Placental Parts Research Articles

OC22.08: Feasibility of magnetic resonance imaging as a preoperative guidance tool for laser coagulation in twin–twin transfusion syndrome

Background: Fetoscopic laser coagulation of the vascular anastomoses is currently the best available treatment method for severe twin–twin-transfusion syndrome (TTTS) diagnosed < 26 weeks. However, postoperative single intrauterine fetal death (sIUFD) commonly occurs, in which unequal placental distribution may play an important role. Objectives: To evaluate the use of preoperative Magnetic Resonance Imaging (MRI) to determine placental volume distribution and to correlate unequal placental distribution with the occurrence of postoperative sIUFD. Material and methods: Preoperative MRI (T1-T2-Diffusion) of the monochorionic placenta was performed in 28 cases of TTTS to determine the placental volume ratios. Placental distribution was considered to be unequal when the placental volume ratios were less than 30/70. An ultrasound scan was performed 24 and 48 hours after the procedure to check fetal viability. Postoperative sIUFD was defined as demise of 1 twin within 48 hours. After birth, volumetric CT angiography was performed of 9 placentas with double survivors. The placental volume ratios measured on postnatal CT angiography were compared with the predicted values on preoperative MRI. Results: Determination of the placental volume ratios was possible in 22/28 (79%) of cases on T2-weighted MRI as well as on ADC maps. In 8/9 placentas examined after birth, preoperative MRI had accurately predicted the placental distribution. In 3/4 cases with predicted unequal placental distribution, sIUFD occurred, of which 2 fetuses had the largest placental part and 1 had the smallest part. In contrast, sIUFD occurred in only 3/18 cases (17%) with equal placental distribution (P < 0.05). Conclusion: Preoperative MRI seems to accurately predict placental volume distribution in most cases with TTTS. Also, unequal placental distribution appears to be a risk factor for sIUFD after laser treatment. However, sIUFD was not restricted to the fetus with the smallest placental part.

Time factor in oxygen transfer from mother to fetus.

The time factor in the oxygen transfer from mother to fetus was studied by the tcPO2 technique. When a fairly constant fetal circulation made estimation possible, the decrease in fetal tcPO2 synchronous with and due to the uterine contractions in more than 400 events was always delayed 50--60 sec. Since the time lag in the increase in fetal tcPO2 following administration of pure oxygen to the mother was found to be of the same order of magnitude, the placental part of the delay in the oxygen transfer from mother to fetus can be assumed to be 50--60 sec. This determination supports the prevalent hypothesis that type II dips or late decelerations in the fetal heart rate are caused by hypoxia while type I dips or early decelerations are initiated by other factors.

PROGESTERONE AND 20α-DIHYDROPROGESTERONE IN HUMAN MYOMETRIUM DURING PREGNANCY

PROGESTERONE AND 20α-DIHYDROPROGESTERONE IN HUMAN MYOMETRIUM DURING PREGNANCY

The influence of endemic goiter on the course of pregnancy, labour and puerperium.

ABSTRACT The influence of endemic goiter on the course of pregnancy, labour and birth is still unsettled, the informations in the literature being scanty and incomplete. Investigation into the course of pregnancy, labour and the puerperium on 2101 pregnant women from 4 different areas with different incidence of endemic goiter shows conclusively that endemic goiter has an unfavourable influence on the course of pregnancy, birth and the puerperium. The following conclusions are drawn: Endemic goiter brings about a greater incidence of complications in pregnancy (imminent abortions, early and later toxaemia of pregnancy), an increase in the number of prolonged labours and a decrease in the number of shortened labours, a higher incidence of birth complications (retention of placenta, retention of placental parts, postpartum uterine atony, lacerations of the soft genital tissues) and an increase in the complications of the puerperium.