Obstetric determinants of preterm delivery in a regional hospital, Accra, Ghana 2016

According to the World Health Organization (WHO), each year, 8 million infants die before reaching their first birthday worldwide [1]. Of these, over 1 million are born preterm. Globally, 1 out of every 10 babies is born prematurely. Preterm birth is an issue of major public health concern causing deaths and high rates of morbidity and disability among survivors [2]. Preterm birth is the major cause of death during the first month of life contributing about 30–40%, and contributing 20–30% to infant and under-five mortality respectively [3]. Complications of preterm birth are the single largest direct cause of neonatal deaths. It is a significant cause of long-term loss of human potential amongst survivors. Babies who make it often face a lifetime of medical setbacks [4, 5].

Several risk factors for preterm labor and premature birth including; extremes of age (being below 19 years and being above 35 years), socio-economic status, preeclampsia, gestational diabetes, Preterm Premature Rupture of Membrane (PPROM) and foetal conditions such as foetal distress have been determined in various settings [6‐9]. Other antecedents of preterm births are multiple gestations arising from the use of assisted reproductive technologies that involve implantation of multiple embryos and advanced maternal age [8‐10].

To achieve the WHO-United Nations 2010 goal of reducing mortality due to preterm birth by 50% in 2025, it is essential that risk factors of preterm birth and their dynamics in different settings are well understood. Although preterm rates are higher in low-and-middle income countries including Ghana, pertinent information on risk factors of preterms are not adequately documented or readily available in the national database.

Lack of knowledge and proper documentation of the obstetric factors associated with preterm delivery in Ghana can lead to preventable preterm deliveries and its associated mortalities. The study sought to determine the obstetric factors associated with preterm delivery in Greater Accra Regional Hospital (GARH) -Ridge, Accra from October, 2015 to May, 2016.

The study recruited a total of 390 mothers who delivered in Greater Accra Regional Hospital comprising 130 cases (preterm deliveries) and 260 controls (term deliveries).

Out of the 130 preterm deliveries, 28% (36/130) were classified as early preterm (28 - 32 weeks gestation) and 72% (94/130) were moderate to late preterm (33–36 weeks gestation) based on the WHO classification.

Preterm and its complications was one of the greatest challenges that prevented developing countries like Ghana from achieving the millennium development goal four (MDG 4) that focused on reducing under-five mortality [8]. This study assessed the obstetric determinants of preterm deliveries at Greater Accra Regional Hospital, Ridge, Accra. In our study, factors found to be associated with pre-term delivery and its complications were: number of ANC visits made, number of babies delivered, PROM and severe pre-eclampsia/eclampsia.

In Ghana, pre-eclampsia/eclampsia is one of the five main causes of maternal mortality with Greater Accra region recording the highest cases of pre-eclampsia in the country [11]. Three out of ten women in our study had pre-eclampsia/eclampsia. This proportion is similar to what was found by a study on hypertensive disorders in pregnancy in a referral hospital in Ghana [12] but higher than the national prevalence of almost two in ten [13]. The reason for the higher prevalence in our study could also be attributed to the fact that it is a referral facility and is located in the Greater Accra region. The odds of preterm delivery was increased by at least 3.4 times in a mother with hypertensive complication in pregnancy compared to a mother who was free of hypertensive complications in pregnancy. Our results were similar to that observed in Ethiopia where mothers who had PIH and Antepartum Haemorrhage (APH) were 2.9 times more likely to have preterm birth compared to mothers without any of the above exposures [14].

Reasons for these findings could be because; elevated blood pressure in pregnancy in itself is detrimental to the health of the mother and foetus. It compromises perfusion to the foetus and has a medical risk of cardiovascular complications for the mother. When it is complicated with urine protein and elevated uric acid level, it tips the mother into severe pre-eclampsia (imminent eclampsia) and if no action is taken eclampsia, which is life threatening for both mother and foetus ensues. This is usually unpredictable and its management is difficult, with a concomitant high mortality. Providers are therefore extremely careful in managing mothers with hypertensive complications in pregnancy. Most often, when the blood pressure become uncontrollable and/or eclampsia occurs, the quickest means of emptying the uterus become the choice for mainstay management. Thus the intervention before term accounts for the preterm delivery.

We found APH to be significantly associated with preterm delivery. The odds of preterm delivery were increased about thrice as much among mothers with APH compared to mothers who did not have APH. This is similar to a study in Nigeria where APH was observed to be significantly associated with preterm delivery [9].

Commonly the underlying causes of APH include localised vaginal bleeding and bleeding from the uterus. Localised vaginal bleeding could be as a result of trauma, spontaneous bleeding and bleeding varices. Bleeding from the uterus include placentae Previa and placentae abruption. Since bleeding from the vagina in a pregnant woman who has reached viability (> 28 weeks) requires less exploration in the vagina, a quick assessment of the mother and foetus may favour a quick emptying of the uterus. Thus, once it happens, the provider is careful not to lose either or both of the mother and baby. Mostly these obstetric indications favour a quick delivery and ultimately preterm delivery.

From our study, a mother who had Preterm Premature Rupture of Membrane (PROM) was about twice more likely to have a preterm delivery compared to a mother who did not have PROM. These findings are similar to a study in Kenya on preterm birth [10]. This is evident because anytime the membrane ruptures and the mother loses liquor, it could lead to oligohydramnios/anhydramnois with an ultimate complication of foetal distress/stillbirth or chorioamnionitis, which has far-reaching complications for the mother. This can lead to sepsis and ultimately mortality. Thus, in order to prevent these complications, providers usually intervene by either inducing them to have a vaginal delivery if the cervix is favourable or abdominally depending on whichever is the quickest way to save the mother and/or baby.

Multiple gestation, which is a grave contributor and well-established fact determining preterm delivery, was found to be positively associated with preterm delivery. This is expected because multiple gestation is typically associated with complications. In the study, there were 18 multiple gestations of which 13 were preterms and five were term.. When number of babies delivered were cross-tabulated with mode of delivery, it was noted that of the 13, only three were also delivered by caesarean section from hypertensive complication and/or PPROM. These finding are similar to earlier studies in Kenya and Ethiopia on preterm delivery [11].

Some established reasons for iatrogenic preterm delivery are maternal conditions, such as preeclampsia, and foetal distress. However, in the past decade, the number of preterm cesarean sections performed, regardless of gestational age, has increased worldwide without a similar change in maternal risk profiles [15, 16]. In this study, a mother who delivered by LUSCS was about twice more likely to be preterm compared to spontaneous delivery. These results are similar to a study on determinants of preterm delivery conducted in Ilorin, Nigeria [9].

Parity was not significantly associated with preterm delivery in this study. This is probably so because GARH is a secondary level facility and nearly all the mothers have come for high level Emergency Obstetric and Neonatal Care (EMONC) services and acts as a one stop shop facility. These findings are contrary findings of similar studies on preterm delivery, which observed that multiparity was associated to pre-term delivery [10, 17, 18]. However, a systematic review and meta-analysis on parity and preterm delivery by Shah observed that nulliparity was not significantly associated with preterm delivery [19].

In this study, a history of preterm delivery was not significantly associated with preterm delivery. The indication for the previous and the current preterm delivery is also important. Most especially if there is a predisposing obstetric indication for the previous preterm delivery and the mother did not experience the same or different obstetric indication, then, current preterm delivery is not expected. Generally, if the previous preterm delivery was spontaneous, then there is a higher odds of a current preterm delivery but in this study, an increased proportion of the preterm delivery were by caesarean section. This is supported by a study by Mazaki-Tovi and Co who observed that previous preterm delivery and recurrent preterm delivery were strongly associated with a current preterm delivery especially if it was spontaneous labour (with intact or ruptured membranes) [20]. This study findings contrasts a study done in 2014 in Kenya on preterm delivery where previous preterm birth was associated with preterm delivery [10]. The earlier the gestational age of the preterm birth, the higher the likelihood of recurrence. Therefore, counselling is advised even prior to conception to prepare the couple psychologically and efforts are being made to identify potentially treatable causes even though the attributable risk of these conditions for preterm birth is extremely low and in this study is insignificant.

We assessed the obstetric determinants of preterm deliveries at Greater Accra Regional Hospital, Accra. Mothers who attend ANC ≥4times are protected against present preterm delivery. However, hypertensive complications in pregnancy, antepartum haemorrhage (APH) preterm premature rupture of membrane (PPROM) were found to be determinants of preterm birth.

We recommended to ANC healthcare providers of the hospital to predict preterm delivery when a pregnant woman was found to have gestational hypertension and/or its complication, antepartum haemorrhage, preterm premature rupture of membrane and act appropriately by referring such clients to the doctor.