 women who were pregnant, 60 734 (19.4%) requested pregnancy termination. The odds ratio for pregnancy termination request was 3.18 (95% CI 3.11-3.25) for women without paid employment. Adjustments were made for age, number of children, and region of residence in Norway. CONCLUSION: Being without paid employment was more common among women in the general population and among women requesting pregnancy termination than among women who gave birth. Hence, women seem to have children when they are in paid employment. The role of women's paid employment for reproductive choices should be further investigated.

Preeclampsia in pregnancies with and without diabetes: the associations with placental weight. A population study of 655 842 pregnancies.

INTRODUCTION: Women with diabetes are at increased risk of preeclampsia, and women with diabetes tend to deliver placentas and offspring that are large-for-gestational-age. We therefore studied placental weight in preeclamptic pregnancies according to maternal diabetes status. MATERIAL AND METHODS: Information on all singleton births from 1999 through 2010 (n = 655 842) were obtained from the Medical Birth Registry of Norway. We used z-scores of placental weight to adjust for differences in gestational age at birth between deliveries, and compared the distribution of placental weight z-scores, in deciles, in preeclamptic pregnancies with and without diabetes, and in non-preeclamptic pregnancies with and without diabetes. RESULTS: Overall, the prevalence of preeclampsia was higher in pregnancies with diabetes than in pregnancies without diabetes (9.9% vs. 3.6%). Among preeclamptic pregnancies, having a placental weight in the highest decile was nearly three times more frequent (28.8%) in pregnancies with diabetes than in pregnancies without diabetes (9.8%). In the lowest decile, preeclamptic pregnancies with diabetes were underrepresented (7.5%), and preeclamptic pregnancies without diabetes were overrepresented (13.6%). Among pregnancies with preterm delivery, the above patterns were more pronounced, with 30.1% of the placentas in in preeclamptic pregnancies with diabetes in the highest decile, and 19.5% of the placentas in preeclamptic pregnancies without diabetes in the lowest decile. CONCLUSIONS: These results suggest that women with diabetes who develop preeclampsia have a higher placental weight than other women with preeclampsia or non-preeclamptic women.

Characteristics of women with repeat termination of pregnancy: a study of all requests for pregnancy termination in Norway during 2007-2011.

INTRODUCTION: We studied the proportion of all pregnancy terminations requested by women with a history of pregnancy termination. We also studied risk factors for repeat pregnancy termination. MATERIAL AND METHODS: We used data from the Norwegian Register of Pregnancy Termination during the period 2007-2011, a total of 80,346 requests for pregnancy termination before the end of the 12th gestational week. Odds ratios for repeat pregnancy termination were estimated according to age, parity, contraceptive use, marital status, education, employment status and region of residency by applying logistic regression analyses. Repeat pregnancy termination was defined as request for pregnancy termination for the second time or more. RESULTS: Among the 80 346 requests for pregnancy termination, 36.7% were among women with a history of pregnancy termination. In total, 25.0% had one prior termination and 11.7% had two or more. Factors associated with repeat pregnancy termination were; age ≥25 years, having one or more children, and use of contraception at the time of conception. College/university education as compared with primary school only, was associated with reduced risk of repeat termination. CONCLUSION: Among all requests for pregnancy termination in Norway, 36.7% were from women with a history of pregnancy termination. Many women with repeat pregnancy termination have children and/or used contraception at the time of conception. Our findings therefore suggest that high fecundity is an underlying risk factor for repeat pregnancy termination.

Placental weight relative to birthweight in pregnancies with maternal diabetes mellitus.

OBJECTIVES: To study the association of maternal diabetes mellitus with placental weight, birthweight and placental weight-to-birthweight ratio. DESIGN: Population-based study. SETTING: Medical Birth Registry of Norway. POPULATION: All singleton births in Norway during 1999-2008 (n = 536,997). METHODS: We compared the distribution of placental weight z-scores and placental weight-to-birthweight ratio between pregnancies with and without diabetes. The associations of diabetes with placental weight z-scores were also estimated as odds ratios with and without adjustment for birthweight, maternal age, parity, preeclampsia, smoking and cesarean delivery. MAIN OUTCOME MEASURES: Placental weight, birthweight and placental weight-to-birthweight ratio. RESULTS: Mean placental weight was 736.6 g in diabetic pregnancies and 672.1 g in non-diabetic pregnancies. The corresponding birthweights were 3682.1 g and 3557.0 g. In diabetic pregnancies, 26.2% of the placentas were in the highest decile of placental weight z-score, as compared with 9.7% in non-diabetic pregnancies (p < 0.001). The corresponding figures for being in the highest decile of placental weight-to-birthweight ratio were 18.2 and 9.9% (p < 0.001). The crude odds ratio for having a placenta in the highest decile of placental weight z-score was 3.29 (95% confidence interval 3.14-3.45) in diabetic pregnancies with non-diabetic pregnancies as the reference. After adjustment for birthweight and other variables, the odds ratio was 2.42 (95% confidence interval 2.29-2.56). CONCLUSIONS: In diabetic pregnancies, placental weight as well as placental weight relative to birthweight were higher than in non-diabetic pregnancies.