The main finding of the study was that the strongest risk factors during the first pregnancy for the development of FOC in the subsequent pregnancy were pre-existing FOC and the turning of trial of labour into unplanned or emergency CS. Furthermore, complications during labour, such as third- or fourth-degree tears of the perineum and shoulder dystocia, markedly increased the odds for FOC. Adverse neonatal outcomes had less of an effect on the development of FOC. Indeed, among those patients with FOC in the first pregnancy, spontaneous vaginal delivery decreased the rate of FOC in the second pregnancy.
The odds ratio for the development of FOC after emergency CS was over 5-times higher, and nearly 4-times higher after unplanned CS. In 1999, a study with a similar study design, but with a small population of only 100 patients with FOC, investigated the effects of previous delivery mode on the risk of FOC. The study revealed that the risk of FOC after emergency CS was nearly 27-times higher , which is much higher than our results. The main reason behind the increased odds for FOC after unplanned or emergency CS is most likely the fear of repeat challenges or complications during childbirth, as they are indications for converting trial of labour into CS. According to the previous literature, presumed foetal compromise and prolonged labour remained the main indications for unplanned and emergency cesareans . A 1998 study examining the feelings of women towards emergency CS found that the decision to undertake a caesarean section brought with it a feeling of relief . However, this feeling was soon replaced by fear as the operation approached . The thoughts of the women centred around the impending delivery and operation until after the event, when the new born baby occupied their attention and happiness predominated . According to another study, women who underwent unplanned CS or instrumental delivery experienced more general mental distress and post-traumatic stress than women who underwent normal vaginal delivery or elective CS . Therefore, previous unplanned mode of delivery might be one explanation for the development of FOC. However, the exact reason for the development of FOC remains unclear due to the crude nature of our data. Further, it remains unclear whether the possible cause of FOC in the previous pregnancy was the delivery mode itself or the factors leading to the mode of delivery.
Complications during childbirth, such as shoulder dystocia and third- or fourth-degree tears of the perineum, markedly increased the odds for the development of FOC. Indeed, the odds for the development of FOC was nearly 3-times higher after these complications. The increased odds for developing FOC after third- or fourth-degree perineum tear was an expected result, as it is known that these events can have physical and psychological consequences. In some cases, women may experience social isolation and marginalisation due to their ongoing symptomatology . In addition, the injury can be painful for the mother . It is also known that a previous tear of the perineum increases the risk for the recurrence of perineal tear , which might be one further reason behind the development of FOC. However, it should be acknowledged that delivery complications, such as shoulder dystocia and perineal tear, can both occur during the same pregnancy. Therefore, the exact cause of any future FOC cannot be deduced based on our data.
Even though complications, such as shoulder dystocia and perineal tear, can also occur in pregnancies with spontaneous vaginal delivery, our results reveal that those women with diagnosed FOC in the first pregnancy who had a spontaneous vaginal delivery had a notably lower rate of FOC in the subsequent pregnancy, indicating that spontaneous vaginal deliveries might be associated with a successful course of childbirth. Based on our data, a successful vaginal delivery is a strong factor for the disappearance of FOC. As psychological support is generally useful in preventing FOC , psychological support should also be offered after a complicated delivery to prevent secondary FOC.
Interestingly, adverse neonatal outcomes had less of an effect on the odds for the development of FOC than alternate delivery methods or complications during childbirth. The increase after neonatal intensive care was truly restrained when compared to the effect of delivery methods and complications during childbirth. Moreover, the clinical importance is non-existent, as it can be associated with other factors, such as complications during childbirth. The odds for the development of FOC was 2-times higher after perinatal mortality. However, the rate of perinatal mortality in Finland is among the lowest globally, and the number of patients with neonatal mortality was extremely low , resulting in increased imprecision in the estimates.
The strengths of our study are the large nationwide register data used and the long study period, which allowed us to analyse the rates of FOC using a large study population. The register data used in our study are routinely collected in structured forms using national instructions, which ensures good coverage (over 99%) and reduces possible reporting and selection biases.
The main limitation of this study is that the severity of the FOC is unknown because, at present, there is no uniform criteria or definitions for FOC. Generally, FOC is defined as anxiety and fear of pregnancy, childbirth or the parenting of a child that impair daily wellbeing. FOC takes different forms in different women and may manifest as physical complaints, nightmares and difficulties to concentrate .