Major Traumas and Reproductive Health in Women

To date, only a few studies have assessed the effects of previous major trauma (pelvic fractures, spine fractures, etc.) on the reproductive health of fertile-aged women, as most studies focus either on traumas of the reproductive system, traumas occurring during pregnancy, or on the delivery mode after traumas. Moreover, the studies assessing the effects of major orthopedic traumas, such as pelvic fractures and spine fractures, are limited to small or local studies. Pelvic fractures and spine fractures are known to increase the rate of cesarean section (CS), but there is scarcity of studies assessing the effect of these fractures on neonatal health or complications during pregnancy. In addition, although traumatic brain injuries (TBIs) are known to cause disorders in the menstrual cycle and increase the risk for amenorrhea, the long-term effects of TBIs on subsequent pregnancies, deliveries, and neonatal health have not been studied previously.

The overall aim of this nationwide retrospective cohort study was to calculate the incidences of skeletal or brain traumas in fertile-aged women, and to analyze reproductive health after these major traumas in a nationwide setting. In study I, we calculated the incidence of pelvic fractures and surgeries among fertile-aged women and analyzed the effects of these on later pregnancies and neonatal outcomes. In study II, we calculated the incidence of spine fractures, spine fracture surgeries, and fusion surgeries for other reasons in fertile-aged women and analyzed the effects of these on later pregnancy outcomes. In study III, we calculated the incidence of TBIs in fertile-aged women and analyzed the effects of these on subsequent pregnancies and neonatal outcomes. In study IV, we calculated incidence of major traumas (pelvic fractures, spine fractures, TBIs, and hip or thigh fractures) in fertile-aged women and calculated the subsequent birth rate after these traumas. In addition, the risk for a woman to have a pregnancy leading to birth after major traumas when compared to minor traumas was analyzed in study IV. The risk for fractures among women who smoked when compared to no-smokers, using the smoking status found in the medical birth register (MBR), was analyzed in study V.

The participants in this study were gathered from two nationwide registries: the National Medical Birth Register (MBR) and the Care Register for Health Care. The registers were linked using the unique pseudonymized identification code of each person selected for the study. The study period was from 1998 to 2018. Information on trauma hospitalizations and surgeries was obtained from the Care Register for Health Care and the information on pregnancies was gathered from the MBR. A total of 628 908 women with 1 192 825 deliveries was found in the MBR. In studies I, II, and III, pregnancies occurring after specific traumas formed the patient group, which was then compared to pregnancies without preceding trauma. In study IV, patients with major trauma were compared to patients with palmar fracture and the hazard for the event of giving birth after trauma was analyzed. In study V, the risk for fractures after pregnancy were compared between smoking and non-smoking women. In statistical analyses, logistic regression models (studies I, II, and III) and Cox proportional hazard models (studies IV, and V) were used. The results were interpreted as adjusted odds ratios (aOR), hazard ratios (HRs), or adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs).

The probability for preterm deliveries (aOR 1.32, 95 % CI 1.01 – 1.69), CS (aOR 1.57, 95% CI 1.34 – 1.83), and weakened health of the neonate (aOR 1.31, 95% CI 1.07 – 1.58) was higher among women with previous pelvic fracture in study I. In study II, the probability for CS (aOR 1.30, 95% CI 1.17 – 1.45), and weakened health of the neonate (aOR 1.19, 95% CI 1.05 – 1.34) was higher after spine fracture. Further, after fusion surgery due to instability, the probability for CS (aOR 1.63, 95% CI 1.34 – 1.96) and weakened health of the neonate (aOR 1.35, 95% CI 1.07 – 1.68) was higher. Especially after fusion surgery in lumbar spine, the probability for CS was higher (aOR 1.80, CI 1.38 – 2.34). In addition, the incidence of spine fusion surgeries unrelated to fracture increased strongly during the study period (156%). In study III, the probability for preterm deliveries (aOR 1.19, 95% CI 1.11 – 1.28), CS (aOR 1.25, 95% CI 1.19 – 1.31), and weakened health of the neonate (aOR 1.26, CI 1.19 – 1.33) was higher among women with TBI before pregnancy. Furthermore, the incidence of TBIs increased during our study period from 103 per 100 000 person-years in 1998 to 257 per 100 000 person-years in 2018. In study IV, women with fractures of hip or thigh had the lowest birth rate during the 5-year follow-up period after the fracture (12.4%). Interestingly, women with TBI had the highest birth rate during the 5-year follow-up (19.0%), which was also higher than for women in the reference group with palmar fractures (18.7%). The risk for a pregnancy leading to birth during a 5-year follow-up for women with hip or thigh fracture was lower in the 15-24 years age group (HR 0.72, CI 0.58 – 0.88) and the 15-34 years group (HR 0.65, CI 0.52 – 0.82), when compared to palmar fractures. Women with pelvic fracture in the 25-34 years age group also had a lower risk for a pregnancy leading to birth during a 5-year follow-up (HR 0.79, CI 0.64 – 0.97), when compared to control group. In study V, the overall risk for fractures after pregnancy was higher at 1-year follow-up (aHR 1.73, CI 1.53 – 1.96) and 5-year follow-up (aHR 1.74, CI 1.64 – 1.84) for smoking women when compared to non-smoking women. The risk was also higher for all anatomic regions, polytraumas, severe (hospitalization period over one day), and non-severe fractures (hospitalization period less than a day).

Our result suggests that vaginal delivery is generally possible for the mother and safe for the neonate after pelvic fracture, spine fracture or surgery, and TBI. Preterm deliveries, the need for intensive care for the neonate, labor analgesia, and instrumental vaginal deliveries, were more prevalent in women with previous TBI, indicating that a history of TBI should be identified as a possible factor affecting the delivery and health of the neonate. Further, our results also suggest that women with pelvic, hip, or thigh fractures had a lower birth rate in 5-year follow-up after trauma. Our results also show that maternal smoking during pregnancy is associated with a higher risk for sustaining a fracture after giving birth.