Thromboembolism and in vitro fertilization - a systematic review.

INTRODUCTION: There is no accepted consensus on thromboprophylaxis in relation to in vitro fertilization (IVF). We aimed to study the frequency of thromboembolism and to assess thromboprophylaxis in relation to IVF. MATERIAL AND METHODS: We performed a systematic review. All study designs were accepted except single case reports. Language of included articles was restricted to English. RESULTS: Of 338 articles, 21 relevant articles (nine cohort studies, six case-control studies, three case series, and three reviews of case series) were identified. The antepartum risk of venous thromboembolism (VTE) after IVF is doubled (odds ratio 2.18, 95% CI 1.63-2.92), compared with the background pregnant population. This is due to a 5- to 10-fold increased risk during the first trimester in IVF pregnancies, in turn related to a very high risk of VTE after ovarian hyperstimulation syndrome (OHSS), i.e. up to a 100-fold increase, or an absolute risk of 1.7%. The interval from embryo transfer to VTE was 3-112 days and the interval from embryo transfer to arterial thromboembolism was 3-28 days. No robust study on thromboprophylaxis was found. CONCLUSIONS: The antepartum risk of VTE after IVF is doubled, compared with the background pregnant population, and is in turn related to a very high risk of VTE after OHSS in the first trimester. We recommend that IVF patients with OHSS be prescribed low-molecular-weight heparin during the first trimester, whereas other IVF patients should be given thromboprophylaxis based on the same risk factors as other pregnant women.

Randomized controlled study in pregnancy on treatment of marked hyperglycemia that is short of overt diabetes.

INTRODUCTION: A randomized multicenter study was conducted in the Stockholm-Örebro areas in Sweden to evaluate how treatment aiming at normoglycemia affects fetal growth, pregnancy and neonatal outcome in pregnant women with severe hyperglycemia. MATERIAL AND METHODS: Pregnant women with hyperglycemia defined as fasting capillary plasma glucose <7.0 mmol/L and a two-hour plasma glucose value ≥10.0 and <12.2 mmol/L following a 75-g oral glucose tolerance test (OGTT) diagnosed before 34 weeks of gestation were randomized to treatment (n = 33) or controls (n = 36). Women assigned to the control group were blinded for the OGTT results and received routine care. The therapeutic goal was fasting plasma glucose 4-5 mmol/L, and <6.5 mmol/L after a meal. Primary outcomes were size at birth and number of large-for-gestational age (>90th percentile) neonates. Secondary outcomes were pregnancy complications, neonatal morbidity and glycemic control. RESULTS: The planned number of participating women was not reached. There was a significantly reduced rate of large-for-gestational age neonates, 21 vs. 47%, P < 0.05. Group differences in pregnancy complications and neonatal morbidity were not detected because of limited statistical power. In total, 66.7% of the women in the intervention group received insulin. Of all measured plasma glucose values, 64.1% were in the target range, 7.2% in the hypoglycemic range and 28.7% above target values. There were no cases of severe hypoglycemia. CONCLUSIONS: Aiming for normalized glycemia in a pregnancy complicated by severe hyperglycemia reduces fetal growth but is associated with an increased rate of mild hypoglycemia.