114 women whose previous pregnancy ended in stillbirth gave birth at the Royal Women’s Hospital between 2020 and 2022 inclusive. This accounted for 120 infants, including 4 sets of twins and 1 set of triplets. The mean maternal age at birth was 32.9 years (95% CI, 32.0–33.9). The mean maternal body mass index (BMI) pre-pregnancy was 26.5 kg/m² (95% CI, 25.3–27.7), with 26.3% (n = 30) and 21.1% (n = 24) of women having overweight (25.0–29.9 kg/m²) and obese ($\ge$30.0 kg/m²) BMIs respectively.

Prior to their pregnancy, most patients had a parity of one (46.5%, n = 53) or two (31.6%, n = 36), identified as neither Aboriginal nor Torres Strait Islander (94.7%, n = 108), and were non-smokers at less than 20 weeks’ gestation (93.9%, n = 107). Those who did smoke (6.1%, n = 7) all continued to do so for the rest of their pregnancy. Most pregnancies were spontaneously conceived (93.0%, n = 106). Most patients did not have pre-existing diabetes mellitus (95.6%, n = 109) or hypertension (99.1%, n = 113) (Table 1).

The mean gestational age at which stillbirths occurred was 27.2 weeks (95% CI, 26.0–28.3, not stated n = 2). Most stillbirths occurred prior to 28 weeks’ gestation (64.9%, n = 74), and were fetal deaths in utero (72.8%, n = 83) as opposed to terminations of pregnancy (27.2%, n = 31).

Per patient records, the leading three causes of stillbirth overall were congenital fetal anomaly (28.9%, n = 33), unexplained antepartum fetal death (14.0%, n = 16) and placental dysfunction (14.0%, n = 16). Per patient records, the leading three causes of fetal death in utero were unexplained antepartum fetal death (19.3%, n = 16), placental dysfunction (16.9%, n = 14) and spontaneous preterm labour or rupture of membranes (10.8%, n = 9). The leading cause of termination of pregnancy alone was by far congenital fetal anomaly (80.6%, n = 25), followed by maternal psychosocial indications (9.7%, n = 3) and placental dysfunction (6.5%, n = 2). Women gave birth again on average 1.8 years (95% CI, 1.5–2.1, not stated n = 19) after their previous stillbirth (Table 2).

The mean gestational age at first antenatal visit was 11.9 weeks (95% CI, 10.9–12.8, no antenatal care n = 1), with approximately two-thirds of patients’ booking visits occurring at less than 14 weeks (68.4%, n = 78). Most patients had an obstetrician as their main antenatal care provider (88.6%, n = 101). One woman that did not seek antenatal care due to psychosocial reasons relating to a complex history of substance use disorder and involvement with child protection services.

The mean number of antenatal ultrasounds women underwent at the hospital was 5.9 (95% CI, 5.2–6.5, range 0–17), with nearly three-quarters of patients having 3 to 10 ultrasounds (72.8%, n = 83). The mean number of antenatal visits to the hospital was 12.4 (95% CI, 11.2–13.6, range 0–40). These do not include ultrasounds or antenatal visits outside of the hospital. 22.8% (n = 26) of women were diagnosed with gestational diabetes mellitus, most after 24 weeks of gestation (n = 17). Over a half of these women required management with insulin (61.5%, n = 16) (Table 3).

Most women had an obstetrician as their intrapartum lead carer (74.6%, n = 85). The average gestational age at birth was 37.6 weeks (95% CI, 37.1–38.2), with majority giving birth at term (75.4%, n = 86). The most common mode of birth was a spontaneous vaginal birth (50.0%, n = 57), followed by planned caesarean birth (20.2%, n = 23) and then unplanned caesarean section without labour (15.8%, n = 18). The overall caesarean rate was 41.3% (n = 47).

Most women underwent an induction of labour (39.5%, n = 45), of whom 66.7% (n = 30) had a spontaneous vaginal birth, 22.2% (n = 10) an assisted vaginal birth and 11.1% (n = 5) proceeded to unplanned caesarean section without labour. The mean estimated blood loss in pregnancy was 464.9 mL (95% CI, 393.0–536.8). 28.0% (n = 25) of patients experienced postpartum haemorrhage, which we defined as $>$500 mL within 24 hours of birth, of whom 10.7% (n = 3) required blood transfusion (Table 4).

120 infants were born between 2020 and 2022, including 4 sets of twins and 1 set of triplets. 97.5% (n = 117) were liveborn and 2.5% (n = 3) were stillborn and died before labour. Of those three stillborn, two were fetal deaths in utero due to antepartum haemorrhage and one was a medical termination of pregnancy.

Of the two fetal deaths in utero, one of these occurred at 29.9 weeks in a patient whose last stillbirth occurred 17 months prior at 36.0 weeks, due to severe fetal growth restriction 1st centile with abnormal dopplers. The other of these occurred at 25.0 weeks in a patient whose last stillbirth occurred three years prior at 24.7 weeks gestation, with unclear aetiology due to the patient refusing care, with long term disengagement with health services and substance abuse disorder.

The one termination of pregnancy at 25.0 weeks was due to fetal craniosynostosis syndrome, secondary to a de novo mutation identified on exome testing, in a patient whose last stillbirth seven months previously was also medically terminated for a fetal anomaly. This patient subsequently had a liveborn baby at 38.7 weeks without complications one year later.

53.3% (n = 64) of infants were female. The mean birthweight was 2945.0 g (95% CI, 2795.3–3094.5 g). Most babies had Apgar scores between 7 and 10 at both 1 minute and 5 minutes (87.5%, n = 105 and 94.2%, n = 113 respectively). 2.5% (n = 3) of infants were born with congenital anomalies, all of which were identified antenatally. Two were cardiac (truncus arteriosus, first-degree heart block) and one was cranial (craniosynostoses) (Table 5).

23.3% (n = 28) of infants were admitted to neonatal care after birth, half to the neonatal intensive care unit (53.6%, n = 15) and half to the special care nursey (46.4%, n = 13). Of the 28 babies born pre-term (37 weeks), 42.8% (n = 12) were admitted to neonatal intensive care. Of those admitted to the neonatal intensive care unit, there is only one known mortality at 80 days old due to severe cardiac anomalies first detected in the antenatal period.

Years before next birth was unknown for 18 women due to incomplete patient records, thus total number was 94. The total number of antenatal visits was unknown for 15 women due to incomplete patient records, thus total number was 97 (Table 6).

There was no significant relationship between neither gestation (28 vs. $\ge$28 weeks) or mode (fetal death in utero vs. termination of pregnancy) of stillbirth, and the antenatal, birth and neonatal outcomes of the subsequent pregnancy. Namely, there was no statistically significant difference in the gestational age at booking and the number of antenatal visits or ultrasound scans, gestational age, mode of birth, labour in subsequent pregnancy, livebirth rates and baby birthweights (Table 7).

Our results highlight a potential need for more lifestyle counselling surrounding weight loss and smoking cessation, with the average BMI of 26.5 kg/m² corresponding to the overweight category, and 6.1% of patients who continued smoking beyond 20 weeks’ gestation in their pregnancy. BMI and smoking are both established modifiable risk factors for stillbirth, and improving smoking cessation rates has been a long-time national priority to reduce stillbirth rates [12, 13].

Most women gave birth again within 1.8 years of their index stillbirth, which is consistent with previous studies [3, 4, 5]. This may reflect many patients’ intense desires for parenthood after stillbirth as one patient described, “there is such a gap, it has to be filled” [4, 5]. The optimum time to conceive after stillbirth has been widely debated with no clear consensus, although a prior international cohort study of 14,452 births by Regan et al. [14] demonstrated that conception within one year of stillbirth was not associated with increased rates of stillbirth, preterm birth or small-for-gestational age birth.

Reassuringly, most women who have had a history of stillbirth had an obstetrician as their primary care provider in the antenatal and intrapartum setting in their subsequent pregnancy. The Australian Pregnancy Care Guidelines by the Department of Health and Aged Care (2020) recommends 7 antenatal visits for multiparous patients with uncomplicated pregnancies, and more if they have experience stillbirth in a previous pregnancy [15]. It is therefore reassuring to see that patients attended on average 12.4 antenatal visits throughout their pregnancy.

Patients in our cohort received, on average, more ultrasound scans than the standard two typically offered to all pregnant women. The standard schedule usually includes one scan between 8 to 14 weeks to assess gestational age, and another between 18 to 20 weeks for fetal morphology assessment [15]. This increased antenatal surveillance aligns with existing research and guidelines. For example, due to the higher risk of bearing a small-for-gestational-age infant, the Royal College of Obstetricians and Gynaecologists (RCOG) recommends serial growth scans from 26–28 weeks for pregnancies following stillbirth [16, 17, 18].

Notably, there is limited high-level evidence to guide the management of pregnancies following a stillbirth, meaning that care remains largely non-standardized and dependent on individual clinician judgment [19]. Several interventions are widely recognized as beneficial, including fetal growth monitoring, smoking cessation, and the optimization of comorbidities such as hypertension and diabetes. The increased number of ultrasound scans and antenatal visits in our cohort likely reflects the implementation of increased growth monitoring. However, the low incidence of smoking and patients with pre-existing hypertension or diabetes, constrain our ability to fully assess the effects of the other interventions.

Other recommendations, such as advising mothers to sleep on their side or to monitor fetal movements, likely played a role in antenatal care but were not consistently documented, making it difficult to quantify their impact in preventing recurrent stillbirth. Similarly, additional support options, such as access to bereavement counselling, direct contact with care providers, and specialist antenatal classes for bereaved parents, may offer benefits but were not routinely offered or measured. Future studies should explore the effects of these interventions in preventing recurrent stillbirth and improving pregnancy outcomes.

Given the variety of care options available, the provision of additional surveillance and interventions must be carefully evaluated to ensure clinical necessity. Many women seek individualised patient-centred care such as additional ultrasound scans and ready access to fetal monitoring, which are in general benign and provide reassurance. In our public hospital system, these services do not incur additional costs, and women usually welcome the choice regarding induction of labour and planned caesarean birth. However, it is also important to consider that such additional care may cause distress in some patients, incur greater costs to the healthcare system, and lead to higher rates of interventions without significantly improving outcomes [20, 21, 22, 23]. These interventions also carry their own risks, including infection, uterine rupture, and increased risks in subsequent pregnancies, such as miscarriage, stillbirth, placenta previa, placenta accreta, and placental abruption [24].

In 2020 in Australia, the leading three causes of stillbirth in descending order included congenital anomaly (31.5%), maternal conditions (13.6%) and unexplained antepartum death (12.7%) [1]. This is in line with data from the Royal Women’s Hospital in 2022, where congenital anomaly was also the leading cause of stillbirth (38%), followed by maternal conditions (27%) including psychosocial reasons and then unexplained antepartum fetal death (8.1%).

Interestingly, in our cohort, while congenital anomaly (28.9%, n = 33) and unexplained antepartum fetal death (14.0%, n = 16) were top causes of stillbirth, they were alongside placental dysfunction (14.0%, n = 16) instead. The reasons for this discrepancy are unclear, however we hypothesise that maternal conditions causing stillbirth may affect fertility and impact patients’ chances of becoming pregnant again, or predispose them to miscarry in future pregnancies prior to 20 weeks.

The 14.0% (n = 16) rate of unexplained antepartum fetal death, while the second most common cause of stillbirth in our cohort, is lower compared to other studies which have reported rates of 16% to 44% [7, 25].

The rate of recurrent stillbirth was 2.5% in our cohort, the same as that reported by Lamont et al. [6] in a systematic review and metanalysis of 16 studies accounting for 3,412,079 pregnancies. It is controversial whether previous stillbirth confers higher risk of stillbirth in future pregnancies, with some studies reporting no to minimal increase, and others up to a five-fold increase [13, 26, 27, 28]. The risk of recurrence may also depend on the characteristics of the index stillbirth, with studies suggesting that recurrence is particularly associated with early gestation and intrapartum stillbirths, and those caused by placental dysfunction [23, 29, 30, 31, 32].

The high rate of caesarean births (41.3%, n = 47) and induction of labour (39.5%, n = 45) aligns with prior studies that have reported an increased risk of both interventions in patients with a history of stillbirth, with the recommendation of inducing labour at 37 to 38 weeks’ gestation to reduce perinatal death [7, 32]. Overall, it is reassuring that most patients gave birth at term (75.4%, n = 86), with unassisted vaginal birth being the most common mode of birth (50.0%, n = 57).

There is little existing literature on the neonatal outcomes of babies born in a pregnancy after stillbirth. It is reassuring to see most babies’ birthweights were between 2500 and 4000 g (75.0%, n = 90). The high proportion of preterm babies admitted to neonatal intensive care (42.8%, n = 12 of 15) is also similar to that reported by Roseingrave et al. [16] in their retrospective cohort study of 145 pregnancies in a large tertiary maternity hospital in Ireland.

Our findings that the extent of antenatal care and outcomes in subsequent pregnancy after previous stillbirth, regardless of gestational age and mode of index stillbirth, affirms that patients received similar care with similar outcomes. This is reassuring, as it suggests that patients received consistent care and experienced comparable outcomes. This contrasts a study of 2716 parents by Wojcieszek et al. [17], which found that patients whose stillbirth occurred at or after 30 weeks’ gestation were more likely to receive more antenatal care visits and ultrasound scans in their subsequent pregnancy. Per Wojcieszek et al. [17], this differential allocation of services did not appear justified, as the risk of stillbirth recurrence and patients’ emotional needs are no less important for those whose stillbirths occurred at earlier gestations.

The strengths of this study are that it is the first at The Women’s exploring pregnancy outcomes after previous stillbirth. It is based on local hospital data, with details on individual patient outcomes. The limitations of this study mainly relate to its small sample size and the lack of a control group, which reduce its statistical power and external validity. Therefore, while our results may be indicative, they are not necessarily generalisable to the broader country or international population. There is a lack of data on antenatal complications, patients’ emotional needs, and pregnancies that ended prior to 20 weeks’ gestation, meaning we may be underestimating the effects of prior stillbirth on future pregnancy. The definition of stillbirth also slightly varies across different countries, and different studies may use different stillbirth classification systems.