Aim: Homeostasis model assessment for insulin resistance (HOMA-IR) was measured during pregnancy to analyze placental weight and efficiency in relation to maternal insulin resistance. Methods: A retrospective study of 510 pregnant women (130 with gestational diabetes mellitus [GDM], 380 with normal glucose tolerance) was conducted. We reviewed the patients' demographic data (age, parity, pre-pregnancy body mass index [BMI]) and perinatal outcomes (birth weight, placental weight, BMI at delivery, maternal weight gain, HOMA-IR). The birth weight to placental weight (B/P) ratio was calculated for placental efficiency. The subjects were categorized by BMI at delivery, and maternal, neonatal and placental characteristics were compared between the groups to investigate the determinants of placental weight and B/P ratios. Results: Obesity was significantly associated with heavier placental weight and lower B/P ratios. The presence of GDM did not affect placental weight, whereas the B/P ratios in women with GDM were significantly lower than in women with normal glucose tolerance. HOMA-IR was positively correlated with placental weight (ρ = 0.217, P < 0.001) and negatively with B/P ratio (ρ = −0.181, P < 0.001). Conclusions: Increased maternal insulin resistance promoted placental growth and inhibited placental efficiency. Maternal insulin resistance may be one of the pathophysiological conditions responsible for altered placental size and function in pregnancies with obesity and GDM.

Insulin-like growth factor-I (IGF-I) has been shown to stimulate extravillous trophoblast (EVT) cell migration and invasion, and to play a crucial role in placental function, thereby, influencing placental development and fetal growth. Insufficient invasion of EVT cells into the uterine endometrium leads to pregnancy-related complications, including spontaneous abortion, fetal growth restriction (FGR), and pregnancy-induced hypertension (PIH). Insulin-resistant conditions such as polycystic ovary syndrome (PCOS) and gestational diabetes mellitus (GDM) have also been associated with abortion and PIH. However, the effects of IGF-I on EVT cells under insulin-resistant conditions have not been elucidated yet. The current study was undertaken to analyze the effects of IGF-I under insulin-resistant conditions and to determine whether improvement in insulin sensitivity alters IGF signaling and cell migration in the EVT. Incubation with pioglitazone, an insulin sensitizer, increased peroxisome proliferator-activated receptor-γ (PPARγ) expression after 48 h. A 48-h pre-incubation with insulin reduced the phosphorylation and concentration of the insulin receptors, which were increased by insulin treatment. Long-term exposure to insulin reduced phosphorylation of the IGF-I receptor, insulin receptor substrate-1 (IRS-1), and Akt, and also reduced EVT cell migration. However, when the cells were incubated with pioglitazone in addition to insulin for 48 h, the phosphorylation of these proteins was restored. This combination partially reversed the inhibitory effect of insulin on EVT cell migration. These results suggest that abnormalities in pregnancy that are induced by loss of insulin sensitivity can be treated by improving insulin sensitivity.

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by severe headache and diffuse segmental constriction of the cerebral arteries that resolves spontaneously within a few months. Pregnancy is one of the precipitating factors of RCVS and most of the reported cases occurred in the post-partum period. We report a case of RCVS that occurred in a pregnant women with pre-eclampsia during her antepartum period. A 34-year-old woman in full-term pregnancy presented with a severe and acute headache. Magnetic resonance angiography (MRA) showed multiple segmental constrictions of the cerebral arteries. Magnetic resonance imaging revealed a high-intensity lesion in the left occipital lobe, consistent with reversible posterior leukoencephalopathy syndrome, on fluid attenuated inversion recovery sequences. The case was also complicated by severe pre-eclampsia and the patient underwent emergency cesarean section. Although her symptoms resolved rapidly, MRA revealed new lesions of arterial constriction 4 days after onset. The vasoconstriction completely resolved on MRA after 10 days and the patient was discharged without neurological sequelae.

Maternal pre-pregnancy obesity has a promoting effect on fetal growth from the third trimester through birth.

Umbilical artery thrombosis (UAT) is rare and few prenatally diagnosed cases have been reported. We describe 2 cases of fetal growth restriction prenatally diagnosed as UAT by ultrasound examination. In each case the cross section of the umbilical cord showed one normal artery and a small echogenic area which was suspected as an occluded thrombotic artery and they were surrounded by a highly curving ‘C-shaped' vein. UAT was confirmed by histological examinations after deliveries in both cases. The characteristic ultrasound finding of the umbilical vessel, which is the so-called ‘orange grabbed sign', enables the prenatal diagnosis of UAT and it is valuable with respect to perinatal fetal management because UAT is associated with increased perinatal morbidity and mortality.