Jouko Pirhonen

A multicenter interventional program to reduce the incidence of anal sphincter tears.

OBJECTIVE: In Norway, we have experienced a gradual increase in the incidence of obstetric anal sphincter injuries from under 1% in the late 1960s to 4.3% in 2004. This study was aimed to assess whether an interventional program causes a decrease in the frequency of anal sphincter tears. METHODS: In all, 40,152 vaginal deliveries between 2003 and 2009 were enrolled in the interventional cohort study from four Norwegian obstetric departments. The focus of the intervention was on manual assistance during the final part of the second stage of labor. Data were analyzed in relation to occurrence of obstetric anal sphincter tears. RESULTS: The proportion of parturients with anal sphincter tears decreased from 4–5% to 1–2% during the study period in all four hospitals (P<.001). The tears associated with both noninstrumental and instrumental deliveries decreased dramatically. The number of patients with grades 3 and 4 anal sphincter ruptures decreased significantly, and the reduction was most pronounced in grade 4 tears (−63.5%) and least in 3c tears (−47.5%) (both P<.001). The number of episiotomies increased in two hospitals but remained unchanged in the other two. The lowest proportion of tears at the end of the intervention (1.2% and 1.3%, respectively) was found in the two hospitals with an unchanged episiotomy rate. CONCLUSION: The multicenter intervention caused a highly significant decrease in obstetric anal sphincter injuries. LEVEL OF EVIDENCE: II

Frequency of anal sphincter rupture at delivery in Sweden and Finland ‐ result of difference in manual help to the baby's head

BACKGROUND Anal sphincter rupture is a serious complication of vaginal delivery and almost half the affected women have persistent defecatory symptoms despite adequate primary repair. During the past decade, the incidence of anal sphincter ruptures has been increasing in Sweden and is currently estimated to occur in 2.5% of vaginal deliveries. The aim of the study was to report the frequency of anal sphincter ruptures in two university hospitals in two Scandinavian countries, Malmö in Sweden and Turku in Finland, and analyze the potential determinants. METHODS Retrospective analysis of a population of 30,933 deliveries (26,541 vaginal) during the years 1990 to 1994. RESULTS The incidence of anal sphincter ruptures in Malmö, Sweden was 2.69%, and in Turku, Finland 0.36%. There were no significant population differences for the known risk factors (fetal weight, nulliparity or fetal head circumference). However, there is a difference in manual support given to the perineum and to the babys head when crowning through the vaginal introitus between Malmö and Turku. The proportion of operative vaginal deliveries and abnormal presentations was significantly higher in Turku reflected in the lower Apgar score at 5 minutes and longer duration of second phase of labor. When high risk deliveries (operative vaginal delivery, abnormal presentation and newborns over 4,000 g) were excluded, the risk for anal sphincter ruptures was estimated to be 13 times higher in Malmö than in Turku. CONCLUSIONS The difference in the incidence of anal sphincter rupture between Malmö, Sweden and Turku, Finland may be due to the difference in manual control of the babys head when crowning.

Decreasing the Incidence of Anal Sphincter Tears During Delivery

OBJECTIVE: To estimate if an interventional program causes a decrease in the frequency of anal sphincter ruptures. METHODS: A total of 12,369 vaginal deliveries between 2002 and March 2007 were enrolled in the interventional cohort study. Slowing the delivery of the infant’s head and instructing the mother not to push while the head is delivered was the intervention. Data were analyzed in relation to occurrence of anal sphincter tears. RESULTS: The proportion of parturients with anal sphincter tears decreased significantly during the study period from 4.03% (285 of 7,069) to 1.17% (42 of 3,577) (P<.001). A similar decrease was observed for instrumental deliveries (from 16.26% to 4.90%; P<.001) and noninstrumental deliveries (from 2.70% to 0.72%; P<.001). Although the number of patients with fourth-degree anal sphincter ruptures from 2002 through 2004 was 10, 13, and 11 per year, respectively, there was just one fourth-degree anal sphincter rupture during the whole study period of 18 months (P<.001). The number of episiotomies increased from 13.9% (980 of 7,069) in the years 2002–2004, to 23.1% during the first 9 months of the intervention (416 of 1,776; P<.001), but decreased to 21.1% (381 of 1,801) during the last 9 months of the intervention. CONCLUSION: As a result of this intervention the number of anal sphincter ruptures was reduced from 4.03% to 1.17%. LEVEL OF EVIDENCE: II

Episiotomy characteristics and risks for obstetric anal sphincter injuries: a case‐control study

Please cite this paper as: Stedenfeldt M, Pirhonen J, Blix E, Wilsgaard T, Vonen B, Øian P. Episiotomy characteristics and risks for obstetric anal sphincter injuries: a case‐control study. BJOG 2012;119:724–730.

Long-term effects of hormone replacement therapy on the uterus and on uterine circulation

OBJECTIVE Our purpose was to study the effects of postmenopausal hormone replacement therapy on the uterus and uterine circulation. STUDY DESIGN The study population consisted of 432 women, 58 to 59 years of age. Color Doppler ultrasonography with a transvaginal probe was used to measure the size of the uterus and the uterine artery pulsatility index. RESULTS The mean endometrial thickness in group 1 (controls without hormone replacement therapy) was significantly thinner compared with group 2 hormone replacement therapy and with group 3 after discontinuance of hormone replacement therapy. The mean uterine artery pulsatility index was lower both in group 2 and 3 compared with group 1. When hormone replacement therapy was initiated 2 to 10 years after menopause, the endometrial thickness did not differ from that among those who had started hormone replacement therapy earlier, but the pulsatility index was significantly higher. There was positive correlation between the size of the uterus and the pulsatility index in group 1, but the correlation was negative in group 2. In general, the duration of hormone replacement therapy had no effect on the pulsatility index. Estrogen users had a significantly thicker endometrium compared with estrogen-progestogen users. The pulsatility index was highest in the estrogen users with progestogen added every month. CONCLUSION The duration, onset of treatment in relation to menopause, discontinuance of hormone replacement therapy, and mode of treatment modify both the normal postmenopausal endometrial thickness and the uterine vascular resistance.

Risk factors for obstetric anal sphincter injury after a successful multicentre interventional programme

To evaluate and compare the risk profile of sustaining obstetric anal sphincter injuries (OASIS) and associated risks in five risk groups (low to high), after the OASIS rate was reduced from 4.6% to 2.0% following an interventional programme. The main focus of the intervention was on manual assistance during the final part of second stage of labour.

Thermal response to submaximal exercise before, during and after pregnancy: a longitudinal study

Background: Heat stress in early pregnancy is known to have a teratogenic effect. Exercise produces excess heat and during pregnancy might therefore present a theoretical risk of malformations. Our aim was to assess the thermal response to exercise of healthy pregnant women in a longitudinal study. Methods: Fourteen women were examined before pregnancy, and followed five times during, and twice after pregnancy, using a submaximal bicycle test with a target heart rate of 85% of the predicted age-adjusted maximum. The main aim was to present reference values. Results: The temperature at submaximal work load declined continuously from preconception to postpartum levels (37.8°C vs. 36.9°C, p = 0.04). The difference between peak and basal core temperature fell from 0.6°C to 0.05°C at 29 and 36 weeks of gestation, reaching preconception levels at 24 weeks after delivery (0.8°C lower). Conclusion: During submaximal exercise the temperature response seemed to provide thermal protection for the embryo and the fetus.

Core body temperature and the thermoneutral zone: a longitudinal study of normal human pregnancy

Aim:  Using a longitudinal study design, we investigated changes in maternal core temperature and ambient temperatures before and after a localized cooling procedure to the right hand.

Maternal cerebral Doppler velocimetry before, during, and after a normal pregnancy: a longitudinal study

Objective. Our purpose was to determine normative data for maternal cerebral blood flow indices. Study design. A prospective longitudinal study. Methods. The maternal middle cerebral artery was examined by transcranial Doppler ultrasound in 14 healthy women before (0–10 months prior to conception) and during pregnancy (at 8, 15, 22, 29, and 36 weeks of gestation), and twice after delivery (at 8 and 24 weeks). Middle cerebral artery blood flow velocities were recorded, and pulsatility index and cerebral perfusion pressure were calculated. Results and conclusion. Pulsatility index of middle cerebral artery peaked in mid‐pregnancy and was constantly increased between 8 and 29 weeks of gestation. The diastolic middle cerebral artery velocity remained fairly constant at about 40 cm/s during the study period, while the systolic velocity peaked at 15 weeks (mean 102 cm/s). Cerebral perfusion pressure dropped to its lowest levels in mid‐pregnancy and after delivery.

A longitudinal study of maternal oxygen saturation during short-term submaximal exercise.

Purpose:  Longitudinal prospective study before, during and after normal pregnancy of the effect of short‐term submaximal exercise on maternal oxygen saturation.