Placental location and risk of retained placenta in women with a previous cesarean section: A population-based cohort study.

INTRODUCTION: Some studies have shown that women with a previous cesarean section, compared with women with a previous vaginal delivery, have an increased risk of retained placenta during a subsequent vaginal delivery. It is unknown whether this is mediated by anterior placental location, when the placenta might cover the uterine scar. The aim of this study was to evaluate whether the increased risk of retained placenta in women with a previous cesarean section is mediated by anterior placental location. MATERIAL AND METHODS: This is a population-based cohort study, with data from the regional population-based Stockholm-Gotland Obstetric Cohort, Sweden, from 2008 to 2014. The overall study population included 49 598 women with a vaginal second delivery, where adequate information about placental location from the second-trimester ultrasound scan was available. For the main analysis, including the 3921 women with a previous cesarean section, we calculated the relative risk of retained placenta in women with an anterior placental location, using women with non-anterior placental locations as reference. Relative risks were calculated as odds ratios (OR) with 95% CI. In a second model, adjustments were made for maternal age, height, country of birth, smoking in early pregnancy, infant sex, and in vitro fertilization. RESULTS: In the overall study population, the rate of retained placenta at the second delivery was 2.0%. The proportion of women with a retained placenta was higher among women with a previous cesarean compared with those with a previous vaginal delivery (3.4% vs 1.9%; P < .0001). In the main analysis, including women with a previous cesarean section, the risk for retained placenta was not increased with anterior compared with non-anterior placental location (OR 0.84, 95% CI 0.60-1.20). Adjustments did not affect the estimates in a significant way. CONCLUSIONS: The increased risk of retained placenta in women with a previous cesarean section is not mediated by anterior placental location.

Placental location and pregnancy outcomes in nulliparous women: A population-based cohort study.

INTRODUCTION: The impact of placenta previa on pregnancy, delivery and infant outcomes has been extensively studied. However, less is known about the possible association of placental location other than previa with pregnancy outcomes. The aim of this study was to investigate if placental location other than previa is associated with adverse pregnancy, delivery and infant outcomes. MATERIAL AND METHODS: This is a population-based cohort study, with data from the regional population-based Stockholm-Gotland Obstetric Cohort, Sweden, from 2008 to 2014. The study population included 74 087 nulliparous women with singleton pregnancies resulting in live-born infants, with information about placental location from the second-trimester ultrasound screening. The association between placental location (fundal, lateral, anterior or posterior) and pregnancy outcomes was estimated using logistic regression analysis. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated, and adjustments were made for maternal age, height, country of birth, smoking in early pregnancy, sex of the infant and in vitro fertilization. Main outcome measures were pregnancy, delivery and infant outcomes. RESULTS: Compared with posterior placental location, fundal and lateral placental locations were associated with a number of adverse pregnancy outcomes, the most important being: very preterm birth (<32 weeks of gestation) (adjusted OR [aOR] 1.78, 95% CI 1.18-2.63 and aOR 2.12, 95% CI 1.39-2.25, respectively), moderate preterm birth (32-36 weeks of gestation) (aOR 1.23, 95% CI 1.001-1.51 and aOR 1.62, 95% CI 1.32-2.00, respectively), small-for-gestational-age birth (aOR 1.67, 95% CI 1.34-2.07 and aOR 1.77, 95% CI 1.39-2.25, respectively) and manual removal of the placenta in vaginal births (aOR 3.27, 95% CI 2.68-3.99 and aOR 3.27, 95% CI 2.60-4.10, respectively). Additionally, lateral placental location was associated with preeclampsia (aOR 1.30, 95% CI 1.03-1.65) and severe postpartum hemorrhage (aOR 1.42, 95% CI 1.27-1.82). CONCLUSIONS: Compared with posterior placental location, fundal and lateral placental locations are associated with a number of adverse pregnancy, delivery and infant outcomes.

Iodine deficiency in a study population of pregnant women in Sweden.

INTRODUCTION: Iodine deficiency in utero may impair neurological development of the fetus. In Sweden, iodine nutrition is considered to be adequate in the general population. The aim of this study was to evaluate iodine nutrition during pregnancy in Sweden. MATERIAL AND METHODS: In this cross-sectional study, the total study population (n = 459) consisted of two cohorts (Värmland County, n = 273, and Uppsala County, n = 186) of pregnant non-smoking women without pre-gestational diabetes mellitus or known thyroid disease before or during pregnancy. Spot urine samples were collected in the third trimester of pregnancy for median urinary iodine concentration (UIC) analysis. RESULTS: The median UIC in the total study population was 98 µg/L (interquartile range 57-148 µg/L). CONCLUSIONS: According to WHO/UNICEF/IGN criteria, population-based median UIC during pregnancy should be 150-249 µg/L. Thus, our results indicate insufficient iodine status in the pregnant population of Sweden. There is an urgent need for further assessments in order to optimize iodine nutrition during pregnancy.

Thyroid testing and management of hypothyroidism during pregnancy: a population-based study.

CONTEXT: There are international guidelines on thyroid function testing and management of hypothyroidism during pregnancy. Few studies have evaluated how they are implemented into clinical practice. OBJECTIVE: In this descriptive study, we assessed the implementation of international guidelines in this field into local guidelines and also into clinical practice. DESIGN AND PARTICIPANTS: In a nationwide survey, all guidelines in Sweden were collected (n = 29), and the adherence of the local guidelines to The Endocrine Society Guidelines 2007 was evaluated. In a follow-up in 1 district, 5254 pregnant women with an estimated date of delivery between January 1, 2009, and December 31, 2011, were included for subsequent review of their medical reports. RESULTS: All but 1 district had guidelines on the subject. All local guidelines included fewer than the 10 listed reasons for thyroid testing recommended by The Endocrine Society Guidelines. Furthermore, most guidelines recommended additional types of thyroid function tests to TSH sampling and lower trimester-specific TSH upper reference limits for women on levothyroxine treatment (P < .001). In the follow-up, the thyroid testing rate was 20%, with an overall frequency of women with trimester-specific elevated TSH of 18.5%. More than half of the women (50.9%) who were on levothyroxine treatment at conception had an elevated TSH level at thyroid testing according to The Endocrine Society Guidelines. CONCLUSIONS: The local guidelines are variable and poorly compliant with international guidelines. Performance of thyroid testing is not optimal, and rates of elevated TSH at testing are extremely high in subgroups.

Phosphodiesterase 8B gene polymorphism in women with recurrent miscarriage: a retrospective case control study.

BACKGROUND: Recurrent miscarriage affects approximately 1% of all couples. There is a known relation between hypothyroidism and recurrent miscarriage. Phosphodiesterase 8B (PDE8B) is a regulator of cyclic adenosine monophosphate (cAMP) with important influence on human thyroid metabolism. Single nucleotide polymorphism (SNP) rs 4704397 in the PDE8B gene has been shown to be associated with variations in serum Thyroid Stimulating Hormone (TSH) and thyroxine (T4) levels. The aim of this study was to investigate whether there is an association between the SNP rs 4704397 in the PDE8B gene and recurrent miscarriage. METHODS: The study was designed as a retrospective case control study. 188 cases with recurrent miscarriage were included and compared with 391 controls who had delivered at least once and with no history of miscarriage or assisted reproduction. RESULTS: No difference between cases and controls concerning age was found. Bivariate associations between homozygous A/A (OR 1.57, 95% CI 0.98-2.52) as well as G/G carriers (OR 1.52, 95% CI 1.02-2.25) of SNP rs 4704397 in PDE8B and recurrent miscarriage were verified (test for trend across all 3 genotypes, p=0.059). After adjustment for known confounders such as age, BMI and smoking the association between homozygous A/A (AOR 1.63, 95% CI 1.01-2.64, p=0.045) and G/G (AOR 1.52, 95% CI 1.02-2.27, p=0.039) carriers of SNP rs 4704397 in PDE8B and recurrent miscarriage remained. CONCLUSIONS: Our findings suggest that there is an association between homozygous A/A as well as homozygous G/G carriers of SNP rs 4704397 in PDE8B and recurrent miscarriage.