Grand multiparity as a predictor of adverse pregnancy outcome among women who delivered at a tertiary hospital in Northern Tanzania

As Sustainable Development Goal’s (SDG) efforts to address promotion of maternal health and reduction of child mortality becomes intensified, regional specific investigation to inform the public health on potential effect of factors that presents a significant risk to the pregnant mother and the birth outcome are imperative. Huge disparity in the fertility rate exist between the developed and developing countries. Low-and-middle income countries including Tanzania’s fertility rate have still relatively high annual fertility rate as compared to high income countries [1]. This trend may pose substantial risk to the pregnant mother and result in adverse birth outcome. Among other factors, grand multiparity is hypothesized to play a significant role in adverse maternal outcomes especially in low-and-middle income countries like Tanzania.

Grand-multiparity (GMP) condition has been defined differently in several literature [1‐3]. Some literature define it as a woman who delivered four or more times while others consider of six or more deliveries [4]. Furthermore, the International Federation of Gynecology and Obstetrics defined GMP as deliveries of a fifth to ninth, while naming those undergoing their tenth or more deliveries as great grand-multiparous or huge great grand-multiparous [5‐8]. According to the CDC report of 2004, the prevalence of grand multiparity was reported as low as 3–4% in developed countries as compared to 19.3% in developing countries, [9, 10]. The lower prevalence in developed countries has been attributed to high use of modern family planning and optimal obstetric care while the high prevalence of GMP in low income countries is fueled by gender desirability, low education and desire for more offspring to have large family size [11, 12]. Adverse outcomes associated with GMP include diabetes, premature labor, maternal and perinatal mortality, placenta previa, genital sepsis, postpartum hemorrhage (PPH), utero-vaginal prolapse, hypertension and Intrauterine fetal death (IUFD) [6, 7, 10, 13]. Controversy prevails in the effect of high parity on these complications since some other studies report no increased incidences of obstetric complications [1, 14]. Despite efforts to reduce maternal and perinatal adverse outcomes in Tanzania, maternal morbidities and mortalities are high. This study takes advantage of existing large scale birth registry data to reaffirm existing small scale evidence conducted in 2013 in one of the tertiary facility in Tanzania and attempt to account for change in magnitude of grandmultiparity overtime with an additional capability to capture infrequent adverse outcome. Moreover, describing a trend of grand multiparity overtime may provide a reflection of effectiveness of contraceptive coverage in this population. This study’s primary aim was to determine the association between GMP and adverse pregnancy outcome. Moreover, we aimed at assessing the prevalence, trend and associated pregnancy outcomes of grand multiparity in a tertiary hospital in Northern Tanzania over nine (9) years.

The prevalence of grand multiparity at the institution over nine years found was found to be 9.44%. This study found that grand multiparity was associated with maternal and perinatal complications such as prelabour rupture of membranes, stillbirth and preterm birth. The prevalence of grand multiparity in this study was consistent with a study done in Saudia by Alsammamiet al which reported a prevalence of 5.3% [15]. However, this is slightly lower compared to other studies which reported the high prevalence of 10.2 and 26.5% respectively [9, 13]. The higher prevalence in the later studies could be explained by high prevalence of young marriage and poor acceptance of modern family planning methods. The lower prevalence in this study can be attributed to standard literacy level of grand multiparas, as over 52% had at least primary level of education.

In the present study, we found that the trend of grand multiparity to be decreasing over nine years.. This decline could have a broader range of attributes including availability of higher education to women and increased community awareness on the health risks of giving birth at an advanced maternal age. The study site has better schools and universities that provides with an opportunity to learn and become aware of reproductive health status. However, the first five (5) years in the trend show no bigger differences while in the year 2011 the rise is seen and then followed by the decline. This can be explained by the fact that at this particular time, the country had adapted well to the strategic plan developed in 2008 known as One Plan which aimed to provide guidance and improve reproductive, maternal, newborn and child health [16].

In this study we found a significant increased risk of prelabour rupture of membranes (PROM) in grand multiparous women compared to those with low parity. Our result is consistent with previous studies done in Nigeria that describe a 3.6–4.2% increase in PROM in grand multiparas as compared to multiparas [16, 17]. Advanced maternal age (AMA) has been reported as a major risk factor in developing other maternal conditions including hypertension, diabetes mellitus, renal diseases, and other chronic infections which in turn are associated with PROM [18, 19]. This could be the case in the present study.

In multivariable regression analyses, our study did not find a significant association between PPH and GMP. This is in consistent with study done by Selo-Ojemeet al among Nigerian women [21]. Similar findings were reported by Combs et al who studied women from the United States [22]. We also found that GMP was significantly associated with an increased risk of PPH when controlled by maternal age and educational level attainment. However, addition of other covariates in the model led to non-significant association. Hence, it may suffice to say that, in this population, PPH is well explained by GMP condition, maternal age and education level. Due to increased maternal age and repeated deliveries, the uterine wall becomes weak resulting in inability to adequately contract leading to development of PPH [22]. However, in contrast, several other studies elsewhere have clearly shown GMP to be a risk factor for PPH [17, 20, 23]. Few data that didn’t demonstrate an increased risk for PPH in grand multiparity could be attributed to a small scale design with inability to capture rare adverse events [13].

This study has demonstrated that GMP women had an increased odds of experiencing stillbirth and preterm births as compared to women with low parity as previously described in published data from Uganda and Nigeria [9, 21, 22]. This could be explained by the fact that since AMA is a major risk for various maternal complications, thus fetus and neonates may always be susceptible to mortality and morbidity. Other fetal complications which have been reported in other studies in Tanzania with inadequately controlled intrapartum confounders include meconium stained liquor and low apgar score which were found to be insignificant complications in the present study.

Despite low prevalence of GMP at the institution, it continues to pose additional challenges to fetal and maternal health. Although the GMP proportion has decreased over years, our result reveals a rather gradual decline of GMP overtime. The study warrants more emphasis to be directed towards community sensitization on the adverse maternal and fetal outcomes that might be attributable to GMP. The study also suggests a need for establishment of a referral system unit at this institution that will be specifically managing deliveries occurring in women with high parity as well as advanced age.