Arvo building, Jarmo Visakorpi auditorium, address: Arvo Ylpön katu 34.
Doctoral defence of Lic.Med. Elli Toivonen
The field of science of the dissertation is Obstetrics and Gynaecology.
The opponent is docent Mika Nuutila (University of Helsinki). Professor Johanna Mäenpää acts as the custos.
The language of the dissertation defence is Finnish
Breech presentation. Outcome according to the mode of delivery, fetal heart rate monitoring and maternal childbirth experience
The fetus is in breech presentation (bottom of the infant instead of the head is born first) in 3-4% of term and up to 40% of preterm deliveries. Breech infants have increased risk of complications during and after the delivery compared to cephalic infants, but it is unclear whether routine cesarean delivery could reduce the risks. Cesarean delivery carries more risks to the mother compared to vaginal delivery. In Finland, mothers expecting breech infants are evaluated for eligibility for a trial of labor and, in absence of contraindications, vaginal delivery is offered as an option. Vaginal breech delivery is managed as a high-risk delivery, which may have an effect on the maternal childbirth experience.
The aims of this study were to compare the prognosis of breech deliveries by intended mode of delivery in both term and preterm breech deliveries and to compare the maternal childbirth experience and features of fetal heart rate traces between breech and cephalic deliveries. The outcomes of intended vaginal breech deliveries were also compared to those of intended vaginal cephalic deliveries.
Two studies assessed the outcome according to the planned mode of delivery, one in term breech presentation and the other in preterm breech deliveries (gestational age 32+0 – 36+6 weeks). Low Apgar scores at the age of one minute were more common in infants in the intended vaginal delivery groups compared to the cephalic groups in both term and preterm cohorts, and in term deliveries, also compared to the planned cesarean breech delivery group. However, no differences were observed in low Apgar scores at the age of five minutes, nor regarding the need for neonatal intensive care or the rate of neonatal morbidity.
No major differences between the childbirth experiences of mothers who had delivered a breech infant and mothers who had delivered a cephalic infant were observed. However, mothers in the breech group felt more often than mothers in the cephalic group that they could not choose the birthing position. Primiparity, actual cesarean delivery, infant birth trauma, prolonged second stage of labor and prolonged hospital stay predicted negative delivery experience in both breech and cephalic deliveries.
Fetal heart rate traces from breech deliveries displayed late decelerations and decreased variability more often compared to traces from cephalic deliveries. Complicated variable decelerations, pathological trace and breech presentation predicted low Apgar scores and low umbilical artery pH values.
Allowing a trial of labor in selected women with the fetus in breech presentation remains a justified option based on this study. However, strict criteria in selecting the candidates for and managing a trial of vaginal breech labor should be applied. The maternal delivery experience is as positive as in cephalic delivery, but mothers expecting a breech infant should be informed of the increased risk of emergency CD. Fetal heart rate traces from breech deliveries display pathological patterns more often than those from cephalic deliveries. Fortunately, neonatal depression necessitating treatment is rare after vaginal breech delivery.
The dissertation is published in the publication series of Acta Universitatis Tamperensis; 2375, Tampere University Press, Tampere 2018. The dissertation is also published in the e-series Acta Electronica Universitatis Tamperensis; 1881, Tampere University Press 2018.